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[ { "abstract": "Low cost, field deployable, near time methods for assessing water quality are not available when and where waterborne infection risks are greatest. We describe the development and testing of a novel device for the measurement of tryptophan like fluorescence (TLF) making use of recent advances in deep ultraviolet light emitting diodes (UV LEDs) and sensitive semiconductor photodiodes and photomultipliers. TLF is an emerging indicator of water quality that is associated with members of the coliform group of bacteria and therefore potential fecal contamination. Following the demonstration of close correlation between TLF and E. coli in model waters and proof of principle with sensitivity of 4 CFU/mL for E. coli, we further developed a two LED flow through configuration capable of detecting TLF levels corresponding to \"high risk\" fecal contamination levels >10 CFU/100 mL) Findings to date suggest that this device represents a scalable solution for remote monitoring of drinking water supplies to identify high risk drinking water in near time. Such information can be immediately actionable to reduce risks.", "author_names": [ "Emily Bedell", "Taylor Sharpe", "Timothy Purvis", "Joe Brown", "Evan A Thomas" ], "corpus_id": 218956663, "doc_id": "218956663", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Demonstration of Tryptophan Like Fluorescence Sensor Concepts for Fecal Exposure Detection in Drinking Water in Remote and Resource Constrained Settings", "venue": "", "year": 2020 }, { "abstract": "The current study is an attempt made to decide the best scheduling approach to a construction project in order to deliver it on time, quality and cost. The major constraints typically observed in any construction project are time overruns, cost overruns. It is, therefore, necessary for a project manager to attempt the best scheduling approach based on the study of project ideals and project constraints. A Project ideal is a measure of success. Common project ideals identified are Highest client satisfaction, Highest quality for deliverables, shortest time possible and lowest cost possible. The typical project constraints are Knowledge, Time, cost, resource and risk constraints. After having a project PIC analysis, the best scheduling approach is decided like an Agile approach when knowledge is a constraint or when the ideal is the highest client satisfaction, Critical path method when time is dominant and time is ideal, Resource Critical Path RCP) approach in any resource constrained project. A logical sequence of activities with assigned duration and resources is made and the schedule is prepared. The critical path method is the approach used widely in a construction project. Critical path and critical activities are studied in advance with the use of MSP 2016 or any other computer software and critically monitored so that these activities are completed on time and there should not be any delay in completing these activities.", "author_names": [ "Sandeep M Joshi", "Dr Navnath V Khadake" ], "corpus_id": 218786358, "doc_id": "218786358", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "An attempt of best scheduling approach for a construction project", "venue": "", "year": 2020 }, { "abstract": "This paper proposes a nonlinear integer program for determining an optimal plan of zero defect, single sampling by attributes for incoming inspections in assembly lines. Individual parts coming to an assembly line differ in the non conforming (NC) risk, NC severity, lot size, and inspection cost effectiveness. The proposed optimization model is able to determine the inspection sample size for each of the parts in a resource constrained condition where a product's NC risk is not a linear combination of NC risks of the individual parts. This paper develops a three step solution procedure that effectively reduces the solution time for larger size problems commonly seen in assembly lines. The proposed optimization model provides insightful implications for quality management. For example, it reveals the principle of sample size decisions for heterogeneous, dependent parts waiting for incoming inspections; as well as provides a tool for quantifying the expected return from investing additional inspection resources. The optimization model builds a foundation for extensions to advanced inspection sampling plans.", "author_names": [ "Ruwen Qin", "Elizabeth A Cudney", "Zlatan Hamzic" ], "corpus_id": 34394074, "doc_id": "34394074", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "An optimal plan of zero defect single sampling by attributes for incoming inspections in assembly lines", "venue": "Eur. J. Oper. Res.", "year": 2015 }, { "abstract": "The current construction environment is characterized by risk aversion, and the delivery of value is constrained by the tension between time, cost and quality. Similarly, the approach to sustainability in the built environment remains largely focused on waste reduction and minimization of the carbon footprint. Yet the challenges of global environmental issues call for a paradigm shift from this reductionist, 'scarcity' approach to one of sustainable prosperity through resource renewal and value generation. The industry has recognized the need for a more integrated approach, not just to fix the process, but to transform it to deliver value beyond the tangible building product. Lean construction stands out as the approach which can facilitate a net enhancement of sustainability value through fully integrated design and delivery processes. The author explores the synergy between lean construction and sustainability, as expressed through the construct of value. Data from exemplary lean projects are gathered through survey and interviews of both prime contractor and owners, offering a two point perspective for enhanced data quality and reliability. The findings suggest a strong correlation between the cohesiveness of lean thinking and the level of collaboration on the delivery of sustainability values.", "author_names": [ "Vera M Novak" ], "corpus_id": 62886270, "doc_id": "62886270", "n_citations": 20, "n_key_citations": 3, "score": 0, "title": "Value Paradigm: Revealing Synergy Between Lean and Sustainability", "venue": "", "year": 2012 }, { "abstract": "The purpose of this paper is to develop a framework to optimize time, cost and quality in a multi mode resource constrained project scheduling environment.,A case study approach identified the activity execution modes in building construction projects in India to support multi mode resource constrained project scheduling. The data required to compute time, cost and quality of each activity are compiled from real construction projects. A binary integer programming model has been developed to perform multi objective optimization and identify Pareto optimal solutions. The RR PARETO3 algorithm was used to identify the best compromise trade off solutions. The effectiveness of the proposed framework is demonstrated through sample case study projects.,Results show that good compromise solutions are obtained through multi objective optimization of time, cost and quality.,Case study data sets were collected only from eight building construction projects in India.,It is feasible to adopt multi objective optimization in practical construction projects using time, cost and quality as the objectives; Pareto surfaces help to quantify relationships among time, cost and quality. It is shown that cost can be reduced by increasing the duration, and quality can be improved only by increasing the cost.,The use of different activity execution modes compiled from multiple projects in optimization is illustrated, and good compromise solutions for the multi mode resource constrained project scheduling problems using multi objective optimization are identified.", "author_names": [ "Marimuthu Kannimuthu", "Benny Raphael", "Ekambaram Palaneeswaran", "Ananthanarayanan Kuppuswamy" ], "corpus_id": 59345892, "doc_id": "59345892", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Optimizing time, cost and quality in multi mode resource constrained project scheduling", "venue": "", "year": 2019 }, { "abstract": "Purpose The purpose of this paper is to examine projects crashing based on the factors including cost, time, quality, risk and the law of diminishing returns. Design/methodology/approach The paper first investigated effective factors on project crashing then proposed a grey linear programming model. In the proposed grey linear programming model, the costs of quality of works that include the cost of conformance and non conformance of deliverables in the project were studied. The results are presented for considering the existing uncertainties using positioned programming under the sensitivity analysis table and graphs. Findings The lack of consideration of project risks will reduce the project success probability in future. The proposed model reduces the existing uncertainties to a significant extent by covering the project risks completely. Based on the law of diminishing returns, after a certain point technically known as saturation point, the increase of resources does not lead to the reduction of time and may even have negative impacts. Finding the saturation point for each activity prevents the excessive allocation of resources that can lead to reduction of productivity. Practical implications The main duty of each project manager is finishing the project in the framework of the determined objectives. In most of the cases, after the preparation of the initial project schedule by the project team, it is seen that there is a need for the time reduction. This study has used a grey linear programming model for optimum crashing of project activities. In order to make the model more realistic and applicable, the authors endeavoured to consider most of the factors that are involved in doing a project. Originality/value In the present study, to the best of the authors' knowledge the factors of time, cost, quality, risk and the law of diminishing returns are simultaneously considered in project crashing for the first time and the grey theory was used for considering the uncertainties of project parameters. Also, \"the law of diminishing returns\" has not been considered during crashing in the studies conducted so far.", "author_names": [ "Amin Mahmoudi", "Mohammad Reza Feylizadeh" ], "corpus_id": 49680588, "doc_id": "49680588", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "A grey mathematical model for crashing of projects by considering time, cost, quality, risk and law of diminishing returns", "venue": "Grey Syst. Theory Appl.", "year": 2018 }, { "abstract": "The paper proposes a multi objective model to shorten the overall project duration.The impact of different project factors on the optimal solution has been assessed.The results indicate that the proposed model could yield more efficient solutions compared with traditional techniques. One of the main issues in any scheduling of projects is the difficulty of convincing customer on total project makespan. There are many occasions where customer informs the contractor that the schedule must be shortened. This action could lead to increase in total cost as well as risk, which may also end of having lower quality project. This paper proposes a multi objective mixed integer linear programming for minimizing \"project total extra cost\" \"project total risk enhancement\" and \"project total quality reduction\" subject to time constraint. In other words, the proposed study provides a tradeoff between the three mentioned objectives to shorten the overall project duration. Goal attainment method is used for solving the multi objective model and obtaining the Pareto optimal solutions. The computational experiments are also applied to evaluate the efficiency of the proposed model.", "author_names": [ "Faezeh Mohammadipour", "Seyed Jafar Sadjadi" ], "corpus_id": 30266738, "doc_id": "30266738", "n_citations": 32, "n_key_citations": 2, "score": 0, "title": "Project cost quality risk tradeoff analysis in a time constrained problem", "venue": "Comput. Ind. Eng.", "year": 2016 }, { "abstract": "This paper studies the fuzzy time cost quality environment trade off problem of construction project and establishes a decision making model with multiple modes under resource constrained environment. The objective functions are to minimize the total project time, total resource cost, quality defect of all activities, and the environment impact. Furthermore, a fuzzy based adaptive hybrid genetic algorithm is developed for finding feasible solutions. More specifically, our approach treats the uncertainty by using fuzzy expected value operator or fuzzy simulation. Finally, Jinping II hydroelectric project was used as a practical example to demonstrate the practicality and efficiency of the method. Results and sensitivity analysis are presented to highlight the performances of our optimization method, which is very effective and efficient as compared with other algorithms.", "author_names": [ "Huan Zheng" ], "corpus_id": 112111755, "doc_id": "112111755", "n_citations": 3, "n_key_citations": 1, "score": 0, "title": "The Fuzzy Time Cost Quality Environment Trade off Analysis of Resource Constrained Multi mode Construction Systems for Large Scale Hydroelectric Projects", "venue": "", "year": 2014 }, { "abstract": "Abstract The Discrete Time Cost Quality Trade off Problem (DTCQTP) is one of the most important problems in project scheduling applications. In DTCQTP an optimal combination of construction methods is decided with the objective of minimizing cost and time while maximizing quality. Due to real world resource constrained situations in projects, this model is expanded to mode identity resource constrained DTCQTP model. In this model, each activity has multiple modes to be performed. In each mode, the required resources for performing the activity are different in at least one type. In addition, each activity can be done either in a normal way or in a crashing way in each performing mode. Based on the mode identity situation, the activities belonging to the same subset should be executed in the same mode. In this paper, we present a Multi Objective Imperialist Competitive Algorithm (MOICA) to solve our proposed model. We explain the elements of the algorithm and solve some problems generated for this model including large size and small size instances by this algorithm. The performance of our proposed algorithm is evaluated by comparison with four well known algorithms: NSGAII; PESAII clustering; PESAII grid based; and SPEA2. The obtained results show the effectiveness of the proposed algorithm.", "author_names": [ "Elham Nabipoor Afruzi", "Amir Abbas Najafi", "Emad Roghanian", "Mostafa Mazinani" ], "corpus_id": 11986753, "doc_id": "11986753", "n_citations": 49, "n_key_citations": 3, "score": 1, "title": "A Multi Objective Imperialist Competitive Algorithm for solving discrete time, cost and quality trade off problems with mode identity and resource constrained situations", "venue": "Comput. Oper. Res.", "year": 2014 }, { "abstract": "Abstract Construction managers often face with projects containing multiple units wherein activities repeat from unit to unit. Therefore effective resource management is crucial in terms of project duration, cost and quality. Accordingly, researchers have developed several models to aid planners in developing practical and near optimal schedules for repetitive projects. Despite their undeniable benefits, such models lack the ability of pure simultaneous optimization because existing methodologies optimize the schedule with respect to a single factor, to achieve minimum duration, total cost, resource work breaks or various combinations, respectively. This study introduces a novel approach called \"opposition multiple objective symbiotic organisms search\" (OMOSOS) for scheduling repetitive projects. The proposed algorithm used an opposition based learning technique for population initialization and for generation jumping. Further, this study integrated a scheduling module (M1) to determine all project objectives including time, cost, quality and interruption. The proposed algorithm was implemented on two application examples in order to demonstrate its capabilities in optimizing the scheduling of repetitive construction projects. The results indicate that the OMOSOS approach is a powerful optimization technique and can assist project managers in selecting appropriate plan for project.", "author_names": [ "Duc-Hoc Tran", "Long Luong-Duc", "Minh-Tin Duong", "Trong Nhan Le", "Anh-Duc Pham" ], "corpus_id": 13747275, "doc_id": "13747275", "n_citations": 25, "n_key_citations": 1, "score": 0, "title": "Opposition multiple objective symbiotic organisms search (OMOSOS) for time, cost, quality and work continuity tradeoff in repetitive projects", "venue": "J. Comput. Des. Eng.", "year": 2018 } ]

[ { "abstract": "Solar cells are semiconductor devices that generate electricity through charge generation upon illumination. For optimal device efficiency, the photo generated carriers must reach the electrical contact layers before they recombine. A deep understanding of the recombination process and transport behavior is essential to design better devices. Halide perovskite solar cells are commonly made of a polycrystalline absorber layer, but there is no consensus on the nature and role of grain boundaries. This review paper concerns theoretical approaches for the investigation of extended defects. We introduce recent computational studies on grain boundaries, and their influence on point defect distributions, in halide perovskite solar cells. We conclude the paper with discussion of future research directions.", "author_names": [ "Ji-Sang Park", "Aron Walsh" ], "corpus_id": 215547985, "doc_id": "215547985", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Modelling Grain Boundaries in Polycrystalline Halide Perovskite Solar Cells", "venue": "", "year": 2020 }, { "abstract": "The parallel multi junction solar cell design has recently been proposed to reduce the costs of photovoltaics, while maintaining or improving device performance. This design uses alternating layers of n and p type semiconductor to ensure that every point in the device is much less than one diffusion length from a collecting junction, producing relatively high currents. Device voltages can be maintained through heavier doping than would normally be used. This approach is particularly suited to very low quality material where the diffusion lengths are much shorter than the device thickess required for significant photogeneration. In particular, this design strategy is seen as a way to realize the potential of thin film polycrystalline silicon solar cells for large scale, cost effective energy generation. A brief description of the parallel multi junction solar cell is presented, along with some analysis where parallel multi junction solar cells differ from conventional cells. Results from an analytical one dimensional model and two dimensional numerical simulations are presented, highlighting some of the significant advantages of parallel multi junction solar cells.", "author_names": [ "S Edmiston", "Alistair B Sproul", "Martin A Green", "S R Wenham" ], "corpus_id": 95765579, "doc_id": "95765579", "n_citations": 15, "n_key_citations": 0, "score": 0, "title": "Modelling of Thin film Crystalline Silicon Parallel Multi junction Solar Cells", "venue": "", "year": 1995 }, { "abstract": "A two dimensional (2D) analytical model based on the Green's Function method is applied to an n p thin film polycrystalline solar cell that allows us to calculate the conversion efficiency. This model considers the effective Gaussian doping profile in the p region in order to improve cell efficiency. The dependence of mobility and lifetime on grain doping is also investigated. This model is implemented through a simulation program in order to optimize conversion efficiency while varying thickness and doping profile in the base region of the cell. Compared with n p standard structure, our proposed structure shows a 43% improvement in conversion efficiency for a polycrystalline solar cell. PACS. 85.30.De Semiconductor device, characterization, design and modelling. 88.40.hj Efficiency and performance of solar cells.", "author_names": [ "Sami Kolsi", "Mohamed Ben Amar", "Hekmet Samet", "A Ouali" ], "corpus_id": 110523894, "doc_id": "110523894", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Effect of Gaussian doping profile on the performance of a thin film polycrystalline solar cell", "venue": "", "year": 2012 }, { "abstract": "Abstract The \"classical\" Volger Petritz Berger barrier model of the thin polycrystalline layer is developed, thereby enabling a coherent mathematical description of this model in stationary conditions to be given. The symmetric and asymmetric barriers as well as the effect of the thickness of the grain boundary region on the height of the potential barrier (the diffusion barrier) are analysed. The model presented is based on abrupt low high type semiconductor structures and is complementary to and a development of theoretical models with Schottky barriers, p n junctions, heterojunctions or trapping. The development of the trapping model, which is the most advanced model theoretically and which is particularly useful for polycrystalline layers of elemental semiconductors, is outlined. The literature quoted enables the results obtained with both models to be compared. The present results are applicable in analyses of the electrical properties of polycrystalline solar cells.", "author_names": [ "Zbigniew T Kuznicki" ], "corpus_id": 98589722, "doc_id": "98589722", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Modelling of semiconductor polycrystalline layers in the stationary state", "venue": "", "year": 1984 }, { "abstract": "Abstract Chemical bath deposition (CBD) generates has been successfully employed for the fabrication of II VI semiconductor thin films. Thin film polycrystalline solar cells, such as the BP Solar 'Apollo' CdS:CdTe heterojunction device, offer the potential for low cost solar energy conversion. The large scale exploitation of these devices is partly dependent on a reduction of the potential environmental impact of the technology. The fabrication of CdS window layers by CBD at present generates considerable Cd containing waste. Use and disposal of cadmium containing compounds and wastes are highly regulated in the EU and elsewhere. For CdS CBD, the extent of the desired heterogeneous reaction on the substrate surface is limited by two major factors, the competing homogeneous reaction in solution and deposition of material on the CBD reactor walls. In this paper we describe our initial successful efforts to address these problems with the development of a novel high efficiency CdS CBD system. Chemical modelling and speciation studies have enabled us to develop a process that comprises low cadmium concentrations and eliminates ammonia (which is volatile and undesirable for large scale CBD operations) Films have been characterised by spectroscopic methods (UV vis, PL and XPS) microscopy (SEM and TEM) and powder XRD.", "author_names": [ "David S Boyle", "Alexander Bayer", "Markus R Heinrich", "Odile Robbe", "Paul O'Brien" ], "corpus_id": 95312818, "doc_id": "95312818", "n_citations": 61, "n_key_citations": 1, "score": 0, "title": "Novel approach to the chemical bath deposition of chalcogenide semiconductors", "venue": "", "year": 2000 }, { "abstract": "Although this is the 16th volume in a long standing and successful series, the focus is no longer limited to hydrogenated amorphous silicon (a Si:H) The distinction between short and medium range order, and between homogeneous and heterogeneous semiconductor materials, is indeed too difficult to maintain. Instead, the volume covers amorphous and microcrystalline silicon from materials physics to new applications. Papers from a joint session with a symposium on Flat Panel Display Materials and Large Area Processes are included. The volume also features special focused sessions on heterogeneous materials, color sensors and radiation imaging, and parameter extraction and device modelling. Topics include: amorphous and polycrystalline thin film transistors; solar cells; color and X ray sensors, novel devices, luminescence and sensitization; device modelling and parameter extraction; growth, alloys and clathrates; metastability, hydrogen, atomic and electronic structure; defects and charge transport; and heterogeneous silicon formation, properties and devices.", "author_names": [ "Ruud E I Schropp" ], "corpus_id": 135858433, "doc_id": "135858433", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Amorphous and microcrystalline silicon technology 1998 symposium held April 14 17, 1998, San Francisco, California, U.S.A.", "venue": "", "year": 1999 }, { "abstract": "Abstract An overview is given of various electronic effects present in polycrystalline thin film solar cells, which do not occur in standard crystalline Si solar cells. It is explained how these effects are treated numerically in a numerical solar cell simulation tool, SCAPS, developed at the author's institute. The capabilities and limitations of SCAPS are discussed. Simulation examples of current voltage, capacitance voltage and capacitance frequency characteristics are given. The agreement between the simulations and measurements is shown and discussed, both for CdTe and for Cu(In,Ga)Se 2 solar cells.", "author_names": [ "Marc Burgelman", "Peter Nollet", "Stefaan Degrave" ], "corpus_id": 18862423, "doc_id": "18862423", "n_citations": 1032, "n_key_citations": 47, "score": 1, "title": "Modeling polycrystalline semiconductor solar cells", "venue": "", "year": 1999 }, { "abstract": "A model has been developed to characterize the photovoltaic properties of a thin film polycrystalline semiconductor solar cell with a metal insulator semiconductor (MIS) structure and an accumulated back contact which forms a back surface field. Semiconductor doping density, thickness, grain size, and grain boundary trap density are the parameters used to characterize the semiconductor. Collection velocity, diode ideality factor, effective junction barrier height, and light transmittance are the parameters used to characterize the MIS interfacial region. The three dimensional grain size and grain boundary problem is simplified by transforming it to an equivalent one dimensional single level bulk trap problem. The majority carrier density and the built in potential are assumed to be affected by light intensity, doping and trap densities. The effects of deep level grain boundary traps and of surface passivation on the short circuit current, open circuit voltage, fill factor, collection and conversion efficiencies of these cells are calculated based on the potential distribution in the thin film semiconductor. Recombination current and series and shunt resistance are not included and the superposition principle is not used in the calculation. Sample calculations are included for the specific case of electrodeposited n type CdTe MIS solar cells. Methods to improve the conversion efficiency and the application of modeling are discussed.", "author_names": [ "S M So", "", "Peter V Meyers", "C H Liu" ], "corpus_id": 23693847, "doc_id": "23693847", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Modeling of grain boundary effects on photovoltaic properties of metal insulator thin film polycrystalline semiconductor solar cells", "venue": "IEEE Transactions on Electron Devices", "year": 1984 }, { "abstract": "Computational models can provide significant insight into the operation mechanisms and deficiencies of photovoltaic solar cells. Solcore is a modular set of computational tools, written in Python 3, for the design and simulation of photovoltaic solar cells. Calculations can be performed on ideal, thermodynamic limiting behaviour, through to fitting experimentally accessible parameters such as dark and light IV curves and luminescence. Uniquely, it combines a complete semiconductor solver capable of modelling the optical and electrical properties of a wide range of solar cells, from quantum well devices to multi junction solar cells. The model is a multi scale simulation accounting for nanoscale phenomena such as the quantum confinement effects of semiconductor nanostructures, to micron level propagation of light through to the overall performance of solar arrays, including the modelling of the spectral irradiance based on atmospheric conditions. In this article, we summarize the capabilities in addition to providing the physical insight and mathematical formulation behind the software with the purpose of serving as both a research and teaching tool.", "author_names": [ "Diego Alonso-Alvarez", "Tom Wilson", "Phoebe M Pearce", "Markus Fuhrer", "Daniel J Farrell", "Nicholas J Ekins-Daukes" ], "corpus_id": 56475407, "doc_id": "56475407", "n_citations": 36, "n_key_citations": 3, "score": 0, "title": "Solcore: a multi scale, Python based library for modelling solar cells and semiconductor materials", "venue": "", "year": 2018 }, { "abstract": "Abstract A theoretical approach based on the Matthiessen rule for scattering lifetime is presented to formulate the effective characteristics of polycrystalline solar cells. Application of this method to Perovskite solar cells obtains polycrystalline bulk defect density for diverse grain sizes along with the determination of surface recombination velocity at grain boundaries. Unlike previous works on Silicon based solar cells that use an independently weighted average equation for extracting mobility, we introduce a variation of Drude Smith model for calculating the mobility from carrier lifetime and defect density. In agreement with the experiments, introduced method reveals sub picosecond background scattering times associated with phonon lattice vibrations. Obtained carrier diffusion length spans over multi micron to multi millimeter scale for grain sizes ranging from 100 nm to 1 mm. Calculated monomolecular recombination lifetimes explains elevated Photoluminescence Yield and peak position in larger grain sizes. Presented method is verified by feeding extracted parameters into Drift Diffusion equations and fitting with reported experimental photovoltaic conversion efficiency data. Finally, through employing a Gaussian distribution for grain sizes, we also study the reduction of device efficiency caused by non uniform grain size distribution as a more realistic case.", "author_names": [ "Babak Olyaeefar", "Sohrab Ahmadi-kandjani", "Asghar Asgari" ], "corpus_id": 102776267, "doc_id": "102776267", "n_citations": 24, "n_key_citations": 1, "score": 0, "title": "Classical modelling of grain size and boundary effects in polycrystalline perovskite solar cells", "venue": "", "year": 2018 } ]

[ { "abstract": "We present a first principle study of interaction of toxic gas molecules (NO, NO2 and SO2) with monolayer MoSe2. The predicted order of sensitivity of gas molecule is NO2 SO2 NO. Adsorbed molecules strongly influence the electronic behaviour of monolayer MoSe2 by inducing impurity levels in the vicinity of Fermi energy. NO and SO2 is found to induce p type doping effect while semiconductor to metallic transitions occur on NO2 adsorption. Our findings may guide the experimentalist for fabricating sensor devices based on MoSe2 monolayer.", "author_names": [ "Munish Sharma", "Pooja Jamdagni", "Ashok Kumar", "Pushpa Ahluwalia" ], "corpus_id": 100262877, "doc_id": "100262877", "n_citations": 24, "n_key_citations": 0, "score": 1, "title": "Interactions of gas molecules with monolayer MoSe2: A first principle study", "venue": "", "year": 2016 }, { "abstract": "Dissolved gas analysis (DGA) in transformer oil is a workable approach to evaluate the operation status of transformers. In this paper, we proposed a Cu doped Se vacancy MoSe2 (Cu MoSe2) monolayer as a promising sensing material for DGA based on first principles theory. Three typical dissolved gases, namely, CO, C2H2, and C2H4, are the representatives to investigate the potential of the Cu MoSe2 monolayer upon their adsorption and sensing. Our results indicate that Cu doping causes strong n doping for the Se vacancy MoSe2 monolayer, and the Cu MoSe2 monolayer exhibits strong chemisorption the three gas molecules, with a calculated adsorption energy (Ead) of 1.25, 1.06, and 1.16 eV, respectively. Such strong interactions lead to remarkable changes in the electrical conductivity of the Cu MoSe2 monolayer, allowing its application as a resistance type sensor. Besides, work function (WF) analysis shows the potential of the Cu MoSe2 monolayer as a promising field effect transistor sensor as well. It is our hope that our work can stimulate more leading edge studies of the TM doped MoSe2 monolayer for sensing applications in many fields.", "author_names": [ "Sunzhi Yang", "Xian-lin Chen", "Zurong Gu", "Tieyong Ling", "Yanling Li", "Shouxiao Ma" ], "corpus_id": 227268025, "doc_id": "227268025", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Cu Doped MoSe2 Monolayer: A Novel Candidate for Dissolved Gas Analysis in Transformer Oil", "venue": "ACS omega", "year": 2020 }, { "abstract": "Lattice defects and dielectric environment play a crucial role for 2D materials. Gas molecules can get physisorbed easily on the surface through van der Waals forces and can modify dramatically their electronic and optical properties. In this work, we investigate the impact of the physisorbed gas molecules on the optical properties of MoSe2 monolayers by means of low temperature photoluminescence (PL) More specifically, we focus on the physics of excitons localized by gas molecules. The associated PL peak is observed to show a systematic and large red shift with temperature and a blue shift with laser irradiation. Both energy shifts are explained in terms of thermal instability of the localization in combination with hopping effects. Finally, a model is presented, which can reproduce the experimental data with excellent agreement. Published under license by AIP Publishing. https:/doi.org/10.1063/1.5094118 In recent years, a lot of scientific research has been conducted to understand the electronic and optical properties of transition metal dichalcogenide (TMD) monolayers (MoS2, WSe2, 1 The interest in these materials is closely connected with the atomic vertical scale of these semiconductors. This geometrical property made the scientific community face new interesting physics and at the same time new technological opportunities and challenges. An effect related to the extreme surface to volume ratio is the huge influence of physisorption and chemisorption of gas molecules on the optical and electronic properties. This efficient interaction can be exploited to engineer the materials for related applications, for instance, chemical treatment for enhancing and tuning photoluminescence (PL) emission as well as gas sensing and biosensing using modulations in electronic and optical responses as fingerprints for physisorbed gas molecules. In this context, PL offers an elegant, low power consuming, and contactless tool. Furthermore, physisorption is strongly connected with other prominent effects on TMD monolayers, i.e. photo annealing and photo doping. Regarding optical properties, it has been shown that the exposure to low intensity visible laser light changes drastically the optical response of the material. On one hand, these effects have to be kept under control for research investigations, but, on the other hand, they can be used for technological applications such as reversible optical control of the doping. Even if the effects of physisorption are well documented in literature, discussions and comprehension of the physics of such effects on localized excitons are still missing. For this purpose, we present here a systematic experimental study on the impact of gas molecules present in air on optical properties of a MoSe2 monolayer via lowtemperature PL. We follow the temperature evolution of the localized excitons related to gas molecules (GM LX) We observe a large redshift, and we present a model that can reproduce the data with excellent agreement. Within the same approach, we analyze the evolution of the GM LX peak for different laser irradiation doses, where a blueshift of the peak is observed with increasing irradiation doses. We suggest that both the red shift and the blue shift can be explained by hopping between localized states. Finally, we also introduce an effective temperature particularly important at low temperature in order to describe the disorder potential induced by the physisorbed gas molecules. We focus our attention on a MoSe2 monolayer, that is, a paradigmatic compound of TMDs. Nevertheless, in comparison with other W based TMD monolayers, it shows cleaner optical spectra, a condition that allows us to isolate more easily the effects of the physisorbed gas molecules. Moreover, the possibility to use MoSe2 monolayers Appl. Phys. Lett. 114, 172106 (2019) doi: 10.1063/1.5094118 114, 172106 1 Published under license by AIP Publishing Applied Physics Letters ARTICLE scitation.org/journal/apl", "author_names": [ "Tommaso Venanzi", "Himani Arora", "Artur Erbe", "Alexej Pashkin", "", "Manfred Helm", "Harald Schneider" ], "corpus_id": 221408283, "doc_id": "221408283", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Helmholtz Zentrum Dresden Rossendorf (HZDR) Exciton localization in MoSe2 monolayer induced by adsorbed gas molecules", "venue": "", "year": 2020 }, { "abstract": "Abstract The adsorptions of noble metals including Pd, Pt and Au atoms on the MoSe2 monolayers were explored using the density functional theory calculations. The results of the adsorption energies indicated that all Pd, Pt and Au adsorbed MoSe2 monolayers are energetically stable. Based on band structure calculations, all the noble metal adsorbed MoSe2 systems showed semiconductor feature. The smallest stability occurs in Au adsorption to the surface, whereas the highest stability corresponds to the Pt adsorption with the TM Se bond length being lower than that of Au adsorption system. Au adsorbed MoSe2 monolayer revealed magnetism, while Pd and Pt adsorbed monolayers possess nonmagnetic nature. The adsorption configurations of CO, CO2, NO, and NH3 molecules on the Pt adsorbed MoSe2 monolayers were also examined in this work. These gas molecules ae weakly physisorbed on the pure MoSe2 monolayer, while on the Pt adsorbed one, the gas molecules were strongly chemisorbed. The nature of covalent interaction between the gases and Pt adsorbed system can be also verified by large overlaps in the density of states plots.", "author_names": [ "Wang Si Hui", "Gong Chang", "Wei Gao" ], "corpus_id": 219068320, "doc_id": "219068320", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Exploring the electronic and magnetic properties of noble metal (Pd, Pt, Au) adsorbed MoSe2 monolayers and their performance towards sensing gas molecules", "venue": "", "year": 2020 }, { "abstract": "This paper explores the two dimensional (2D) MoSe2 materials and their sensing properties by exploring it to hazardous N2O gas molecule. The gas sensing behavior is analyzed with charge transfer (QT) as one of its parameter. Charge transfer is used to explain the extent to which the gas molecule interacts with the 2D material. A comparison between charge transfers by varying the adsorption distance between the adsorbent gas molecule and among adsorbent atoms from 2A to 1A with a uniform step of 0.5A is dealt with. The impact on the bond length is also analyzed and calculated to be decreasing with increase in charge transfer. It is observed that higher will be the charge transfer between the adsorbent gas molecule and 2D MoSe2 material, higher will be interaction.", "author_names": [ "Neha Mishra", "Bramha P Pandey" ], "corpus_id": 220073026, "doc_id": "220073026", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Detection of N2O gas using 2D MoSe2 Monolayer: A DFT Theory", "venue": "2020 International Conference on Electrical and Electronics Engineering (ICE3)", "year": 2020 }, { "abstract": "Using first principles theory, we investigated the most stable configuration for the Rh dopant on a MoSe2 monolayer, and the interaction of the Rh doped MoSe2 (Rh MoSe2) monolayer with four toxic gases (CO, NO, NO2 and SO2) to exploit the potential application of the Rh MoS2 monolayer as a gas sensor or adsorbent. Based on adsorption behavior comparison with other 2D adsorbents and desorption behavior analysis, we assume that the Rh MoSe2 monolayer is a desirable adsorbent for CO, NO and NO2 storage or removal given the larger adsorption energy (Ead) of 2.00, 2.56 and 1.88 eV, respectively, compared with other materials. In the meanwhile, the Rh MoSe2 monolayer is a good sensing material for SO2 detection according to its desirable adsorption and desorption behaviors towards the target molecule. Our theoretical calculation would provide a first insight into the TM doping effect on the structural and electronic properties of the MoSe2 monolayer, and shed light on the application of Rh MoSe2 for the sensing or disposal of common toxic gases.", "author_names": [ "Hao Cui", "Guozhi Zhang", "Xiaoxing Zhang", "Ju Tang" ], "corpus_id": 139609567, "doc_id": "139609567", "n_citations": 106, "n_key_citations": 0, "score": 0, "title": "Rh doped MoSe2 as a toxic gas scavenger: a first principles study", "venue": "", "year": 2019 }, { "abstract": "Abstract On the basis of recent findings reported, gas sensors constructed from MoS2 and MoSe2 monolayers have superior sensing performance compared to the gas sensors fabricated from graphene. In this work, we scrutinized the adsorption of NO, and CO gas molecules on the perfect and Ti doped MoS2 and MoSe2 monolayers by means of the density functional theory method. The obtained results revealed that the Ti doped MoS2 and MoSe2 monolayers have more sensitivity towards NO and CO detection than the pristine systems with substantial adsorption energies of gas molecules on these surfaces. The higher sensitivity and larger adsorption energy of Ti doped systems are responsible for the strong interaction between NO/CO molecules and MoS2/MoSe2 systems. There are considerable electronic density between the metal site of substrates and N/C atoms of NO/CO molecules, which can be attributed to the strong interaction between them. Moreover, the effect of external electric field on the adsorption process was evaluated, which indicates that the sensitivity of gas sensor can substantially be modulated via applying external electric field. This work aims at suggesting a promising material based on Ti doped MoS2 and MoSe2 systems for sensing toxic NO and CO gases in the atmosphere.", "author_names": [ "Yafeng Yang", "Muhammad Ashraf", "Kittisak Jermsittiparsert", "Lilin Jiang", "Dangquan Zhang" ], "corpus_id": 213668877, "doc_id": "213668877", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "RETRACTED: Enhancing the adsorption performance and sensing capability of Ti doped MoSe2 and MoS2 monolayers by applying electric field", "venue": "", "year": 2020 }, { "abstract": "Recent experiments demonstrate the synthesis of 2D black arsenic exhibits excellent electronic and transport properties for nanoscale device applications. Herein, we study by first principle calculations density functional theory together with non equilibrium Greens function methods, the structural, electronic, adsorption strength, charge transfer, and transport properties of five gas molecules CO, CO2, NO, NO2, and NH3 on a monolayer of black arsenic. Our findings suggest optimum sensing performance of black arsenic that can even surpass that of other 2D material such as graphene. Further, we note the optimum adsorption sites for all the five gas molecules on the black arsenic and significant charge transfer between the gas molecules and black arsenic are responsible for optimum adsorption strength. Particularly, the significant charger transfer is a sign that the interaction between the target gas molecule and nanoscale device is sufficient to yield noticeable changes in the electronic transport properties. As a proof of principle, we have examined the sensitivity of a modeled nano scale device towards CO, CO2, NO, NO2, and NH3 gas molecules, indicating that it is indeed possible to reliably detect all the five gas molecules. Thus, based on all these findings, such as sensitivity and selectivity to all the five gas molecules adsorption make black arsenic a promising material as an optimum gas sensor nano scale device.", "author_names": [ "Rameshwar L Kumawat", "Milan Kumar Jena", "Biswarup Pathak Discipline of Metallurgy Engineering", "Materials Science", "Discipline of Chemistry", "Indian Institute of Technology", "" ], "corpus_id": 214714271, "doc_id": "214714271", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Black Arsenic as an Optimum Gas Sensor: vdW Corrected Density Functional Theory Calculations", "venue": "", "year": 2020 }, { "abstract": "Using first principles theory, we investigated the most stable configuration for the Rh dopant on a MoSe2 monolayer, and the interaction of the Rh doped MoSe2 (Rh MoSe2) monolayer with four toxic gases (CO, NO, NO2 and SO2) to exploit the potential application of the Rh MoS2 monolayer as a gas sensor or adsorbent. Based on adsorption behavior comparison with other 2D adsorbents and desorption behavior analysis, we assume that the Rh MoSe2 monolayer is a desirable adsorbent for CO, NO and NO2 storage or removal given the larger adsorption energy (Ead) of 2.00, 2.56 and 1.88 eV, respectively, compared with other materials. In the meanwhile, the Rh MoSe2 monolayer is a good sensing material for SO2 detection according to its desirable adsorption and desorption behaviors towards the target molecule. Our theoretical calculation would provide a first insight into the TM doping effect on the structural and electronic properties of the MoSe2 monolayer, and shed light on the application of RhMoSe2 for the sensing or disposal of common toxic gases.", "author_names": [ "Hao Cui", "Guozhi Zhang", "Xiaoxing Zhang", "J Tangc" ], "corpus_id": 201107866, "doc_id": "201107866", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "as a toxic gas scavenger a fi rst principles study", "venue": "", "year": 2019 }, { "abstract": "In the monolayer limit, transition metal dichalcogenides become direct bandgap, light emitting semiconductors. The quantum yield of light emission is low and extremely sensitive to the substrate used, while the underlying physics remains elusive. In this work, we report over 100 times modulation of light emission efficiency of these two dimensional semiconductors by physical adsorption of O2 and/or H2O molecules, while inert gases do not cause such effect. The O2 and/or H2O pressure acts quantitatively as an instantaneously reversible \"molecular gating\" force, providing orders of magnitude broader control of carrier density and light emission than conventional electric field gating. Physi sorbed O2 and/or H2O molecules electronically deplete n type materials such as MoS2 and MoSe2, which weakens electrostatic screening that would otherwise destabilize excitons, leading to the drastic enhancement in photoluminescence. In p type materials such as WSe2, the molecular physisorption results in the opposite effect. Unique and universal in two dimensional semiconductors, the effect offers a new mechanism for modulating electronic interactions and implementing optical devices.", "author_names": [ "Sefaattin Tongay", "Jian Zhou", "Can Ataca", "Jonathan Liu", "Jeong Seuk Kang", "Tyler Scott Matthews", "Long You", "Jingbo Li", "Jeffrey C Grossman", "Junqiao Wu" ], "corpus_id": 15471156, "doc_id": "15471156", "n_citations": 528, "n_key_citations": 3, "score": 0, "title": "Broad range modulation of light emission in two dimensional semiconductors by molecular physisorption gating.", "venue": "Nano letters", "year": 2013 } ]

[ { "abstract": "As the micro electro mechanical machine (MEMS) industry is maturing, an increased array of product applications and devices are being introduced. As these devices are being developed new processes are required to control and attain the desired levels of polysilicon stress. In this work the relationship between polysilicon blanket residual stress and dopant concentration and anneal conditions are investigated. It was found that as the sheet resistance increased, the magnitude of the stress increased several orders of magnitude. Annealing the wafers for increased durations and multiple cycles lowered the level of stress observed while reducing the response to dopant concentration. The response was reduced by fifty percent for a time increase from 20 to 180 minutes. It is suggested that specific levels of stress are best attained with modifications to the dopant concentration for the required thermal cycles. The characterization performed allows for reduced learning cycles and cost in the development of new MEMS process flows to achieve first pass success for device specific requirements.", "author_names": [ "Jerzy Woloszyn" ], "corpus_id": 29987722, "doc_id": "29987722", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "A method for controlling residual film stress in LPCVD polysilicon films for surface micromachined MEMS", "venue": "2004 IEEE/SEMI Advanced Semiconductor Manufacturing Conference and Workshop (IEEE Cat. No.04CH37530)", "year": 2004 }, { "abstract": "While spin qubits based on gate defined quantum dots have demonstrated very favorable properties for quantum computing, one remaining hurdle is the need to tune each of them into a good operating regime by adjusting the voltages applied to electrostatic gates. The automation of these tuning procedures is a necessary requirement for the operation of a quantum processor based on gate defined quantum dots, which is yet to be fully addressed. We present an algorithm for the automated fine tuning of quantum dots, and demonstrate its performance on a semiconductor singlet triplet qubit in GaAs. The algorithm employs a Kalman filter based on Bayesian statistics to estimate the gradients of the target parameters as function of gate voltages, thus learning the system response. The algorithm's design is focused on the reduction of the number of required measurements. We experimentally demonstrate the ability to change the operation regime of the qubit within 3 to 5 iterations, corresponding to 10 to 15 minutes of lab time.", "author_names": [ "Julian D Teske", "Simon Sebastian Humpohl", "Ren'e Otten", "Patrick Bethke", "Pascal Cerfontaine", "Jonas Dedden", "Arne Ludwig", "Andreas Dirk Wieck", "Hendrik Bluhm" ], "corpus_id": 117683624, "doc_id": "117683624", "n_citations": 28, "n_key_citations": 1, "score": 0, "title": "A machine learning approach for automated fine tuning of semiconductor spin qubits", "venue": "Applied Physics Letters", "year": 2019 }, { "abstract": "Semiconductor manufacturers aim to fabricate defect free wafers in order to improve product quality, increase yields, and reduce costs. Typically, wafer defects form spatial patterns that provide useful information, helping to identify problems and faults during the fabrication process. Machine learning (ML) methods have been used to classify these defects in order to locate the root causes of failure. This paper proposes a novel deep structured ML approach as an extension of our previous randomized general regression network (RGRN) model, to identify and classify both single defect and mixed defect patterns. The principal motivation for this paper is that a shallow structured RGRN performs well on single pattern defects, achieving an accuracy of 99.8% but performs poorly when a wafer has mixed defect patterns. The proposed approach improves RGRN performance, particularly on mixed pattern defects, by incorporating a novel information gain (IG) based splitter as well as deep structured ML. A spatial filter is applied to remove random noise and reduce model bias during training. During the first detection stage, the splitter generates unique rules that are built using the IG theory and splits the defects data into single defect and mixed defect patterns. Single defect patterns are then classified by RGRN, whereas mixed defect patterns are fed into the deep structured ML model for further classification. This combination improves the ability of the proposed approach to classify diverse defect patterns and achieve a better overall performance. Our experimental results demonstrate that the proposed approach achieves an overall detection accuracy of 86.17% on a dataset that contains real data representing both single defect and mixed defect patterns, as commonly found in real manufacturing scenarios, outperforming existing ML based models.", "author_names": [ "Ghalia Tello", "Omar Y Al-Jarrah", "Paul Yoo", "Yousof Al-Hammadi", "Sami Hakam Muhaidat", "Uihyoung Lee" ], "corpus_id": 23814032, "doc_id": "23814032", "n_citations": 49, "n_key_citations": 0, "score": 1, "title": "Deep Structured Machine Learning Model for the Recognition of Mixed Defect Patterns in Semiconductor Fabrication Processes", "venue": "IEEE Transactions on Semiconductor Manufacturing", "year": 2018 }, { "abstract": "Semiconductor cluster equipment adds an integral component to the modern semiconductor manufacturing process. These complex tools provide a flexible deployment option to group multiple processing steps into a single piece of equipment, allowing for more efficient processing. They also contribute to a reduction in the number of times a wafer must go through the atmospheric vacuum atmospheric cycle. Such highly automated tools present a complex scheduling challenge where process specific requirements are balanced against a need to achieve maximum wafer throughput in a fault tolerant manner. Software engineers typically build schedulers using a set of manually configured heuristics but this can be a labor intensive process where small changes to the cluster configuration or process requirements can require large changes to the scheduler. Our motivation for this work was to investigate whether a machine learning approach to complex cluster scheduling could be developed more efficiently and at a lower cost than existing methods.", "author_names": [ "Doug Suerich", "Terry Young" ], "corpus_id": 199509662, "doc_id": "199509662", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Machine Learning for Optimized Scheduling in Complex Semiconductor Equipment", "venue": "2019 30th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC)", "year": 2019 }, { "abstract": "In this paper, we show the possibility of using Technology Computer Aided Design (TCAD) to assist machine learning for semiconductor device failure trouble shooting and device reverse engineering. When TCAD simulation models and parameters are properly chosen and calibrated, large number of devices with random defects and structural characteristics can be generated and simulated. The results can then be used to train machine learning algorithms to predict the defect and structural characteristics of a device with given electrical characteristics (such as IV's and CV's) 1D PIN diode with various layer thicknesses and doping concentrations are used in this study. It is showed that with less than 2000 training samples, by using simple linear regression, one can achieve good prediction of layer thickness and doping of a given IV curve.", "author_names": [ "Y S Bankapalli", "Hiu Yung Wong" ], "corpus_id": 204820625, "doc_id": "204820625", "n_citations": 9, "n_key_citations": 0, "score": 1, "title": "TCAD Augmented Machine Learning for Semiconductor Device Failure Troubleshooting and Reverse Engineering", "venue": "2019 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD)", "year": 2019 }, { "abstract": "Machine learning and big data analytics are the latest spotlights with all the glare of fame ranging from media coverage to booming start up companies to eye catching merges and acquisitions. On the contrary, the $336 billion industry of semiconductor was seen as an \"old fashioned\" business, with fading interests from the best and brightest among young graduates and engineers. This chapter argues that this does not have to be that way because many research problems and solutions as studied in the semiconductor industry are in fact closely related to these machine learning and big data problems. To illustrate this point, we discuss a number of practical but challenging problems arising from semiconductor manufacturing process in this chapter. We first show how machine learning techniques, especially those regression related problems, often under the \"disguise\" of optimization problems, have been used frequently (often with nontrivial modeling skills and mathematical sophistications) to solve the semiconductor problems. We discuss such examples as process variation modeling and VLSI chip testing. For some other types of semiconductor problems, such as manufacturing process monitoring and improvement, we show that some existing machine learning algorithms are not necessarily well positioned to solve them, and novel machine learning techniques involving temporal, structural, and hierarchical properties need to be further developed. In either scenario, we convey the message that machine learning and existing semiconductor industry researches are closely related, and researchers often contribute to and benefit from each other.", "author_names": [ "Jinjun Xiong", "Yada Zhu", "Jingrui He" ], "corpus_id": 88499733, "doc_id": "88499733", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Machine Learning for VLSI Chip Testing and Semiconductor Manufacturing Process Monitoring and Improvement", "venue": "", "year": 2019 }, { "abstract": "Abstract The progress of digitalization enables new potentials to supply chain management by available data as well as by analysis methods like machine learning. This paper focuses on the master production planning matching demand and supply for a midterm time horizon, in a volatile, diverse and capacity constrained environment. Therefore, a framework for measuring instability is outlined, a machine learning approach to predict instability is developed and applied using the CRISP DM methodology on real data of a semiconductor manufacturer. The evaluation and results foster the concept and the field of application, but request the next step of prescriptive instability minimization.", "author_names": [ "Tim Lauer", "Sarah Legner", "Michael Henke" ], "corpus_id": 213671070, "doc_id": "213671070", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Application of machine learning on plan instability in master production planning of a semiconductor supply chain", "venue": "", "year": 2019 }, { "abstract": "In this work, we present a unique approach of combining TCAD modelling and machine learning to detect the defect locations of a bridging defect in a single fin FinFET. The prediction of the defect location is guided by the predictive model consisting of Random Forest algorithm which is trained with the measureable electrical attributes from the I V. High accuracy in predicting the defect location is achieved by the proposed scheme which can further enhance the FA success rate, expediting the cycle of design to product.", "author_names": [ "C W Teo", "Kain Lu Low", "Vinod Narang", "Aaron Voon-Yew Thean" ], "corpus_id": 204820227, "doc_id": "204820227", "n_citations": 8, "n_key_citations": 1, "score": 1, "title": "TCAD Enabled Machine Learning Defect Prediction to Accelerate Advanced Semiconductor Device Failure Analysis", "venue": "2019 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD)", "year": 2019 }, { "abstract": "Reliable and robust process control solutions are pivotal in the era of advanced technology nodes where the stochastic effects dominate the pattern characteristics. The key ingredients ofthe modern process control solutions are huge amount of data and smart data analytics algorithms. The state of the art machine learning methods allow screening large amounts of data for statistically relevant, but so far unknown and unexpected correlations, hence providing new options for process optimizations.", "author_names": [ "Eugen Foca" ], "corpus_id": 202096500, "doc_id": "202096500", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Machine Learning Solutions for Process Control in Semiconductor Manufacturing", "venue": "2019 International Symposium on VLSI Technology, Systems and Application (VLSI TSA)", "year": 2019 }, { "abstract": "The stock market was affected by different variables, such as the overall economic situation, political events, Sino US relations and corporate operations. Therefore, if you want to get returns in the stock market, predicting the time series of financial markets in advance is the most important thing for analysts and investors. However, predicting the direction of the stock market need to access information from existing markets and past historical data. Under such complicated work and costs, it is always the most difficult and important issue to achieve accurate forecasting and reduce forecasting costs. In this paper, the backpropagation neural network is used as a research tool to analyze the historical data of Taiwan Semiconductor Manufacturing Company (hereinafter referred to as TSMC) during the sample period from 2014 to 2018. In this study, the standardized technical analysis indicators and the related variables of TSMC are taken as input variables, and the closing price of the next day is taken as the output variable to predict the closing price for TSMC of the next day. The empirical results confirm that this method does improve the forecast of stock price of TSMC.", "author_names": [ "Po-Chao Lan", "Wei-Ling Kung", "Yao-Lun Ou", "Chun-Yueh Lin", "Wen-Cheng Hu", "Yi-Hsien Wang" ], "corpus_id": 211120483, "doc_id": "211120483", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Machine learning model with technical analysis for stock price prediction: Empirical study of Semiconductor Company in Taiwan", "venue": "2019 International Symposium on Intelligent Signal Processing and Communication Systems (ISPACS)", "year": 2019 } ]

[ { "abstract": "Graphene is very popular because of its many fascinating properties, but its lack of an electronic bandgap has stimulated the search for 2D materials with semiconducting character. Transition metal dichalcogenides (TMDCs) which are semiconductors of the type MX2, where M is a transition metal atom (such as Mo or W) and X is a chalcogen atom (such as S, Se or Te) provide a promising alternative. Because of its robustness, MoS2 is the most studied material in this family. TMDCs exhibit a unique combination of atomic scale thickness, direct bandgap, strong spin orbit coupling and favourable electronic and mechanical properties, which make them interesting for fundamental studies and for applications in high end electronics, spintronics, optoelectronics, energy harvesting, flexible electronics, DNA sequencing and personalized medicine. In this Review, the methods used to synthesize TMDCs are examined and their properties are discussed, with particular attention to their charge density wave, superconductive and topological phases. The use of TMCDs in nanoelectronic devices is also explored, along with strategies to improve charge carrier mobility, high frequency operation and the use of strain engineering to tailor their properties. Two dimensional transition metal dichalcogenides (TMDCs) exhibit attractive electronic and mechanical properties. In this Review, the charge density wave, superconductive and topological phases of TMCDs are discussed, along with their synthesis and applications in devices with enhanced mobility and with the use of strain engineering to improve their properties.", "author_names": [ "Sajedeh Manzeli", "Dmitry Ovchinnikov", "Diego Jose Pasquier", "Oleg V Yazyev", "Andras Kis" ], "corpus_id": 136182991, "doc_id": "136182991", "n_citations": 1703, "n_key_citations": 8, "score": 1, "title": "2D transition metal dichalcogenides", "venue": "", "year": 2017 }, { "abstract": "In recent years, 2D layered materials have received considerable research interest on account of their substantial material systems and unique physicochemical properties. Among them, 2D layered transition metal dichalcogenides (TMDs) a star family member, have already been explored over the last few years and have exhibited excellent performance in electronics, catalysis, and other related fields. However, to fulfill the requirement for practical application, the batch production of 2D TMDs is essential. Recently, the chemical vapor deposition (CVD) technique was considered as an elegant alternative for successfully growing 2D TMDs and their heterostructures. The latest research advances in the controllable synthesis of 2D TMDs and related heterostructures/superlattices via the CVD approach are illustrated here. The controlled growth behavior, preparation strategies, and breakthroughs on the synthesis of new 2D TMDs and their heterostructures, as well as their unique physical phenomena, are also discussed. Recent progress on the application of CVD grown 2D materials is revealed with particular attention to electronics/optoelectronic devices and catalysts. Finally, the challenges and future prospects are considered regarding the current development of 2D TMDs and related heterostructures.", "author_names": [ "Yuanyuan Zhang", "Yuyu Yao", "Marshet Getaye Sendeku", "Lei Yin", "Xueying Zhan", "Feng Wang", "Zhenxing Wang", "Jun He" ], "corpus_id": 199539243, "doc_id": "199539243", "n_citations": 85, "n_key_citations": 0, "score": 0, "title": "Recent Progress in CVD Growth of 2D Transition Metal Dichalcogenides and Related Heterostructures.", "venue": "Advanced materials", "year": 2019 }, { "abstract": "AbstractRoom temperature (RT) gas sensing is desirable for battery powered or self powered instrumentation that can monitor emissions associated with pollution and industrial processes. This review (with 171 references) discusses recent advances in three types of porous nanostructures that have shown remarkable potential for RT gas sensing. The first group comprises hierarchical oxide nanostructures (mainly oxides of Sn, Ni, Zn, W, In, La, Fe, Co) The second group comprises graphene and its derivatives (graphene, graphene oxides, reduced graphene oxides, and their composites with metal oxides and noble metals) The third group comprises 2D transition metal dichalcogenides (mainly sulfides of Mo, W, Sn, Ni, also in combination with metal oxides) They all have been found to enable RT sensing of gases such as NOx, NH3, H2, SO2, CO, and of vapors such as of acetone, formaldehyde or methanol. Attractive features also include high selectivity and sensitivity, long term stability and affordable costs. Strengths and limitations of these materials are highlighted, and prospects with respect to the development of new materials to overcome existing limitations are discussed. Graphical AbstractThe review summarizes the most significant progresses related to room temperature gas sensing by using hierarchical oxide nanostructures, graphene and its derivatives and 2D transition metal dichalcogenides, highlighting the peculiar gas sensing behavior with enhanced selectivity, sensitivity and long term stability.", "author_names": [ "Nirav Joshi", "Takeshi Hayasaka", "Yumeng Liu", "Huiliang Liu", "Osvaldo N Oliveira", "Liwei Lin" ], "corpus_id": 4589763, "doc_id": "4589763", "n_citations": 275, "n_key_citations": 3, "score": 0, "title": "A review on chemiresistive room temperature gas sensors based on metal oxide nanostructures, graphene and 2D transition metal dichalcogenides", "venue": "Microchimica Acta", "year": 2018 }, { "abstract": "Investigations on monolayered transition metal dichalcogenides (TMDs) and TMD heterostructures have been steadily increasing over the past years due to their potential application in a wide variety of fields such as microelectronics, sensors, batteries, solar cells, and supercapacitors, among others. The present work focuses on the characterization of TMDs using transmission electron microscopy, which allows not only static atomic resolution but also investigations into the dynamic behavior of atoms within such materials. Herein, we present a body of recent research from the various techniques available in the transmission electron microscope to structurally and analytically characterize layered TMDs and briefly compare the advantages of TEM with other characterization techniques. Whereas both static and dynamic aspects are presented, special emphasis is given to studies on the electron driven in situ dynamic aspects of these materials while under investigation in a transmission electron microscope. The collection of the presented results points to a future prospect where electron driven nanomanipulation may be routinely used not only in the understanding of fundamental properties of TMDs but also in the electron beam engineering of nanocircuits and nanodevices.", "author_names": [ "Rafael Gregorio Mendes", "Jinbo Pang", "Alicja Bachmatiuk", "Huy Quang Ta", "Liang Zhao", "Thomas Gemming", "Lei Fu", "Zhongfan Liu", "Mark Hermann Rummeli" ], "corpus_id": 59225922, "doc_id": "59225922", "n_citations": 41, "n_key_citations": 0, "score": 0, "title": "Electron Driven In Situ Transmission Electron Microscopy of 2D Transition Metal Dichalcogenides and Their 2D Heterostructures.", "venue": "ACS nano", "year": 2019 }, { "abstract": "The optimization of traditional electrocatalysts has reached a point where progress is impeded by fundamental physical factors including inherent scaling relations among thermokinetic characteristics of different elementary reaction steps, non Nernstian behavior, and electronic structure of the catalyst. This indicates that the currently utilized classes of electrocatalysts may not be adequate for future needs. This study reports on synthesis and characterization of a new class of materials based on 2D transition metal dichalcogenides including sulfides, selenides, and tellurides of group V and VI transition metals that exhibit excellent catalytic performance for both oxygen reduction and evolution reactions in an aprotic medium with Li salts. The reaction rates are much higher for these materials than previously reported catalysts for these reactions. The reasons for the high activity are found to be the metal edges with adiabatic electron transfer capability and a cocatalyst effect involving an ionic liquid electrolyte. These new materials are expected to have high activity for other core electrocatalytic reactions and open the way for advances in energy storage and catalysis.", "author_names": [ "Leily Majidi", "Poya Yasaei", "Robert E Warburton", "Shadi Fuladi", "John Cavin", "Xuan Hu", "Zahra Hemmat", "Sung Beom Cho", "Pedram Abbasi", "Marton Voros", "Lei Cheng", "Baharak Sayahpour", "Igor L Bolotin", "Peter Zapol", "Jeffrey P Greeley", "Robert F Klie", "Rohan Mishra", "Fatemeh Khalili-Araghi", "Larry A Curtiss", "Amin Salehi-Khojin" ], "corpus_id": 205289197, "doc_id": "205289197", "n_citations": 21, "n_key_citations": 0, "score": 0, "title": "New Class of Electrocatalysts Based on 2D Transition Metal Dichalcogenides in Ionic Liquid.", "venue": "Advanced materials", "year": 2019 }, { "abstract": "Two dimensional semiconducting transition metal dichalcogenides (TMDCs) have recently become attractive materials for several optoelectronic applications, such as photodetection, light harvesting, phototransistors, light emitting diodes, and lasers. Their bandgap lies in the visible and near IR range, and they possess strong excitonic resonances, high oscillator strengths, and valley selective response. Coupling these materials to optical nanocavities enhances the quantum yield of exciton emission, enabling advanced quantum optics and nanophotonics devices. Here, we review the state of the art advances of hybrid exciton polariton structures based on monolayer TMDCs coupled to plasmonic and dielectric nanocavities. We discuss the optical properties of 2D WS2, WSe2, MoS2 and MoSe2 materials, paying special attention to their energy bands, photoluminescence/absorption spectra, excitonic fine structure, and to the dynamics of exciton formation and valley depolarization. We also discuss light matter interactions in such hybrid exciton polariton structures. Finally, we focus on weak and strong coupling regimes in monolayer TMDCs based exciton polariton systems, envisioning research directions and future opportunities for this material platform.", "author_names": [ "Alexander E Krasnok", "Sergey Lepeshov", "Andrea Alu" ], "corpus_id": 52030141, "doc_id": "52030141", "n_citations": 72, "n_key_citations": 1, "score": 0, "title": "Nanophotonics with 2D transition metal dichalcogenides [Invited]", "venue": "Optics express", "year": 2018 }, { "abstract": "Recent research has revealed a gamut of interesting properties present in layered two dimensional (2D) transition metal dichalcogenides (TMDCs) such as photoluminescence, comparatively high electron mobility, flexibility, mechanical strength and relatively low toxicity. The large surface to area ratio inherent in these materials also allows easy functionalization and maximal interaction with the external environment. Due to its unique physical and chemical properties, much work has been done in tailoring TMDCs through chemical functionalization for use in a diverse range of biomedical applications as biosensors, drug delivery carriers or even as therapeutic agents. In this review, current progress on the different types of TMDC functionalization for various biological applications will be presented and its future outlook will be discussed.", "author_names": [ "Zibiao Li", "Swee Liang Wong" ], "corpus_id": 27126710, "doc_id": "27126710", "n_citations": 90, "n_key_citations": 1, "score": 0, "title": "Functionalization of 2D transition metal dichalcogenides for biomedical applications.", "venue": "Materials science engineering. C, Materials for biological applications", "year": 2017 }, { "abstract": "Alloying in 2D results in the development of new, diverse, and versatile systems with prospects in bandgap engineering, catalysis, and energy storage. Tailoring structural phase transitions using alloying is a novel idea with implications in designing all 2D device architecture as the structural phases in 2D materials such as transition metal dichalcogenides are correlated with electronic phases. Here, this study develops a new growth strategy employing chemical vapor deposition to grow monolayer 2D alloys of Re doped MoSe2 with show composition tunable structural phase variations. The compositions where the phase transition is observed agree well with the theoretical predictions for these 2D systems. It is also shown that in addition to the predicted new electronic phases, these systems also provide opportunities to study novel phenomena such as magnetism which broadens the range of their applications.", "author_names": [ "Vidya Kochat", "Amey Apte", "Jordan A Hachtel", "Hiroyuki Kumazoe", "Aravind Krishnamoorthy", "Sandhya Susarla", "Juan Carlos Idrobo", "Fuyuki Shimojo", "Priya Vashishta", "Rajiv K Kalia", "Aiichiro Nakano", "Chandra Sekhar Tiwary", "Pulickel M Ajayan" ], "corpus_id": 5428229, "doc_id": "5428229", "n_citations": 107, "n_key_citations": 0, "score": 0, "title": "Re Doping in 2D Transition Metal Dichalcogenides as a New Route to Tailor Structural Phases and Induced Magnetism.", "venue": "Advanced materials", "year": 2017 }, { "abstract": "As a hole transport layer (HTL) material, poly(3,4 ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) was often criticized for its intrinsic acidity and hygroscopic effect that would in the long run affect the stability of perovskite solar cells (Pero SCs) As alternatives, herein water soluble two dimensional (2D) transition metal dichalcogenides (TMDs) such as MoS2 and WS2 were used as HTLs in p i n Pero SCs. It was found that the content of 1T phase in 2D TMDs HTLs is centrally important to the power conversion efficiencies (PCEs) of Pero SCs, and the 1T rich TMDs (as achieved from exfoliation and without postheating) lead to much higher PCEs. More importantly, as PEDOT:PSS was replaced by 2D TMDs, both the PCEs and stability of Pero SCs were significantly improved. The highest PCEs of 14.35 and 15.00% were obtained for the Pero SCs with MoS2 and WS2, respectively, whereas the Pero SCs with PEDOT:PSS showed a highest PCE of only 12.44% These are up to date the highest PCEs using 2D TMDs as HTLs. After being stored in a glovebox for 56 days, PCEs of the Pero SCs using MoS2 and WS2 HTLs remained 78 and 72% respectively, whereas the PCEs of Pero SCs with PEDOT:PSS almost dropped to 0 over 35 days. This study demonstrates that water soluble 2D TMDs have great potential for application as new generation of HTLs aiming at high performance and long term stable Pero SCs.", "author_names": [ "Peng Huang", "Zhao-wei Wang", "Yanfeng Liu", "Kai-cheng Zhang", "Ligang Yuan", "Yi Zhou", "Bo Song", "Yongfang Li" ], "corpus_id": 206455908, "doc_id": "206455908", "n_citations": 61, "n_key_citations": 0, "score": 0, "title": "Water Soluble 2D Transition Metal Dichalcogenides as the Hole Transport Layer for Highly Efficient and Stable p i n Perovskite Solar Cells.", "venue": "ACS applied materials interfaces", "year": 2017 }, { "abstract": "Two dimensional (2D) transition metal dichalcogenides (TMDs) have stimulated the modern technology due to their unique and tunable electronic, optical, and chemical properties. Therefore, it is very important to study the control parameters for material preparation to achieve high quality thin films for modern electronics, as the performance of TMDs based device largely depends on their layer number, grain size, orientation, and morphology. Among the synthesis methods, chemical vapor deposition (CVD) is an excellent technique, vastly used to grow controlled layer of 2D materials in recent years. In this review, we discuss the different growth routes and mechanisms to synthesize high quality large size TMDs using CVD method. We highlight the recent advances in the controlled growth of mono and few layer TMDs materials by varying different growth parameters. Finally, different strategies to control the grain size, boundaries, orientation, morphology and their application for various field of are also thoroughly discussed.", "author_names": [ "Jiawen You", "Md Delowar Hossain", "Zhengtang Luo" ], "corpus_id": 53441028, "doc_id": "53441028", "n_citations": 43, "n_key_citations": 0, "score": 0, "title": "Synthesis of 2D transition metal dichalcogenides by chemical vapor deposition with controlled layer number and morphology", "venue": "Nano Convergence", "year": 2018 } ]

[ { "abstract": "Abstract Because their chemical and physical properties may be tailored over a wide range of characteristics, the use of polymers is finding a permanent place in sophisticated electronic measuring devices such as sensors. During the last 5 years, polymers have gained tremendous recognition in the field of artificial sensor in the goal of mimicking natural sense organs. Better selectivity and rapid measurements have been achieved by replacing classical sensor materials with polymers involving nano technology and exploiting either the intrinsic or extrinsic functions of polymers. Semiconductors, semiconducting metal oxides, solid electrolytes, ionic membranes, and organic semiconductors have been the classical materials for sensor devices. The developing role of polymers as gas sensors, pH sensors, ion selective sensors, humidity sensors, biosensor devices, etc. are reviewed and discussed in this paper. Both intrinsically conducting polymers and non conducting polymers are used in sensor devices. Polymers used in sensor devices either participate in sensing mechanisms or immobilize the component responsible for sensing the analyte. Finally, current trends in sensor research and also challenges in future sensor research are discussed.", "author_names": [ "Basudam Adhikari", "Sarmishtha Majumdar" ], "corpus_id": 137131089, "doc_id": "137131089", "n_citations": 1008, "n_key_citations": 8, "score": 1, "title": "Polymers in sensor applications", "venue": "", "year": 2004 }, { "abstract": "Conducting (or conjugated) polymers (CPs) are widely used for fabricating chemical and biosensors. These materials enable fabrication of devices in short lead time and at relatively low costs owing to their unique advantages of light weight, easy processability, compatibility with biological systems, tunable electronic and optic properties, large area fabrication and potential for flexible or wearable sensors. This chapter describes the basic concepts underlying the interaction of analyte with CPs as well as the other components of sensors. The operating principles of transducers used in the sensor are discussed in detail. Sensors based on conducting polymers are classified in accordance with the changes in the properties of conducting polymers. These changes involve changes in (i) doping levels, (ii) optical properties and (iii) changes due to weak interactions. Furthermore, the sensors have been reviewed for various conducting polymers such as polyaniline, polythiophene, polypyrrole, polydaicetylene for analysis of wide variety of analysts including toxic gases, radiation, pH, temperature, external stimuli; and recent advances in sensors based on conducting polymers have been discussed. Future directions and thrust in emerging field have been projected in the area of molecular engineering, material synthesis, film preparation and transducers, circuits and algorithms for developing futuristic sensors especially wearable sensors.", "author_names": [ "Vibha Saxena", "Dinesh K Aswal" ], "corpus_id": 136285378, "doc_id": "136285378", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Conducting polymers in sensor applications", "venue": "", "year": 2016 }, { "abstract": "Previous publications have shown that polymer based materials hold a great potential for the use as substrates for sensors, for example for AMR sensors. Polymers can substitute expensive substrates such as silicon or silicon oxide, and pre structured substrates can eliminate many necessary cleanroom and micro technological processes, especially photolithography. Ultimately, process optimization can yield manufacturing processes without expensive procedures (through silicon vias) guaranteeing a complete abandonment of processes such as photolithography, CMP and the like. At this point, injection molding with laser direct structuring (LDS) polymers offers distinct advantages, such as the electroless and selective deposition of metals through the directly laser activated polymers, which can be used to implement through vias. In this context, the LDS capable polyetheretherketone (PEEK) is employed herein. The thermoplastic polymer has a high glass transition temperature and features chemical resistances to many solvents. As a result, sensors can potentially cover varying areas of application, and it is additionally possible to integrate these components in micro technological processes. The presented sensor structures were produced by micro technological processes and contacted using vias realized with the LDS method. As a result, the cost effective polymer based module or rather the substrate can be integrated directly into other processes and modules, such as a system on a chip system, without the need for costly process adaptation based on high process variability. To verify this, temperature and magnetic field sensors based on the AMR effect were prepared and evaluated. Accordingly, this article aims to show that wafer level sensors can be fabricated using a process developed at the Institute of Micro Production Technology (IMPT)", "author_names": [ "Sebastian Bengsch", "Marc Christopher Wurz", "Kevin Cromwell", "Maximilian Aue" ], "corpus_id": 201743072, "doc_id": "201743072", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Structuring of Laser Activated Polymers for Sensor Applications", "venue": "2019 IEEE 69th Electronic Components and Technology Conference (ECTC)", "year": 2019 }, { "abstract": "Polymeric sensors play an increasingly important role in monitoring the environment we live in, providing relevant information for a host of applications. Among them, significant efforts have been made to fabricate polymeric sensors useful for healthcare related application fields, such as the sensitive detection of biomolecules and cellular interfacing. Within the well established field of biomedical polymeric sensors, surface modification and/or functionalization using plasma is just emerging as a technology to improve selectivity and sensitivity in the biodetection process. Treatments based on plasma irradiation of polymer surfaces, which have been traditionally applied for cleaning, etching, activating or cross linking, are currently being used to induce the formation of electrocatalytic species able to promote the oxidation of, for example, bioanalytes and/or gas molecules harmful for human health. Here, we summarize the main advances in the utilization of plasma technologies for the fabrication of polymeric sensors for advanced biomedical applications (e.g. humidity, temperature, pH, neurotransmitter, and glucose sensors)", "author_names": [ "Carlos Aleman", "Georgina Fabregat", "Elaine Armelin", "Jorge J Buendia", "Jordi Llorca" ], "corpus_id": 203933673, "doc_id": "203933673", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "Plasma surface modification of polymers for sensor applications.", "venue": "Journal of materials chemistry. B", "year": 2018 }, { "abstract": "Polymeric sensors play an increasingly important role in monitoring the environment we live in, providing relevant information for a host of applications. Among them, significant efforts have been made to fabricate polymeric sensors useful for healthcare related application fields, such as the sensitive detection of biomolecules and cellular interfacing. Within the well established field of biomedical polymeric sensors, surface modification and/or functionalization using plasma is just emerging as a technology to improve selectivity and sensitivity in the biodetection process. Treatments based on plasma irradiation of polymer surfaces, which have been traditionally applied for cleaning, etching, activating or cross linking, are currently being used to induce the formation of electrocatalytic species able to promote the oxidation of, for example, bioanalytes and/or gas molecules harmful for human health. Here, we summarize the main advances in the utilization of plasma technologies for the fabrication of polymeric sensors for advanced biomedical applications (e.g. humidity, temperature, pH, neurotransmitter, and glucose sensors)", "author_names": [ "Carlos Enrique Aleman Llanso", "Georgina Fabregat Jove", "Elaine Aparecida Armelin Diggroc", "J J Morales", "Jordi Llorca Pique" ], "corpus_id": 104400874, "doc_id": "104400874", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Plasma surface modification of polymers for sensor applications", "venue": "", "year": 2018 }, { "abstract": "Surface modification of polystyrene and polyethylene naphthalate by a KrF pulse excimer UV laser under the angles of incidence of the laser beam in the range of 0 to 60Adeg with a step of 7.5Adeg was studied in this paper. The influence of the angle of incidence on the period of the resulting surface structures and the modified refractive index of the substrates was determined with all the other parameters of the laser radiation held constant. All data was acquired on the basis of surface analysis. Atomic force microscopy was used to study the morphological changes in the laser treated samples and to determine the period of the ripple like surface structures, from which the modified refractive index was subsequently calculated. Selected samples were metallized with gold with aim to determine the influence of patterned substrate on consequently formed nanolayer. These information may be useful for consequently constructed SERS system based on ripple metal system.", "author_names": [ "Vaclav Svorcik", "Oldrich Nedela", "Petr Slepicka", "Oleksiy Lyutakov", "Nikola Slepickova Kasalkova", "Zdenka Kolska" ], "corpus_id": 140085786, "doc_id": "140085786", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Construction and Properties of Ripples on Polymers for Sensor Applications", "venue": "", "year": 2018 }, { "abstract": "Thermoplastic polymers like polyolefins, polyesters, polyamide, and styrene polymers are the most representative commodity plastics thanks to their cost efficient manufacturing processes, excellent thermomechanical properties and their good environmental compatibility, including easy recycling. In the last few decades much effort has been devoted worldwide to extend the applications of such materials by conferring on them new properties through mixing and blending with different additives. In this latter context, nanocomposites have recently offered new exciting possibilities. This review discusses the successful use of nanostructured dispersed substrates in designing new stimuli responsive nanocomposites; in particular, it provides an updated description of the synthetic routes to prepare nanostructured systems having the typical properties of thermoplastic polymers (continuous matrix) but showing enhanced optical, conductive, and thermal features dependent on the dispersion topology. The controlled nanodispersion of functional labeled clays, noble metal nanoparticles and carbon nanotubes is here evidenced to play a key role in producing hybrid thermoplastic materials that have been used in the design of devices, such as NLO devices, chemiresistors, temperature and deformation sensors.", "author_names": [ "Serena Coiai", "Elisa Passaglia", "Andrea Pucci", "Giacomo Ruggeri" ], "corpus_id": 17715777, "doc_id": "17715777", "n_citations": 52, "n_key_citations": 1, "score": 0, "title": "Nanocomposites Based on Thermoplastic Polymers and Functional Nanofiller for Sensor Applications", "venue": "Materials", "year": 2015 }, { "abstract": "Molecularly Imprinted Polymers (MIP) were prepared by photochemical route. Photoinduced polymerization was used to achieve the preparation of the MIP and at the same time spatially controlled irradiation allowed shaping the material to confer it an optical function useful for interrogation. Such route significantly simplifies the integration of MIP for sensor applications. Specific photopolymerizable MIP were designed for photopolymerization at different wavelengths and advanced methods of photopatterning were used including optical near field, interference or self guiding lithography. Photopatterning appears thereby as one of the most suitable methods for patterning MIP at the micro and nano scale, directly on the transducer surface.", "author_names": [ "Yannick Fuchs", "Xu Ton", "Karsten Haupt", "Ihab Dika", "Olivier Soppera", "Andrew G Mayes" ], "corpus_id": 11199282, "doc_id": "11199282", "n_citations": 136, "n_key_citations": 0, "score": 0, "title": "Photopolymerization and photostructuring of molecularly imprinted polymers for sensor applications", "venue": "2012 IEEE Sensors", "year": 2012 }, { "abstract": "Molecularly Imprinted Polymers (MIP) were prepared by photochemical route. Photoinduced polymerization was used to achieve the preparation of the MIP and at the same time spatially controlled irradiation allowed shaping the material to confer it an optical function useful for interrogation. Such route significantly simplifies the integration of MIP for sensor applications. Specific photopolymerizable MIP were designed for photopolymerization at different wavelengths and advanced methods of photopatterning were used including optical near field, interference or self guiding lithography. Photopatterning appears thereby as one of the most suitable methods for patterning MIP at the micro and nano scale, directly on the transducer surface.", "author_names": [ "Yannick Fuchs", "Xu Ton", "Karsten Haupt", "Ihab Dika", "Olivier Soppera", "Andrew G Mayes" ], "corpus_id": 110516789, "doc_id": "110516789", "n_citations": 43, "n_key_citations": 1, "score": 0, "title": "Photopolymerization and photostructuring of molecularly imprinted polymers for sensor applications", "venue": "", "year": 2012 }, { "abstract": "Molecular imprinting is the process of template induced formation of specific recognition sites in a polymer. Synthetic receptors prepared using molecular imprinting possess a unique combination of properties such as robustness, high affinity, specificity, and low cost production, which makes them attractive alternatives to natural receptors. Improvements in polymer science and nanotechnology have contributed to enhanced performance of molecularly imprinted polymer (MIP) sensors. Encouragingly, recent years have seen an increase in high quality publications describing MIP sensors for the determination of biomolecules, drugs of abuse, and explosives, driving toward applications of this technology in medical and forensic diagnostics. This review aims to provide a focused overview of the latest achievements made in MIP based sensor technology, with emphasis on research toward real life applications.", "author_names": [ "Omar Sheej Ahmad", "Thomas S Bedwell", "Cem Esen", "Alvaro Garcia-Cruz", "Sergey A Piletsky" ], "corpus_id": 52312515, "doc_id": "52312515", "n_citations": 169, "n_key_citations": 1, "score": 0, "title": "Molecularly Imprinted Polymers in Electrochemical and Optical Sensors.", "venue": "Trends in biotechnology", "year": 2019 } ]

[ { "abstract": "Semiconductor p n junctions are essential building blocks for electronic and optoelectronic devices. In conventional p n junctions, regions depleted of free charge carriers form on either side of the junction, generating built in potentials associated with uncompensated dopant atoms. Carrier transport across the junction occurs by diffusion and drift processes influenced by the spatial extent of this depletion region. With the advent of atomically thin van der Waals materials and their heterostructures, it is now possible to realize a p n junction at the ultimate thickness limit. Van der Waals junctions composed of p and n type semiconductors each just one unit cell thick are predicted to exhibit completely different charge transport characteristics than bulk heterojunctions. Here, we report the characterization of the electronic and optoelectronic properties of atomically thin p n heterojunctions fabricated using van der Waals assembly of transition metal dichalcogenides. We observe gate tunable diode like current rectification and a photovoltaic response across the p n interface. We find that the tunnelling assisted interlayer recombination of the majority carriers is responsible for the tunability of the electronic and optoelectronic processes. Sandwiching an atomic p n junction between graphene layers enhances the collection of the photoexcited carriers. The atomically scaled van der Waals p n heterostructures presented here constitute the ultimate functional unit for nanoscale electronic and optoelectronic devices.", "author_names": [ "Chul-Ho Lee", "Gwan-Hyoung Lee", "Arend M van der Zande", "Wenchao Chen", "Yilei Li", "Minyong Han", "Xu Cui", "Ghidewon Arefe", "Colin P Nuckolls", "Tony F Heinz", "Jing Guo", "James C Hone", "Philip Kim" ], "corpus_id": 9066135, "doc_id": "9066135", "n_citations": 1448, "n_key_citations": 9, "score": 1, "title": "Atomically thin p n junctions with van der Waals heterointerfaces.", "venue": "Nature nanotechnology", "year": 2014 }, { "abstract": "We report on a new chemical sensor based on black phosphorus/molybdenum diselenide van der Waals hetero junctions. Due to the atomically thin nature of two dimensional (2D) materials, surface adsorption of gas molecules can effectively modulate the band alignment at the junction interface, making the device a highly sensitive detector for chemical adsorptions. Compared to sensors made of homogeneous nanomaterials, the hetero junction demonstrates considerably lower detection limit and higher sensitivity toward nitrogen dioxide. Kelvin probe force microscopy and finite element simulations have provided experimental and theoretical explanations for the enhanced performance, proving that chemical adsorption can induce significant changes in band alignment and carrier transport behaviors. The study demonstrates the potential of van der Waals hetero junction as a new platform for sensing applications, and provides more insights into the interaction between gaseous molecules and 2D hetero structures.", "author_names": [ "Zhihong Feng", "Buyun Chen", "Shuangbei Qian", "Linyan Xu", "Liefeng Feng", "Yuanyuan Yu", "Rui Zhang", "Jiancui Chen", "Qianqian Li", "Quanning Li", "Chongling Sun", "Hao Zhang", "Jing Liu", "Wei Pang", "Daihua Zhang" ], "corpus_id": 99984131, "doc_id": "99984131", "n_citations": 49, "n_key_citations": 0, "score": 0, "title": "Chemical sensing by band modulation of a black phosphorus/molybdenum diselenide van der Waals hetero structure", "venue": "", "year": 2016 }, { "abstract": "Abstract Atomically thin vertically stacked 2D vdW heterostructures have recently emerged as a new kind of device with intriguing novel phenomena for both academic and industrial interests. However, the lack of p type materials remains a challenging issue to create useful devices for the realization of practical applications. Here, we demonstrate the first vertically stacked few layered p type GaSe and n type SnS2 vdW heterostructure for high performance optoelectronic applications. It is found that the phototransistors based on a few layered GaSe/SnS2 p n junction show superior performance with the responsivity, EQE and specific detectivity as high as ~35 AW 1, 62% and 8.2 x 1013 J, respectively, which exceed all the reported values derived from 2D materials. Also, the GaSe/SnS2 p n junction can serve as a photovoltaic cell with a high power conversion efficiency of about ~2.84% Moreover, the heterostructures can be deposited on flexible PET substrates with excellent performance. Through a detailed study, the underlying mechanism responsible for the high performance can be attributed to the unique type II band alignment and excellent quality of the interface. The heterojunctions presented in this work demonstrate a new illustration for the stacking of 2D materials, which is very useful for the development of next generation novel optoelectronic devices.", "author_names": [ "Packiyaraj Perumal", "Rajesh Kumar Ulaganathan", "Raman Sankar", "Ling Zhu" ], "corpus_id": 224865113, "doc_id": "224865113", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Staggered band offset induced high performance opto electronic devices: Atomically thin vertically stacked GaSe SnS2 van der Waals p n heterostructures", "venue": "", "year": 2021 }, { "abstract": "In nano device applications using two dimensional (2D) van der Waals materials, a heat dissipation through nano scale interfaces can be a critical issue for optimizing device performances. By using a time domain thermoreflectance measurement technique, we examine a cross plane thermal transport through mono layered (n 1) and bi layered (n 2) WSe2 flakes which are sandwiched by top metal layers of Al, Au, and Ti and the bottom Al2O3 substrate. In these nanoscale structures with hetero and homo junctions, we observe that the thermal boundary resistance (TBR) is significantly enhanced as the number of WSe2 layers increases. In particular, as the metal is changed from Al, to Au, and to Ti, we find an interesting trend of TBR depending on the WSe2 thickness; when referenced to TBR for a system without WSe2, TBR for n 1 decreases, but that for n 2 increases. This result clearly demonstrates that the stronger bonding for Ti leads to a better thermal conduction between the metal and the WSe2 layer, but in return gives rise to a large mismatch in the phonon density of states between the first and second WSe2 layers so that the WSe2 WSe2 interface becomes a major thermal resistance for n 2. By using photoemission spectroscopy and optical second harmonic generation technique, we confirm that the metallization induces a change in the valence state of W ions, and also recovers a non centrosymmetry for the bi layered WSe2.", "author_names": [ "Young-Gwan Choi", "Do-Gyeom Jeong", "Hwiin Ju", "Chang Jae Roh", "Geonhwa Kim", "Bongjin Simon Mun", "Tae Yun Kim", "Sang-Woo Kim", "Jong Sung Lee" ], "corpus_id": 119467901, "doc_id": "119467901", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Covalent bonding induced strong phonon scattering in the atomically thin WSe2 layer", "venue": "Scientific Reports", "year": 2019 }, { "abstract": "The two dimensional limit of layered materials has recently been realized through the use of van der Waals (vdW) heterostructures composed of weakly interacting layers. In this paper, we describe two different classes of vdW heterostructures: inorganic vdW heterostructures prepared by co lamination and restacking; and organic inorganic hetero epitaxy created by physical vapor deposition of organic molecule crystals on an inorganic vdW substrate. Both types of heterostructures exhibit atomically clean vdW interfaces. Employing such vdW heterostructures, we have demonstrated various novel devices, including graphene/hexagonal boron nitride (hBN) and MoS2 heterostructures for memory devices; graphene/MoS2/WSe2/graphene vertical p n junctions for photovoltaic devices, and organic crystals on hBN with graphene electrodes for high performance transistors.", "author_names": [ "Gwan-Hyoung Lee", "Chul-Ho Lee", "Arend van der Zande", "Minyong Han", "Xu Cui", "Ghidewon Arefe", "Colin P Nuckolls", "Tony F Heinz", "James C Hone", "Philip Kim" ], "corpus_id": 38284994, "doc_id": "38284994", "n_citations": 51, "n_key_citations": 1, "score": 0, "title": "Heterostructures based on inorganic and organic van der Waals systems", "venue": "", "year": 2014 }, { "abstract": "Graphene/two dimensional (2D) semiconductor heterostructures have been demonstrated to possess many advantages for electronic and optoelectronic devices. However, there are few reports about the utilization of a 2D semiconductor monolayer to tune the properties of graphene. Here, we report the fabrication and characterization of graphene p n junctions based on graphene/MoS2 hybrid interfaces. Monolayered graphene across the monolayered MoS2 boundary is divided into n type regions on the MoS2 and p type regions on the SiO2 substrate. Such van der Waals heterostructure based graphene p n junctions show good photoelectric properties. The photocurrent modulation of such devices by a single back gate is also demonstrated for the first time, which shows that the graphene on and off MoS2 regions have different responses to the gate voltage. Our results suggest that the atomic thin hybrid structure can remarkably extend the device applications.", "author_names": [ "Jie Meng", "Huading Song", "Caizhen Li", "Yibo Jin", "Lei Tang", "Dameng Liu", "Zhimin Liao", "Faxian Xiu", "Daqing Yu" ], "corpus_id": 205977896, "doc_id": "205977896", "n_citations": 36, "n_key_citations": 1, "score": 0, "title": "Lateral graphene p n junctions formed by the graphene/MoS2 hybrid interface.", "venue": "Nanoscale", "year": 2015 }, { "abstract": "Atomically thin and sharp van der Waals heterojunction can be created by vertically stacking p type monolayer tungsten diselenide (WSe2) onto n type molybdenum disulfide (MoS2) Theory predicts that stacked MoS2 and WSe2 monolayer forms type II p n junction, creating a built in electric field across the interface which facilitates electron hole separation and transfer. Gaining insights into the dynamics of charge transfer across van der Waals heterostructure is central to understanding light photocurrent conversion at these ultrathin interfaces. Herein, we investigate the exciton dissociation and charge transfer in a MoS2/WSe2 van der Waals hetero structure. Our results show that ultrafast electron transfer from WSe2 to MoS2 take place within 470 fs upon optical excitation with 99% charge transfer efficiency, leading to drastic photoluminescence quenching and decreased lifetime. Our findings suggest that van der Waals heterostructure may be useful as active components in ultrafast optoelectronic devices.", "author_names": [ "Bo Peng", "Guannan Yu", "Xinfeng Liu", "Bo Liu", "Xiao Liang", "Lei Bi", "Longjiang Deng", "Tze Chien Sum", "Kian Ping Loh" ], "corpus_id": 102102813, "doc_id": "102102813", "n_citations": 131, "n_key_citations": 3, "score": 0, "title": "Ultrafast charge transfer in MoS 2 /WSe 2 p n Heterojunction", "venue": "", "year": 2016 }, { "abstract": "Synthesized two dimensional GaSe/MoSe2 misfit heterostructures form p n junctions with a gate tunable photovoltaic response. Two dimensional (2D) heterostructures hold the promise for future atomically thin electronics and optoelectronics because of their diverse functionalities. Although heterostructures consisting of different 2D materials with well matched lattices and novel physical properties have been successfully fabricated via van der Waals (vdW) epitaxy, constructing heterostructures from layered semiconductors with large lattice misfits remains challenging. We report the growth of 2D GaSe/MoSe2 heterostructures with a large lattice misfit using two step chemical vapor deposition (CVD) Both vertically stacked and lateral heterostructures are demonstrated. The vertically stacked GaSe/MoSe2 heterostructures exhibit vdW epitaxy with well aligned lattice orientation between the two layers, forming a periodic superlattice. However, the lateral heterostructures exhibit no lateral epitaxial alignment at the interface between GaSe and MoSe2 crystalline domains. Instead of a direct lateral connection at the boundary region where the same lattice orientation is observed between GaSe and MoSe2 monolayer domains in lateral GaSe/MoSe2 heterostructures, GaSe monolayers are found to overgrow MoSe2 during CVD, forming a stripe of vertically stacked vdW heterostructures at the crystal interface. Such vertically stacked vdW GaSe/MoSe2 heterostructures are shown to form p n junctions with effective transport and separation of photogenerated charge carriers between layers, resulting in a gate tunable photovoltaic response. These GaSe/MoSe2 vdW heterostructures should have applications as gate tunable field effect transistors, photodetectors, and solar cells.", "author_names": [ "Xufan Li", "Ming-Wei Lin", "Junhao Lin", "Bing Huang", "Alexander A Puretzky", "Cheng Ma", "Kai Wang", "Wu Zhou", "Sokrates T Pantelides", "Miaofang Chi", "Ivan I Kravchenko", "Jason D Fowlkes", "Christopher M Rouleau", "David B Geohegan", "Kai Xiao" ], "corpus_id": 4413373, "doc_id": "4413373", "n_citations": 163, "n_key_citations": 0, "score": 0, "title": "Two dimensional GaSe/MoSe2 misfit bilayer heterojunctions by van der Waals epitaxy", "venue": "Science Advances", "year": 2016 }, { "abstract": "Description", "author_names": [ "Tiancheng Song", "Eric Anderson", "Matisse Wei-Yuan Tu", "Kyle L Seyler", "Takashi Taniguchi", "Kenji Watanabe", "Michael A McGuire", "Xiaosong Li", "Ting Cao", "Di Xiao", "Wang Yao", "Xiaodong Xu" ], "corpus_id": 231986578, "doc_id": "231986578", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Spin photovoltaic effect in magnetic van der Waals heterostructures", "venue": "Science advances", "year": 2021 }, { "abstract": "van der Waals junctions of two dimensional materials with an atomically sharp interface open up unprecedented opportunities to design and study functional heterostructures. Semiconducting transition metal dichalcogenides have shown tremendous potential for future applications due to their unique electronic properties and strong light matter interaction. However, many important optoelectronic applications, such as broadband photodetection, are severely hindered by their limited spectral range and reduced light absorption. Here, we present a p g n heterostructure formed by sandwiching graphene with a gapless band structure and wide absorption spectrum in an atomically thin p n junction to overcome these major limitations. We have successfully demonstrated a MoS2 graphene WSe2 heterostructure for broadband photodetection in the visible to short wavelength infrared range at room temperature that exhibits competitive device performance, including a specific detectivity of up to 10(11) Jones in the near infrared region. Our results pave the way toward the implementation of atomically thin heterostructures for broadband and sensitive optoelectronic applications.", "author_names": [ "Mingsheng Long", "Erfu Liu", "Peng Jie Wang", "Anyuan Gao", "Hui Xia", "Wei Luo", "Baigeng Wang", "Junwen Zeng", "Yajun Fu", "Kang Xu", "Wei Zhou", "Yangyang Lv", "Shu-hua Yao", "Minghui Lu", "Yanfeng Chen", "Zhenhua Ni", "Yumeng You", "Xueao Zhang", "Shiqiao Qin", "Yi Shi", "Weida Hu", "Ding-yu Xing", "Feng Miao" ], "corpus_id": 23949545, "doc_id": "23949545", "n_citations": 207, "n_key_citations": 2, "score": 0, "title": "Broadband Photovoltaic Detectors Based on an Atomically Thin Heterostructure.", "venue": "Nano letters", "year": 2016 } ]

[ { "abstract": "In an environment of intense global competition, both creative and proven strategies need to be considered in order to bring about the effectiveness and efficiency in manufacturing operation. Total Productive Maintenance (TPM) is one of the effective maintenance strategy in enhancing the equipment effectiveness and to achieve a significant competitive advantage. This research paper addresses the impact of three TPM pillars namely planned maintenance (PM) autonomous maintenance (AM) and focused maintenance (FM) on overall equipment effectiveness (OEE) of die attach equipment in the production line of semiconductor industry. The effect of TPM on the OEE is also investigated depending on the equipment types, in where die attach process consist of two models CANON and ESEC. The primary data was collected from an organization's database and was analysed by SPSS V23. The preliminary results of the analysis showed that the performance of OEE in ESEC is better than the CANON after the implementation of TPM. The analysis also showed that out of the three TPM practices deployed, planned maintenance of equipment by production and maintenance team played the biggest role in increasing the equipment effectiveness. In conclusion, this study provides insights the importance of implementing TPM in order to succeed in a highly demanding market arena.", "author_names": [ "Soo-Fen Fam", "Ser Lee Loh", "M S Haslinda", "Heri Yanto", "Linda Mei Sui Khoo", "Diana Hwa Yieng Yong" ], "corpus_id": 54754829, "doc_id": "54754829", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Overall Equipment Efficiency (OEE) Enhancement in Manufacture of Electronic Components Boards Industry through Total Productive Maintenance Practices", "venue": "", "year": 2018 }, { "abstract": "Persaingan yang semakin tinggi menuntut perusahaan untuk bisa beroperasi dengan produktivitas yang maksimal melalui penerapan berbagai strategi optimasi produksi diantaranya adalah TPM Total Productive Maintenance TPM sendiri menurut Ahuja (2008) merupakan kunci kesuksesan dari setiap manufacturing optimization strategies karena tanpa mesin yang andal semua program optimasi produksi/manufaktur tidak akan bisa berjalan dengan sempurna. Salah satu metode mengukur tingkat keberhasilan penerapan TPM adalah melalui pengikuran nilai Overall Equipment Effectiveness (OEE) PT. TES merupakan perusahaan yang bergerak di bidang industri pangan yaitu produk susu sereal. Permasalahan terbesar yang dihadapi perusahaan saat ini ialah tingginya downtime mesin wrapping Efek dari downtime tersebut adalah menurunnya kecepatan dan performa mesin sehingga menyebabkan rendahnya OEE. Untuk itulah penelitian ini dilakukan. Data dikumpulkan langsung di lapangan selama 12 minggu (3 bulan) Langkah selanjutnya adalah menghitung nilai OEE diikuti dengan analisa six big losses serta dianalisa dengan menggunakan pareto chart fishbone diagram dan regresi berganda. Dari pengolahan data diperoleh nilai OEE tertinggi yaitu terdapat pada periode minggu ke 8 dengan persentase sebesar 70,70% sedangkan nilai OEE terendah terdapat pada periode minggu ke 8 yaitu sebesar 58,50% dengan OEE rata rata 68.31% Faktor six big losses yang paling berpengaruh terhadap rendahnya OEE mesin Wrapping High Speed Line 4 diketahui dengan analisa korelasi berganda adalah variabel X2 yaitu Breakdown loss dengan R sebesar 0,46.", "author_names": [ "Herry Agung Prabowo", "Milla Agustiani" ], "corpus_id": 169712454, "doc_id": "169712454", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "EVALUASI PENERAPAN TOTAL PRODUCTIVE MAINTENANCE (TPM) MELALUI PENDEKATAN OVERALL EQUIPMENT EFFECTIVENESS (OEE) UNTUK MENINGKATKAN KINERJA MESIN HIGH SPEED WRAPPING DI PT. TES", "venue": "", "year": 2018 }, { "abstract": "Manufacturing strives to reduce waste and increase Overall Equipment Effectiveness (OEE) When managing machine tool maintenance a manufacturer must apply an appropriate decision technique in order to reveal hidden costs associated with production losses, reduce equipment downtime competently and similarly identify the machines' performance. Total productive maintenance (TPM) is a maintenance program that involves concepts for maintaining plant and equipment effectively. OEE is a powerful metric of manufacturing performance incorporating measures of the utilisation, yield and efficiency of a given process, machine or manufacturing line. It supports TPM initiatives by accurately tracking progress towards achieving \"perfect production.\" This paper presents a review of maintenance management methodologies and their application to positional error calibration decision making. The purpose of this review is to evaluate the contribution of maintenance strategies, in particular TPM, towards improving manufacturing performance, and how they could be applied to reduce downtime due to inaccuracy of the machine. This is to find a balance between predictive calibration, on machine checking and lost production due to inaccuracy. This work redefines the role of maintenance management techniques and develops a framework to support the process of implementing a predictive calibration program as a prime method to supporting the change of philosophy for machine tool calibration decision making. Keywords maintenance strategies, down time, OEE, TPM, decision making, predictive calibration.", "author_names": [ "Abubaker Shagluf", "Andrew Longstaff", "Simon Fletcher" ], "corpus_id": 115212146, "doc_id": "115212146", "n_citations": 15, "n_key_citations": 0, "score": 1, "title": "Maintenance strategies to reduce downtime due to machine positional errors", "venue": "", "year": 2014 }, { "abstract": "In the modern industrial world, effective role of maintenance activities in the survival of organizations and enhancing their productivity is undeniable. Variety of equipments in the industrial organizations and their exclusivities in terms of longevity and failures modes, clear the importance of choosing a strategy for the maintenance of any equipment. Thus, knowing the type of the failure is so important for maintenance manager and engineers. Important introduced indicators in this domain such as indicator of reliability, MTBF and MTTR can be used to predicting and detecting approximate failure time and analyzing life cycle status. On the other hand, due to fluctuating time of system availability because of work continuity and loss of a performance indicator, by combining RCM indicators and Overall Equipment Effectiveness (OEE) indicator the most compatible strategy could be chosen. The aim of this article which differs from other studies in this field is to apply a composed indicator, including different parameters of RCM, which is obtained based on the equipment life status.", "author_names": [ "Mohammad Zadhoosh", "Amir Afshin Fattahi" ], "corpus_id": 53579809, "doc_id": "53579809", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Simultaneous effect of RCM key indicators, related to equipment lifecycle for maintenance strategies (in production systems)", "venue": "", "year": 2015 }, { "abstract": "Process output and profitability of the operations are mainly determined by how the equipment is being used. The production planning, operations and machine maintenance influence the overall equipment effectiveness (OEE) of the machinery, resulting in more 'good parts' at the end of the day. The target of the predictive maintenance approaches in this respect is to increase efficiency and effectiveness by optimizing the way machines are being used and to decrease the costs of unplanned interventions for the customer. To this end, development of ad hoc strategies and their seamless integration into predictive maintenance systems is envisaged to bring substantial advantages in terms of productivity and competitiveness enhancement for manufacturing systems, representing a leap towards the real implementation of the Industry 4.0 vision. Inspired by this challenge, the study provides an approach to develop a novel predictive maintenance platform capable of preventing unexpected breakdowns based on integrated strategies for extending the operating life span of production systems. The approach and result in this article are based on the development and implementation in a large collaborative EU funded H2020 research project entitled Z Bre4k, i.e. Strategies and predictive maintenance models wrapped around physical systems for zero unexpected breakdowns and increased operating life of factories.", "author_names": [ "Gokan May", "Nikos Kyriakoulis", "Konstantinos Apostolou", "Sangje Cho", "Konstantinos Grevenitis", "Stefanos Kokkorikos", "Jovana Milenkovic", "Dimitris Kiritsis" ], "corpus_id": 52094844, "doc_id": "52094844", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Predictive Maintenance Platform Based on Integrated Strategies for Increased Operating Life of Factories", "venue": "APMS", "year": 2018 }, { "abstract": "Abstract Planned and unplanned downtime emanating from maintenance, production, and operational function adversely affects the performance of manufacturing plants. This paper develops joint maintenance, production and process/operations control policies integrating Opportunistic Maintenance (OM) which takes advantage of external (operational related downtimes) and internal maintenance opportunities. The study quantifies the effects of maintenance strategies on the plant's performance, here, the overall equipment effectiveness (OEE) which importantly presents insights on maintenance decision support for production facilities facing significant operational related stoppages. The study integrates both economic and structural dependence and models the influence of alternative maintenance actions of different maintenance policies, on product quality. The developed model is validated by applying to a multi unit repairable, imperfectly maintained raw meal grinding system of a cement plant. From the simulation modelling results, integration of the opportunistic maintenance approach, complementary to corrective, preventive and condition based maintenance strategies, show more enhanced equipment performance, as measured through the OEE.", "author_names": [ "James Wakiru", "Liliane Pintelon", "Peter N Muchiri", "Peter Chemweno" ], "corpus_id": 216356541, "doc_id": "216356541", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Integrated maintenance policies for performance improvement of a multi unit repairable, one product manufacturing system", "venue": "", "year": 2020 }, { "abstract": "Maintenance plays a significant role in asset management of power organisations. Utilisation of right maintenance strategy contributes to high availability and reliability of power plants. Inexperience in implementing modern maintenance programmes and lack of utilising effective maintenance strategies results in bad maintenance practices, low productivity, and a negative impact on financial performance. Thus, effective maintenance strategies become a complex task that deals with multifaceted nature of actions like irregular and uncertain nature. Total Productive Maintenance (TPM) is an ideal approach to support the development and implementation of operation performance improvement. It systematically aims to achieve zero breakdowns, zero defects and zero accidents in order to have high overall equipment effectiveness (OEE) Implementation of TPM programme needs strategic planning. However, there has been almost no research applied in this area within Middle East power plants. In the power sector of Abu Dhabi, assets management is extremely significant, and it thus requires efficient and effective support of equipment management. The aim of this paper is to investigate technical barriers to successful TPM implementation in the Abu Dhabi power industry. The study has been conducted in the context of a leading power company in the UAE. Questionnaires were distributed with 224 employees, including engineers, maintenance planners, technicians, and operators using a postal questionnaire. The findings of this research identified six key barriers, thus: maintenance policy and methods; maintenance resources, tools and spare parts; computerized maintenance management system (CMMS) housekeeping; participation of autonomous maintenance and maintenance audits. With respect to the understanding of these barriers and obstacles in TPM implementation, the findings can contribute towards improved equipment operations and maintenance in power organisations.", "author_names": [ "Abdulla Alseiari", "Peter Farrell", "Yassin Z Osman" ], "corpus_id": 219421173, "doc_id": "219421173", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Technical and Operational Barriers that Affect the Successful Total Productive Maintenance (TPM) Implementation: Case Studies of Abu Dhabi Power Industry", "venue": "", "year": 2020 }, { "abstract": "The exploration for improving productivity in the current competitive global environment since customers are becoming more and more quality centered and demands among customers are increased. To meet customer demand industries must work with efficiency oriented. One of the way to increase efficiency and productivity is to increase the OEE (Overall Equipment Effectiveness) of the plant or machines. OEE can be improved by continuous improvement of TPM (Total Productive Maintenance).This review study discusses an application of industrial engineering techniques such as TPM ,OEE. Total productive maintenance (TPM) is one of the most popular maintenance strategies to ensure high machine reliability, maintaining equipment in top working condition to avoid breakdowns and minimize downtimes in the manufacturing process. Keywords Total productive maintenance, Overall equipment effectiveness Vol. XI Issue No. 6 June 2018", "author_names": [ "Darpit N Gandhi", "Vivek A Deshpande" ], "corpus_id": 116478316, "doc_id": "116478316", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "A REVIEW OF TPM TO IMPLEMENT OEE TECHNIQUE IN MANUFACTURING INDUSTRY", "venue": "", "year": 2018 }, { "abstract": "Nowadays, with changes in the world scenario in the midst of globalization, the emergence of new technologies and new forms of organization have been driving companies to become more competitive, to redesign their strategies and operations processes, especially with efficient use of all its resources. Maintenance management is fundamental in this process in order to maintain the proper functioning of production processes. Previous studies on the efficiency analysis through indicators have investigated the application of the OEE (Overal Equipment Eficient) indicator in several contexts. The objective of this research was to analyze the impact of the lack of spare parts on the production efficiency using as metric the OEE indicator. For that, a case study was carried out in a chemical company that uses industrial operations in a continuous way. The results indicated that the lack of an essential part for the operation of a machine impaired the entire productive chain in which it is inserted.", "author_names": [ "Everaldo Francisco da Silva", "Luis Fernando Ferreira Damasceno", "Adriano Manicoba da Silva", "William de Paula Ferreira" ], "corpus_id": 169677187, "doc_id": "169677187", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Impact of missing spare part on production efficiency: An analysis with the OEE indicator", "venue": "", "year": 2018 }, { "abstract": "The Electrical and Electronics (E&E) industry continues to be a key driver of Malaysia's Industrial development and contributes significantly to GDP growth, export earnings, investment, and employment. Malaysia has become a major global manufacturing hub for the E&E industry and four decades and continues to be a preferred E&E investment destination. In order to sustain and stay competitive, the Malaysian semiconductor companies are urged to implement world class maintenance techniques that will improve equipment utilization and thus reducing capital expenditure. Total Productive Maintenance (TPM) is one of the effective maintenance strategies for enhancing the overall equipment effectiveness (OEE) to achieve a significant competitive advantage. The aim of the study is to determine the effectiveness of TPM to improve OEE in the E&E industry. This study used the real time data for two types of die attach equipment models, namely CANON and ESEC. The data was collected from an E&E company in Malaysia. The real time data was recorded by software known as Global Operator User Interface (GOUI) system. GOUI system captures the real time data directly from the machine. The result shows that the implementation of TPM gives a significant difference in OEE for both different equipment models. In addition, this study also shows that the three TPM practices namely planned maintenance, autonomous maintenance, and focused maintenance are able to explain 91.2% of the total variation of OEE in the E&E industry.", "author_names": [ "Soo-Fen Fam", "Dedy Dwi Prastyo", "Ser Lee Loh", "Sekar Utami", "Diana Hwa Yieng Yong" ], "corpus_id": 56018471, "doc_id": "56018471", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Total Productive Maintenance Practices in Manufacture of Electronic Components Boards Industry in Malaysia", "venue": "", "year": 2018 } ]

[ { "abstract": "Abstract This work reports the first investigation on the physical vapor deposition of thin films of tin sulfide doped lead sulfide (SnS:PbS) In situ synthesis route using diethyldithiocarbamate (DTC) ligand was adopted for SnS DTC, PbS DTC and SnS:PbS DTC complex formation. PbS DTC and SnS:PbS DTC expressed an average crystallite size of 30.98 and 29.74 nm, respectively shown by X ray diffraction (XRD) analysis. A face centered cubic geometry was revealed from XRD. Ultraviolet visible spectrophotometry expressed a direct and indirect band gap of 3.4 and 3.2 eV, respectively for SnS:PbS DTC. A smooth morphology with presence of larger agglomerated particles was disclosed by scanning electron microscopy for SnS:PbS DTC thin films with 615 nm thickness. SnS:PbS DTC thin films expressed remarkable electrochemical behavior explored via cyclic voltammetry, linear sweep voltammetry and chronoamperometry showing an improvement in the photo current response upon potential bias increment. The results of the current research indicated the potential of SnS:PbS DTC thin films for utilization in different types of photovoltaic devices. Graphical Abstract", "author_names": [ "Aimen Zafar", "Khuram Shahzad Ahmad", "Shaan Bibi Jaffri", "Manzar Sohail" ], "corpus_id": 225387088, "doc_id": "225387088", "n_citations": 7, "n_key_citations": 0, "score": 1, "title": "Physical vapor deposition of SnS:PbS dithiocarbamate chalcogenide semiconductor thin films: elucidation of optoelectronic and electrochemical features", "venue": "", "year": 2020 }, { "abstract": "Abstract Current work reports the diethyl ammonium dithiocarbamate based metallic chalcogenide semiconductor complexes of Ag2S (dtc)2 [where dtc dithiocarbamate] BaS (dtc)2 and Ba:Ag2S (dtc)2 in an in situ chemosynthetic route for first time. Current work is also the first investigation reporting the physical vapor deposition of pristine [Ag2S (dtc)2]/SnO2 and doped [Ba:Ag2S (dtc)2]/SnO2 thin films was carried out in a resistive heating unit. Synthesized complexes and thin films expressed remarkable crystalline, vibrational, optical, morphological and elemental compositional characteristics revealed from different analytical tools. X ray diffraction disclosed the acanthite type orientation for the pristine and doped thin films with average crystallite sizes of 43.23 and 38.11 nm, respectively. Fourier transform infra red spectroscopy supported a myriad of functional groups, bond types and molecular arrangements in the single source precursor synthesized complexes. The optical analysis via ultra violet visible spectrophotometry expressed an alleviation in the both direct and indirect bandgaps from 3.9 to 3.7 eV and 3.8 to 2.7 eV determined from Tauc's plot for the doped [Ba:Ag2S (dtc)2]/SnO2 thin films showing the tailoring power of barium doping. Tightly packed thin films with presence of agglomerated particles were expressed by microstructural analysis done via scanning electron microscopy. Elemental profiling and thin film thickness measurement via Rutherford back scattering spectrometry supported strong signals for Ag, S and Ba with film thickness of 275 nm acquired for [Ba:Ag2S (dtc)2]/SnO2 thin films. Profound electrochemical functionality was expressed by cyclic voltammetry, linear sweep voltammetry and chronoamperometry showing the suitability of fabricated films for a wide range of optoelectronic and photovoltaic devices. Current work can be extended to achieving further improvement in the optoelectronic aspects of the synthesized films before they can be practically used in different photovoltaic contraptions.", "author_names": [ "Khuram Shahzad Ahmad", "Aimen Zafar", "Shaan Bibi Jaffri", "Muhammad Khalid Alamgir", "Manzar Sohail", "Rana Farhat Mehmood", "Misbah ur Rehman", "Daoud Ali" ], "corpus_id": 229406674, "doc_id": "229406674", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Chemosynthesis and physical vapor deposition of acanthite thin films: Characterization and electrochemistry explorationwe", "venue": "", "year": 2020 }, { "abstract": "Understanding how dipolar, non centrosymmetric organic semiconductors self assemble, nucleate, and crystallize is integral for designing new molecular solids with unique physical properties and light matter interactions. However, dipole dipole and van der Waals interactions compete to direct the assembly of these compounds, making it difficult to predict how solids are formed from individual molecules. Here, we investigate four small molecules (TpCPD, TpDCF, AcCPD, and AcDCF) possessing anisotropic, non planar structures and large dipole moments, and establish robust algorithms to control their molecular self assembly via simple physical vapor deposition. Each molecule contains a central polar moiety, consisting of either a cyclopentadienone (CPD, ca. 3.5 D dipole moment) or dicyanofulvene (DCF, ca. 7.0 D dipole moment) core, that is surrounded by either four twisted phenyl (Tp) groups or a fused aromatic (acenaphthene, Ac) ring system. We find that only molecules containing the fused ring system form 1D nanowires due to the stronger van der Waals associations of the long, planar acenaphthene moieties. We examine the kinetics of self assembly for AcDCF and create diverse 1D morphologies, including both curved and linear nanostructures. Finally, using conductive AFM (c AFM) measurements, we show that 1D AcDCF wires support higher current densities relative to randomly oriented clusters lacking long range order.", "author_names": [ "Kwang-Won Park", "David W Bilger", "Trisha L Andrew" ], "corpus_id": 204302091, "doc_id": "204302091", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "1D nanowires of non centrosymmetric molecular semiconductors grown by physical vapor deposition", "venue": "", "year": 2020 }, { "abstract": "Anisotropic materials, especially two dimensional (2D) layered materials formed by van der Waals force (vdW) with low symmetry, have become a scientific hot spot because their electrical, optical, and thermoelectric properties are highly polarization dependent. The 2D GeSe, a typical anisotropic layered orthorhombic structure and narrow bandgap (1.1 1.2 eV) semiconductor, potentially meets these demands. In this report, the ultrathin elongated hexagonal GeSe nanoplates were successfully synthesized by the rapid physical vapor deposition method developed here. The ultrathin elongated hexagonal GeSe nanoplates have a zigzag edge in the long edge and an armchair edge in the short edge. In addition, the typical Raman mode exhibited 90deg periodic vibration, having its maximum intensity between the zigzag direction or the zigzag and armchair direction, indicating an anisotropic electron phonon interaction. Furthermore, the field effect transistor devices based on the elongated hexagonal GeSe nanoplates were constructed and exhibited the p type semiconducting behavior with a high photoresponse characteriscs. Finally, the polarized sensitive photocurrent was identified, further revealing the intrinsically anisotropy of the GeSe nanoplate. The results illustrated here may give a useful guidance to synthesize the 2D layered anisotropic nanomaterials and further advance the development of the polarized photodetector.", "author_names": [ "Jinyang Liu", "Yuhan Zhou", "Yue Lin", "Mingling Li", "Hongbing Cai", "Yichun Liang", "Mengyu Liu", "Zhigao Huang", "Fachun Lai", "Feng Huang", "Weifeng Zheng" ], "corpus_id": 58557580, "doc_id": "58557580", "n_citations": 22, "n_key_citations": 0, "score": 0, "title": "Anisotropic Photoresponse of the Ultrathin GeSe Nanoplates Grown by Rapid Physical Vapor Deposition.", "venue": "ACS applied materials interfaces", "year": 2019 }, { "abstract": "In this work, the effects of different extraction parameters on the particle size of the nanopowders extracted from titanium dioxide thin film samples were studied. These nanopowders were obtained by the conjunctional freezing assisted ultrasonic extraction method. Titanium dioxide thin films were different in their structures (anatase only, rutile only, and mixed phase) and their structural characteristics were determined. Results showed that extraction parameters such as freezing temperature, ultrasonic frequency, and application time are very effective in determining the nanoparticle size, which is very important for many applications and uses of highly pure nanomaterials and nanostructures.", "author_names": [ "Oday A Hammadi" ], "corpus_id": 219283714, "doc_id": "219283714", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Effects of Extraction Parameters on Particle Size of Titanium Dioxide Nanopowders Prepared by Physical Vapor Deposition Technique", "venue": "Plasmonics", "year": 2020 }, { "abstract": "Modified g C3N4 sheets (CNS) with a bandgap of 2.61 eV were fabricated through physical vapor deposition (PVD) of g C3N4. During the PVD process, a series of gaseous derivatives derived from pristine g C3N4 at 700 degC condense into CNS at low temperature <400 degC) As a result, CNS still retains a typical semiconductor structure (bandgap of 2.61 eV) while at the same time, CN and O H defect groups were introduced to its tri s triazine based structure.", "author_names": [ "Xiaohui Sun", "Xianghui An", "Sa Zhang", "Zhongtao Li", "Jing Zhang", "W Wu", "Mingbo Wu" ], "corpus_id": 132863424, "doc_id": "132863424", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Physical Vapor Deposition (PVD) A Method to Fabricate g C3N4 Sheet", "venue": "", "year": 2019 }, { "abstract": "Abstract Lead selenide (PbSe) is a new emerging semiconductor with layer dependent bandgap that has attracted much interest due to its high infrared response and good environmental stability. We have prepared large scale PbSe films with the area of 7 cm2 and thickness of 25 nm based on physical vapor deposition approach at 160degC. The PbSe films exhibit saturable absorption property at 1.55 mm and a polarization sensitive saturable absorber is obtained by growing PbSe on D shaped fiber. Single pulse with the duration of 490 fs is generated at the pump of 12 mW and the mode locking operation is maintained at the pump of 1500 mW, indicating the high damage threshold of the D shaped fiber based saturable absorber. Two polarization insensitive saturable absorbers are achieved by depositing PbSe on fiber facet and polyvinyl alcohol film, respectively. For fiber facet (polyvinyl alcohol film) based saturable absorber, the repetition rate of Q switched pulses increases from 8.6 (16.3) kHz to 45.4 (59.2) kHz while the duration decreases from 7.92 (12) ms to 2.06 (3.12) ms by tuning the pump from 15 mW to 90 (60) mW. Such large scale PbSe films possess features of low cost and high modulation ability, and can find important applications in infrared optical modulators and detectors.", "author_names": [ "Qun Gao", "Hao Yang", "Cuichen Hu", "Zhiwen He", "Hua Lu", "Wending Zhang", "Dong Mao", "Ting Mei", "Jianlin Zhao" ], "corpus_id": 213982176, "doc_id": "213982176", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Physical vapor deposition of large scale PbSe films and its applications in pulsed fiber lasers", "venue": "", "year": 2019 }, { "abstract": "Growth of gallium phosphide nanowires by vapor deposition of simple thermally evaporated inorganic precursors is generally accompanied by unintentional formation of thick oxide coating, which may compromise the optical and electrical properties of the nanowires. Controlling and eliminating this outer layer during thermal evaporation growth of GaP nanowires represents a barrier to simple and scalable preparation of this technologically important material. In this article, we systematically investigated the role of different parameters (temperature, hydrogen flow rate, and starting Ga/P ratio) in the synthesis of GaP nanowires, and mapped out the conditions for the growth of oxide layer free nanowires. Increase in temperature, hydrogen flow, and phosphorus concentration led to diminished oxide layer thickness and improved nanowire morphology. Long and straight nanowires with the near perfect stoichiometry and complete absence of oxide outer layer were obtained for 1050 degC, 100 sccm hydrogen flow rate, and Ga/P flux ratio of 0.5. In contrast to other reports, this work emphasizes the importance of introducing hydrogen flow and excess phosphorus, which provide for reducing environment and reduced rate of the reaction of Ga with O in the growth process, respectively. The ability to control dielectric medium around GaP NWs by controlling the formation of oxide overlayer was demonstrated by Raman spectroscopy. The results of this work demonstrate a full control of the multi parameter space in the simple, inexpensive, and scalable synthesis of GaP NWs, and may provide a guideline for rational improvement of the growth conditions for other types of semiconductor nanowires.", "author_names": [ "Yun-yan Wang", "M S Hegde", "Shuo Wei Chen", "Penghui Yin", "Pavle V Radovanovic" ], "corpus_id": 103337531, "doc_id": "103337531", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Control of the spontaneous formation of oxide overlayers on GaP nanowires grown by physical vapor deposition", "venue": "", "year": 2018 }, { "abstract": "Anisotropic layered semiconductors have attracted significant interest due to the huge possibility of bringing new functionalities to thermoelectric, electronic and optoelectronic devices. Currently, most reports on anisotropy have concentrated on black phosphorus and ReS2, less effort has been contributed to other layered materials. In this work, two dimensional (2D) orthorhombic SnS flakes on a large scale have been successfully synthesized via a simple physical vapor deposition method. Angle dependent Raman spectroscopy indicated that the orthorhombic SnS flakes possess a strong anisotropic Raman response. Under a parallel polarization configuration, the peak intensity of Ag (190.7 cm( 1) Raman mode reaches the maximum when incident light polarization is parallel to the armchair direction of the 2D SnS flakes, which strongly suggests that the Ag (190.7 cm( 1) mode can be used to determine the crystallographic orientation of the 2D SnS. In addition, temperature dependent Raman characterization confirmed that the 2D SnS flakes have a higher sensitivity to temperature than graphene, MoS2 and black phosphorus. These results are useful for the future studies of the optical and thermal properties of 2D orthorhombic SnS.", "author_names": [ "Jing Xia", "Xuan-Ze Li", "Xing Yi Huang", "Nannan Mao", "Dandan Zhu", "Lei Wang", "Hua Xu", "Xiangmin Meng" ], "corpus_id": 46537488, "doc_id": "46537488", "n_citations": 127, "n_key_citations": 2, "score": 0, "title": "Physical vapor deposition synthesis of two dimensional orthorhombic SnS flakes with strong angle/temperature dependent Raman responses.", "venue": "Nanoscale", "year": 2016 }, { "abstract": "DOI: 10.1002/admi.201801379 stretchable conductor is to disperse conductive 0D, 1D, and 2D nanomaterials onto soft elastomeric substrates. These include nanoparticles,[6 8] carbon nanotubes,[9 11] silver nanowires,[12 14] and graphene,[15 19] all of which have demonstrated high conductivity and large stretchability. Another method is based on geometry, where thin conductive layers with micro/nanoscale corrugated structure maintain conductivity by unbending during stretching. These structures can be induced by surface buckling[19 22] or self assembled patterns.[23] Our recent work has demonstrated that interference lithography and atomic layer deposition (ALD) can be used to create a freestanding nano accordion structure,[24,25] which can be simultaneously stretchable, conductive, and transparent. This approach allows precise control of the structure period, height, and thickness to allow independent design of material properties. However, this approach relies on ALD of the conductive film, which has high cost and long deposition time. The ability to obtain conformal thinfilm coating using a low cost process can facilitate scale up manufacturing and broad implementation of flexible electronics. ALD is a widely employed vapor phase technique, where two gas precursors are introduced in alternating cycles to create a self limited surface reaction.[26,27] Each cycle result in a single monolayer coating, allowing precise control of film thickness by using discrete cycles. Since the gas precursors can permeate within rough topography and deep pores, ALD has demonstrated conformal coating in high aspect ratio grating structures,[24,25] high density nanoscale features,[28,29] and 3D porous lattice.[30 34] However, ALD also has a number of drawbacks, such as long reaction time and expensive precursor gases, contributing to high process cost. Compared with physical vapor deposition (PVD) the selection of deposition material is also limited. Furthermore, metal ALD generally requires high synthesis temperature, which can be problematic for polymer surfaces or template structures. A more established alternative is PVD, which is one of the most widely used technique for precise deposition of thin films, including metals and a diverse range of organic/inorganic materials. Representing a class of techniques where the Physical vapor deposition (PVD) is a versatile thin film coating technique that can deposit a wide selection of inorganic materials at low cost. However, the process is based on line of sight transfer, which can lead to shadowing effects and limit film uniformity over nonplanar topographies. This work describes improving conformal PVD coating on polymer nanostructures by increasing surface energy using a thin oxide interlayer deposited by atomic layer deposition (ALD) The proposed ALD assisted PVD process allows conformal coating at low cost, and can be adopted for a wide variety of materials compatible with tradition PVD. Conformal gold films over nanostructures with 500 nm half pitch and aspect ratio up to 1.5 are demonstrated. The film uniformity is characterized using cross sectional electron microscopy, energy dispersive X ray spectroscopy, and electrical measurements, showing a clear improvement in coating uniformity with the oxide interlayer. This PVD process is then used to fabricate metallic nano accordion structures, which can be used for stretchable conductors. The demonstrated process can improve material selection and reduce process cost of conformal coating, which can find applications in integrated circuit manufacturing, stretchable electronics, and wearable sensors.", "author_names": [ "Joong-Hee Min", "Yen Lin Chen", "I Te Chen", "Tianlei Sun", "Dennis T Lee", "Chengjun Li", "Yong Zhu", "Brendan T O'Connor", "Gregory N Parsons", "Chih-Hao Chang" ], "corpus_id": 139490300, "doc_id": "139490300", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Conformal Physical Vapor Deposition Assisted by Atomic Layer Deposition and Its Application for Stretchable Conductors", "venue": "", "year": 2018 } ]

[ { "abstract": "A new experiment finds direct evidence for anyons in a semiconductor heterostructure The standard model of particle physics classifies all elementary particles as fermions or bosons. Fermions, like electrons, avoid each other. Bosons, like photons, can bunch together. The classification rests on a fundamental spin statistics theorem of quantum field theory and keeps these two types of particles distinct from each other. However, on page 173 of this issue, Bartolomei et al. (1) report an observation of particles that are neither bosons nor fermions.", "author_names": [ "Dima E Feldman" ], "corpus_id": 215550904, "doc_id": "215550904", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "The smallest particle collider", "venue": "Science", "year": 2020 }, { "abstract": "Preface 1. Fundamentals of QCD 2. Asymptotic freedom and confinement 3. QCD in electron positron annihilation 4. Deep inelastic scattering 5. Parton branching and jet simulation 6. Jet properties beyond fixed order 7. Hadroproduction of jets and photons 8. Electroweak interactions 9. The production of vector bosons 10. Heavy quarks 11. Higgs bosons at high energy colliders 12. Measurements of the strong coupling constant Index.", "author_names": [ "R Keith Ellis", "William James Stirling", "Bryan Webber" ], "corpus_id": 209834576, "doc_id": "209834576", "n_citations": 745, "n_key_citations": 89, "score": 0, "title": "QCD and Collider Physics", "venue": "", "year": 1990 }, { "abstract": "We extract new parton distribution functions (PDFs) of the proton by global analysis of hard scattering data in the general mass framework of perturbative quantum chromodynamics. Our analysis includes new theoretical developments together with the most recent collider data from deep inelastic scattering, vector boson production, and single inclusive jet production. Because of the difficulty in fitting both the D0 Run II W lepton asymmetry data and some fixed target DIS data, we present two families of PDFs, CT10 and CT10W, without and with these high luminosity W lepton asymmetry data included in the global analysis. With both sets of PDFs, we study theoretical predictions and uncertainties for a diverse selection of processes at the Fermilab Tevatron and the CERN Large Hadron Collider.", "author_names": [ "Hung-Liang Lai", "Marco Guzzi", "J Huston", "Zhao Li", "Pavel M Nadolsky", "Jon Pumplin", "C -P Yuan" ], "corpus_id": 118664723, "doc_id": "118664723", "n_citations": 2617, "n_key_citations": 473, "score": 0, "title": "New parton distributions for collider physics", "venue": "", "year": 2010 }, { "abstract": "We introduce a variable useful for measuring masses of particles pair produced at hadron colliders, where each particle decays to one particle that is directly observable and another particle whose existence can only be inferred from missing transverse momenta. This variable is closely related to the transverse mass variable commonly used for measuring the $W$ mass at hadron colliders, and like the transverse mass our variable extracts masses in a reasonably model independent way. Without considering either backgrounds or measurement errors we consider how our variable would perform measuring the mass of selectrons in a mSUGRA SUSY model at the LHC.", "author_names": [ "Christopher G Lester", "David J Summers" ], "corpus_id": 16308304, "doc_id": "16308304", "n_citations": 588, "n_key_citations": 29, "score": 0, "title": "Measuring masses of semi invisibly decaying particles pair produced at hadron colliders", "venue": "", "year": 1999 }, { "abstract": "The latest CTEQ6.6 parton distributions, obtained by global analysis of hard scattering data in the framework of general mass perturbative QCD, are employed to study theoretical predictions and their uncertainties for significant processes at the Fermilab Tevatron and CERN Large Hadron Collider. The previously observed increase in predicted cross sections for the standard candle W and Z boson production processes in the general mass scheme (compared to those in the zero mass scheme) is further investigated and quantified. A novel method to constrain parton distribution function (PDF) uncertainties in LHC observables, by effectively exploiting PDF induced correlations with benchmark standard model cross sections, is presented. Using this method, we show that the tt cross section can potentially serve as a standard candle observable for the LHC processes dominated by initial state gluon scattering. Among other benefits, precise measurements of tt cross sections would reduce PDF uncertainties in predictions for single top quark and Higgs boson production in the standard model and minimal supersymmetric standard model.", "author_names": [ "Pavel M Nadolsky", "Hung-Liang Lai", "Q-H Cao", "J Huston", "Jon Pumplin", "Daniel Robert Stump", "W K Tung", "C -P Yuan" ], "corpus_id": 118735114, "doc_id": "118735114", "n_citations": 1468, "n_key_citations": 120, "score": 0, "title": "Implications of CTEQ global analysis for collider observables", "venue": "", "year": 2008 }, { "abstract": "We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs along with the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition is addressed.", "author_names": [ "Malcolm Fairbairn", "Aafke Christine Kraan", "David Milstead", "Torbjorn Sjostrand", "Peter Skands", "Terence Sloan" ], "corpus_id": 14872649, "doc_id": "14872649", "n_citations": 303, "n_key_citations": 19, "score": 0, "title": "Stable massive particles at colliders", "venue": "", "year": 2007 }, { "abstract": "We study observables in a conformal field theory which are very closely related to the ones used to describe hadronic events at colliders. We focus on the correlation functions of the energies deposited on calorimeters placed at a large distance from the collision. We consider initial states produced by an operator insertion and we study some general properties of the energy correlation functions for conformal field theories. We argue that the small angle singularities of energy correlation functions are controlled by the twist of non local light ray operators with a definite spin. We relate the charge two point function to a particular moment of the parton distribution functions appearing in deep inelastic scattering. The one point energy correlation functions are characterized by a few numbers. For 1 superconformal theories the one point function for states created by the R current or the stress tensor are determined by the two parameters a and c characterizing the conformal anomaly. Demanding that the measured energies are positive we get bounds on a/c. We also give a prescription for computing the energy and charge correlation functions in theories that have a gravity dual. The prescription amounts to probing the falling string state as it crosses the AdS horizon with gravitational shock waves. In the leading, two derivative, gravity approximation the energy is uniformly distributed on the sphere at infinity, with no fluctuations. We compute the stringy corrections and we show that they lead to small, non gaussian, fluctuations in the energy distribution. Corrections to the one point functions or antenna patterns are related to higher derivative corrections in the bulk.", "author_names": [ "Diego M Hofman", "Juan Martin Maldacena" ], "corpus_id": 9290753, "doc_id": "9290753", "n_citations": 515, "n_key_citations": 95, "score": 0, "title": "Conformal collider physics: energy and charge correlations", "venue": "", "year": 2008 }, { "abstract": "We review the methods which have been proposed for measuring masses of new particles at the Large Hadron Collider paying particular attention to the kinematical techniques suitable for extracting mass information when invisible particles are expected.", "author_names": [ "A J Barr", "Christopher G Lester" ], "corpus_id": 55355301, "doc_id": "55355301", "n_citations": 134, "n_key_citations": 3, "score": 0, "title": "A review of the mass measurement techniques proposed for the Large Hadron Collider", "venue": "", "year": 2010 }, { "abstract": "We have determined the theoretical predictions for the cross sections of squark and gluino production at p p and pp colliders (Tevatron and LHC) in next to leading order of supersymmetric QCD. By reducing the dependence on the renormalization/factorization scale considerably, the theoretically predicted values for the cross sections are much more stable if these higher order corrections are implemented. If squarks and gluinos are discovered, this improved stability translates into a reduced error on the masses, as extracted experimentally from the size of the production cross sections. The cross sections increase significantly if the next to leading order corrections are included at a renormalization/factorization scale near the average mass of the produced massive particles. This rise results in improved lower bounds on squark and gluino masses. By contrast, the shape of the transverse momentum and rapidity distributions remains nearly unchanged when the next to leading order corrections are included.", "author_names": [ "Wim Beenakker", "R Hopker", "Michael Spira", "Peter M Zerwas" ], "corpus_id": 124471144, "doc_id": "124471144", "n_citations": 611, "n_key_citations": 27, "score": 0, "title": "Squark and gluino production at hadron colliders", "venue": "", "year": 1997 }, { "abstract": "This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2158 new measurements from 551 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 108 reviews are many that are new or heavily revised including those on neutrino mass, mixing, and oscillations, QCD, top quark, CKM quark mixing matrix, V ud V us, V cb V ub, fragmentation functions, particle detectors for accelerator and non accelerator physics, magnetic monopoles, cosmological parameters, and big bang cosmology.", "author_names": [ "K Nakamura", "Kaoru Hagiwara", "Ken-ichi Hikasa", "Hitoshi Murayama", "Masaharu Tanabashi", "Taizan Watari", "Claude Amsler", "M Antonelli", "David Asner", "Howard Baer", "H R Band", "R M Barnett", "Tullio Basaglia", "E Bergren", "Juerg Beringer", "Gregorio Bernardi", "Willi Bertl", "Hans Bichsel", "O Biebel", "Edward Blucher", "Steven R Blusk", "Robert Cahn", "M Carena", "Augusto Ceccucci", "Dhiman Chakraborty", "Mu-Chun Chen", "R Sekhar Chivukula", "Glen Cowan", "Orin I Dahl", "G D'ambrosio", "Thibault Damour", "Daniel de Florian", "Andr'e de Gouvea", "Thomas A DeGrand", "Gunther Dissertori", "Bogdan A Dobrescu", "M Doser", "Manuel Drees", "David A Edwards", "Semen Eidelman", "Jens Erler", "Vladimir V Ezhela", "Wulf Fetscher", "Brian D Fields", "Brian Foster", "Thomas K Gaisser", "L Garren", "Hannes J Gerber", "Gilles Gerbier", "Tony Gherghetta", "Gian Francesco Giudice", "Sunil R Golwala", "Maury Charles Goodman", "C Grab", "A V Gritsan", "J -F Grivaz", "Donald E Groom", "M Grunewald", "Atul Gurtu", "Thomas Gutsche", "Howard E Haber", "Christian Hagmann", "Kenneth G Hayes", "Michael Heffner", "Brian K Heltsley", "Juan Jose Hernandez-Rey", "Andreas Hocker", "J Holder", "J Huston", "Jon David Jackson", "K F Johnson", "T R Junk", "Albrecht Karle", "D Karlen", "Boris J Kayser", "David Kirkby", "Spencer R Klein", "Christopher Kolda", "R Kowalewski", "B Krusche", "Yu V Kuyanov", "Y -J Kwon", "Ofer Lahav", "Paul Langacker", "Andrew R Liddle", "Zoltan Ligeti", "Che-Yun Lin", "T M Liss", "Laurence S Littenberg", "K S Lugovsky", "S B Lugovsky", "J E A Lys", "Hanna Mahlke", "Thomas Mannel", "Aneesh V Manohar", "William J Marciano", "Alan D Martin", "Alberto Masoni", "David Milstead", "Ramon Miquel", "K Monig", "Meenakshi Narain", "Paolo Nason", "Sergio Sanchez Navas", "P Nevski", "Yosef Nir", "Keith A Olive", "Luc Pape", "Claudia Patrignani", "John A Peacock", "Serguey T Petcov", "Andreas Piepke", "Giovanni Punzi", "Arnulf Quadt", "Stuart Raby", "Georg Raffelt", "B N Ratcliff", "Peter J Richardson", "Stefan Roesler", "Simona Rolli", "A Romaniouk", "Leslie J Rosenberg", "Jonathan L Rosner", "Christopher T C Sachrajda", "Yoshihide Sakai", "G P Salam", "Subir Sarkar", "Fabio Sauli", "O Schneider", "Kate Scholberg", "Douglas Scott", "William Seligman", "Michael Herman Shaevitz", "Marco Silari", "Torbjorn Sjostrand", "Jg Smith", "George F Smoot", "Stefan Spanier", "H Spieler", "A Stahl", "Todor Stanev", "Sheldon Stone", "Takayuki Sumiyoshi", "M Syphers", "John Terning", "M Titov", "N P Tkachenko", "Nils A Tornqvist", "D R Tovey", "Thomas G Trippe", "German Valencia", "Karl A van Bibber", "Giuseppe Venanzoni", "M G Vincter", "Petr Vogel", "A Vogt", "Wolfgang Walkowiak", "C W Walter", "David R Ward", "Bryan Webber", "Georg Weiglein", "Erick Weinberg", "James D Wells", "A Wheeler", "Lawrence Richard Wiencke", "Charles G Wohl", "Lincoln Wolfenstein", "John Lewis Womersley", "Craig Woody", "Ron Workman", "A Yamamoto", "Weiming Yao", "O Zenin", "Jiayu Zhang", "Ren-Yuan Zhu", "Piotr Zyla", "G Harper", "V S Lugovsky", "Paul Schaffner" ], "corpus_id": 123175461, "doc_id": "123175461", "n_citations": 3947, "n_key_citations": 471, "score": 0, "title": "Review of Particle Physics", "venue": "", "year": 2010 } ]

[ { "abstract": "In the semiconductor industry the number of circuits per chip is still drastically increasing. This fact and strong competition lead to the particular importance of quality control and quality assurance. As a result a vast amount of data is recorded during the fabrication process, which is very complex in structure and massively affected by noise. The evaluation of this data is a vital task to support engineers in the analysis of process problems. The current work tackles this problem by identifying the features responsible for success or failure in the manufacturing process (feature selection)", "author_names": [ "Michael Bensch", "Michael Tangermann", "Martin Bogdan", "Wolfgang Rosenstiel" ], "corpus_id": 18497849, "doc_id": "18497849", "n_citations": 14, "n_key_citations": 1, "score": 1, "title": "Feature selection for high dimensional industrial data", "venue": "ESANN", "year": 2005 }, { "abstract": "Feature selection, as a preprocessing step to machine learning, is effective in reducing dimensionality, removing irrelevant data, increasing learning accuracy, and improving result comprehensibility. However, the recent increase of dimensionality of data poses a severe challenge to many existing feature selection methods with respect to efficiency and effectiveness. In this work, we introduce a novel concept, predominant correlation, and propose a fast filter method which can identify relevant features as well as redundancy among relevant features without pairwise correlation analysis. The efficiency and effectiveness of our method is demonstrated through extensive comparisons with other methods using real world data of high dimensionality", "author_names": [ "Lei Yu", "Huan Liu" ], "corpus_id": 5322427, "doc_id": "5322427", "n_citations": 2171, "n_key_citations": 188, "score": 0, "title": "Feature Selection for High Dimensional Data: A Fast Correlation Based Filter Solution", "venue": "ICML", "year": 2003 }, { "abstract": "This paper introduces concepts and algorithms of feature selection, surveys existing feature selection algorithms for classification and clustering, groups and compares different algorithms with a categorizing framework based on search strategies, evaluation criteria, and data mining tasks, reveals unattempted combinations, and provides guidelines in selecting feature selection algorithms. With the categorizing framework, we continue our efforts toward building an integrated system for intelligent feature selection. A unifying platform is proposed as an intermediate step. An illustrative example is presented to show how existing feature selection algorithms can be integrated into a meta algorithm that can take advantage of individual algorithms. An added advantage of doing so is to help a user employ a suitable algorithm without knowing details of each algorithm. Some real world applications are included to demonstrate the use of feature selection in data mining. We conclude this work by identifying trends and challenges of feature selection research and development.", "author_names": [ "Huan Liu", "Lei Yu" ], "corpus_id": 1607600, "doc_id": "1607600", "n_citations": 2447, "n_key_citations": 139, "score": 0, "title": "Toward integrating feature selection algorithms for classification and clustering", "venue": "IEEE Transactions on Knowledge and Data Engineering", "year": 2005 }, { "abstract": "In this paper, we examine a method for feature subset selection based on Information Theory. Initially, a framework for defining the theoretically optimal, but computationally intractable, method for feature subset selection is presented. We show that our goal should be to eliminate a feature if it gives us little or no additional information beyond that subsumed by the remaining features. In particular, this will be the case for both irrelevant and redundant features. We then give an efficient algorithm for feature selection which computes an approximation to the optimal feature selection criterion. The conditions under which the approximate algorithm is successful are examined. Empirical results are given on a number of data sets, showing that the algorithm effectively handles datasets with a very large number of features.", "author_names": [ "Daphne Koller", "Mehran Sahami" ], "corpus_id": 1455429, "doc_id": "1455429", "n_citations": 1726, "n_key_citations": 85, "score": 0, "title": "Toward Optimal Feature Selection", "venue": "ICML", "year": 1996 }, { "abstract": "Feature selection has been the focus of interest for quite some time and much work has been done. With the creation of huge databases and the consequent requirements for good machine learning techniques, new problems arise and novel approaches to feature selection are in demand. This survey is a comprehensive overview of many existing methods from the 1970's to the present. It identifies four steps of a typical feature selection method, and categorizes the different existing methods in terms of generation procedures and evaluation functions, and reveals hitherto unattempted combinations of generation procedures and evaluation functions. Representative methods are chosen from each category for detailed explanation and discussion via example. Benchmark datasets with different characteristics are used for comparative study. The strengths and weaknesses of different methods are explained. Guidelines for applying feature selection methods are given based on data types and domain characteristics. This survey identifies the future research areas in feature selection, introduces newcomers to this field, and paves the way for practitioners who search for suitable methods for solving domain specific real world applications.", "author_names": [ "Manoranjan Dash", "Huan Liu" ], "corpus_id": 14573187, "doc_id": "14573187", "n_citations": 3060, "n_key_citations": 159, "score": 0, "title": "Feature Selection for Classification", "venue": "Intell. Data Anal.", "year": 1997 }, { "abstract": "A central problem in machine learning is identifying a representative set of features from which to construct a classification model for a particular task. This thesis addresses the problem of feature selection for machine learning through a correlation based approach. The central hypothesis is that good feature sets contain features that are highly correlated with the class, yet uncorrelated with each other. A feature evaluation formula, based on ideas from test theory, provides an operational definition of this hypothesis. CFS (Correlation based Feature Selection) is an algorithm that couples this evaluation formula with an appropriate correlation measure and a heuristic search strategy. CFS was evaluated by experiments on artificial and natural datasets. Three machine learning algorithms were used: C4.5 (a decision tree learner) IB1 (an instance based learner) and naive Bayes. Experiments on artificial datasets showed that CFS quickly identifies and screens irrelevant, redundant, and noisy features, and identifies relevant features as long as their relevance does not strongly depend on other features. On natural domains, CFS typically eliminated well over half the features. In most cases, classification accuracy using the reduced feature set equaled or bettered accuracy using the complete feature set. Feature selection degraded machine learning performance in cases where some features were eliminated which were highly predictive of very small areas of the instance space. Further experiments compared CFS with a wrapper a well known approach to feature selection that employs the target learning algorithm to evaluate feature sets. In many cases CFS gave comparable results to the wrapper, and in general, outperformed the wrapper on small datasets. CFS executes many times faster than the wrapper, which allows it to scale to larger datasets. Two methods of extending CFS to handle feature interaction are presented and experimentally evaluated. The first considers pairs of features and the second incorporates iii feature weights calculated by the RELIEF algorithm. Experiments on artificial domains showed that both methods were able to identify interacting features. On natural domains, the pairwise method gave more reliable results than using weights provided by RELIEF.", "author_names": [ "Mark A Hall" ], "corpus_id": 8312711, "doc_id": "8312711", "n_citations": 3343, "n_key_citations": 393, "score": 0, "title": "Correlation based Feature Selection for Machine Learning", "venue": "", "year": 2003 }, { "abstract": "Data mining applications place special requirements on clustering algorithms including: the ability to find clusters embedded in subspaces of high dimensional data, scalability, end user comprehensibility of the results, non presumption of any canonical data distribution, and insensitivity to the order of input records. We present CLIQUE, a clustering algorithm that satisfies each of these requirements. CLIQUE identifies dense clusters in subspaces of maximum dimensionality. It generates cluster descriptions in the form of DNF expressions that are minimized for ease of comprehension. It produces identical results irrespective of the order in which input records are presented and does not presume any specific mathematical form for data distribution. Through experiments, we show that CLIQUE efficiently finds accurate cluster in large high dimensional datasets.", "author_names": [ "Rakesh Agrawal", "Johannes Gehrke", "Dimitrios Gunopulos", "Prabhakar Raghavan" ], "corpus_id": 1260437, "doc_id": "1260437", "n_citations": 2633, "n_key_citations": 237, "score": 0, "title": "Automatic subspace clustering of high dimensional data for data mining applications", "venue": "SIGMOD '98", "year": 1998 }, { "abstract": "Variable and feature selection have become the focus of much research in areas of application for which datasets with tens or hundreds of thousands of variables are available. These areas include text processing of internet documents, gene expression array analysis, and combinatorial chemistry. The objective of variable selection is three fold: improving the prediction performance of the predictors, providing faster and more cost effective predictors, and providing a better understanding of the underlying process that generated the data. The contributions of this special issue cover a wide range of aspects of such problems: providing a better definition of the objective function, feature construction, feature ranking, multivariate feature selection, efficient search methods, and feature validity assessment methods.", "author_names": [ "Isabelle Guyon", "Andre Elisseeff" ], "corpus_id": 379259, "doc_id": "379259", "n_citations": 13537, "n_key_citations": 658, "score": 0, "title": "An Introduction to Variable and Feature Selection", "venue": "J. Mach. Learn. Res.", "year": 2003 }, { "abstract": "In real world concept learning problems, the representation of data often uses many features, only a few of which may be related to the target concept. In this situation, feature selection is important both to speed up learning and to improve concept quality. A new feature selection algorithm Relief uses a statistical method and avoids heuristic search. Relief requires linear time in the number of given features and the number of training instances regardless of the target concept to be learned. Although the algorithm does not necessarily find the smallest subset of features, the size tends to be small because only statistically relevant features are selected. This paper focuses on empirical test results in two artificial domains; the LED Display domain and the Parity domain with and without noise. Comparison with other feature selection algorithms shows Relief's advantages in terms of learning time and the accuracy of the learned concept, suggesting Relief's practicality.", "author_names": [ "Kenji Kira", "Larry A Rendell" ], "corpus_id": 33296374, "doc_id": "33296374", "n_citations": 2704, "n_key_citations": 236, "score": 0, "title": "A Practical Approach to Feature Selection", "venue": "ML", "year": 1992 }, { "abstract": "Feature selection is applied to reduce the number of features in many applications where data has hundreds or thousands of features. Existing feature selection methods mainly focus on finding relevant features. In this paper, we show that feature relevance alone is insufficient for efficient feature selection of high dimensional data. We define feature redundancy and propose to perform explicit redundancy analysis in feature selection. A new framework is introduced that decouples relevance analysis and redundancy analysis. We develop a correlation based method for relevance and redundancy analysis, and conduct an empirical study of its efficiency and effectiveness comparing with representative methods.", "author_names": [ "Lei Yu", "Huan Liu" ], "corpus_id": 7580221, "doc_id": "7580221", "n_citations": 1897, "n_key_citations": 183, "score": 0, "title": "Efficient Feature Selection via Analysis of Relevance and Redundancy", "venue": "J. Mach. Learn. Res.", "year": 2004 } ]

[ { "abstract": "Charge transport in conjugated polymer semiconductors has traditionally been thought to be limited to a low mobility regime by pronounced energetic disorder. Much progress has recently been made in advancing carrier mobilities in field effect transistors through developing low disorder conjugated polymers. However, in diodes these polymers have to date not shown much improved mobilities, presumably reflecting the fact that in diodes lower carrier concentrations are available to fill up residual tail states in the density of states. Here, we show that the bulk charge transport in low disorder polymers is limited by water induced trap states and that their concentration can be dramatically reduced through incorporating small molecular additives into the polymer film. Upon incorporation of the additives we achieve space charge limited current characteristics that resemble molecular single crystals such as rubrene with high, trap free SCLC mobilities up to 0.2 cm2/Vs and a width of the residual tail state distribution comparable to kBT.Charge transport in organic diodes based on conjugated polymers is severely limited by the high water related trap concentration and energetic disorder. Here, the authors report high mobility trap free charge transport in low disorder conjugated polymers by incorporating small molecular additives.", "author_names": [ "Mark Nikolka", "Katharina Broch", "John Armitage", "David A Hanifi", "Peer J Nowack", "Deepak Venkateshvaran", "Aditya Sadhanala", "Jan Saska", "Mark Mascal", "Seok-Heon Jung", "Jin-Kyun Lee", "Iain McCulloch", "Alberto Salleo", "Henning Sirringhaus" ], "corpus_id": 148572200, "doc_id": "148572200", "n_citations": 46, "n_key_citations": 0, "score": 1, "title": "High mobility, trap free charge transport in conjugated polymer diodes", "venue": "Nature Communications", "year": 2019 }, { "abstract": "Room temperature flexible heat harvesters based on conducting polymers are ideally suited to cover the energy demands of the modern nomadic society. The optimization of their thermoelectric efficiency is usually sought by tuning the oxidation levels of the conducting polymers, even if such methodology is detrimental to the Seebeck coefficient (S) as both the Seebeck coefficient and the electrical conductivity (s) are antagonistically related to the carrier concentration. Here we report a concurrent increase of S and s and we experimentally derive the dependence of Seebeck coefficient on charge carrier mobility for the first time in organic electronics. Through specific control of the conducting polymer synthesis, we enabled the formation of a denser percolation network that facilitated the charge transport and the thermodiffusion of the charge carriers inside the conducting polymer layer, while the material shifted from a Fermi glass towards a semi metal, as its crystallinity increased. This work sheds light upon the origin of the thermoelectric properties of conducting polymers, but also underlines the importance of enhanced charge carrier mobility for the design of efficient thermoelectric polymers.", "author_names": [ "Ioannis Petsagkourakis", "Eleni Pavlopoulou", "Eric Cloutet", "Yan Chen", "Xjianjie Liu", "Mats Fahlman", "Magnus Berggren", "Xavier Crispin", "Stefan Dilhaire", "Guillaume Fleury", "Georges Hadziioannou" ], "corpus_id": 103902413, "doc_id": "103902413", "n_citations": 35, "n_key_citations": 1, "score": 1, "title": "Correlating the Seebeck coefficient of thermoelectric polymer thin films to their charge transport mechanism", "venue": "", "year": 2018 }, { "abstract": "Beating the heat by blending Charge carriers move through semiconductor polymers by hopping transport. In principle, these polymers should be more conductive at higher temperatures. In practice, conductivity drops at high temperatures because interchain contacts are disrupted, which limits potential applications. Gumyusenge et al. now show that appropriate blending of a semicrystalline conjugated polymer with an insulating polymer that has a high glass transition temperature creates a morphology that stabilizes a network of semiconductor channels. High charge conductivity was maintained in these materials up to 220degC. Science, this issue p. 1131 Polymer semiconductors can maintain their conductivity at high temperatures when blended into insulating host polymers. Although high temperature operation (i.e. beyond 150degC) is of great interest for many electronics applications, achieving stable carrier mobilities for organic semiconductors at elevated temperatures is fundamentally challenging. We report a general strategy to make thermally stable high temperature semiconducting polymer blends, composed of interpenetrating semicrystalline conjugated polymers and high glass transition temperature insulating matrices. When properly engineered, such polymer blends display a temperature insensitive charge transport behavior with hole mobility exceeding 2.0 cm2/V*s across a wide temperature range from room temperature up to 220degC in thin film transistors.", "author_names": [ "Aristide Gumyusenge", "Dung Thuy Thi Tran", "Xuyi Luo", "Gregory Matthew Pitch", "Yan Zhao", "Kaelon A Jenkins", "Tim J Dunn", "Alexander L Ayzner", "Brett M Savoie", "Jianguo Mei" ], "corpus_id": 54457109, "doc_id": "54457109", "n_citations": 72, "n_key_citations": 1, "score": 0, "title": "Semiconducting polymer blends that exhibit stable charge transport at high temperatures", "venue": "Science", "year": 2018 }, { "abstract": "Charge transport and film microstructure evolution are investigated in a series of polyethylenimine (PEI) doped (0.0 6.0 wt% amorphous metal oxide (MO) semiconductor thin film blends. Here, PEI doping generality is broadened from binary In2O3 to ternary (e.g. In+Zn in IZO, In+Ga in IGO) and quaternary (e.g. In+Zn+Ga in IGZO) systems, demonstrating the universality of this approach for polymer electron doping of MO matrices. Systematic comparison of the effects of various metal ions on the electronic transport and film microstructure of these blends are investigated by combined thin film transistor (TFT) response, AFM, XPS, XRD, X ray reflectivity, and cross sectional TEM. Morphological analysis reveals that layered MO film microstructures predominate in PEI In2O3, but become less distinct in IGO and are not detectable in IZO and IGZO. TFT charge transport measurements indicate a general coincidence of a peak in carrier mobility (mpeak) and overall TFT performance at optimal PEI doping concentrations. Optimal PEI loadings that yield mpeak values depend not only on the MO elemental composition but also, equally important, on the metal atomic ratios. By investigating the relationship between the MO energy levels and PEI doping by UPS, it is concluded that the efficiency of PEI electron donation is highly dependent on the metal oxide matrix work function in cases where film morphology is optimal, as in the IGO compositions. The results of this investigation demonstrate the broad generality and efficacy of PEI electron doping applied to electronically functional metal oxide systems and that the resulting film microstructure, morphology, and energy level modifications are all vital to understanding charge transport in these amorphous oxide blends.", "author_names": [ "Wei Huang", "Peijun Guo", "Li Zeng", "Ran Li", "Binghao Wang", "Gang Wang", "Xinan Zhang", "R P H Chang", "Junsheng Yu", "Michael J Bedzyk", "Tobin J Marks", "Antonio F Facchetti" ], "corpus_id": 4775361, "doc_id": "4775361", "n_citations": 21, "n_key_citations": 0, "score": 0, "title": "Metal Composition and Polyethylenimine Doping Capacity Effects on Semiconducting Metal Oxide Polymer Blend Charge Transport.", "venue": "Journal of the American Chemical Society", "year": 2018 }, { "abstract": "T.D.A. and A.F.P acknowledge financial support from Cambridge Display Technology (Company No. 2672530) O.S. acknowledges the support of the Center for Absorption in Science of the Ministry of Immigrant Absorption under the framework of the KAMEA Program.", "author_names": [ "Alexandra F Paterson", "Yen-Hung Lin", "Alexander D Mottram", "Zhuping Fei", "Muhammad Rizwan Niazi", "Ahmad R Kirmani", "Aram Amassian", "Olga Solomeshch", "Nir Tessler", "Martin Heeney", "Thomas D Anthopoulos" ], "corpus_id": 140094810, "doc_id": "140094810", "n_citations": 38, "n_key_citations": 0, "score": 0, "title": "The Impact of Molecular p Doping on Charge Transport in High Mobility Small Molecule/Polymer Blend Organic Transistors", "venue": "", "year": 2018 }, { "abstract": "Significance Shear printing of electroactive polymers using natural brushes is a promising film deposition technique for printed electronics capable of microstructure control and electrical properties enhancement over large areas. Nevertheless, the interplay between film printing parameters, microstructure development, and charge transport is not well understood. We report that natural brush printing greatly enhances charge transport by as much as 5.7x through control of polymer nanofibril aggregate growth and backbone alignment, attributable to the oriented squamae of the natural hair. However, while brush shear induced aggregation enhances charge transport, we show that backbone alignment alone does not guarantee charge transport anisotropy. These results provide additional understanding of shear induced enhanced charge transport and set processing guidelines for high performance printed organic circuitry. Shear printing is a promising processing technique in organic electronics for microstructure/charge transport modification and large area film fabrication. Nevertheless, the mechanism by which shear printing can enhance charge transport is not well understood. In this study, a printing method using natural brushes is adopted as an informative tool to realize direct aggregation control of conjugated polymers and to investigate the interplay between printing parameters, macromolecule backbone alignment and aggregation, and charge transport anisotropy in a conjugated polymer series differing in architecture and electronic structure. This series includes (i) semicrystalline hole transporting P3HT, (ii) semicrystalline electron transporting N2200, (iii) low crystallinity hole transporting PBDTT FTTE, and (iv) low crystallinity conducting PEDOT:PSS. The (semi )conducting films are characterized by a battery of morphology and microstructure analysis techniques and by charge transport measurements. We report that remarkably enhanced mobilities/conductivities, as high as 5.7x/3.9x, are achieved by controlled growth of nanofibril aggregates and by backbone alignment, with the adjusted R2 (R2adj) correlation between aggregation and charge transport as high as 95% However, while shear induced aggregation is important for enhancing charge transport, backbone alignment alone does not guarantee charge transport anisotropy. The correlations between efficient charge transport and aggregation are clearly shown, while mobility and degree of orientation are not always well correlated. These observations provide insights into macroscopic charge transport mechanisms in conjugated polymers and suggest guidelines for optimization.", "author_names": [ "Gang Wang", "Wei Huang", "Nicholas D Eastham", "Simone Fabiano", "Eric F Manley", "Li Zeng", "Binghao Wang", "Xinan Zhang", "Zhihua Chen", "Ran Li", "R P H Chang", "Lin X Chen", "Michael J Bedzyk", "Ferdinand S Melkonyan", "Antonio F Facchetti", "Tobin J Marks" ], "corpus_id": 12750153, "doc_id": "12750153", "n_citations": 76, "n_key_citations": 0, "score": 0, "title": "Aggregation control in natural brush printed conjugated polymer films and implications for enhancing charge transport", "venue": "Proceedings of the National Academy of Sciences", "year": 2017 }, { "abstract": "Morphology of conjugated polymers is a critical factor that significantly affects intrinsic charge transport characteristics and in turn performance of polymer based devices. Morphological defects including misaligned crystalline grains and grain boundaries significantly impede efficient charge hopping between transport sites, resulting in degradation of device performance. Therefore, one important challenge is to control morphology of active polymer thin films for achieving high performance flexible electronic devices. In the past decade, significant progress has been achieved in morphology control of conjugated polymer thin films using solution based processing techniques. This review focuses on recent advances in processing strategies that can tune the morphologies and thus impact charge transport properties of conjugated polymer thin films. Of the available processing strategies, polymer solution treatments and film deposition techniques will be mainly highlighted. The correlation between processing conditions, active layer morphologies, and device performance will be also be discussed.", "author_names": [ "Mincheol Chang", "Gyun-Taek Lim", "Byoungnam Park", "Elsa Reichmanis" ], "corpus_id": 11272085, "doc_id": "11272085", "n_citations": 41, "n_key_citations": 0, "score": 0, "title": "Control of Molecular Ordering, Alignment, and Charge Transport in Solution Processed Conjugated Polymer Thin Films", "venue": "Polymers", "year": 2017 }, { "abstract": "Although the effects of alkyl chain spacers have been extensively studied for p type conjugated polymers with a donor (D) acceptor (A) repeating unit, few studies have examined their effects for n type polymers with an A D A architecture having two different acceptors in the repeating unit. Herein, diketopyrrolopyrrole thiophene bithiazole A D A type polymer semiconductors (DPPBTz) containing branched alkyl chains of 24 alkyl with C1 spacer (P 24 DPPBTz) and 29 alkyl with C6 spacer (P 29 DPPBTz) were designed and synthesized to elucidate the effect of the alkyl chain branching position on the electron dominant charge transport system. Due to the strong electron deficiency and trans planar conformation of the bithiazole group, DPPBTz based polymer semiconductors exhibit n type dominant electrical properties with a high electron mobility of up to 1.87 cm2 V 1 s 1. Systematic studies on the photophysical properties, thin film microstructures, and electrical properties of the DPPBTz polymers revealed that upon modification of the branching position, A D A n type dominant semiconductors differently behave compared to D A p type dominant semiconductors. This is attributed to the relatively weaker intermolecular interactions in A D A type semiconductors, making the C1 spacer more efficient for electron transport. These findings reveal the molecular design rule of alkyl side chains in A D A n type dominant conjugated polymers for the first time.", "author_names": [ "Hojeong Yu", "Hyong Nam Kim", "Inho Song", "Yeon Hee Ha", "Hyungju Ahn", "Joon Hak Oh", "Yun-Hi Kim" ], "corpus_id": 52233091, "doc_id": "52233091", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "Effect of alkyl chain spacer on charge transport in n type dominant polymer semiconductors with a diketopyrrolopyrrole thiophene bithiazole acceptor donor acceptor unit", "venue": "", "year": 2017 }, { "abstract": "Abstract A metal free photoanode nanojunction architecture, composed of B doped carbon nitride nanolayer and bulk carbon nitride, was fabricated by a one step approach. This type of nanojunction (s BCN) overcomes a few intrinsic drawbacks of carbon nitride film (severe bulk charge recombination and slow charge transfer) The top layer of the nanojunction has a depth of ca. 100 nm and the bottom layer is ca. 900 nm. The nanojunction photoanode results into a 10 fold higher photocurrent than bulk graphitic carbon nitride (G CN) photoanode, with a record photocurrent density of 103.2 mA cm 2 at 1.23 V vs. RHE under one sun irradiation and an extremely high incident photon to current efficiency (IPCE) of ca. 10 at 400 nm. Electrochemical impedance spectroscopy, Mott Schottky plots, and intensity modulated photocurrent spectroscopy show that such enhancement is mainly due to the mitigated deep trap states, a more than 10 times faster charge transfer rate and nearly three times higher conductivity due to the nanojunction architecture.", "author_names": [ "Qiushi Ruan", "Wenjun Luo", "Jijia Xie", "Yiou Wang", "Xu Liu", "Zhiming Bai", "Claire J Carmalt", "Junwang Tang" ], "corpus_id": 36628028, "doc_id": "36628028", "n_citations": 86, "n_key_citations": 0, "score": 0, "title": "A Nanojunction Polymer Photoelectrode for Efficient Charge Transport and Separation", "venue": "Angewandte Chemie", "year": 2017 }, { "abstract": "The properties of molecularly doped films of conjugated polymers are explored as the crystallinity of the polymer is systematically varied. Solution sequential processing (SqP) was used to introduce 2,3,5,6 tetrafluoro 7,7,8,8 tetracyanoquinodimethane (F4TCNQ) into poly(3 hexylthiophene 2,5 diyl) (P3HT) while preserving the pristine polymer's degree of crystallinity. X ray data suggest that F4TCNQ anions reside primarily in the amorphous regions of the film as well as in the P3HT lamellae between the side chains, but do not p stack within the polymer crystallites. Optical spectroscopy shows that the polaron absorption redshifts with increasing polymer crystallinity and increases in cross section. Theoretical modeling suggests that the polaron spectrum is inhomogeneously broadened by the presence of the anions, which reside on average 6 8 A from the polymer backbone. Electrical measurements show that the conductivity of P3HT films doped by F4TCNQ via SqP can be improved by increasing the polymer crystallinity. AC magnetic field Hall measurements show that the increased conductivity results from improved mobility of the carriers with increasing crystallinity, reaching over 0.1 cm2 V 1 s 1 in the most crystalline P3HT samples. Temperature dependent conductivity measurements show that polaron mobility in SqP doped P3HT is still dominated by hopping transport, but that more crystalline samples are on the edge of a transition to diffusive transport at room temperature.", "author_names": [ "D Tyler Scholes", "Patrick Y Yee", "Jeffrey R Lindemuth", "Hyeyeon Kang", "Jonathan W Onorato", "Raja Ghosh", "Christine K Luscombe", "Frank C Spano", "Sarah H Tolbert", "Benjamin J Schwartz" ], "corpus_id": 37307486, "doc_id": "37307486", "n_citations": 105, "n_key_citations": 0, "score": 0, "title": "The Effects of Crystallinity on Charge Transport and the Structure of Sequentially Processed F4TCNQ Doped Conjugated Polymer Films", "venue": "", "year": 2017 } ]

[ { "abstract": "This papers describes the capabilities of modern SiGe semiconductor technologies for the highly integrated realization of Frequency Modulated Continuous Wave (FMCW) Radar sensors. Based on an ultra wideband oscillator, synthesizer and receiver, an ultra wide bandwidth of 25 GHz around a center frequency of 80 GHz is demonstrated. This enables high resolution radar measurements with a multi target resolution of 7.1 mm and an absolute distance accuracy better than 1 mm, which enables new potentials for contact free distance measurements even in harsh environments.", "author_names": [ "Nils Pohl", "Timo Jaeschke", "Simon Kuppers", "Christian Bredendiek", "Dirk Nussler" ], "corpus_id": 49651313, "doc_id": "49651313", "n_citations": 12, "n_key_citations": 0, "score": 1, "title": "A compact ultra wideband mmWave radar sensor at 80 GHz based on a SiGe transceiver chip (Focused session on highly integrated millimeter wave radar sensors in SiGe BiCMOS technologies)", "venue": "2018 22nd International Microwave and Radar Conference (MIKON)", "year": 2018 }, { "abstract": "Summary form only given. In February 2002, a law and order of the federal communications commission (FCC) gave the \"green light\" (spectral mask in the range 3.1 10.6 GHz) for commercial applications of ultra wideband (UWB) systems. Since this recent FCC release, UWB has emerged as an exciting technology whose \"time has come\" for wireless communications, and local area networking. Conveying information over ultra short waveforms, UWB technology allows for very accurate delay estimates providing position and localization capabilities within a few centimeters. The scarcity of bandwidth resources coupled with the capability of IR to overlay existing systems, welcomes UWB connectivity in the workplace, and at home for indoor and especially short range wireless links. However, to realize these attractive features, UWB research and development has to cope with formidable challenges. This plenary will provide the fundamentals of UWB communication systems, driving applications, recent developments, and open problems.", "author_names": [ "Georgios B Giannakis" ], "corpus_id": 60880434, "doc_id": "60880434", "n_citations": 530, "n_key_citations": 38, "score": 0, "title": "Ultra wideband communications: an idea whose time has come", "venue": "2003 4th IEEE Workshop on Signal Processing Advances in Wireless Communications SPAWC 2003 (IEEE Cat. No.03EX689)", "year": 2003 }, { "abstract": "UWB technology provides an excellent means for wireless positioning due to its high resolution capability in the time domain. Its ability to resolve multipath components makes it possible to obtain accurate location estimates without the need for complex estimation algorithms. In this article, theoretical limits for TOA estimation and TOA based location estimation for UWB systems have been considered. Due to the complexity of the optimal schemes, suboptimal but practical alternatives have been emphasized. Performance limits for hybrid TOA/SS and TDOA/SS schemes have also been considered. Although the fundamental mechanisms for localization, including AOA TOA TDOA and SS based methods, apply to all radio air interface, some positioning techniques are favored by UWB based systems using ultrawide bandwidths.", "author_names": [ "Sinan Gezici", "Zhi Hong Tian", "Georgios B Giannakis", "Hisashi Kobayashi", "Andreas F Molisch", "H Vincent Poor", "Zafer Sahinoglu" ], "corpus_id": 2174942, "doc_id": "2174942", "n_citations": 1857, "n_key_citations": 72, "score": 0, "title": "Localization via ultra wideband radios: a look at positioning aspects for future sensor networks", "venue": "IEEE Signal Processing Magazine", "year": 2005 }, { "abstract": "The recent approval granted by the Federal Communications Commission (FCC) for the use of ultra wideband signals for vehicular radar applications has provided a gateway for the introduction of these sensors in the commercial arena as early as 2004. However, the rules governing the allowable spectral occupancy create significant constraints on the sensors' operation. This is further complicated by the variety of applications that these sensors are being required to fulfill. A review of the motivation for the development of these sensors is followed by a discussion of the consequent implications for waveform design and limitations on system architecture. Other practical considerations such as available semiconductor technology, packaging, and assembly techniques are reviewed, and results are presented for conventional surface mount plastic packages illustrating their usefulness in the greater than 20 GHz frequency range. Suitable antenna technology for wide band transmission is presented that is compliant with the specific restrictions stipulated in the FCC ruling. Finally, all of these considerations are combined with the presentation of a compatible integrated circuit based transceiver architecture. Measured results are presented for several critical circuit components including a +12 dBm driver amplifier for the transmitter, an RF pulse generator that can produce sub 1 ns pulses at a carrier frequency of 24 GHz, and a single chip homodyne in phase/quadrature down conversion receiver that has a cascaded noise figure of less than 7 dB. All circuit components are fabricated in SiGe.", "author_names": [ "Ian Gresham", "Alan Peter Jenkins", "R G Egri", "Channabasappa Eswarappa", "Noyan Kinayman", "Nitin Jain", "R Anderson", "Frank S Kolak", "R Wohlert", "Shawn Bawell", "J Bennett", "J P Lanteri" ], "corpus_id": 17624121, "doc_id": "17624121", "n_citations": 286, "n_key_citations": 14, "score": 0, "title": "Ultra wideband radar sensors for short range vehicular applications", "venue": "IEEE Transactions on Microwave Theory and Techniques", "year": 2004 }, { "abstract": "The market for driver assistance systems based on millimeter wave radar sensor technology is gaining momentum. In the near future, the full range of newly introduced car models will be equipped with radar based systems which leads to high volume production with low cost potential. This paper provides background and an overview of the state of the art of millimeter wave technology for automotive radar applications, including two actual silicon based fully integrated radar chips. Several advanced packaging concepts and antenna systems are presented and discussed in detail. Finally measurement results of the fully integrated radar front ends are shown.", "author_names": [ "Jurgen Hasch", "Eray Topak", "Raik Schnabel", "Thomas Zwick", "Robert Weigel", "Christian Waldschmidt" ], "corpus_id": 17069433, "doc_id": "17069433", "n_citations": 748, "n_key_citations": 43, "score": 0, "title": "Millimeter Wave Technology for Automotive Radar Sensors in the 77 GHz Frequency Band", "venue": "IEEE Transactions on Microwave Theory and Techniques", "year": 2012 }, { "abstract": "A radar system with an ultra wide FMCW ramp bandwidth of 25.6 GHz (32% around a center frequency of 80 GHz is presented. The system is based on a monostatic fully integrated SiGe transceiver chip, which is stabilized using conventional fractional N PLL chips at a reference frequency of 100 MHz. The achieved in loop phase noise is 88 dBc/Hz (10 kHz offset frequency) for the center frequency and below 80 dBc/Hz in the wide frequency band of 25.6 GHz for all offset frequencies ;1 kHz. The ultra wide PLL stabilization was achieved using a reverse frequency position mixer in the PLL (offset PLL) resulting in a compensation of the variation of the oscillators tuning sensitivity with the variation of the N divider in the PLL. The output power of the transceiver chip, as well as of the mm wave module (containing a waveguide transition) is sufficiently flat versus the output frequency (variation ;3 dB) In radar measurements using the full bandwidth an ultra high spatial resolution of 7.12 mm was achieved. The standard deviation between repeated measurements of the same target is 0.36 mm.", "author_names": [ "Nils Pohl", "Timo Jaeschke", "Klaus Aufinger" ], "corpus_id": 15180486, "doc_id": "15180486", "n_citations": 194, "n_key_citations": 11, "score": 0, "title": "An Ultra Wideband 80 GHz FMCW Radar System Using a SiGe Bipolar Transceiver Chip Stabilized by a Fractional N PLL Synthesizer", "venue": "IEEE Transactions on Microwave Theory and Techniques", "year": 2012 }, { "abstract": "Nowadays emerging industrial radar applications demand for high resolution, high precision and at the same time low cost radar sensors. Recent advances in semiconductor technology allow highly integrated radar sensors at frequencies up to several hundred GHz in mass production suitable and cost effective SiGe bipolar technologies. In this contribution, a SiGe MMIC based 240 GHz radar sensor with more than 60GHz bandwidth is presented. It consists of a MMIC chip including the high frequency components and a digital control module with the PLL stabilisation, ramp generation, and data acquisition. The antenna is realized by on chip patch antennas, which are focused by using an additional dielectric lens. The radar allows fast and highly linear frequency sweeps from 204 GHz to 265 GHz with an maximum output power of 1dBm EIRP (patch only) A phase noise of 65 dBc/Hz >1 kHz offset) is achieved over the complete tuning range. Additionally range profile, jitter and imaging measurements are presented to demonstrate the achieved system performance.", "author_names": [ "Timo Jaeschke", "Christian Bredendiek", "Nils Pohl" ], "corpus_id": 22086629, "doc_id": "22086629", "n_citations": 69, "n_key_citations": 3, "score": 0, "title": "A 240 GHz ultra wideband FMCW radar system with on chip antennas for high resolution radar imaging", "venue": "2013 IEEE MTT S International Microwave Symposium Digest (MTT)", "year": 2013 }, { "abstract": "The design and measured results of a single substrate transceiver module suitable for 76 77 GHz pulsed Doppler radar applications are presented. Emphasis on ease of manufacture and cost reduction of commercial millimeter wave systems is employed throughout as a design parameter. The importance of using predictive modeling techniques in understanding the robustness of the circuit design is stressed. Manufacturing techniques that conform to standard high volume assembly constraints have been used. The packaged transceiver module, including three waveguide ports and intermediate frequency output, measures 20 mm/spl times/22 mm/spl times/8 mm. The circuit is implemented using discrete GaAs/AlGaAs pseudomorphic high electron mobility transistors (pHEMTs) GaAs Schottky diodes, and varactor diodes, as well as GaAs p i n and pHEMT monolithic microwave integrated circuits mounted on a low cost 127 /spl mu/m thick glass substrate. A novel microstrip to waveguide transition is described to transform the planar microstrip signal into the waveguide launch. The module is integrated with a quasi optical antenna. The measured performance of both the component parts and the complete radar transceiver module is described.", "author_names": [ "Ian Gresham", "Nitin Jain", "Thomas P Budka", "Angelos Alexanian", "Noyan Kinayman", "B A Ziegner", "S Brown", "Peter W Staecker" ], "corpus_id": 15179021, "doc_id": "15179021", "n_citations": 143, "n_key_citations": 3, "score": 0, "title": "A compact manufacturable 76 77 GHz radar module for commercial ACC applications", "venue": "", "year": 2001 }, { "abstract": "The proliferation of mobile computing devices and local area wireless networks has fostered a growing interest in location aware systems and services. In this paper we present RADAR, a radio frequency (RF) based system for locating and tracking users inside buildings. RADAR operates by recording and processing signal strength information at multiple base stations positioned to provide overlapping coverage in the area of interest. It combines empirical measurements with signal propagation modeling to determine user location and thereby enable location aware services and applications. We present experimental results that demonstrate the ability of RADAR to estimate user location with a high degree of accuracy.", "author_names": [ "Paramvir Bahl", "Venkata N Padmanabhan" ], "corpus_id": 7965352, "doc_id": "7965352", "n_citations": 8390, "n_key_citations": 935, "score": 0, "title": "RADAR: an in building RF based user location and tracking system", "venue": "Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064)", "year": 2000 }, { "abstract": "In this paper, a miniaturized D band frequency modulated continuous wave (FMCW) radar sensor with 48 GHz bandwidth (32.8% 122 170 GHz) and a high measurement rate of 1 kHz for multi target vibration measurements is presented. The sensor is based on a SiGe transceiver monolithic microwave integrated circuit manufactured via Infineon's B7HF200 bipolar production technology with an fT of 170 GHz and fmax of 250 GHz. Gilbert cell, push pull, and varactor based doubler concepts on manufactured chips are compared, and the most promising signal source is embedded into a transceiver chip, which forms the main component of the presented radar sensor. The maximum output power of the system is 10 dBm and a phase noise of 80 dBc/Hz is achieved. Measurements are provided to demonstrate the sensor characteristics and show the promising results of FMCW radar in highest precision distance and multi target vibration measurement applications. Due to the covered wide bandwidth, a range resolution of 5.88 mm is achieved 6 dB width, Tukey window) The sensor's distance measurement repeatability is 290 nm (65 nm with 10 x averaging and 0.5 m target distance) and the distance measurement accuracy is m for a target in 65 cm distance moving 1 cm. Additionally, vibration measurement results and range Doppler plots for advanced multi target applications are presented.", "author_names": [ "Timo Jaeschke", "Christian Bredendiek", "Simon Kuppers", "Nils Pohl" ], "corpus_id": 14402718, "doc_id": "14402718", "n_citations": 98, "n_key_citations": 4, "score": 0, "title": "High Precision D Band FMCW Radar Sensor Based on a Wideband SiGe Transceiver MMIC", "venue": "IEEE Transactions on Microwave Theory and Techniques", "year": 2014 } ]

[ { "abstract": "The power conversion efficiencies of single junction III V solar cells based on InGaP, GaAs, InGaAsP, and InGaAs for wireless power transmission were investigated by varying the wavelength and incident power of a laser diode. The GaAs solar cell exhibited the highest conversion efficiency of 52.7% at a laser wavelength of 824 nm and a laser beam irradiance of 4 suns. For each solar cell, the conversion efficiency peaked at an optimal incident laser wavelength and this effect was examined in detail. It was found that the conversion efficiency is maximal when the laser photon energy is 80 100 meV higher than the bandgap of the semiconductor material.", "author_names": [ "Ryota Jomen", "Fumiaki Tanaka", "Toshiki Akiba", "Mitsutaka Ikeda", "Kosei Kiryu", "Mikiya Matsushita", "Hiroyasu Maenaka", "Pan Dai", "Shulong Lu", "Shiro Uchida" ], "corpus_id": 116470468, "doc_id": "116470468", "n_citations": 11, "n_key_citations": 0, "score": 1, "title": "Conversion efficiencies of single junction III V solar cells based on InGaP, GaAs, InGaAsP, and InGaAs for laser wireless power transmission", "venue": "", "year": 2018 }, { "abstract": "We demonstrate efficient generation of terahertz (THz) frequency radiation by pulsed excitation, at wavelengths between 800 and 1550 nm, of photoconductive (PC) switches fabricated using Fe doped InGaAsP wafers, grown by metal organic chemical vapor deposition (MOCVD) Compared to our previous studies of Fe doped InGaAs wafers, Fe:InGaAsP wafers exhibited five times greater dark resistivity to give a value of 10 kO cm, and Fe:InGaAsP PC switches produced five times higher THz power emission. The effect of Fe doping concentration (between 1E16 and 1.5E17 cm 3) on optical light absorption (between 800 and 1600 nm) on resistivity, and on THz emission is also discussed.", "author_names": [ "O Hatem", "Joshua R Freeman", "John E Cunningham", "P J Cannard", "Michael James Robertson", "Edmund H Linfield", "A G Davies", "David Graham Moodie" ], "corpus_id": 13868049, "doc_id": "13868049", "n_citations": 21, "n_key_citations": 0, "score": 0, "title": "Generation of Terahertz Radiation from Fe doped InGaAsP Using 800 nm to 1550 nm Pulsed Laser Excitation", "venue": "", "year": 2016 }, { "abstract": "915nm high power and high reliability single emitter laser diodes based on Asymmetric Decoupled Confinement Heterostructure (ADCH) are demonstrated. Advantage of ADCH is that it can optimize active layer confinement and confinement ratio of p to n doped layer (p/n) independently, to manage large effective spot size and low internal loss without any penalty in carrier confinement. 4mm cavity, 100m wide stripe LDs with large effective spot size of 1.5m demonstrates record high Catastrophic optical damage (COD) free operation over 42W output. Accelerated aging tests are conducted for 325 devices in total with 1.8 million device hours. Mean time to failure of random failure mode is estimated to be 1.1 million hours for 12W at room temperature.", "author_names": [ "Yuji Yamagata", "Yumi Yamada", "Masanori Muto", "Syunta Sato", "Ryozaburo Nogawa", "Akira Sakamoto", "Masayuki Yamaguchi" ], "corpus_id": 123041783, "doc_id": "123041783", "n_citations": 22, "n_key_citations": 0, "score": 0, "title": "915nm high power broad area laser diodes with ultra small optical confinement based on Asymmetric Decoupled Confinement Heterostructure (ADCH)", "venue": "Photonics West Lasers and Applications in Science and Engineering", "year": 2015 }, { "abstract": "A buried ridge stripe (BRS) structure InGaAsP Si hybrid laser based on selective area metal bonding (SAMB) method is demonstrated. This novel hybrid laser structure combines the SAMB method's advantage of low bonding requirements and great flexibility and the BRS lasers' low threshold, high thermal performance, and good optical field and carrier confinement. The 300 \\mu m long hybrid laser has a threshold current of 14 mA and a maximum single facet output power of 5.4 mW at room temperature, with a slope efficiency of 0.17 W/A. The laser has a characteristic temperature of 50 K, with continuous wave operation at temperature >50 degC.", "author_names": [ "Lijun Yuan", "Li Tao", "Weixi Chen", "Yanping Li", "Dan Lu", "Song Liang", "Hongyan Yu", "Guangzhao Ran", "Jiao-qing Pan", "Wei Wang" ], "corpus_id": 13592601, "doc_id": "13592601", "n_citations": 13, "n_key_citations": 1, "score": 0, "title": "A Buried Ridge Stripe Structure InGaAsP Si Hybrid Laser", "venue": "IEEE Photonics Technology Letters", "year": 2015 }, { "abstract": "A 1.55 <formula formulatype=\"inline\"<tex Notation=\"TeX\"\\mu{\\rm m}/tex>/formula> InGaAsP Si hybrid laser operating at 10<formula formulatype=\"inline\"<tex Notation=\"TeX\"\\circ}\\rm C}/tex>/formula> under continuous wave operation is fabricated using a selective area metal bonding method with AuGeNi/Au on InGaAsP gain structure as both cathode and bonding metal and AuSn on silicon on insulator (SOI) as bonding metal. The maximum single facet output power is 9 mW. The slope efficiency of the hybrid laser is 0.04 W/A, four times that of the laser before bonding. A semi insulating InP:Fe buried heterostructure laser is flip chip bonded onto an SOI waveguide. The light generated in the active area is evanescently coupled into the silicon waveguide. The simplicity and flexibility of the fabrication process and high yield make the hybrid laser a promising light source.", "author_names": [ "Lijun Yuan", "Li Tao", "Hongyan Yu", "Weixi Chen", "Dan Lu", "Yanping Li", "Guangzhao Ran", "Jiao-qing Pan" ], "corpus_id": 2409466, "doc_id": "2409466", "n_citations": 23, "n_key_citations": 0, "score": 0, "title": "Hybrid InGaAsP Si Evanescent Laser by Selective Area Metal Bonding Method", "venue": "IEEE Photonics Technology Letters", "year": 2013 }, { "abstract": "A passively mode locked extended cavity quantum well ring laser at 1.58 mm with repetition rate of 2.5 GHz in the form of a photonic integrated circuit is presented. The device is realized using InP based active passive integration technology. The 33mm long cavity contains gain, saturable absorption and passive waveguide sections as well as a phase shifter sections to enable fine tuning of the spectral position of the lasing modes. Passive mode locked operation and with wavelength tuning of the laser modes are experimentally demonstrated. This laser is the lowest reported repetition rate for a monolithically integrated ring laser.", "author_names": [ "Sylwester Latkowski", "V Moskalenko", "Saeed Tahvili", "Meint Smit", "Erwin Bente", "Luc M Augustin" ], "corpus_id": 7302180, "doc_id": "7302180", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Monolithic 2.5 GHz Quantum Well InGaAsP Extended Cavity Modelocked Ring Laser with an Integrated Phase Modulator", "venue": "2014 International Semiconductor Laser Conference", "year": 2014 }, { "abstract": "", "author_names": [ "Mohammad Nasir Uddin", "Takaaki Kizu", "Yasuhiro Hinokuma", "Kazuhiro Tanabe", "Akio Tajima", "Kazutoshi Kato", "Kiichi Hamamoto" ], "corpus_id": 35100139, "doc_id": "35100139", "n_citations": 7, "n_key_citations": 1, "score": 0, "title": "Split pump region in 1.55 mm InGaAsP/InGaAsP asymmetric active multi mode interferometer laser diode for improved modulation bandwidth", "venue": "IEICE Trans. Electron.", "year": 2014 }, { "abstract": "A 1.5 m.m InGaAsP/ITO/Si hybrid laser with indium tin oxide (ITO) as both a cathode and a light coupling material is presented. The InGaAsP gain structure with a transparent ITO cathode is flip chip bonded onto a patterned silicon on insulator wafer. The light generated in the InGaAsP multiquantum wells is coupled through the ITO cathode into the Si waveguide to form an InGaAsP/ITO/Si hybrid laser. The threshold current density of this hybrid laser is 20 kA/cm2 at 210 K. Due to the advantages of post bonding and simplicity of the fabrication process, such a hybrid laser may be a promising Si light source.", "author_names": [ "Tao Hong", "Yan-ping Li", "Wei-xi Chen", "Guangzhao Ran", "Guogang Qin", "Hongliang Zhu", "Song Liang", "Y Wang", "Jiao-qing Pan", "Wei Wang" ], "corpus_id": 2316354, "doc_id": "2316354", "n_citations": 21, "n_key_citations": 1, "score": 0, "title": "Bonding InGaAsP/ITO/Si Hybrid Laser With ITO as Cathode and Light Coupling Material", "venue": "IEEE Photonics Technology Letters", "year": 2012 }, { "abstract": "In spite of many years of research, the quantum well intermixing technique has not been able to deliver multibandgap III V semiconductor wafers at highly attractive costs. We report that UV laser irradiation of InGaAs/InGaAsP/InP quantum well (QW) microstructures in deionized water and rapid thermal annealing (RTA) allows achieving, mask free, wafers with blueshifted photoluminescence (PL) emission of intensity exceeding almost 10x that of the RTA only wafers. Our calculations indicate that a ~40 nm thick InOx layer formed on top of the investigated microstructure induces compressive strain in the QW region and leads to this record high enhanced PL amplitude. (Some figures may appear in colour only in the online journal) The selective area control of the bandgap of semiconductor wafers is one of the key factors in the development of photonic integrated circuits (PICs) (Estrella et al 2012) Post growth quantum well intermixing (QWI) has been reported as a relatively simple and potentially cost effective method allowing area selective bandgap tuning of Si/Si1 xGex (Dubowski et al 1999) and III V quantum well (QW) wafers (Skogen et al 2005, Genest et al 2008, Xu and Mei 2009,", "author_names": [ "Neng Liu", "Suzie Poulin", "Jan J Dubowski" ], "corpus_id": 119772239, "doc_id": "119772239", "n_citations": 8, "n_key_citations": 2, "score": 0, "title": "Enhanced photoluminescence emission from bandgap shifted InGaAs/InGaAsP/InP microstructures processed with UV laser quantum well intermixing", "venue": "", "year": 2013 }, { "abstract": "Large bandgap blueshifts in III V quantum semiconductor microstructures are achievable with UV laser induced quantum well intermixing (QWI) We report on the application of the UV laser QWI technique to investigate bandgap engineering of a compressively strained InGaAsP/InP quantum well laser microstructure. The attractive performance of the technique, determined by the ability of a laser to generate point defects, has been demonstrated with bandgap blueshifts reaching 142 nm, with enhancement of photoluminescence intensity. We have also investigated this technique for post growth wafer level processing designed for the fabrication of laser diodes.", "author_names": [ "Mohammad Kaleem", "Xin Zhang", "Yuan Zhuang", "Jian-jun He", "Neng Liu", "Jan J Dubowski" ], "corpus_id": 122941904, "doc_id": "122941904", "n_citations": 8, "n_key_citations": 1, "score": 0, "title": "UV laser induced selective area bandgap engineering for fabrication of InGaAsP/InP laser devices", "venue": "", "year": 2013 } ]

[ { "abstract": "This updated version of its internationally popular predecessor provides and introductory problem solved text for understanding fundamental concepts of electronic devices, their design, and their circuitry. Providing an interface with Pspice, the most widely used program in electronics, new key features include a new chapter presenting the basics of switched mode power supplies, thirty one new examples, and twenty three PS solved problems. Table of contents Circuit Analysis: Port Point of ViewSemiconductor DiodesCharacteristics of Bipolar Junction TransistorsCharacteristics of Field Effect Transistors and TriodesTransistor Bias ConsiderationsSmall Signal Midfrequency BJT AmplifiersSmall Signal Midfrequency FET AmplifiersFrequency Effects in AmplifiersOperational AmplifiersSwitched Mode Power Supplies", "author_names": [ "Jimmie J Cathey" ], "corpus_id": 64101465, "doc_id": "64101465", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Schaum's Outline of Electronic Devices and Circuits, Second Edition", "venue": "", "year": 2002 }, { "abstract": "Easy Outlines are concise, easy to use versions of the biggest and best selling classics in the Schaum's Outlines series. This is a continuation of the Schaum's Easy Outline Series, successfully launched in 1999. Every book in the series is a pared down, simplified, and tightly focused version of a top selling Schaum's Outline. In the aggregate, these titles have sold more than 4,000,000 copies. Format will be streamlined and updated for a contemporary look and feel Each book will extract the absolute essence of the subject, presenting it in concise and readily understandable form, emphasizing clarity and brevity Graphic elements like sidebars, reader alert icons, and boxed highlights will feature selected points from the text, emphasizing keys to learning and giving students quick pointers to the essentials", "author_names": [ "William Alan Bartley", "Dominick Salvatore", "Eugene A Diulio" ], "corpus_id": 60384893, "doc_id": "60384893", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Principles of economics based on Schaum's outline of theory and problems of principles of economics, second edition, by Dominick Salvatore and Eugene Diulio", "venue": "", "year": 2003 }, { "abstract": "You can catch up on the latest developments in the number one, fastest growing programming language in the world with this fully updated Schaum's guide. Schaum's Outline of Data Structures with Java has been revised to reflect all recent advances and changes in the language. Table of contents Chapter 1. Advanced Java Chapter 2. Object Oriented Programming Chapter 3. Abstract Data Types Chapter 4. Generics in java Chapter 5. Linked Structures Chapter 6. Stacks Chapter 7. Queues Chapter 8. Collections Chapter 9. Lists Chapter 10. Hash Tables Chapter 11. Recursion Chapter 12. Trees Chapter 13. Binary Trees Chapter 14. Search Trees Chapter 15. Heaps and Priority Queues Chapter 16. Sorting Chapter 17. Sets Chapter 18. Graphs", "author_names": [ "J Richard Hubbard" ], "corpus_id": 63455217, "doc_id": "63455217", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Schaum's Outline of Data Structures with Java, Second Edition", "venue": "", "year": 2007 }, { "abstract": "Chapter 1 Carbohydrates Chapter 2 Amino Acids and Peptide Chapter 3 Proteins Chapter 4 Proteins: Supramolecular Structure Chapter 5 Lipids, Membranes, Transport, and Signalling Chapter 6 Nucleic Acids Chapter 7 Enzyme Catalysis and Kinetics Chapter 8 Metabolism: Underlying Theoretical Principles Chapter 9 Carbohydrate Metabolism Chapter 10 The Citric Acid Cycle Chapter 11 Lipid Metabolism Chapter 12 Oxidative Phosphorylation Chapter 13 Nitrogen Metabolism Chapter 14 Replication and Maintenance of the Genetic Material Chapter 15 Gene Expression and Protein Synthesis", "author_names": [ "Katherine E Cullen" ], "corpus_id": 83139883, "doc_id": "83139883", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Biochemistry based on Schaum's outline of biochemistry, second edition, by Philip W. Kuchel, Ph.D. and Gregory B. Ralston, Ph.D. [and others]", "venue": "", "year": 2003 }, { "abstract": "Schaum's outline of theory and problems of differnetial and integral. Schaum's outline of theory and problems of differnetial and integral. khtbkhnh dyjytly dnshgh `lwm pzshkhy w khdmt drmny shhyd bhshty", "author_names": [ "First and second editions by Frank Ayers" ], "corpus_id": 208972761, "doc_id": "208972761", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Schaum's outline of theory and problems of differnetial and integral.", "venue": "", "year": 2016 }, { "abstract": "More than 44,000 copies sold of second edition More than 230,000 students are enrolled in trigonometry courses Required study for all mathematics majors Hundreds of practical problems solved step by step Complements most popular textbooks", "author_names": [ "Frank Ayres", "Robert E Moyer" ], "corpus_id": 118335815, "doc_id": "118335815", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Schaum's Outline of Theory and Problems of Trigonometry", "venue": "", "year": 1990 }, { "abstract": "From the Publisher: Programming with C+,Second Edition,is an update of the highly successful first editiona bestseller in Schaum's computer science lineand reflects the new ISO standard for C+,rendering previous C+ guides obsolete. Essential for programmers,280,000 computer science students taking first level classes,and thousands of advanced placement students,this book is the perfect supplement to the leading textbooks in introductory and higher level programming courses. Master programming with C+ with Schaum'sthe high performance study guide. It will help you cut study time,hone problem solving skills,and achieve your personal best on exams and projects! Students love Schaum's Outlines because they produce results. Each year,hundreds of thousands of students improve their test scores and final grades with these indispensable study guides. Get the edge on your classmates. Use Schaum's! If you don't have a lot of time but want to excel in class,use this book to: brush up before tests; find answers fast; study quickly and more effectively; get the big picture without poring over lengthy textbooks. Schaum's Outlines give you the information your teachers expect you to know in a handy and succinct formatwithout overwhelming you with unnecessary detail. You get a complete overview of the subject. Plus,you get plenty of practice exercises to test your skill. Compatible with any classroom text,Schaum's Outlines let you study at your own pace and remind you of all the important facts you need to rememberfast! And Schaum's Outlines are so complete,they're perfect for preparing for graduate or professional exams.Inside,you will find: Full coverage of Computer Science I II,using the computing language taught by 83% of all colleges; Simplified explanations of recursion,logic,polymorphism,algorithms,and more; 470 solved problems in computer science,including step by step annotations; Examples and worked problems that help you master programming with C+ If you want top grades and a thorough understanding of programming with C+,this powerful study tool is the best tutor you can have!", "author_names": [ "J Richard Hubbard" ], "corpus_id": 62235127, "doc_id": "62235127", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Schaum's Outline Programming with C+", "venue": "", "year": 1996 }, { "abstract": "", "author_names": [ "Dominick Salvatore", "Eugene A Diulio" ], "corpus_id": 201580556, "doc_id": "201580556", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "EBOOK Based on SChaum s Outline of Theory and Problems of Principles of Economics (Second Edition)", "venue": "", "year": 2003 }, { "abstract": "Algebra, 3rd Edition PDF Semantic Scholar Abstract Algebra, 3rd Edition A First Course in Abstract Algebra (3rd Edition) A Plus Notes for Beginning Algebra: Pre Algebra and Algebra 1 Applied Abstract Algebra with MapleTM and MATLABA(r) Third Edition: A Maple and MATLAB Approach, Third Edition (Textbooks in Mathematics) A Book of Abstract Algebra: Second Edition (Dover Books on Linear Algebra Abridged Linear Algebra Abridged is generated from Linear Algebra Done Right (by Sheldon Axler, third edition) by excluding all proofs, examples, and exercises, along with most comments The full version of Linear Algebra Done Right is available at springercom and amazoncom in both printed and electronic forms Linear Algebra Joshua vector spaces, linear maps, determinants, and eigenvalues and eigenvectors Another standard is book's audience: sophomores or juniors, usually with a background of at least one semester of calculus First Course In Abstract Algebra PDF me that Fraleigh has been teaching a course very similar to mine, to students very similar to mine, out Fraliegh 10 1 in all things Linear Algebra However, I'd say the first 250 pages of \"Topics in MATLABA(r) Third Edition: A Maple and MATLAB Approach, Third Edition (Textbooks in Mathematics) A Book of Abstract Algebra 2nd Second Download A First Course in Abstract Algebra, John B A first course in linear algebra with optional introduction to groups, rings, and fields, Raymond A Beauregard, John B Fraleigh, Feb 1, 1973, Mathematics, 410 pages Considered a classic by many, A First Course in Abstract Algebra, Seventh EditionEURis an in depth MATHEMATICS 131 LINEAR ALGEBRA I Text: Linear Algebra MATHEMATICS 131 LINEAR ALGEBRA I Text: Linear Algebra, Third Edition, by J Fraleigh and R Beauregard Instructor: Zhuang dan Daniel Guan Class: MWF 110{200pm, SPTH 1222 First Class: March 29, Monday O ce Hours: TTH 230{400pm, Surge 237 An introduction to vector spaces, matrices, and solutions of systems of linear equations 1.1 SOLUTIONS suumsvaagmn Nov 03, 2011 6 CHAPTER 1 Linear Equations in Linear Algebra 25 14 7 1 4 7 1 4 7 0 3 5 ~035 ~0 3 5 25 9 0 3 5 2 0 0 0 2 gg g hh h kkg kgh Let b denote the number k 2g hThen the third equation represented by the augmented matrix above Schaum's Outline of Linear Algebra Linear algebra has in recent years become an essential part of the mathematical background required by mathematicians and mathematics teachers,", "author_names": [], "corpus_id": 214591737, "doc_id": "214591737", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Linear Algebra Third Edition Fraleigh", "venue": "", "year": 2020 }, { "abstract": "From the Book: Two years ago, Addison Wesley approached me to write a book about the then new UML. At that time, there was a lot of interest in the UML, but only a standards document from which to learn about it. We broke many records to quickly produce a short introductory guide to the new UML, something that would provide some guidance until the more detailed and official books were to appear later that year. We didnit expect this book to last after more detailed books appeared. Most people believed that given the choice between a slim overview and a detailed text, everyone would pick the detailed text. Although that was the general view, I believed that even in the presence of detailed books, there was still room for a concise summary. Two years later, my hopes have been realized more than I could have wished. UML Distilled has been, in computer industry terms, a best seller. Even though good detailed books have appeared on the UML, the book still sells well. Better than that, more slim books have appeared, confirming my belief that in a world with so much information, there is value in well chosen brevity. Now, thatis all very well, but should you buy this book? Iim going to assume youive heard about the UML. It has become the standard way to draw diagrams of object oriented designs, and it has also spread into non OO fields. The major pre UML methods have all died out. The UML has arrived and ishere to stay. If you want to learn about the UML, this book is one way to do it. The main reason for starting with this book is that itis a small book. Buying a big book will give you more information, but it will also take you longer to read. Iive selected the most important parts of the UML so that you donit have to. With this book, youill pick up the key elements of the notation and what they mean. If you want to move further, you can move to a more detailed book later. If you want a longer tutorial to the UML, I suggest the Unified Modeling Language User Guide (Booch, Rumbaugh, and Jacobson 1999) The User Guide is able to cover a lot more ground. Itis well written and organized in a way that explains how to apply the UML to various modeling problems. Both this book and the User Guide assume that you know something about OO development. Although many people have told me that this book is a good introduction to objects, I didnit write it with that in mind. If youire looking for an introduction to objects with the UML, you should also consider Craig Larmanis book (Larman 1998) Although the main point of this book is the UML, Iive also added material that complements the UML material. The UML is a relatively small part of what you need to know to succeed with objects, and I think that itis important to point out some of the other things here. The most important of these is software process. The UML is designed to be independent of process. You can do anything you like; all the UML does is say what your diagrams mean. However, the diagrams donit make much sense without a process to give them context. I also believe that process is important and that a good process doesnit need to be complicated. So, Iive described a lightweight outline process for OO software development. This provides a context for the techniques and will help to get you going in using objects. The other topics include patterns, refactoring, self testing code, design by contract, and CRC cards. None of these are part of the UML, yet they are valuable techniques that I use regularly. Structure of the Book Chapter 1 looks at what the UML is, the history of its development, and the reasons why you might want to use it. Chapter 2 discusses the object oriented development process. Although the UML exists independent of process, I find it hard to discuss modeling techniques without talking about where they fit in with object oriented development. Chapters 3 through 6 discuss the three most important techniques in the UML: use cases, class diagrams, and interaction models. The UML is a large beast, but you donit need all of it. These three techniques are the core that almost everyone needs. Start with these and add the others as you need them. (Note that since class diagrams are so complicated in themselves, Iive put the key parts of class diagrams in Chapter 4 and the advanced concepts in Chapter 6. Chapters 7 through 10 explore the remaining techniques. All of these are valuable, but not every project needs every technique. So these chapters provide enough information to tell you what the technique is and whether you need it. For all of these techniques, I describe the notation, explain what the notation means, and provide tips about using the techniques. My philosophy is to make clear what the UML says and, at the same time, to give you my opinions on how best to use it. Iive also added pointers to other books that provide more detail. Chapter 11 gives a small example to show how the UML fits in with programming using (of course) Java. The inside covers summarize the UML notation. You may find it useful to refer to these as you are reading the chapters so that you can check on the notation for the various modeling concepts. If you find this book interesting, you can find other information on my work related to using the UML, patterns, and refactoring at my home page (see page xxi) Changes for the Second Edition As the UML evolved, and I received feedback about the first edition of the book, I continually updated it. We reprinted every two or three months; nearly every printing contained updates, which resulted in considerable strain on the processes of the publishing industry. With the change from UML 1.2 to 1.3, we decided to do a more thorough overhaul of the book, enough to produce a second edition. Since the book has been so popular, Iive tried not to change the essential spirit of the book. Iive carefully tried to not add much, and to see whether there are things I can take away. The biggest changes are in Chapter 3, about use cases, and Chapter 9, about activity diagrams, which have each received a severe rewrite. Iive also added a section on collaborations to Chapter 7. Elsewhere, Iive taken the opportunity to make a host of smaller changes, based on feedback and my experiences over the last couple of years. Martin Fowler Melrose, Massachusetts April 1999 [email protected] http:/ourworld.compuserve.com/homepages/Martin_Fowler", "author_names": [ "Martin Fowler", "Kendall V Scott" ], "corpus_id": 31426402, "doc_id": "31426402", "n_citations": 835, "n_key_citations": 28, "score": 1, "title": "UML distilled a brief guide to the Standard Object Modeling Language (2. ed.", "venue": "notThenot Addison Wesley object technology series", "year": 2000 } ]

[ { "abstract": "In spite of recent significant research into various two dimensional (2D) materials after the emergence of graphene, the development of a new 2D material that provides both high mobility and an appropriate energy band gap (which are crucial for various device applications) remains elusive. In this report, we demonstrate that the carrier transport behaviour of 2D Ti2CTx, which belongs to the family of 2D transition metal carbides and nitrides, can be tuned by modifying the surface group Tx OH, F, and O) Our results show that 2D Ti2C(OH)xFy and Ti2COx films can be obtained via simple chemical treatment, thermal annealing, and mechanical exfoliation processes. For the first time, we study the carrier transport properties of 2D Ti2CTx field effect transistors (FETs) obtaining the high field effect carrier mobilities of 10(4) cm(2) V( 1) s( 1) at room temperature. The temperature dependent resistivity of the Ti2COx film exhibits semiconductor like Arrhenius behaviour at zero gate voltage, from which we estimate the energy gap of 80 meV. One interesting feature of the FETs based on transition metal carbides is that the field effect mobility at room temperature is less sensitive to the measured transport gaps, which may arise from the dominant charge transport of activated carriers over the narrow energy gaps of the transition metal carbides. Our results open up the possibility that new 2D materials with high mobilities and appropriate band gaps can be achieved, and broaden the range of electronic device applications of Ti2CTx films.", "author_names": [ "Shen Lai", "Jaeho Jeon", "Sung Kyu Jang", "Jiao Xu", "Young Jin Choi", "Jin-Hong Park", "Euyheon Hwang", "Sungjoo Lee" ], "corpus_id": 205983562, "doc_id": "205983562", "n_citations": 134, "n_key_citations": 0, "score": 2, "title": "Surface group modification and carrier transport properties of layered transition metal carbides (Ti2CT(x) T: OH, F and O)", "venue": "Nanoscale", "year": 2015 }, { "abstract": "Correction for 'Surface group modification and carrier transport properties of layered transition metal carbides (Ti2CTx, T: OH, F and O) by Shen Lai, et al. Nanoscale, 2015, DOI: 10.1039/c5nr06513e.", "author_names": [ "Shen Lai", "Jaeho Jeon", "Sung Kyu Jang", "Jiao Xu", "Young Jin Choi", "Jin-Hong Park", "Euyheon Hwang", "Sungjoo Lee" ], "corpus_id": 205988947, "doc_id": "205988947", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Correction: Surface group modification and carrier transport properties of layered transition metal carbides (Ti2CT(x) T: OH, F and O)", "venue": "Nanoscale", "year": 2016 }, { "abstract": "An acetylcholinesterase biosensor modified with graphene and transition metal carbides was prepared to detect organophosphorus pesticides. Cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy were used to characterize the electrochemical catalysis of the biosensor: acetylcholinesterase/chitosan transition metal carbides/graphene/glassy carbon electrode. With the joint modification of graphene and transition metal carbides, the biosensor has a good performance in detecting dichlorvos with a linear relationship from 11.31 mM to 22.6 nM and the limit of detection was 14.45 nM. Under the premise of parameter optimization, the biosensor showed a good catalytic performance for acetylcholine. Compared to the biosensors without modification, it expressed a better catalytic performance due to the excellent electrical properties, biocompatibility and high specific surface area of graphene, transition metal carbides. Finally, the biosensor exhibits good stability, which can be stored at room temperature for one month without significant performance degradation, and has practical potential for sample testing.", "author_names": [ "Bo Wang", "Yiru Li", "Huaying Hu", "Wenhao Shu", "Lianqiao Yang", "Jianhua Zhang" ], "corpus_id": 217547844, "doc_id": "217547844", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Acetylcholinesterase electrochemical biosensors with graphene transition metal carbides nanocomposites modified for detection of organophosphate pesticides", "venue": "PloS one", "year": 2020 }, { "abstract": "With the advantages of zero carbon emission and high gravimetric energy density, hydrogen energy is recognized as a primary choice for the future energy supply. Electrochemical water splitting provides a promising strategy for effective and sustainable hydrogen production through renewable electricity, and one of the immediate challenges toward its large scale application is the availability of low cost and efficient electrocatalysts for the hydrogen evolution reaction (HER) Given the enormous effort in the exploration of potential transition metal carbide (TMC) electrocatalysts, the aim of this review is to summarise the recent advances in preparation and modification of TMC electrocatalysts. Special attention is focused on nanostructuring, hybridization and heteroatom doping that can regulate the surface properties of TMC electrocatalysts to improve catalytic performance. Additionally, the perspectives for the development of novel efficient TMC based catalysts are also proposed.", "author_names": [ "Han Zhang", "Xiao-Hui Yang", "Huijuan Zhang", "Jin-Ling Ma", "Zhengyong Huang", "Juan Li" ], "corpus_id": 226948139, "doc_id": "226948139", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Recent advances in transition metal carbides: from controlled preparation to hydrogen evolution reaction application.", "venue": "Chemistry", "year": 2020 }, { "abstract": "The development of renewable energy conversion and storage devices, aiming at high efficiency, stable operation, environmental friendliness, and low cost goals, provides a promising approach to resolve the global energy crisis. Recently, two dimensional (2D) layered materials have drawn enormous attention due to their unique layered structure and intriguing electrical characteristics, which brings the unprecedented board applications in the fields ranging from electronic, optical, optoelectronic, thermal, magnetic, quantum devices to energy storage and catalysis. Graphene based 2D layered materials show promising applications in energy storage and conversion owing to their high specific surface area, which have been used for supercapacitor electrode materials based on the electrical double layer capacitance model. However, graphene has a limited value of theoretical electrical double layer capacitance when the whole surface area is fully utilized. Among several classes of 2D layered materials beyond graphene, transition metal dichalcogenides, transition metal carbides, and nitrides may exhibit excellent electrochemical properties due to the distinctive features of these 2D materials, such as large specific surface area, good hydrophilic nature, highly exposed active edge sites, and ease of intercalation and modification. Therefore, careful design and construction of these 2D compounds make them become potential candidates used for electrochemical supercapacitors and electrocatalytic hydrogen evolution. This review emphasizes the recent important advances of the 2D layered materials composed of transition metal dichalcogenides, transition metal carbides, and nitrides for supercapacitors and electrocatalysts. Furthermore, we discuss the challenges and perspectives in this energy field in terms of the classes of two dimensional layered materials.", "author_names": [ "Shuoguo Yuan", "Sin-Yi Pang", "Jianhua Hao" ], "corpus_id": 219000985, "doc_id": "219000985", "n_citations": 35, "n_key_citations": 0, "score": 0, "title": "2D transition metal dichalcogenides, carbides, nitrides, and their applications in supercapacitors and electrocatalytic hydrogen evolution reaction", "venue": "", "year": 2020 }, { "abstract": "Two dimensional transition metal carbides and nitrides known as MXenes, with a general formula of Mn+1Xn (n 1 3) integrate the advantages of metallic conductive transition metals with large groups of carbides, nitrides, or carbonitrides. They have led to a burgeoning research interest in biomedical applications due to their ultrathin structure and fascinating physiochemical (electronic, optical, magnetic, etc. properties. In this review, we summarize recent advances in biomedical applications for MXenes. We first introduce the preparation methods and surface modifications with respect to MXenes. Their unique properties are then elaborated. Thirdly, we highlight their various biomedical applications, such as with biosensors, antibacterial materials, bioimaging probes, therapeutics, and theranostics. In the end, the current challenges and new opportunities for MXenes in regard to their biomedical applications are also discussed.", "author_names": [ "Kai Huang", "Zhongjun Li", "Jing Lin", "Gang Han", "Peng Huang" ], "corpus_id": 4941072, "doc_id": "4941072", "n_citations": 282, "n_key_citations": 3, "score": 1, "title": "Two dimensional transition metal carbides and nitrides (MXenes) for biomedical applications.", "venue": "Chemical Society reviews", "year": 2018 }, { "abstract": "The surface modification of 2D semiconducting materials, such as transition metal dichalcogenides (TMDCs) is becoming important for a diverse range of applications, such as biosensing, catalysis, energy generation and energy storage. Due to the chemical inertness of their basal plane, the surface modification of 2D TMDCs is mainly limited to their defective sites, or it requires a conversion of TMDC from its semiconducting into a metallic phase. In this work, we show that the basal plane of a 2D semiconductor molybdenum disulfide (MoS2) can be modified by electrochemical grafting of aryl diazonium salt, such as 3,5 bis(trifluoromethyl)benzenediazonium tetrafluoroborate. To investigate the applicability of this method, we perform electrografting on MoS2 nanoribbons by addressing them individually via a different electrode. High spatial selectivity of this method on the nanoscale opens the possibility for specific surface modification of neighboring 2D layers and nanostructures that are contacted by electrodes. This method could be potentially applicable to other 2D semiconducting materials that are active in the same potential window in which the electrochemical reduction of aryl diazonium salts occurs.", "author_names": [ "Martina Lihter", "Michael Graf", "Damir Ivekovi'c", "Tzu-Hsien Shen", "Yanfei Zhao", "Vasiliki Tileli", "Aleksandra Radenovic" ], "corpus_id": 220055469, "doc_id": "220055469", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Electrochemical Surface Modification of a 2D MoS2 Semiconductor", "venue": "", "year": 2020 }, { "abstract": "Abstract Two dimensional transition metal carbides and nitrides (MXenes) demonstrate excellent performances in various field as a result of their unique surface group structures and high electrical conductivity. In this work, we employ a simple strategy of surface group modification to optimize the semiconductor performance of a high conductivity Ti3C2Tx film for thermoelectric energy conversion. In the process, the hydrothermal treatment with different concentrations, temperatures, and types of alkali solutions has significant effects on the thermoelectric properties of Ti3C2Tx. As a result, the modified free standing Ti3C2Tx film maintained its originally high conductivity (1652 S cm 1) and the Seebeck coefficient is improved threefold, leading to an optimized power factor of 44.98 mW m 1K 2 at room temperature. This study provides a new method for the development of the thermoelectric performance of highly conductive MXene films.", "author_names": [ "Lan Lan Shen", "Peipei Liu" ], "corpus_id": 216286536, "doc_id": "216286536", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Surface termination modification on high conductivity MXene film for energy conversion", "venue": "", "year": 2020 }, { "abstract": "Modifying MXene surfaces Unlike graphene and transition metal dichalcogenides, two dimensional transition metal carbides (MXenes) have many surface sites that can be chemically modified. Etching of the aluminum layer of a parent MAX phase Ti3AlC2 layered material with hydrofluoric acid leads to the MXene Ti3C2 with various surface terminations. Molten salts can achieve uniform chloride terminations, but these are difficult to further modify. Kamysbayev et al. show that etching of MAX phases in molten cadmium bromide leads to bromide terminated MXenes that can then be substituted with oxygen, sulfur, selenium, tellurium, and NH groups as well as with vacancy sites. The surface groups can alter electronic transport. For example, the Nb2C MXenes exhibit surface group dependent superconductivity. Science, this issue p. 979 Substitution and elimination reactions in molten inorganic salts modified two dimensional transition metal carbide surfaces. Versatile chemical transformations of surface functional groups in two dimensional transition metal carbides (MXenes) open up a previously unexplored design space for this broad class of functional materials. We introduce a general strategy to install and remove surface groups by performing substitution and elimination reactions in molten inorganic salts. Successful synthesis of MXenes with oxygen, imido, sulfur, chlorine, selenium, bromine, and tellurium surface terminations, as well as bare MXenes (no surface termination) was demonstrated. These MXenes show distinctive structural and electronic properties. For example, the surface groups control interatomic distances in the MXene lattice, and Tin+1Cn (n 1, 2) MXenes terminated with telluride (Te2 ligands show a giant >18% in plane lattice expansion compared with the unstrained titanium carbide lattice. The surface groups also control superconductivity of niobium carbide MXenes.", "author_names": [ "Vladislav Kamysbayev", "Alexander S Filatov", "Huicheng Hu", "Xue Rui", "Francisco Lagunas", "Di Wang", "Robert F Klie", "Dmitri V Talapin" ], "corpus_id": 220327998, "doc_id": "220327998", "n_citations": 126, "n_key_citations": 2, "score": 0, "title": "Covalent surface modifications and superconductivity of two dimensional metal carbide MXenes", "venue": "Science", "year": 2020 }, { "abstract": "Abstract Two dimensional transition metal carbides and nitrides (MXene) have shown outstanding performances in electrochemical energy storage, but their investigations of both mechanical and electrochemical performance for structural power systems are lack of being discussed. In this work, modified MXene films with mechanically strong structures and high electrochemical performance are obtained via directly annealing strategies. Due to the beneficial chemical composition on the surface and the structural variation under appropriate annealing treatment conditions, the modified Ti3C2Tx MXene electrode can deliver an ultrahigh volumetric capacitance of 1590 F cm 3 with a gravimetric value of 442 F g 1 at 0.5 A g 1, a good rate capability of 1030 F cm 3 at 20 A g 1, a cycling stability with a retention of 95.4% after 5000 cycles in the acid electrolyte and a high tensile strength of 32 MPa, demonstrating its great potential as a multifunctional electrode for structural energy and power systems. The influences of different electrolytes on the intercalation induced electrochemical process of modified MXene films were also probed. Furthermore, the assembled symmetric supercapacitor with the modified Ti3C2Tx MXene film demonstrates a favorable volumetric energy density of 15.2 Wh L 1 and a power density of 204.8 W L 1.", "author_names": [ "Xin Zhao", "Zhe Wang", "Jie Dong", "Tao Huang", "Qinghua Zhang", "Lili Zhang" ], "corpus_id": 224975942, "doc_id": "224975942", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Annealing modification of MXene films with mechanically strong structures and high electrochemical performance for supercapacitor applications", "venue": "", "year": 2020 } ]

[ { "abstract": "TiO2 doped with metal atoms shows better photoconversion efficiency compared with undoped TiO2. In this work, we have calculated the electronic structure of monodoped and co doped anatase TiO2. The calculations were carried out using Quantum ESPRESSO package which implements density functional theory and pseudopotential method. Our results show that band gap reduction in doped anatase titania and it is compared with the previous work. The chosen GGA and ultrasoft pseudopotential provides better band gap reduction. In dopant case, Cu creates acceptor levels just above the valence band and shifts conduction band to 1.9eV from 2.05eV and N substitution creates donor level just below to the conduction band. The PDOS explains the impurity states created by dopants.", "author_names": [ "Arun Suresh", "N Soundararajan", "A B M Ahmed" ], "corpus_id": 137822780, "doc_id": "137822780", "n_citations": 1, "n_key_citations": 0, "score": 3, "title": "Electronic gap reduction in co doped (Cu N) anatase TiO 2 semiconductor: A DFT study", "venue": "", "year": 2014 }, { "abstract": "Abstract Substitutionally and interstitially Cu/N co doped anatase TiO 2 (101) surface is investigated by using density functional theory (DFT) calculations. The results suggest improved visible light photocatalytic activity over undoped anatase TiO 2 Sizable lattice relaxation around the dopants is observed, followed by a formation of N O bond. Depending on the local arrangement of atoms, localized states above the valence band maximum, deep into the band gap, and below the conduction band minimum are found. In addition, our calculation also predict band gap narrowing. The hybridization of the Cu 3d and N 2p states within the band gap and the other electronic and optical properties suggest a synergistic effect of the dopants in the enhancement of the visible light absorption on the (101) anatase surface.", "author_names": [ "Vasil Koteski", "Jelena Belosevic-Cavor", "Ana Umicevic", "Valentin N Ivanovski", "Dragan Toprek" ], "corpus_id": 104124930, "doc_id": "104124930", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Improving the photocatalytic properties of anatase TiO 2 (101) surface by co doping with Cu and N: Ab initio study", "venue": "", "year": 2017 }, { "abstract": "Abstract First principles calculations are performed to study the electronic and optical properties of Cu doped, N doped and (Cu+2N) co doped anatase TiO 2 Strong hybridization between Cu 3 d and N 2 p orbitals above the valence band leads to the formation of an isolated intermediate band (IB) deep in the band gap of pure TiO 2 The new energetic features, predicted by DFT, have been experimentally confirmed using UV vis NIR spectroscopy. In particular, the diffuse reflectance spectrum of the co doped TiO 2 sample shows the presence of two edges which confirm the existence of IB in the band gap. This IB in the band gap of TiO 2 is responsible for high visible light absorption through a two step optical transition between valence and conduction bands via the IB. In mono doped samples, only a reduction of the band gap is observed which is consistent with the first principles calculations. X ray photoelectron spectroscopy of mono and co doped TiO 2 samples establishes the chemical states of several atomic elements and especially clarifies the key presence of O vacancies leading to a new position of conduction band minima. The presence of broad IB and the absence of dopant energy levels close to the conduction band minimum in (Cu+2N) co doped TiO 2 qualify it to be an efficient material for photovoltaic conversion, photocatalytic water splitting, and photocatalytic degradation of pollutants.", "author_names": [ "Alpa Dashora", "Nainesh Patel", "Dushyant C Kothari", "Babu Lal Ahuja", "Antonio Miotello" ], "corpus_id": 96894379, "doc_id": "96894379", "n_citations": 58, "n_key_citations": 2, "score": 0, "title": "Formation of an intermediate band in the energy gap of TiO2 by Cu N codoping: First principles study and experimental evidence", "venue": "", "year": 2014 }, { "abstract": "Abstract Reducing the band gap of TiO 2 has a great potential in solar energy application. Among them, doping is a very effective method. We systematically study C/Ni mono doped and (Ni, C) co doped anatase TiO 2 using density functional calculations. We first optimize the geometric structures with pseudopotential plane wave approach. Then on the optimized structure, we perform band structure calculations with HSE06 hybrid functional calculation on the frame of Gaussian type of orbital. Therefore, we can obtain accurate band gaps close to experimental values if they exist at lower computation cost. Among three doped models, the Ni single doped model has the lowest impurity formation energy under reduction condition. Compared with the single doped models, (Ni, C) co doped titanium dioxide has the smallest direct band gap, and the absorption band edge shows an apparent bigger red shift. Through calculating the optical absorption spectra of several doped models in the visible light region (400 760 nm) (Ni, C) co doped model can absorb much more visible light. Thus it has a much higher photocatalytic activity.", "author_names": [ "H M Chen", "Xuechao Li", "Rundong Wan" ], "corpus_id": 136468921, "doc_id": "136468921", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Theoretical studies on the electronic structure and optical absorption property of (Ni, C) co doped anatase TiO2", "venue": "", "year": 2017 }, { "abstract": "Abstract We investigate the density of states and optical properties for Fe, 2B and (Fe, 2B) doped TiO 2 with DFT calculations. The calculated results reveal mono doping introduces midgap states which are half occupied and easy to become the recombination centers of charge carriers, thus inhibiting the enhancement of photocatalystic activity. The coupling of 2p 3d states in the (Fe, 2B) compensated co doped TiO 2 makes gap states couple with the valence bands edge, thus greatly causing the band gap narrowing and higher visible light absorption. Moreover, the gap states cannot become recombination centers of the photoexcited carriers, thus promoting the separation of electron hole pairs, prolonging the lifetime of carriers. The analysis of electron density indicates more electrons from Fe transfer to adjacent B, realizing the charge compensation and forming a stronger Fe B bond. Therefore, the (Fe, 2B) compensated co doped TiO 2 exhibits the higher visible light photocatalystic activity than those of pure and solely doped TiO 2", "author_names": [ "Xuechao Li", "Jianhao Shi", "Hao Chen", "Rundong Wan", "Chongyang Leng", "Ying Lei" ], "corpus_id": 102453374, "doc_id": "102453374", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Electronic and optical properties study on FeB co doped anatase TiO2", "venue": "", "year": 2016 }, { "abstract": "Abstract The present investigation focuses on the structural properties and magnetic response of Co, Mn and Co Mn doped TiO 2 nanoparticles (within 3% dilute doping) along with their optical and electrical studies. X ray diffraction (XRD) patterns for all these samples show the formation of tetragonal TiO 2 anatase phase with no extra impurity phases. Further, Raman bands at 143 cm 1 396 cm 1 516 cm 1 and 639 cm 1 also confirm the anatase phase in these samples. Diamagnetic response has been observed in pure TiO 2 nanoparticles. However, room temperature (RT) ferromagnetism has been observed with Co and/or Mn doping which gets enhanced further with codoping of Co ions. The observed ferromagnetism has been attributed to the formation of shallow levels with doping/codoping. The Co and/or Mn doped TiO 2 nanoparticles are referred as diluted magnetic semiconductors due to their combined semiconducting and ferromagnetic response. UV Vis spectra show the band gap of these samples are in the range of 3.03 eV 3.24 eV and a reduction in band gap is observed after codoping. The temperature dependent electrical conductivity measurements also show an enhancement in conductivity after codoping at RT.", "author_names": [ "Anand Kumar", "Manish K Kashyap", "Namita Sabharwal", "Sarvesh Kumar", "Ashok Kumar", "Parmod Kumar", "Kandasami Asokan" ], "corpus_id": 103559065, "doc_id": "103559065", "n_citations": 21, "n_key_citations": 0, "score": 0, "title": "Structural, optical and weak magnetic properties of Co and Mn codoped TiO 2 nanoparticles", "venue": "", "year": 2017 }, { "abstract": "In this study, for the first time, {111} facet exposed anatase TiO2 single crystals are prepared via both F and ammonia as the capping reagents. In comparison with the most investigated {001} {010} and {101} facets for anatase TiO2, the density functional theory (DFT) calculations predict that {111} facet owns a much higher surface energy of 1.61 J/m, which is partially attributed to the large percentage of undercoordinated Ti atoms and O atoms existed on the {111} surface. These undercoordinated atoms can act as active sites in the photoreaction. Experimentally, it is revealed that this material exhibits the superior electronic band structure which can produce more reductive electrons in the photocatalytic reaction than those of the TiO2 samples exposed with majority {010} {101} and {001} facets. More importantly, we demonstrate that this material is an excellent photocatalyst with much higher photocatalytic activity (405.2 mmol h 1) about 5, 9, and 13 times that of the TiO2 sample exposed with dominant {010} {101} and {001} facets, respectively. Both the superior surface atomic structure and electronic band structure significantly contribute to the enhanced photocatalytic activity. This work exemplifies that the surface engineering of semiconductors is one of the most effective strategies to achieve advanced and excellent performance over photofunctional materials for solar energy conversion.", "author_names": [ "Hua Xu", "Pakpoom Reunchan", "Shuxin Ouyang", "Hua Tong", "Naoto Umezawa", "Tetsuya Kako", "Jinhua Ye" ], "corpus_id": 35717104, "doc_id": "35717104", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Anatase TiO 2 Single Crystals Exposed with High Reactive 111 Facets Toward E ffi cient H 2 Evolution", "venue": "", "year": 2013 }, { "abstract": "Abstract Cu N codoped TiO 2 photocatalyst is synthesized by sol gel method to obtain enhanced optical absorption in the visible region. Optimum concentrations of Cu and N were obtained by maximizing the photocatalytic activity for the monodoped (Cu or N) TiO 2 These optimized concentrations were used for synthesizing (Cu, N) codoped TiO 2 The photocatalysts were characterized using XRD, micro Raman, SEM, XPS, BET surface area analyzer, UV vis diffuse reflectance spectroscopy and photoluminescence. XPS study suggests the incorporation of Cu 2+ into TiO 2 lattice, which assists N to substitutionally replace oxygen in codoped TiO 2 while maintaining the anatase phase even after doping. N doping creates minor variation in the energy band gap of TiO 2 reducing it upto 3.0 eV, while Cu doping was able to narrow the band gap to 2.2 eV mainly due to the localized levels of Cu 3d states and shifting of Ti 3d states to lower energy (due to oxygen vacancies) in the band gap as deduced from XPS data and confirmed by the DFT calculation. In (Cu, N) codoped TiO 2 visible light absorption is higher than the other TiO 2 samples, a feature that is mainly attributed to the formation of an isolated intermediate band (IB) occurring due to the strong hybridization between Cu 3d and N 2p orbitals. This IB contributes to visible light absorption by two step optical transition with the first transition from valence band (VB) to IB and the second from IB to conduction band (CB) The dopant species may also act to reduce the charge carrier recombination by acting as the trapping sites for photogenerated charges. (Cu, N) codoped TiO 2 was able to degrade Methylene Blue dye and p Nitrophenol solution under light irradiation with significantly better rate in comparison to monodoped and undoped TiO 2 High photocatalytic activity is attributed to the presence of IB in the energy band gap of TiO 2 which creates the synergic effect by higher visible light absorption and lower recombination of photogenerated charges.", "author_names": [ "R G Jaiswal", "J S Bharambe", "Nainesh Patel", "Alpa Dashora", "Dushyant C Kothari", "Antonio Miotello" ], "corpus_id": 95548771, "doc_id": "95548771", "n_citations": 124, "n_key_citations": 0, "score": 0, "title": "Copper and Nitrogen co doped TiO2 photocatalyst with enhanced optical absorption and catalytic activity", "venue": "", "year": 2015 }, { "abstract": "Surface modification of nanocrystalline TiO(2) particles (45 A) with catecholate type ligands consisting of an extended aromatic ring system, i.e. 2,3 dihydroxynaphthalene and anthrarobin, was found to alter the optical properties of the nanoparticles in a similar way to modification with catechol. The formation of inner sphere charge transfer (CT) complexes results in a red shift of the semiconductor absorption compared to unmodified nanocrystallites and the reduction of the band gap upon the increase of the electron delocalization on the inclusion of additional rings. The binding structures were investigated by FTIR spectroscopy. The investigated ligands have the optimal geometry for binding to surface Ti atoms, resulting in ring coordination complexes of catecholate type (binuclear bidentate binding bridging) thus restoring the six coordinated octahedral geometry of surface Ti atoms. From the Benesi Hildebrand plot, stability constants in methanol/water 90/10 solutions at pH 2 of the order 10(3) M( 1) have been determined. Quantum chemical calculations on model systems using density functional theory (DFT) were performed to obtain vibrational frequencies of charge transfer complexes, and the calculated values were compared with the experimental data.", "author_names": [ "Tatjana Savic", "Ivana A Jankovic", "Zoran Saponjic", "Mirjana I Comor", "Dusan Z Veljkovic", "Snezana D Zaric", "Jovan M Nedeljkovic" ], "corpus_id": 21102465, "doc_id": "21102465", "n_citations": 38, "n_key_citations": 0, "score": 0, "title": "Surface modification of anatase nanoparticles with fused ring catecholate type ligands: a combined DFT and experimental study of optical properties.", "venue": "Nanoscale", "year": 2012 }, { "abstract": "Introduction Nitrogen oxides (NOx) mainly produced from combustion of fossil fuels and vehicle exhaust, are responsible for atmospheric environmental problems such as haze, photochemical smog, acid rain and so on. Semiconductor photocatalysis, as a \"green\" technology, has been used to remove NOx at ppb levels TiO2 has long been a promising candidate for photocatalysis applications owing to its strong photocatalytic oxidation performance, photostability, natural abundance, and nontoxicity However, the relatively large band gap of TiO2 (3.0 3.2 eV) limits its application in the visible light region (400 nm l 750 nm) which accounts for 43% of the incoming solar energy. Oxygen vacancies are the most important defects in TiO2 for photocatalysis It has been shown that the photocatalytically important properties of TiO2, including the electronic structure, charge transport and surface properties, are closely related to oxygen vacancies. In this study, a series of oxygen deficient TiO2 catalysts was prepared by a facile and low temperature method. The catalysts were utilized to remove gaseous NOx under visible light irradiation. Materials and Methods Oxygen deficient TiO2 was synthesized using a sol gel method. After drying at 110 C, the powder samples were calcined in air at 150, 200, 300, 400 and 500 C for 5 h and were labeled as TiO2 150, TiO2 200, TiO2 300, TiO2 400, and TiO2 500, respectively. The catalysts were characterized by SEM, XRD, Raman, physisorption analysis, UV vis diffuse reflection spectra and photoluminescence (PL) emission spectra. The photocatalytic experiments for the removal of NOx were performed in a homemade continuous flow reactor. A 500 W commercial Xenon arc lamp was used as the simulated solar light source. Two optical filters were used to obtain light in the 420 700 nm range and the integrated light intensity was 35.8 mW/cm. The experiment conditions were: T=25 C, mcat=50 mg, NOinitial=400 ppb, RH=55% F=1.2 L min. The concentration of NO, NO2 and NOx was continuously measured by a chemiluminescence NOx analyzer. DFT calculations were performed using the CASTEP package. The generalized gradient approximation (GGA) with the PBE exchange correlation functional was adopted. The parameters were: ultrasoft pseudo potential, k point mesh of (2x2x2) energy cutoff=380 eV, convergence tolerance: energy<5.0x10 eV/atom, force<0.01 eV/A, stress<0.02 GPa and displacement<5.0x10A. A 108 atom supercell made up by 3x3x1 unit cells was used to simulate an anatase bulk crystal. The oxygen vacancy was modeled by removing one oxygen atom in TiO2 cells, thus forming TiO2 x with x=0.028. After finishing the geometry optimizations, the DFT+U method was used to calculate the band structures and the projected density of states (PDOS) of TiO2 and TiO2 x. A self consistent Hubbard U correction of 3.3 eV for the d electrons of Ti has been calculated Results and Discussion TiO2 200 is highly active for the removal of NOx under visible light. On the basis of the characterization results, the excellent catalytic activity of TiO2 200 was attributed to its larger surface area, greater light absorption in the visible region and more effective charge transport and separation than catalysts prepared at other temperatures, which was caused by the formation of oxygen vacancies in the presence of carbonaceous species.", "author_names": [ "Jinzhu Ma", "Hongming Wu", "Yongchun Liu", "Hong He" ], "corpus_id": 204751132, "doc_id": "204751132", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Photocatalytic removal of NO x over visible light responsive oxygen deficient TiO 2", "venue": "", "year": 2014 } ]

[ { "abstract": "Despite great challenges, the development of new molecular structures with multiple and even conflicting characteristics are eagerly pursued for exploring advanced applications. To develop high performance chiral organic semiconducting molecules, a distorted p system is required for strong coupling with circularly polarized light (CPL) whereas planar p stacking systems are necessary for high charge carrier mobility. To address this dilemma, in this work, we introduce a skeleton merging approach through distortion of a perylene diimide (PDI) core with four fused heteroaromatics to form an ortho p extended PDI double [7]heterohelicene. PDI double helicene inherits a high dissymmetry factor from the helicene skeleton, and the extended p planar system concurrently maintains a high level of charge transport properties. In addition, ortho p extension of the PDI skeleton brings about near infrared (NIR) light absorption and ambipolar charge transport abilities, endowing the corresponding organic phototransistors with high photoresponsivity of 450 and 120 mA W 1 in p and n type modes respectively, along with a high external quantum efficiency (89% under NIR light irradiations. Remarkably, these multiple characteristics enable high performance broadband CPL detections up to NIR spectral region with chiral organic semiconductors. In organic semiconducting molecules materials, distorted p systems enable strong coupling with circular polarized light while planar p stacking systems are necessary for high charge carrier mobility. Here, the authors address this dilemma by introducing a skeleton merging approach through distortion of a perylene diimide core with four fused heteroaromatics to form a p extended double helicene.", "author_names": [ "Li Zhang", "Inho Song", "Jaeyong Ahn", "Myeonggeun Han", "Mathieu Linares", "Mathieu Surin", "Hui-Jun Zhang", "Joon Hak Oh", "Jian-bin Lin" ], "corpus_id": 231202755, "doc_id": "231202755", "n_citations": 6, "n_key_citations": 1, "score": 1, "title": "p Extended perylene diimide double heterohelicenes as ambipolar organic semiconductors for broadband circularly polarized light detection", "venue": "Nature communications", "year": 2021 }, { "abstract": "Circularly polarized light (CPL) sensitive direct detection is attracting increasing attention owing to its various optical technology applications and ultracompact device structures. However, current CPL sensitive direct detection mainly focuses on a single mode, whereas the visible near infrared (vis NIR) dual modal detection, which is important for improving device sensitivity and night vision performance, still remains to be explored. Here, for the first time, the vis NIR dual modal CPL sensitive direct detection is presented in bulk single crystals of two dimensional chiral perovskite (R BPEA)2PbI4 (R BPEA (R) 1 (4 bromophenyl)ethylammonium) Benefiting from the strong light matter interaction of the layered structure, (R BPEA)2PbI4 shows a two photon absorption (TPA) coefficient of up to 55 cm/MW, which almost falls around the highest value of 2D hybrid perovskites. Notably, (R BPEA)2PbI4 exhibits a high vis NIR dual modal CPL sensitive direct detecting performance under both visible light (520 nm) and NIR light (800 nm) with the on/off ratios of current higher than 103, and the anisotropy factors for photocurrent higher than 0.1. This work will shed light on the design of new chiral semiconductors with a large TPA coefficient and promote their applications in vis NIR dual modal CPL sensitive direct detection.", "author_names": [ "Xitao Liu", "Lina Li", "Xiaoying Shang" ], "corpus_id": 237294865, "doc_id": "237294865", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Realization of vis NIR Dual Modal Circularly Polarized Light Detection in Chiral Perovskite Bulk Crystals.", "venue": "Journal of the American Chemical Society", "year": 2021 }, { "abstract": "The emergent properties of chiral organic inorganic hybrid materials offer opportunities in spin dependent optoelectronic devices. One of the most promising applications where spin, charge, and light are strongly coupled is circularly polarized light (CPL) detection. However, the performance of state of the art CPL detectors using chiral hybrid metal halide semiconductors is still limited by the low anisotropy factor, poor conductivity, and limited photoresponsivity. Here, we synthesize 0D chiral copper chloride hybrids, templated by chiral methylbenzylammonium (R/S MBA) i.e. (R /S MBA)2CuCl4, that display circular dichroism for the ligand to metal charge transfer transition with an absorption anisotropy factor (gCD) among the largest reported for chiral metal halide semiconductor hybrids. To circumvent the poor conductivity of the unpercolated inorganic framework of this chiral absorber, we develop a direct CPL detector that utilizes a heterojunction between the chiral (MBA)2CuCl4 absorber layer and a semiconducting single walled carbon nanotube (s SWCNT) transport channel. Our chiral heterostructure shows high photoresponsivity of 452 A/W, a competitive anisotropy factor (gres) of up to 0.21, a current response in microamperes, and low working voltage down to 0.01 V. Our results clearly demonstrate a useful strategy toward high performance chiral optoelectronic devices, where a nanoscale heterostructure enables direct CPL detection even for highly insulating chiral materials.", "author_names": [ "Ji Hao", "Haipeng Lu", "Lingling Mao", "Xihan Chen", "Matthew C Beard", "Jeffrey L Blackburn" ], "corpus_id": 233037124, "doc_id": "233037124", "n_citations": 2, "n_key_citations": 0, "score": 1, "title": "Direct Detection of Circularly Polarized Light Using Chiral Copper Chloride Carbon Nanotube Heterostructures.", "venue": "ACS nano", "year": 2021 }, { "abstract": "Chiral p conjugated molecular systems that are intrinsically sensitive to the handedness of circularly polarized (CP) light potentially allow for miniaturized, low cost CP detection devices. Such devices promise to transform several technologies, including biosensing, quantum optics and communication of data encrypted by exploiting the spin angular momentum of light. Here we realize a simple, bilayer organic photodiode (CP OPD) comprising an achiral p conjugated polymer chiral additive blend as the electron donor layer and an achiral C60 electron acceptor layer. These devices exhibit considerable photocurrent dissymmetry gph, with absolute values as high as 0.85 and dark currents as low as 10 pA. Impressively, they showcase a linear dynamic range of 80 dB, and rise and fall times of 50 and 270 ns respectively, which significantly outperforms all previously reported CP selective photodetectors. Mechanistically, we show that the gph is sensitive to the thickness of both the chiral donor and achiral acceptor layers and that a trade off exists between the external quantum efficiency (EQE) and gph. The fast switching speeds of these devices, coupled with their large dynamic range and highly selective response to CP light, opens up the possibility of their direct application in CP sensing and optical communication.", "author_names": [ "Mary Darlene Ward", "Jessica Wade", "X G Shi", "Jenny Nelson", "Alasdair J Campbell", "Matthew J Fuchter" ], "corpus_id": 235580628, "doc_id": "235580628", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Highly Selective Ultrafast Circularly Polarized Photodiodes Based on p Conjugated Polymers", "venue": "", "year": 2021 }, { "abstract": "While halide perovskites (HPs) have achieved enormous success in the field of optoelectronic applications, much attention has been recently drawn to the unique polarization sensitivity of HPs, either intrinsic or extrinsic, which makes HPs a potential candidate for innovative applications in directly polarized luminescence and detection. Herein, the research status in the field of polarization sensitive HPs, including linear polarization and circular polarization, is comprehensively summarized. To evaluate the effectiveness of HPs in generating and detecting linearly or circularly polarized light, the principles and characterization methods of polarized luminescence and detection are introduced. Sequentially, the state of the art development of the strategies that induce the linear or circular polarization characteristics of HPs is systematically reviewed, based on which the application of polarization sensitive HPs in the field of polarization luminescence and detection are summarized. Moreover, the current challenges and opportunities are discussed, and prospects of the future development in this promising field are outlined.", "author_names": [ "Xiaobo Wang", "Yue Wang", "Weiyin Gao", "Lin Song", "Chenxin Ran", "Yonghua Chen", "Wei Huang" ], "corpus_id": 231926095, "doc_id": "231926095", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "Polarization Sensitive Halide Perovskites for Polarized Luminescence and Detection: Recent Advances and Perspectives.", "venue": "Advanced materials", "year": 2021 }, { "abstract": "Recently, our group produced spin polarized hydrogen (SPH) atoms at densities of at least 10 19 cm 3 from the photodissociation of hydrogen halide molecules with circularly polarized UV light and measured them via magnetization quantum beats with a pickup coil. These densities are approximately 7 orders of magnitude higher than those produced using conventional methods, opening up new fields of application, such as ultrafast magnetometry, the production of polarized MeV and GeV particle beams, such as electron beams with intensities approximately 10 4 higher than current sources, and the study of polarized nuclear fusion, for which the reaction cross sections of D T and D 3 He reactions are expected to increase by 50% for fully polarized nuclear spins. We review the production, detection, depolarization mechanisms, and potential applications of high density SPH. A laser based scheme to produce spin polarized hydrogen (SPH) at much higher densities than conventional methods could create new opportunities in physics. In a review of the topic, Alexandros Spiliotis and coworkers from the University of Create and FORTH Institute of Electronic Structure and Laser in Greece describe how the use of circularly polarized, pulsed ultraviolet laser light can produce SPH with a density of 10 19 cm 3 by photodissociation of hydrogen halide molecules. This high density production approach brings many benefits including the prospect of ultrafast magnetometry and the generation of high energy beams of spin polarized electrons, protons or deuterons by laser plasma acceleration. Furthermore, spin polarized nuclear fusion is expected to be more efficient than conventional fusion.", "author_names": [ "Alexandros K Spiliotis", "Michalis Xygkis", "Michail E Koutrakis", "Konstantinos Tazes", "Gregoris K Boulogiannis", "Chrysovalantis S Kannis", "Georgios E Katsoprinakis", "Dimitrios Sofikitis", "T Peter Rakitzis" ], "corpus_id": 231905020, "doc_id": "231905020", "n_citations": 4, "n_key_citations": 0, "score": 1, "title": "Ultrahigh density spin polarized hydrogen isotopes from the photodissociation of hydrogen halides: new applications for laser ion acceleration, magnetometry, and polarized nuclear fusion", "venue": "Light, science applications", "year": 2021 }, { "abstract": "A polarized laser beam steering system using multiply cascaded rotating polarization gratings (PGs) is presented. The rotating PGs steer incident circularly polarized beams with high optical throughput because the theoretical limitation of the PG diffraction efficiency is 100% The system also offers more rapid rotation when compared with wedge prism pairs because of the weight of the PGs. The beam steering performance was analyzed theoretically for schemes using two and four rotating PGs. The system's feasibility was demonstrated experimentally by projecting Lissajous and raster patterns using PGs fabricated from photocrosslinkable polymer liquid crystal films via a photo alignment technique. The steered beam's diffraction efficiency and ellipticity were maintained at 83~89% and 96~99% respectively, during PG rotation. This beam steering system will be applicable to light detection and ranging, optical imaging, and laser displays.", "author_names": [ "Moritsugu Sakamoto", "Huynh Thanh Nhan", "Kohei Noda", "Tomoyuki Sasaki", "Tadayoshi Kamei", "Takeya Sakai", "Yukitoshi Hattori", "Nobuhiro Kawatsuki", "Hiroshi Ono" ], "corpus_id": 232190299, "doc_id": "232190299", "n_citations": 1, "n_key_citations": 1, "score": 1, "title": "Polarized beam steering using multiply cascaded rotating polarization gratings.", "venue": "Applied optics", "year": 2021 }, { "abstract": "We present a theoretical study of the optical radio frequency (rf) double resonance on hyperfine ground states of alkali metal atoms in the geophysical magnetic field range, in which resonance circularly polarized laser light is used in the optical pumping and detection processes. The analytical expressions of the rf resonance signals corresponding to two ground states are obtained based on atomic multipole moments, where the alignment effect is considered and that is responsible for the resonance shape and linewidth especially when the optical power is relatively strong. In addition, we also obtain the analytical expressions of the linewidths of two separated resonance peaks and one presenting the competition process of the optical pumping, rf field and spin exchange collision. Two different types of light narrowing phenomena are investigated by comparing the longitudinal relaxation rates of atomic multipole moments for two ground states. Applied to rubidium and cesium atoms, we show a particularly close agreement of our analytical results with more elaborate calculations using density matrix theory. Our theoretical model is relevant for optimizing the sensitivity of magnetometers.", "author_names": [ "Pan Qi", "Xu-xing Geng", "Guang-ming Huang" ], "corpus_id": 236599931, "doc_id": "236599931", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Theory of light narrowing of magnetic resonances of alkali metal atoms in the geophysical field range", "venue": "", "year": 2021 }, { "abstract": "Context. Homochirality is a generic and unique property of life on Earth and is considered a universal and agnostic biosignature. Homochirality induces fractional circular polarization in the incident light that it reflects. Because this circularly polarized light can be sensed remotely, it can be one of the most compelling candidate biosignatures in life detection missions. While there are also other sources of circular polarization, these result in spectrally flat signals with lower magnitude. Additionally, circular polarization can be a valuable tool in Earth remote sensing because the circular polarization signal directly relates to vegetation physiology. Aims. While high quality circular polarization measurements can be obtained in the laboratory and under semi static conditions in the field, there has been a significant gap to more realistic remote sensing conditions. Methods. In this study, we present sensitive circular spectropolarimetric measurements of various landscape elements taken from a fast moving helicopter. Results. We demonstrate that during flight, within mere seconds of measurements, we can differentiate (S/N 5) between grass fields, forests, and abiotic urban areas. Importantly, we show that with only nonzero circular polarization as a discriminant, photosynthetic organisms can even be measured in lakes. Conclusions. Circular spectropolarimetry can be a powerful technique to detect life beyond Earth, and we emphasize the potential of utilizing circular spectropolarimetry as a remote sensing tool to characterize and monitor in detail the vegetation physiology and terrain features of Earth itself.", "author_names": [ "C H Lucas Patty", "Jonas G Kuhn", "Petar H Lambrev", "Stefano Spadaccia", "H Jens Hoeijmakers", "Christoph U Keller", "Willeke Mulder", "Vidhya Pallichadath", "Olivier Poch", "Frans Snik", "Daphne M Stam", "Antoine Pommerol", "B O Demory" ], "corpus_id": 235265876, "doc_id": "235265876", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Biosignatures of the Earth", "venue": "Astronomy Astrophysics", "year": 2021 }, { "abstract": "Measuring the polarization state of light is an inherent problem, especially for the detection of circularly polarized light. We propose a metasurface structure based on graphene to investigate the circular polarization detection function in the THz regime by using the finite difference time domain (FDTD) method. The proposed graphene metasurface consists of a layer of graphene arrays, a polymer dielectric spacer, and a layer of graphene bands. By adjusting the Fermi energy, the structure can realize tunable polarization detection functions. On this basis, we combine tunable filters with different angles into the structure to achieve full Stokes parameter measurement. The simulation results show that the structure's working band can be tuned in the range of 25.88 mm 28.68 mm. The structure we designed helps to develop a tunable and integrated polarization detection method.", "author_names": [ "Bowei Yang", "Yuhui Zhang", "Mingzhao Ouyang", "Yuegang Fu" ], "corpus_id": 235307840, "doc_id": "235307840", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Tunable Circular Polarization Detection and Full Stokes Measurement Structure", "venue": "IEEE Photonics Journal", "year": 2021 } ]

[ { "abstract": "The new Heterogeneous Integration Roadmap (HIR) provides a long term vision for the electronics industry, identifying difficult future challenges and potential solutions. Under the sponsorship of SEMI, ASME, and three IEEE Societies, the roadmap offers professionals, industry, academia, and research institutes a comprehensive view of the landscape and strategic technology requirements for the electronics industry's evolution over the next 15 years, and provides a 25 year vision for the heterogeneous integration of emerging devices and emerging materials with longer research and development timelines. The purpose is to stimulate precompetitive collaboration and thereby accelerate the pace of progress. The International Technology Roadmap for Semiconductors (ITRS) set the cadence for the Moore's Law scaling that has been the norm for the semiconductor industry. However, because of scaling, cost and power dissipation issues, as well as the laws of physics, the final ITRS was issued in 2015. The HIR pulls together many strands of that earlier Roadmap, to focus on microelectronics design, materials and packaging issues. The current version covers 2.5D, 3D, and wafer level packaging, integrated photonics, MEMS and sensors, and system in package (SiP) support areas such as test, thermal, simulation, co design, and interconnects; as well as application areas such as high performance computing, 5G, medical, aerospace, automotive, and mobile detailing both near term and longer term metrics and goals. It identifies difficult future challenges and proposes potential solutions. Comprising the output of 22 Technical Working Groups with worldwide participation, it will be substantially updated every two years. Version 1.0 is available freely for download, as well as in the form of a printed softbound book. Details for accessing this new Roadmap are presented. An invitation is made for involvement in version 2.0, now under preparation.", "author_names": [ "Paul B Wesling" ], "corpus_id": 215739966, "doc_id": "215739966", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "The Heterogeneous Integration Roadmap: Enabling Technology for Systems of the Future", "venue": "2020 Pan Pacific Microelectronics Symposium (Pan Pacific)", "year": 2020 }, { "abstract": "The international technology roadmap of semiconductors (ITRS) is approaching the historical end point and we observe that the semiconductor industry is driving complementary metal oxide semiconductor (CMOS) further towards unknown zones. Today's transistors with 3D structure and integrated advanced strain engineering differ radically from the original planar 2D ones due to the scaling down of the gate and source/drain regions according to Moore's law. This article presents a review of new architectures, simulation methods, and process technology for nano scale transistors on the approach to the end of ITRS technology. The discussions cover innovative methods, challenges and difficulties in device processing, as well as new metrology techniques that may appear in the near future.", "author_names": [ "Henry H Radamson", "Huilong Zhu", "Zhenhua Wu", "Xiaobin He", "Hongxiao Lin", "Jinbiao Liu", "Jinjuan Xiang", "Zhenzhen Kong", "Wenjuan Xiong", "Junjie Li", "Hushan Cui", "Jian-feng Gao", "Hong Yang", "Yong Du", "Buqing Xu", "Ben Li", "Xuewei Zhao", "Jiahan Yu", "Yan Dong", "Guilei Wang" ], "corpus_id": 221126630, "doc_id": "221126630", "n_citations": 29, "n_key_citations": 0, "score": 2, "title": "State of the Art and Future Perspectives in Advanced CMOS Technology", "venue": "Nanomaterials", "year": 2020 }, { "abstract": "Abstract Previous studies on open innovation have primarily adopted the perspective of single firms. Against this background we explore how open innovation is managed at the network level for the case of the International Technology Roadmap for Semiconductors (ITRS) Using a longitudinal case study, we report on how the ITRS deals with a technological discontinuity affecting the whole industry, namely the pursuit of an existing technological paradigm using a well established collaborative practice set against a novel and unknown future technological paradigm to be opened up in parallel, even though the necessary knowledge about the ensuing disruption is lacking. This challenge is characterized not only by extreme technological uncertainty, but also by partner related and procedural uncertainty concerning the key activity of ITRS, namely the setting of future technological milestones (roadmapping) We discuss attempts by the ITRS network to overcome these uncertainties and manage technological discontinuities by extending the well established practice of roadmapping to an unknown technological paradigm. We introduce the concept of 'stretching practice' to highlight this phenomenon, and we contribute to the debate on the open innovation and technological discontinuities that arise when venturing beyond firm centric approaches.", "author_names": [ "Jorg Sydow", "Gordon Muller-Seitz" ], "corpus_id": 158897912, "doc_id": "158897912", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Open innovation at the interorganizational network level Stretching practices to face technological discontinuities in the semiconductor industry", "venue": "Technological Forecasting and Social Change", "year": 2020 }, { "abstract": "As Si based electronic devices rapidly reach their scaling limits, novel two dimensional (2D) semiconductors, such as graphene nanoribbon, transition metal dichalcogenides, phosphorene, are becoming promising channel materials. Antimonene has been proved suitable for ultra scaled field effect transistors (FETs) benefiting from its superior semiconducting properties. Considering that antimonene shows different effective mass from 0deg (zigzag) to 30deg (armchair) we have calculated the anisotropic transport property of monolayer (ML) antimonene metal oxide semiconductor FET (MOSFETs) including on state current, subthreshold swing, effective mass, intrinsic delay time and power dissipation. Encouragingly, 0deg (zigzag) and 19.1deg directions ML antimonene MOSFETs with 4 nm gate length and 1 nm underlap achieve International Technology Roadmap for Semiconductors (ITRS) high performance (HP) goal in 2028. The performance of ML antimonene MOSFETs still can fulfill the ITRS HP goal, when the spin orbit coupling effect is considered. The magnitude of on state currents in all calculations generally vary inversely with the effective mass. Therefore, we predict that other transmission directions with effective masses between 0.291 m0 to 0.388 m0 can also achieve ITRS HP goal, which enables antimonene to be a promising channel material.", "author_names": [ "Yiheng Yin", "Chen Shao", "Can Zhang", "Zhaofu Zhang", "Xuewei Zhang", "John Robertson", "Yuzheng Guo" ], "corpus_id": 216084726, "doc_id": "216084726", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "The Anisotropic Transport Property of Antimonene MOSFETs.", "venue": "ACS applied materials interfaces", "year": 2020 }, { "abstract": "Exploring the device performance limits is meaningful for guiding practical device fabrication. We propose archetype tunneling field effect transistors (TFETs) with negative capacitance (NC) and use the rigorous ab initio quantum transport simulation to explore the device performance limits of the TFETs based on monolayer (ML) GeSe and GeTe along with their NC counterparts. With the ferroelectric dielectric acting as a negative capacitance material, the device performances of both the ML GeSe and GeTe NCTFETs outperform their TFET counterparts, particularly for the on state current (Ion) Ion of the optimal ML GeSe and GeTe TFETs fulfills the demands of the International Technology Roadmap for Semiconductors (ITRS 2015 version) for low power (LP) and high performance (HP) devices, at the \"6/5\" node range, while with the aid of 80 nm and 50 nm thickness of ferroelectric SrBi2Nb2O9, both their NC counterparts extend the fulfillments at the \"4/3\" node range.", "author_names": [ "Peipei Xu", "Jiakun Liang", "Hong Li", "Fengbin Liu", "Jun Tie", "Zhiwei Jiao", "Jingyao Luo", "Jing Lu" ], "corpus_id": 219096173, "doc_id": "219096173", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Device performance limits and negative capacitance of monolayer GeSe and GeTe tunneling field effect transistors", "venue": "", "year": 2020 }, { "abstract": "Group III VI family MX (M Ga and In, and X S, Se, and Te) monolayers have attracted global interest for their potential applications in electronic devices due to their unexpectedly high carrier mobility. Herein, via density functional theory calculations as well as ab initio quantum transport simulations, we investigated the performance limits of MX monolayer metal oxide semiconductor field effect transistors (MOSFETs) at the sub 10 nm scale. Our results highlighted that the MX monolayers possessed good structural stability and mechanical isotropy with large ultimate strains and low Young's modulus, which are intensely anticipated in the next generation flexible devices. More importantly, the MX monolayer MOSFETs show excellent device performance under optimal schemes. The on state current, delay time, and power dissipation of the MX monolayer MOSFETs satisfy the International Technology Roadmap for Semiconductors (ITRS) 2013 requirements for high performance devices. Interestingly, the sub threshold swings were in a very low range from 68 mV dec 1 to 108 mV dec 1, which indicated the favorable gate control ability for fast switching. Therefore, we believe that our findings shed light on the design and application of MX monolayer based MOSFETs in next generation flexible electronic devices.", "author_names": [ "Jianhui Chen", "Shuchang Cai", "Rui Xiong", "Baisheng Sa", "Cuilian Wen", "Bo Wu", "Zhimei Sun" ], "corpus_id": 213192669, "doc_id": "213192669", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "High performance III VI monolayer transistors for flexible devices.", "venue": "Physical chemistry chemical physics PCCP", "year": 2020 }, { "abstract": "With the scaling limits of silicon based MOS technology, the critical and challenging issue is to explore more and more alternative materials to improve the performance of devices. Two dimensional (2D) semiconductor WSe2 with proper bandgap and inherent stability under ambient conditions make it be the potential channel materials for realizing the new generation field effect transistors (FETs) In light of the low on state current of the experimental sub 10 nm 2D MoS2 FETs, we explore the limitation of the monolayer (ML) WSe2 device performance by using accurate ab initio quantum transport simulation. We find that the sub 10 nm 2D WSe2 FETs apparently outperform their MoS2 counterpart. The on state current of the optimized p type ML WSe2 FETs can satisfy the criteria of the International Technology Roadmap for Semiconductors (ITRS) on both the high performance (HP) and low power (LP) device until the gate length is scaled down to 2 and 3 nm, respectively. By the aid of the NC (negative capacitance) effect, even the 1 nm gate length WSe2 MOSFETs can satisfy both the HP and LP requirements in the ITRS 2028 completely. Remarkably, the ML WSe2 MOSFET owns the highest theoretical on current in the LP application among the examined 2D MOSFETs at the 5 nm gate length to our knowledge.", "author_names": [ "Xiaotian Sun", "Li-wen Xu", "Yuanwei Zhang", "Weizhou Wang", "Shiqi Liu", "Chen Yang", "Zhiyong Zhang", "Jing Lu" ], "corpus_id": 215758256, "doc_id": "215758256", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Performance Limit of Monolayer WSe2 Transistors: Significantly Outperform their MoS2 Counterpart.", "venue": "ACS applied materials interfaces", "year": 2020 }, { "abstract": "Van der Waals (vdW) type metallic/semiconducting heterostructures have attracted much attention for applications like nanoelectronics. The electronic properties of graphene/SnSe2 vdW heterostructure are investigated by the first principles calculation. The band dispersions of both the graphene and SnSe2 layers are well preserved in the graphene/SnSe2 vdW heterostructure. Notably, n type Ohmic contact is found at the graphene/SnSe2 vdW interface so that graphene is a fantastic electrode for the SnSe2 Schottky barrier field effect transistor (SBFET) The on state current of the 10 nm gate long ML SnSe2 SBFET with graphene electrode is 1535 uA/um for high performance (HP) application, which is twice that of the ML MoS2 SBFET with bulk Ti electrode and exceeds the requirement of the International Technology Roadmap for Semiconductors for HP devices.", "author_names": [ "Hongjun Li", "Peipei Xu", "Jiakun Liang", "Fengbin Liu", "Jingyao Luo", "Jing Lu" ], "corpus_id": 209528744, "doc_id": "209528744", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Ohmic contact in graphene/SnSe2 Van Der Waals heterostructures and its device performance from ab initio simulation", "venue": "Journal of Materials Science", "year": 2020 }, { "abstract": "ABSTRACT In this work, we utilized a digital integrated circuit (IC) testing model (DITM) based on a statistical simulation method, to evaluate the test yield and test quality of semiconductor products. A circuit or chip has multiple parameters and the relationships among these parameters at different levels are complicated. To simply express numerous and complex interrelated IC or chip manufacturing and testing parameters, we assumed a normal distribution of manufacturability and then standardized and related all other parameters. On applying the Digital integrated circuit testing model (DITM) to data on Accuracy Requirements in At Speed Functional Test and International technology roadmap for semiconductors (ITRS Roadmap) the simulated results clearly indicated that when the threshold value of a quality control test is determined, the DITM can accurately and effectively predict future Yt (Test Yield)", "author_names": [ "Chung-Huang Yeh", "Jwu-E Chen" ], "corpus_id": 214006357, "doc_id": "214006357", "n_citations": 1, "n_key_citations": 1, "score": 0, "title": "Test yield and quality analysis models of chips", "venue": "", "year": 2020 }, { "abstract": "Using ab initio quantum transport simulations, we studied the intrinsic transfer characteristics and benchmarks of the ballistic performance of 5.1 nm double gated Schottky barrier field effect transistors (SBFETs) consisting of in plane (IP) heterojunctions of metallic phase (1T or 1T' MTe2 (M Ti, Zr, Hf, Cr, Mo, W) and semiconducting phase (2H) WSe2, WTe2 and Janus WSeTe. The 2H phase Janus WSeTe is a semiconductor with an indirect bandgap (1.26 eV) which is less than the bandgap of 2H phase WSe2 (1.64 eV) and is greater than the bandgap of 2H phase WTe2 (1.02 eV) The band alignments show that all IP 1T/2H contacts are Schottky barrier contacts with the Fermi levels of 1T or 1T' MTe2 (M Ti, Zr, Hf, Cr, Mo, W) located within the bandgaps of 2H WSe2, WTe2 and Janus WSeTe. Although double gated IP WSe2 SBFETs can satisfy the OFF current requirement, their ON currents all fall below the requirements of the high performance transistor outlined by the ITRS (International Technology Roadmap for Semiconductors, 2013 version) for the production year 2028. Double gated IP WTe2 SBFETs cannot overcome the short channel effect leading to minimum drain currents all beyond the OFF current requirement of ITRS (2013 version) for the production year 2028. Fortunately, double gated IP WSeTe SBFETs with 1T MoTe2 or 1T' WTe2 electrodes can overcome the short channel effect and satisfy the requirements of the high performance transistor outlined by the ITRS (2013 version) for the production year 2028.", "author_names": [ "Z Q Fan", "Zhen-Hua Zhang", "Shenghui Yang" ], "corpus_id": 225050370, "doc_id": "225050370", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "High performance 5.1 nm in plane Janus WSeTe Schottky barrier field effect transistors.", "venue": "Nanoscale", "year": 2020 } ]

[ { "abstract": "We report the demonstration of high power semiconductor slab coupled optical waveguide lasers (SCOWLs) operating at a wavelength of 1.5 /spl mu/m. The lasers operate with large (4/spl times/8 /spl mu/m diameter) fundamental mode and produce output power in excess of 800 mW. These structures have very low loss /spl sim/0.5 cm/sup 1/ enabling centimeter long devices for efficient heat removal. The large fundamental mode allows 55% butt coupling efficiency to standard optical fiber (SMF 28) Comparisons are made between SCOWL structures having nominal 4 and 5 /spl mu/m thick waveguides.", "author_names": [ "Jason Plant", "Paul W Juodawlkis", "R K Huang", "Joseph P Donnelly", "Leo J Missaggia", "K G Ray" ], "corpus_id": 41424356, "doc_id": "41424356", "n_citations": 47, "n_key_citations": 0, "score": 1, "title": "1.5 /spl mu/m InGaAsP InP slab coupled optical waveguide lasers", "venue": "IEEE Photonics Technology Letters", "year": 2005 }, { "abstract": "We report the first demonstration of a high power semiconductor optical amplifier (SOA) based on the slab coupled optical waveguide concept. This concept allows the realization of SOAs having large fundamental optical modes, low loss, and small optical confinement factor. These attributes support large output saturation power, long length for efficient heat removal, and direct butt coupling to single mode fibers. The 1.5 /spl mu/m InGaAsP InP quantum well amplifier described here has a length of 1 cm, 1/e/sup 2/ intensity widths of 4 /spl mu/m (vertical) and 8 /spl mu/m (horizontal) a fiber to fiber gain of 13 dB, and a fiber coupled output saturation power of 630 mW +28 dBm) The measured butt coupling efficiency between the amplifier and SMF 28 is 55% Thus, the output saturation power of the amplifier itself is approximately 1.1 W +31 dBm)", "author_names": [ "Paul W Juodawlkis", "Jason Plant", "R K Huang", "Leo J Missaggia", "Joseph P Donnelly" ], "corpus_id": 22577626, "doc_id": "22577626", "n_citations": 65, "n_key_citations": 5, "score": 0, "title": "High power 1.5 /spl mu/m InGaAsP InP slab coupled optical waveguide amplifier", "venue": "IEEE Photonics Technology Letters", "year": 2005 }, { "abstract": "Abstract The development of a high brightness semiconductor diode laser/amplifier concept, which utilizes a slab coupled optical waveguide (SCOW) region to achieve several important advances in performance, is presented. SCOW devices are capable of single spatial mode operation with a single lobed, large area, low aspect ratio beam. The SCOW concept is applicable to a wide variety of semiconductor material systems and wavelengths of interest. To date, SCOW devices have been demonstrated in the InGaAs/AlGaAs/GaAs, InGaAsP/InP, and AlGaAsSb/GaAs. High power lasers and optical amplifiers have been developed for numerous applications, including arrays for wavelength and coherent beam combining, narrow linewidth external cavity lasers, and mode locked lasers.", "author_names": [ "Joseph P Donnelly", "Paul W Juodawlkis", "Robin K Huang", "Jason Plant", "G M Smith", "Leo J Missaggia", "William Loh", "Shawn M Redmond", "Bien Chann", "Michael K Connors", "Reuel B Swint", "George W Turner" ], "corpus_id": 92166352, "doc_id": "92166352", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Chapter 1 High Power Slab Coupled Optical Waveguide Lasers and Amplifiers", "venue": "", "year": 2012 }, { "abstract": "This study demonstrates that the large mode slab coupled optical waveguide concept can be applied to semiconductor optical amplifiers as well as to lasers. The (slab coupled optical waveguide laser) SCOWL concept is extended to 1.5 /spl mu/amplifiers with mode sizes that are compatible with standard SMF 28 fiber for simplified coupling. The performance of these initial devices is primarily limited by reduction in efficiency at high current. This limitation can be reduced through improved design of the heterobarriers that provide carrier confinement.", "author_names": [ "Paul W Juodawlkis", "Jason Plant", "Robin K Huang", "Leo J Missaggia", "Joseph P Donnelly" ], "corpus_id": 117085943, "doc_id": "117085943", "n_citations": 4, "n_key_citations": 1, "score": 0, "title": "High power 1.5 /spl mu/m InGaAsP slab coupled optical waveguide amplifiers and lasers", "venue": "The 16th Annual Meeting of the IEEE Lasers and Electro Optics Society, 2003. LEOS 2003.", "year": 2003 }, { "abstract": "We have demonstrated the first SCOWL operating in a colliding pulse mode locked configuration. This laser has a repetition rate of 8.54 GHz with 70 dB fundamental mode suppression and average output power of 170 mW per facet. We measured a detection limited pulse width of 20 ps. The resultant pulse energy and peak power are 19.9 pJ and 1 W, respectively.", "author_names": [ "Jason Plant", "Paul W Juodawlkis" ], "corpus_id": 21619765, "doc_id": "21619765", "n_citations": 3, "n_key_citations": 1, "score": 0, "title": "High power 1.5 mm InGaAsP/InP Colliding Pulse Mode Locked Slab Coupled Optical Waveguide Laser", "venue": "LEOS 2006 19th Annual Meeting of the IEEE Lasers and Electro Optics Society", "year": 2006 }, { "abstract": "This paper reviews the SCOW technology and describe its application in mode locked SCOW external cavity lasers (ML SCOWECLs) optoelectronic oscillators (OEOs) and suppressed bias MWP links, limiting the discussion to 1.5 mm emitters fabricated using InGaAsP/InP quantum wells.", "author_names": [ "Paul W Juodawlkis", "Jason Plant", "William Loh", "Siva Yegnanarayanan" ], "corpus_id": 37474083, "doc_id": "37474083", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "High power, compact slab coupled optical waveguide (SCOW) emitters and their applications", "venue": "IEEE Avionics, Fiber Optics and Photonics Digest CD", "year": 2012 }, { "abstract": "We demonstrate an external cavity laser comprised of a novel InGaAsP/InP curved channel slab coupled optical waveguide amplifier and a fiber Bragg grating. The laser exhibits a technical noise limited linewidth of 130 kHz with 88 mW output power at 1556 nm", "author_names": [ "Paul W Juodawlkis", "Jason Plant", "Frederick J O'Donnell", "Leo J Missaggia", "R K Huang", "Joseph P Donnelly" ], "corpus_id": 11182591, "doc_id": "11182591", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Narrow linewidth, high power 1556 nm slab coupled optical waveguide external cavity laser", "venue": "(CLEO) Conference on Lasers and Electro Optics, 2005.", "year": 2005 }, { "abstract": "Abstract Broad stripe 1.5 micrometers InGaAsP/InP MQW graded index SCH lasers with different waveguide widths and doping profiles were designed, fabricated and characterized. Studies of the characteristics of lasers with different p doping profiles as well as modeling data show that the heterobarrier electron leakage is responsible for the effect of optical power saturation with current. Broadened waveguide devices containing higher Zn concentration in the vicinity of p cladding/SCH interface yielded maximum output optical pulsed power density giving more than 16W from l00 micrometers aperture. Direct measurements of optical loss for BW lasers with different doping profiles have shown that doping can increase the internal loss of the device by more than two times, which explains the reduction of the device slope efficiency with doping. We have found that the benefit associated with the suppression of heterobarrier electron leakage outweighs lower efficiency near threshold leading to improved linearity of the light current characteristics and higher output optical power and brightness. Broadened waveguide lasers with doped p cladding/SCH interface have twice as high output optical power density and brightness compared to undoped BW devices.", "author_names": [ "Gregory L Belenky" ], "corpus_id": 107975966, "doc_id": "107975966", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Design and Implementation of High Power Pulse Operation Broadened Waveguide 1.5 mum InGaAsP/InP MQW Lasers", "venue": "", "year": 2001 }, { "abstract": "We demonstrate that free carrier absorption in cladding layers of long wavelength /spl lambda/=1.5 /spl mu/m and /spl lambda/=2 /spl mu/m) separate confinement quantum well laser diodes limits the differential efficiency and output power for such lasers if their waveguide thickness is designed from the considerations of the maximum optical confinement factor for quantum wells. Broadening of the waveguide up to 1 /spl mu/m considerably increases laser efficiency and does not increase threshold for the lasers with low and moderate output losses. Broadened waveguide design provides the record output powers at continuous and quasi continuous operation regimes.", "author_names": [ "Dmitri Z Garbuzov", "Raymond J Menna", "Hao Lee", "Ramon U Martinelli", "John C Connolly", "L Xu", "Stephen R Forrest" ], "corpus_id": 119017686, "doc_id": "119017686", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Broadened waveguide, low loss 1.5 /spl mu/m InGaAsP/InP and 2 /spl mu/m InGaAsSb/AlGaAsSb laser diodes", "venue": "Conference Proceedings. 1997 International Conference on Indium Phosphide and Related Materials", "year": 1997 }, { "abstract": "Summary form only given. Single frequency semiconductor lasers with emission wavelength at /spl sim/1.5 /spl mu/m are finding applications as chemical sensors because a large number of molecules have strong absorption bands at this wavelength region including ammonia. Tunable diode laser (TDL) spectroscopy employing tunable single longitudinal mode lasers provides a means in which, trace gases can be accurately monitored using systems that are relatively small in size and low in power consumption. Conventional distributed feedback (DFB) lasers can achieve wavelength selectivity through feedback from a periodic change in index or gain along the laser cavity and this usually requires regrowth, over the corrugation, greatly complicating the fabrication process and making the completed lasers susceptible to unreliability due to the defects at grating/regrowth interface. One way to eliminate this regrowth problem is to introduce the gratings after the lasing cavity is formed and to rely on the coupling of the evanescent optical fields. This has been demonstrated by etching the ridge first and then defining the gratings on both sides of the ridge to fabricate a laterally coupled (LC) ridge waveguide (RW) DFB laser. In this paper, we report on the lasing characteristics of InGaAsP/InP LC RW DFB lasers realized by a greatly simplified fabrication process.", "author_names": [ "Yong Kun Sin", "Yueming Qui", "Richard E Muller", "Paul Donne Maker", "Siamak Forouhar" ], "corpus_id": 122614630, "doc_id": "122614630", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Laterally coupled InGaAsP/InP distributed feedback lasers at 1.5 /spl mu/m for chemical sensing applications", "venue": "CLEO 2001", "year": 2001 } ]

[ { "abstract": "Silicon carbide (SiC) is an important material used in semiconductor industries and nuclear power plants. SiC wafer implanted with H ions can be cleaved inside the damaged layer after annealing, in order to facilitate the transfer of a thin SiC slice to a handling wafer. This process is known as \"ion cut\" or \"Smart Cut\" It is worth investigating the exfoliation efficiency and residual lattice defects in H implanted SiC before and after annealing. In the present paper, lattice damage in the 6H SiC implanted by H2+ to a fluence of 5 x 1016 H2+/cm2 at 450 and 900 degC was investigated by a combination of Raman spectroscopy and transmission electron microscopy. Different levels of damage caused by dynamic annealing were observed by Raman spectroscopy and transmission electron microscopy in the as implanted sample. Atomic force microscopy and scanning white light interferometry were used to observe the sample surface morphology. Surface blisters and exfoliations were observed in the sample implanted at 450 degC and then annealed at 1100 degC for 15 min, whereas surface blisters and exfoliation occurred in the sample implanted at 900 degC without further thermal treatment. This finding can be attributed to the increase in the internal pressure of platelets during high temperature implantation. The exfoliation efficiency, location, and roughness after exfoliation were investigated and possible reasons were discussed. This work provides a basis for further understanding and improving the high efficiency \"ion cut\" technology.", "author_names": [ "Tao Wang", "Zhen Yang", "Bingsheng Li", "Shuai Xu", "Qing Liao", "Fang-fang Ge", "Tongmin Zhang", "Jiaoli Li" ], "corpus_id": 229318002, "doc_id": "229318002", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Lattice Defects and Exfoliation Efficiency of 6H SiC via H2+ Implantation at Elevated Temperature", "venue": "Materials", "year": 2020 }, { "abstract": "Graphene has emerged recently as a new material with outstanding electronic properties1. This includes mass less Dirac fermions, ballistic transport properties at room temperature and good compatibility with silicon planar technology2. Different techniques have been developed in the last six years to fabricate mono or bi layer graphene. They range from exfoliated graphite, either mechanically1 or in a liquid phase solution3 to chemical vapor deposition on a metal surface4, and, more recently, to substrate free synthesis when passing ethanol into an argon plasma5. The method investigated in this work consists in a controlled sublimation of few atomic layers of Si from a single crystal SiC substrate6. Such epitaxial growth of graphene (EG) seems to be the most suitable option for industrial applications but, for easy control, it necessitates either a large and homogeneous sheet of monolayer graphene (MLG) or few layers graphene (FLG) covering the full wafer surface. Basically, on both the Si and C faces of any SiC substrate, graphene grows selectively on some reconstructed parts of the surface. Controlling the growth means then controlling locally the surface reconstruction. At low pressure conditions (below 10 6 Torr) it remains challenging to grow FLG with homogeneous domains larger than few hundred nanometers on both faces7. The homogeneity can be increased by lowering the sublimation rate. It has been demonstrated on the Si face by working at high pressure under a noble gas atmosphere such as argon8,9. In this work10, the surface reconstruction of the C face during the Si sublimation is modified by covering the SiC substrate with a graphite cap. It leads to a strongly step bunched morphology with on few selected terraces the growth of long anisotropic graphene ribbons (5 mm wide and up to 600 mm long) Since the Raman fingerprint of Bernal stacked FLG depends strongly of the number of graphene layers11 and the absorbtance of FLG is almost independent of the wavelength and proportional to the number of graphene layers12, we combine micro Raman spectroscopy with micro transmission measurements to study the quality and thickness uniformity of these ribbons. We find that most of these ribbons are homogeneous monolayers or bilayers of graphene and that the thermal stress between the graphene layer and the 6H SiC substrate is relaxed by the formation of wrinkles. This combination of techniques is especially useful to discriminate without any ambiguity between a monolayer graphene and a misoriented bilayer because their Raman fingerprint are identical. The spectra and extinction coefficient of a monolayer, a Bernal stacked bilayer noted AB, and a misoriented bilayer noted AA' are shown in Figure 1.", "author_names": [ "Antoine Tiberj", "Jean Roch Huntzinger", "B Jouault", "Bilal Jabakhanji", "Jean Camassel", "Nicolas Camara", "Gemma Rius", "Alessandra Caboni", "Francesc Perez-Murano", "Philipe Godignon", "Narcis Mestres" ], "corpus_id": 139674093, "doc_id": "139674093", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Raman spectroscopy of long isolated graphene ribbons grown on the C face of 6H SiC", "venue": "", "year": 2010 }, { "abstract": "6H silicon carbide (SiC) substrates were implanted with nitrogen and aluminum at different doses and annealed in the temperature range from 1300degC 1700degC. Micro Raman Spectroscopy (m RS) measurements were performed in two sample geometries (conventional plane view and cross sectional) Changes of the polytype from 6H to a cubic (SiC) 1 x AIN) x and influences in the 6H SiC wafer up to depths of 2mm were detected. The results obtained by crosssectional m RS are discussed in comparison to other results from Reflection High Electron Energy Diffraction (RHEED) Rutherford Backscattering (RBS) Auger Electron Spectroscopy (AES) Transmission Electron Microscopy (TEM) and Positron Annihilation Spectroscopy (PAS) measurements.", "author_names": [ "Dietrich Rudolf T Zahn", "Th Werninghaus", "M Thumer", "Joerg Pezoldt", "Viton Heera" ], "corpus_id": 98745909, "doc_id": "98745909", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Raman Spectroscopy Investigation of (SiC) 1 x (Ain) x Layers Formed by Ion Implantation in 6H SiC", "venue": "", "year": 1996 }, { "abstract": "A 6H SiC single crystal irradiated in channeling mode by 4 MeV C +3 and Si +3 ions at various doping levels have been examined by SEM and micro Raman spectroscopy in order to study the lattice distortions inflicted by the impinging ions. C ions create zones of strongly damaged regions, parallel to the front face of the wafer with width increasing with the amount of doping. As expected, Si has induced considerably more lattice distortions than C and almost two orders of magnitude less doping induces apparently the same effect as C. Despite the large laser spot size compared with the boundaries of the distorted regions, micro Raman data provided results agreeing with the SEM pictures and the Monte Carlo calculations using the SRIM 2013 software. From the evolution of the crystalline peaks in the Raman spectra one can conclude that the impinging ions do not accommodate as defects in the lattice, but mostly displace the ions breaking the bonds and destroying the long range order.", "author_names": [ "Aikaterini Flessa", "E Ntemou", "Michael Kokkoris", "Efthymios Liarokapis" ], "corpus_id": 222120975, "doc_id": "222120975", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Raman mapping of C and Si channeling implantation of SiC", "venue": "", "year": 2020 }, { "abstract": "Structural perfection of silicon carbide (SiC) single crystals is essential to achieve high performance power devices. A new bulk growth process for SiC proposed by researchers at NASA Glenn Research Center, called large tapered crystal (LTC) growth, based on axial fiber growth followed by lateral expansion, could produce SiC boules with potentially as few as one threading screw dislocation per wafer. In this study, the lateral expansion aspect of LTC growth is addressed through analysis of lateral growth of 6H SiC a/m plane seed crystals by hot wall chemical vapor deposition. Preliminary synchrotron white beam x ray topography (SWBXT) indicates that the as grown boules match the polytype structure of the underlying seed and have a faceted hexagonal morphology with a strain free surface marked by steps. SWBXT Laue diffraction patterns of transverse and axial slices of the boules reveal streaks suggesting the existence of stacking faults/polytypes, and this is confirmed by micro Raman spectroscopy. Transmission x ray topography of both transverse and axial slices reveals inhomogeneous strains at the seed epilayer interface and linear features propagating from the seed along the growth direction. Micro Raman mapping of an axial slice reveals that the seed contains high stacking disorder, while contrast extinction analysis (g*b and g*bxl) of the linear features reveals that these are mostly edge type basal plane dislocations. Further high resolution transmission electron microscopy investigation of the seed homoepilayer interface also reveals nanobands of different SiC polytypes. A model for their formation mechanism is proposed. Finally, the implication of these results for improving the LTC growth process is addressed.", "author_names": [ "Ouloide Yannick Goue", "Balaji Raghothamachar", "Yu Yang", "Jianqiu Guo", "Michael Dudley", "Kim Kisslinger", "Andrew J Trunek", "Philip G Neudeck", "David J Spry", "Andrew Allan Woodworth" ], "corpus_id": 101376044, "doc_id": "101376044", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Study of Defect Structures in 6H SiC a/m Plane Pseudofiber Crystals Grown by Hot Wall CVD Epitaxy", "venue": "Journal of Electronic Materials", "year": 2015 }, { "abstract": "Thin and homogeneous epitaxial graphene (EG) layers on a 6H SiC (000) substrate are fabricated and they cover the whole substrate (10 x 10 mm2) The sample surface is capped by another 6H SiC (000) wafer in a graphite enclosure to form a relatively high Si partial pressure between them, which significantly reduces the extremely high growth rate of EG. The structure and morphology of the EG layers are investigated by Raman spectroscopy, atomic force microscopy and field emission scanning electronic microscopy. The results are compared with an uncapped sample surface, and reveal the obvious existence of ridges on the surface of the EG, and show that capping is indeed beneficial to obtain homogeneous graphene.", "author_names": [ "Deng Pengfei", "Lei Tianmin", "Lu Jin-jun", "Liu Fu-Yan", "Zhang Yuming", "Guo Hui", "Zhang Yi-men", "Wang Yuehu", "Tang Xiaoyan" ], "corpus_id": 123522498, "doc_id": "123522498", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Fabrication of Thin Graphene Layers on a Stacked 6H SiC Surface in a Graphite Enclosure", "venue": "", "year": 2013 }, { "abstract": "The epitaxial graphene on the 4Hor 6H SiC(0001) surface has been intensively studied due to the possibility of wafer scale growt. However the existence of interface layer (zero layer graphene) and its influence on the upper graphene layer have been considered as one of the main obstarcles for the industrial application. Among various methods tried to overcome the strong interaction with the substrate through the interface layer, it has been proved that the hydrogen intercalation successfully passivate the Si dangling bond of the substrate and can produce the quasi free standing epitaxial graphene (QFEG) layers on the siC(0001) surface. In this study, we report the results of the angle resolved photoemission spectroscopy (ARPES) and Raman spectroscopy for the QFEG layers produced by ex situ and in situ hydrogen intercalation.From the ARPES measurement, we confirmed that the Dirac points of QFEG layers exactly coincide with the Fermi level. The band structure of QFEG layer are sustainable upon thermal heating up to 1100 K and robust against the deposition of several metals andmolecular deposition. We also investigated the strain of the QFEG layers by using Raman spectroscopy measurement. From the change of the 2D peak position of graphene Raman spectrum, we found out that unlike the strong compressive strain in the normal epitaxial graphene on the SiC(0001) surface, the strain of the QFEG layer are significantly released and almost similar to that of the mechanically exfoliated graphene on the silicon oxide substrate. These results indicated that various ideas proposed for the ideal free standing graphene can be tested based on the QFEG graphene layers grown on the SiC(0001) surface.", "author_names": [ "" ], "corpus_id": 138225444, "doc_id": "138225444", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Angle Resolved Photoemission Spectroscopy and Raman Spectroscopy Study on the Quasi free Standing Epitaxial Graphene on the 4H SiC(0001) surface", "venue": "", "year": 2013 }, { "abstract": "Abstract 6H SiC has been produced via catalyst free chemical vapor growth method using Si wafer and activated carbon powder as the respective Si and C sources. The effects of heating temperature (1250, 1300, and 1350 degC) and crucible height (9, 13, and 16 cm) on the formation of nanowires and nanoneedles have been systematically investigated. Scanning and transmission electron microscopy, X ray diffraction (XRD) Raman and photoluminescence (PL) spectroscopy have been employed in this study. The reasons for the transformation of nanoneedles to nanowires have also been proposed.", "author_names": [ "Kuan Yew Cheong", "Zainovia Lockman" ], "corpus_id": 137452525, "doc_id": "137452525", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Effects of temperature and crucible height on the synthesis of 6H SiC nanowires and nanoneedles", "venue": "", "year": 2009 }, { "abstract": "Abstract Freestanding graphene on a trench has been fabricated extensively using a transfer process of chemical vapor deposition grown graphene. Here, we demonstrate that freestanding graphene can be grown directly on a trench without a transfer process. A shallow trench was made on a 6H SiC(0001) wafer using a focused ion beam lithography. The shallow trench was heated to a high temperature under Ar atmosphere. The heat treatment made the shallow trench become deeper and wider. Subsequently, epitaxial graphene was floating on the trench, resulting in freestanding graphene, where underlying bulk SiC was self etched after the growth of epitaxial graphene. The freestanding graphene on a trench was characterized using Raman spectroscopy and atomic force microscopy. Such freestanding graphene writing can be applied to semiconductor fabrication process of freestanding graphene devices without a transfer process.", "author_names": [ "I B Khadk", "Junyoung Son", "H -W Kim", "D-H Lee", "B -J Kim", "Dain Sung", "Geun-Yeong Yeom" ], "corpus_id": 224863207, "doc_id": "224863207", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Freestanding graphene writing on a silicon carbide wafer", "venue": "", "year": 2020 }, { "abstract": "Raman spectroscopy has been used to investigate wafers of both 4H SiC and 6H SiC. The wafers studied were semi insulating and n type (nitrogen) doped with concentrations between 2.1x1018 and 1.2x1019 cm 3. Significant coupling of the A1 longitudinal optical (LO) phonon to the plasmon mode was observed. The position of this peak shows a direct correlation with the carrier concentration. Examination of the Raman spectra from different positions on the wafer yielded a rudimentary spatial map of the carrier concentration. These data are compared with a resistivity map of the wafer. These results suggest that Raman spectroscopy of the LO phonon plasmon mode can be used as a noninvasive, in situ diagnostic for SiC wafer production and substrate evaluation.", "author_names": [ "J C Burton", "L Sun", "Milan Pophristic", "S J Lukacs", "Frederick H Long", "Zhe Chuan Feng", "Ian T Ferguson" ], "corpus_id": 119580608, "doc_id": "119580608", "n_citations": 156, "n_key_citations": 2, "score": 2, "title": "Spatial characterization of doped SiC wafers by Raman spectroscopy", "venue": "", "year": 1998 } ]

[ { "abstract": "Power consumption of Global Positioning System (GPS) acquisition is a great challenge for energy constrained applications. In this work, a metric named acquisition mean computation overhead is proposed to measure the energy cost. A novel multi peak double dwell (MP/DD) acquisition method for GPS weak signal is proposed. It adopts multi peak correlation results as candidates in the first acquisition dwell and selects the largest one as the final acquisition result in the second acquisition dwell. Theoretical analysis and numerical simulation are presented in detail. Meanwhile, the very large scale integration (VLSI) implementation of coarse and fine grained acquisition engines applied to the proposed method is done. The detection probability and acquisition mean computation overhead are simulated using the Monte Carlo method, and its mean acquisition power is tested with an actual chip. We fabricated the GPS signal acquisition engine with a 40 nm complementary metal oxide semiconductor (CMOS) process. The simulation results demonstrate that detection probability is promoted from 18% to 67% when signal power is equal to 23 dB/Hz. The acquisition mean computation overhead is reduced greatly by 64% Measurement results show that the energy consumption of this design is only 21.5% of the conventional double dwell/maximum (DD/MAX) method.", "author_names": [ "Zhen Wang", "Hengfeng Zhang", "Min Wang", "Xinning Liu", "Y Zhuang", "Hao Cai", "Jun Yang", "Longxing Shi" ], "corpus_id": 54736502, "doc_id": "54736502", "n_citations": 4, "n_key_citations": 0, "score": 1, "title": "Multi Peak Double Dwell GPS Weak Signal Acquisition Method and VLSI Implementation for Energy Constrained Applications", "venue": "", "year": 2018 }, { "abstract": "Conventional GPS acquisition methods, such as Max selection and threshold crossing (MAX/TC) estimate GPS code/Doppler by its correlation peak. Different from MAX/TC, a multi layer binarized convolution neural network (BCNN) is proposed to recognize the GPS acquisition correlation envelope in this article. The proposed method is a double dwell acquisition in which a short integration is adopted in the first dwell and a long integration is applied in the second one. To reduce the search space for parameters, BCNN detects the possible envelope which contains the auto correlation peak in the first dwell to compress the initial search space to 1/1023. Although there is a long integration in the second dwell, the acquisition computation overhead is still low due to the compressed search space. Comprehensively, the total computation overhead of the proposed method is only 1/5 of conventional ones. Experiments show that the proposed double dwell/correlation envelope identification (DD/CEI) neural network achieves 2 dB improvement when compared with the MAX/TC under the same specification.", "author_names": [ "Zhen Wang", "Y Zhuang", "Jun Yang", "Hengfeng Zhang", "Wei Dong", "Min Wang", "Luchi Hua", "Bo Liu", "Longxing Shi" ], "corpus_id": 13668403, "doc_id": "13668403", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "A Double Dwell High Sensitivity GPS Acquisition Scheme Using Binarized Convolution Neural Network", "venue": "Sensors", "year": 2018 }, { "abstract": "Massive cosmic neutrinos change the structure formation history by suppressing perturbations on small scales. Weak lensing data from galaxy surveys probe the structure evolution and thereby can be used to constrain the total mass of the three active neutrinos. However, much of the information is at small scales where the dynamics are nonlinear. Traditional approaches with second order statistics thus fail to fully extract the information in the lensing field. In this paper, we study constraints on the neutrino mass sum using lensing peak counts, a statistic which captures non Gaussian information beyond the second order. We use the ray traced weak lensing mocks from the Cosmological Massive Neutrino Simulations (MassiveNuS) and apply LSST like noise. We discuss the effects of redshift tomography, multipole cutoff \\ell_{\\rm max} for the power spectrum, smoothing scale for the peak counts, and constraints from peaks of different heights. We find that combining peak counts with the traditional lensing power spectrum can improve the constraint on neutrino mass sum, \\Omega_m$ and $A_s$ by 39% 32% and 60% respectively, over that from the power spectrum alone.", "author_names": [ "Zack Li", "Jia Liu", "Jose Manuel Zorrilla Matilla", "William R Coulton" ], "corpus_id": 55729901, "doc_id": "55729901", "n_citations": 26, "n_key_citations": 0, "score": 0, "title": "Constraining neutrino mass with tomographic weak lensing peak counts", "venue": "Physical Review D", "year": 2019 }, { "abstract": "This paper presents the design of a hybrid harmonic tuned solid state power amplifier (SSPA) for global positioning system (GPS) application. The SSPA provides peak output power of 160 W, with power added efficiency (PAE) of 61% based on a single packaged device from Sumitomo. The targeted power and PAE are obtained by properly tuning the source/load impedance at second and third harmonics also. The realized SSPA is characterized over a bandwidth of 50 MHz in L band (fc=1.575 GHz)", "author_names": [ "Abdul Ali", "Elisa Cipriani", "Paolo Colantonio" ], "corpus_id": 49655172, "doc_id": "49655172", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "A single module compact efficient harmonic tuned 160 W power amplifier for GPS application", "venue": "2018 22nd International Microwave and Radar Conference (MIKON)", "year": 2018 }, { "abstract": "Abstract Glyoxal (CHOCHO) and formaldehyde (HCHO) are organic trace gases that play an important role in tropospheric chemistry as oxidation products of a number of volatile organic compounds (VOCs) In this study, we report year round daytime measurements of glyoxal and formaldehyde in the urban atmosphere of Madrid, Spain. Their vertical concentration profiles were retrieved using the Multi AXis Differential Optical Absorption Spectroscopy (MAX DOAS) technique and a Radiative Transfer Model (RTM) that simulates solar photon paths through the atmosphere. The diurnal variations of HCHO show two distinct peaks during the day, in the early morning and late afternoon in spring and summer, while the second peak is shifted towards noon in autumn and winter, due to lower photolysis rates and more effective boundary layer accumulation of HCHO in those seasons. The HCHO surface mixing ratios range from 6 ppbv to 27 ppbv in spring summer and from 10 ppbv to 30 ppbv in autumn winter. Monthly hourly averaged glyoxal surface mixing ratios in the early morning show higher values during winter, 2 ppbv, than in summer, 0.7 ppbv. We also evaluated the ratio between glyoxal and formaldehyde (RGF) surface mixing ratios, as an indicator of the nature of VOCs precursors. The RGF was also correlated with the measured NO2, which represents a direct signal of anthropogenic emissions, along with the VOCs emission inventories in Madrid. The RGF results yielded higher ratios in spring, 0.1 0.13, than in winter and autumn (in the range of 0.02 0.07) when NO2 levels were higher.", "author_names": [ "Nuria Benavent", "David Garcia-Nieto", "Shanshan Wang", "Alfonso Saiz-Lopez" ], "corpus_id": 106307653, "doc_id": "106307653", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "MAX DOAS measurements and vertical profiles of glyoxal and formaldehyde in Madrid, Spain", "venue": "Atmospheric Environment", "year": 2019 }, { "abstract": "Abstract We present the results of a comprehensive study of traveling ionospheric disturbances (TIDs) occurring over Europe during the total solar eclipse of 20 March 2015. For detection of wave structures and estimation of TID parameters, two remote sensing techniques were combined: incoherent scatter (IS) radars and European and Finnish dense GPS receiver networks. Similar procedures were applied for processing both IS and GPS data. We developed a new method enabling to analyze TEC data separately in the temporal and spatial domain. For the first time, we produced maps of band pass filtered TEC variations and reported both large and medium scale prevailing TIDs observed during this solar eclipse, both having similar periods of about 50 60 min. The downward phase progression indicates that TIDs were induced by atmospheric gravity waves generated at lower altitudes. The variations in IS power attained peak relative amplitudes of 0.22 (22% at 220 km over Tromso and of 0.17 (17% at 200 km over Kharkiv. The vertical phase velocity was about 57 m/s over Tromso. It increased from 25 to 170 m/s over Kharkiv with altitude increasing from 120 to 310 km. Over Western Europe, large scale TIDs (LSTIDs) had prevailing north east direction over the region from 45degto 50degN and 2degW to 8degE. Here, their average horizontal phase velocity V m was 803 281 m/s and the absolute amplitudes of TEC variations usually do not exceed 0.17 TECU. For this region, we found strong differences in LSTID propagation azimuth between the solar eclipse day and the two adjacent days of 19 and 21 March 2015, used as reference. This most likely indicates that these LSTIDs were directly caused by the solar eclipse through local heating/cooling processes occurring during the passing of the Moon penumbra. Over another region, limited by 44deg 50degN and 13deg 19degE, the LSTIDs had south east propagation. Over Finland, the LSTIDs also propagated southeastward having V m 774 202 m/s and TEC amplitudes up to 0.6 TECU. A possible evidence of LSTID generation at high latitudes indirectly by this solar eclipse through an excitation of slow magnetosonic waves was experimentally detected. Medium scale TIDs (MSTIDs) propagated southeastward over both regions having V m values of 144 54 m/s over Western Europe and of 104 43 m/s over Finland. Over Northern Europe, the maximum MSTID amplitudes were greater by a factor of 5 compared to those over Western Europe and reached 0.4 TECU. We did not detect a clear difference in MSTID propagation between solar eclipse and reference days. The IS and GPS results are in consistency with each other. The detected TID parameters of predominant periods, relative amplitudes, altitude range and MSTID horizontal propagation direction generally correspond to the results of other studies.", "author_names": [ "Sergii V Panasenko", "Yuichi Otsuka", "Max van de Kamp", "Leonid Chernogor", "Atsuki Shinbori", "Takuya Tsugawa", "Michi Nishioka" ], "corpus_id": 191151798, "doc_id": "191151798", "n_citations": 8, "n_key_citations": 1, "score": 0, "title": "Observation and characterization of traveling ionospheric disturbances induced by solar eclipse of 20 March 2015 using incoherent scatter radars and GPS networks", "venue": "Journal of Atmospheric and Solar Terrestrial Physics", "year": 2019 }, { "abstract": "In the last decade, important studies have demonstrated that GPS can be also used as an efficient tool for measuring the integrated water vapor (IWV) in the atmosphere which is a useful quantity for climatological and weather forecasting applications. This study presents the first results obtained by using the time series GPS stations of six local stations belonging to the continuously operating Algerian network, and 13 stations of the IGS (International GNSS Service) for the estimation of the value of the IWV locally. In this paper, tropospheric parameters are obtained from double difference processing of GPS observations, collected from 2008 to 2015, using the Bernese 5.2 software. For the validation of GPS IWV values, three approaches are used. In the first, the GPS IWV are compared with the corresponding ERA Interim values derived from interpolations in time and space. The results show a good agreement with correlation coefficients exceeding 85% and an RMS (root mean square) between 2.22 and 5.53 kg m 2. In the second approach, we compare GPS IWV and radiosondes over two stations, where the results showed an acceptable concordance and equivalent to those of the first approach. In the third approach, the GPS ZWD (zenith wet delay) roughly IWV, values are compared with the daily rainfall data provided by the Algerian Meteorological Office. The results show that the temporal variation of ZWD and the high rainfall collected by rain gauges (not far from those of GPS) present a perfect coincidence over the surrounding observed peaks. Finally, the analysis of the annual time cycle of ZWD and precipitation carried out on the data of geographically and climatically different GPS stations shows that these two parameters depend on the latitude of the site. The first experimental results of this study further strengthen the strong potential of GPS in meteorological applications.", "author_names": [ "Hassen Abdellaoui Hassen Abdellaoui", "N Boutarek Zaourar", "Salem Kahlouche" ], "corpus_id": 134741663, "doc_id": "134741663", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Contribution of permanent stations GPS data to estimate the water vapor content over Algeria", "venue": "Arabian Journal of Geosciences", "year": 2019 }, { "abstract": "When does large scale battery storage become economically feasible? To answer this question and put a value on the different services battery storage can provide, we performed techno economic analyses on the use of large scale battery storage in Norwegian electricity distribution systems. In the first use case we looked at the feasibility of batteries for peak load shaving and thereby network charge reduction under the power based tariff structure. In the second use case, battery storage was used to reduce both peak load and peak infeed in order to comply with the 100 kW max feed in rule that is part of the Norwegian prosumer regulation, the \"Plusskundeordning\" Both of these applications are far from economical at current prices. The third use case was about battery storage used to provide balancing power. This seems to be the most feasible application at the moment. We performed sensitivity analyses under different balancing prices, grid charges, battery degradation levels, battery rest value and capital costs, to identify where battery storage becomes profitable in the Norwegian market. We reference the description of new regulations, tariffs structures, the battery degradation model, the methodology used for the economic evaluation and the controller models for all use cases. The study was performed in the project IntegER.", "author_names": [ "Peter Ahcin", "Kjersti Berg", "Idar Petersen" ], "corpus_id": 208634004, "doc_id": "208634004", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Techno economic analyis of battery storage for peak shaving and frequency containment reserve", "venue": "2019 16th International Conference on the European Energy Market (EEM)", "year": 2019 }, { "abstract": "Mobility and spatial interaction data have become increasingly available due to the widespread adoption of location aware technologies. Examples of mobile data include human daily activities, vehicle trajectories, and animal movements. In this study we focus on a special type of mobility data, i.e. origin destination (OD) pairs, and propose a new adapted chord diagram plot to reveal the urban human travel spatial temporal characteristics and patterns of a seven day taxi trajectory data set collected in Beijing; this large scale data set includes approximately 88.5 million trips of anonymous customers. The spatial distribution patterns of the pick up points (PUPs) and the drop off points (DOPs) on weekdays and weekends are analyzed first. The maximum of the morning and the evening peaks are at 8:00 10:00 and 17:00 19:00. The morning peaks of taxis are delayed by 0.5 1 h compared with the commuting morning peaks. Second, travel demand, intensity, time, and distance on weekdays and weekends are analyzed to explore human mobility. The travel demand and high intensity travel of residents in Beijing is mainly concentrated within the 6th Ring Road. The residents who travel long distances >10 km) and for a long time >60 min) mainly from outside the 6th Ring Road and the surrounding new towns of Beijing. The circular structure of the travel distance distribution also confirms the single center urban structure of Beijing. Finally, a new adapted chord diagram plot is proposed to achieve the spatial temporal scale visualization of taxi trajectory origin destination (OD) flows. The method can characterize the volume, direction, and properties of OD flows in multiple spatial temporal scales; it is implemented using a circular visualization package in R (circlize) Through the visualization experiment of taxi GPS trajectory data in Beijing, the results show that the proposed visualization technology is able to characterize the spatial temporal patterns of trajectory OD flows in multiple spatial temporal scales. These results are expected to enhance current urban mobility research and suggest some interesting avenues for future research.", "author_names": [ "Huihui Wang", "Hong Huang", "Xiaoyong Ni", "Weihua Zeng" ], "corpus_id": 192611014, "doc_id": "192611014", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Revealing Spatial Temporal Characteristics and Patterns of Urban Travel: A Large Scale Analysis and Visualization Study with Taxi GPS Data", "venue": "ISPRS Int. J. Geo Inf.", "year": 2019 }, { "abstract": "Thank you to NASA's GHRC, NOAA, Kyoto GIN, blitzortung, weather.us, and timeanddate.com for weather, lightning, precipitation, and geomagnetic data. (a) (b) Figure 3: Examples of two different methods used to locate lightning strikes. Figure 2.a is community sourced lightning map. It shows a six hour time lapse of August 9 starting from 18:00 UTC (Courtesy: blitzortung.org) Figure 2.b is the map of all lightning strikes from August 2018 to February 2019. This data is obtained from the International Space Station (ISS) The red square is one degree by one degree centered on the approximate longitude and latitude of Daytona Beach set at 29degN and 81degW (Courtesy: NASA's GHRC) Figure 1: Radar analysis of the approximate max. elevation of precipitation (echo tops) of thunderstorms on August 9, 2018. The actual cloud top of the storm usually reaches beyond the echo top. The storm shown is over 45000 ft (14 km) The times shown for these days correlate with scintillation observed on these days (Courtesy: weather.us) Figure 6: Sky Plot of the location of PRNs 2 (in blue) and 5 (in red) on August 9, 2018. The degrees on the outer circle represent the azimuth angle, and the inner circles represent the elevation of the satellites. Both PRN trajectories are limited by a 50deg elevation mask to help eliminate possible multipath. Figure 2: Plots from GPS satellite PRN 2 on August 8 10. Possible scintillation can be seen on August 9 two hours after 17:00 UTC and August 10 three and a half hours after 17:00 UTC. August 8 was a normal day used to rule out multipath. Figure 4: Plots from GPS satellite PRN 5 on August 8 10. August 8 and August 10 were used to compare and rule out multipath. Peaks, which are typically scintillation, are mainly seen in the power plot on August 9.", "author_names": [ "Julian T Herrera", "Marissa Priore", "Danayit T Mekonnen" ], "corpus_id": 202198121, "doc_id": "202198121", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Tropospheric Scintillation Signatures: Observations of the Possible Effect Thunderstorms have on GPS Signals", "venue": "", "year": 2019 } ]

[ { "abstract": "Prolonged exposure to NO2 can cause lung tissue inflammation, bronchiolitis fibrosa obliterans, and silo filler's disease. In recent years, nanostructured semiconducting metal oxides have been widely used to fabricate gas sensors because of their unique structure and surface to volume ratio compared to layered materials. In particular, the different morphologies of ZnO based nanostructures significantly affect the detection property of NO2 gas sensors. However, because of the large interaction energy of chemisorption (1 10 eV) metal oxide based gas sensors are typically operated above 100 degC, overcoming the energy limits to attain high sensitivity and fast reaction. High operating temperature negatively affects the reliability and durability of semiconductor based sensors; at high temperature, the diffusion and sintering effects at the metal oxide grain boundaries are major factors causing undesirable long term drift problems and preventing stability improvements. Therefore, we demonstrate NO2 gas sensors consisting of ZnO hemitubes (HTs) and nanotubes (NTs) covered with TiO2 nanoparticles (NPs) To operate the gas sensor at room temperature (RT) we measured the gas sensing properties with ultraviolet illumination onto the active region of the gas sensor for photoactivation instead of conventional thermal activation by heating. The performance of these gas sensors was enhanced by the change of barrier potential at the ZnO/TiO2 interfaces, and their depletion layer was expanded by the NPs formation. The gas sensor based on ZnO HTs showed 1.2 times higher detection property than those consisting of ZnO NTs at the 25 ppm NO2 gas.", "author_names": [ "Hee-Jung Choi", "Soon-Hwan Kwon", "Wonseok Lee", "Kwang-Gyun Im", "Tae-Hyun Kim", "Beom-Rae Noh", "Sunghoon Park", "Semi Oh", "Kyoung-Kok Kim" ], "corpus_id": 212621616, "doc_id": "212621616", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Ultraviolet Photoactivated Room Temperature NO2 Gas Sensor of ZnO Hemitubes and Nanotubes Covered with TiO2 Nanoparticles", "venue": "Nanomaterials", "year": 2020 }, { "abstract": "Abstract Gas sensors based on a chemiresistive metal oxide semiconductor are widely used including nitrogen dioxide (NO 2 at a moderate temperature. In this work efforts are taken to fabricate NO 2 gas sensor using thin films of tungsten oxide (WO 3 grown directly on to a soda lime glass substrate without assistance of any seed layer by a simple and a facile hydrothermal technique. As per our knowledge, the deposition of nanostructured WO 3 thin films without assistance of any seed layer on the glass substrate was rarely reported. The WO 3 thin film samples were synthesized at various deposition times ranging from 3 h to 7 h and were characterized by X ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, UV vis spectroscopy and Brunauer Emmett Teller techniques. The surface morphological and structural characterization showed the two dimensional (2D) nanoplate like structure of as synthesized WO 3 thin films with plate thickness ranging from 90 to 150 nm and had an orthorhombic structure, respectively. Moreover, the 2D nanoplates of WO 3 exhibited a gas response ~10 for 5 ppm for toxic NO 2 gas at relatively low operating temperature. The new synthesis route and sensing behavior of as synthesized WO 3 nanoplates revealed a promising candidate for the fabrication of the cost effective gas sensors.", "author_names": [ "Suresh Shamrao Shendage", "Vithoba L Patil", "Sharadrao A Vanalakar", "Sandip P Patil", "Namdev S Harale", "J L Bhosale", "Jung Ha Kim", "Pramod S Patil" ], "corpus_id": 99860497, "doc_id": "99860497", "n_citations": 188, "n_key_citations": 2, "score": 1, "title": "Sensitive and selective NO2 gas sensor based on WO3 nanoplates", "venue": "", "year": 2017 }, { "abstract": "Single walled carbon nanotubes (SWNTs) are incorporated in different device configurations such as chemiresistors and field effect transistors (FETs) as a sensing element for the fabrication of highly sensitive and specific biochemical sensors. For this purpose, sorting and aligning of semiconducting SWNTs between the electrodes is advantageous. In this work, silicon shadow mask, fabricated using conventional semiconductor processes and silicon bulk micromachining were used to make metal contacts over SWNTs with a minimum feature of 1 um gap between the electrodes. The developed silicon shadow mask based metal contacts patterning process is cost effective, free from photoresist (PR) chemical coatings and thermal processing. After the detailed investigation, sodium dodecyl sulphate (SDS) an anionic surfactant along with ultrasonication process was found effective for the removal of unclamped and metallic SWNTs, resulting in aligned and clamped semiconducting SWNTs between the electrodes. The presence of aligned semiconducting SWNTs was confirmed using atomic force microscopy (AFM) field emission scanning electron microscopy (FESEM) and Raman spectroscopy techniques. The fabricated devices were tested for nitrogen dioxide (NO2) gas sensing as a test case. The sensitivity enhancement of ~21% to 76% in the 20 80 ppm NO2 concentration range has been observed in the case of aligned semiconducting SWNTs devices as compared to the random network SWNT based sensors.", "author_names": [ "Pankaj B Agarwal", "Rishi Sharma", "Dharmesh Mishra", "Navneet Kumar Thakur", "Ajay Agarwal", "Ayyappanpillai Ajayaghosh" ], "corpus_id": 221166024, "doc_id": "221166024", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Silicon Shadow Mask Technology for Aligning and In Situ Sorting of Semiconducting SWNTs for Sensitivity Enhancement: A Case Study of NO2 Gas Sensor.", "venue": "ACS applied materials interfaces", "year": 2020 }, { "abstract": "Abstract The porous flake like Co3O4 and Co3O4/graphene hybrids with different graphene contents were prepared through a facile two step method. The field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) characterizations proved the tight adherence of graphene sheets to the surface of porous Co3O4 slices. Gas sensors based on the as synthesized products were then fabricated to explore their potential applications. The results indicated that the optimal hybrid exhibited a response of 26.8% to 5 ppm of NO2 at room temperature (RT) which was 2.27 times higher than that of undoped Co3O4 (100 degC) The hybrid sensor also showed fast response, excellent selectivity, long term stability and extremely low detection limit toward NO2 at RT. The significantly enhanced sensing properties to NO2 could be attributed to larger specific surface area, more chemisorbed oxygen species and the coupling effect between Co3O4 and graphene in the hybrid. As we all know, as a typical p type semiconductor, the gas sensing properties of Co3O4 toward oxidizing gases including NO2 was rarely reported. We believe that our work could pave the way for the future design of Co3O4 based gas sensors for oxidizing gases detection at low or even room temperature.", "author_names": [ "Bo Zhang", "Ming Cheng", "Guannan Liu", "Yuan Gao", "Lianjing Zhao", "Shanshan Li", "Yipei Wang", "Fangmeng Liu", "Xishuang Liang", "Tong Zhang", "Geyu Lu" ], "corpus_id": 103639528, "doc_id": "103639528", "n_citations": 90, "n_key_citations": 0, "score": 0, "title": "Room temperature NO2 gas sensor based on porous Co3O4 slices/reduced graphene oxide hybrid", "venue": "", "year": 2018 }, { "abstract": "We report the development of a new type of organic semiconductor gas sensor based on a porphyrin based hydrogen bonded organic framework (HOF) Owing to the orderly porous structures, the decoration with rich amino sites and the n type semiconductor nature, this HOF based sensor exhibits selective NO2 sensing performance with ultra fast response/recovery rates (17.6 s/15.4 s over 100 ppb) and a limit of detection lower than 40 ppb, together with high sensitivity, good reproducibility, and long term stability at room temperature. This study demonstrates that HOF based materials have potential application prospects in gas sensing, thereby offering a new way of thinking for the design and development of sensors.", "author_names": [ "Yi-jie Wang", "Di Liu", "Jianbo Yin", "Yanxue Shang", "Juan Du", "Zixi Kang", "Rongming Wang", "Yanli Chen", "Daofeng Sun", "Jianzhuang Jiang" ], "corpus_id": 209390853, "doc_id": "209390853", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "An ultrafast responsive NO2 gas sensor based on a hydrogen bonded organic framework material.", "venue": "Chemical communications", "year": 2019 }, { "abstract": "Abstract ZIF 67 derived from crystalline Co3O4 coupled with g C3N4 nanosheets (NSs) was prepared and adopted for detecting ppb level NO2 gas at room temperature (RT) As obtained Co3O4 particles reside in the rhombohedral and porous framework structure inheriting from ZIF 67, which contact intimately with two dimensional g C3N4 nanosheets, leading to the formation of the p n heterojunction. This structure has maintained the benefits from ZIF 67, such as high surface area and greater porosity. Moreover, the introduction of n type semiconductor g C3N4 NSs has enhanced the local electron density of Co3O4 that can help in the fast transportation of charge carriers and resultantly increase the gas sensing properties. The optimal Co3O4/g C3N4 presents impressive response of 17.83 to 60 ppm to NO2 gas at room temperature, with fast response time (1.06 s) quick recovery time (26.6 s) long term stability and high selectivity. This approach offers new ideas to produce heterostructure between the metal organic frameworks derived metal oxides with g C3N4 NSs resultantly increases the sensitivity of metal oxides based gas sensors, which can be used as highly potential gas sensors.", "author_names": [ "Mohib Ullah", "Xue Bai", "Junkun Chen", "He Lv", "Zhuo Liu", "Jue Wang", "Baihe Sun", "Luming Li", "Keying Shi" ], "corpus_id": 229445810, "doc_id": "229445810", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Metal organic framework material derived Co3O4 coupled with graphitic carbon nitride as highly sensitive NO2 gas sensor at room temperature", "venue": "", "year": 2020 }, { "abstract": "Abstract Solution processed organic field effect transistor (OFET) has great potential in detecting various hazardous gases including nitrogen dioxide (NO2) To overcome the bottleneck of weak gas adsorption/interaction capability in single semiconductor sensing layer, semiconductor composites are used to enhance the sensing response. Here, we report an OFET based NO2 sensor whose active layer consists of diluted poly(3 hexylthiophene 2,5 diyl) (P3HT) with poly[N,N' bis(4 butylphenyl) N,N' bis(phenyl)benzidine] (poly TPD) Due to the site increase effect induced by phase segregation, the 90% diluted device possesses a more than 3 fold enhancement of current responsivity. Furthermore, when the gate voltage is switched from 40 V to 0 V, this device embodies 4.6 fold and 43.6 fold improvements at 0.3 ppm and 30 ppm, respectively. Meanwhile, decent selectivity, environmental stability and an excellent limit of detection of 242.6 ppb are realized.", "author_names": [ "Zuchong Yang", "Xinming Zhuang", "Shijiao Han", "Junsheng Yu" ], "corpus_id": 105856419, "doc_id": "105856419", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Hole transporting polymer dilution driven high performance organic transistor based NO2 gas sensor", "venue": "Materials Letters", "year": 2019 }, { "abstract": "Abstract By using 1D ZnO nanorod, obtained from a simple two step chemical method as the sensor material, we report the fabrication of highly selective metal semiconductor metal (MSM) ultraviolet (UV) photodetector and NO2 gas sensor. The fabricated MSM UV photodetector and gas sensor possesses simplicity in material synthesis and sensor design. The effect of morphological evolution and structural intactness on the sensing properties of UV photodetector and NO2 gas sensor are deeply studied. The well aligned 1 dimensional (1D) ZnO nanorod provides high surface area for the sensing mechanism. The UV photodetector possesses high responsivity in the UV A region (364.81 A/W) with fast photoswitching characteristics at 5 V bias. It shows formation of good ohmic contact between metal semiconductor junctions. NO2 sensing measurement was carried out at relatively lower temperature of about 175 degC. The ZnO nanorods are highly selectivity towards NO2 gas and maximum gas response observed is 35 at 40 ppm of NO2. The NO2 gas sensor shows good repeatability at lower gas concentration of 2 ppm. The present synthesis technique provides cost effective route for obtaining highly ordered ZnO nanorods with simple sensor technology for multifunctional ZnO nanorod sensor.", "author_names": [ "Sohel Khalil Shaikh", "V V Ganbavale", "S V Mohite", "Umakant M Patil", "K Y Rajpure" ], "corpus_id": 125629421, "doc_id": "125629421", "n_citations": 23, "n_key_citations": 0, "score": 0, "title": "ZnO nanorod based highly selective visible blind ultra violet photodetector and highly sensitive NO2 gas sensor", "venue": "", "year": 2018 }, { "abstract": "Because the oxides of nitrogen (NOx) cause detrimental effects on not only the environment but humans, developing a high performance NO2 gas sensor is a crucial issue for real time monitoring. To this end, metal oxide semiconductors have been employed for sensor materials. Because in general, semiconductor type gas sensors require a high working temperature, photoactivation has emerged as an alternative method for realizing the sensor working at room temperature. In this regard, titanium dioxide (TiO2) is a promising material for its photocatalytic ability with ultraviolet (UV) photonic energy. However, TiO2 based sensors inevitably encounter a problem of recombination of photogenerated electron hole pairs, which occurs in a short time. To address this challenge, in this study, TiO2 nanorods (NRs) and Pt nanoparticles (NPs) under a UV LED were used as an NO2 gas sensor to utilize the Schottky barrier formed at the TiO2 Pt junction, thereby capturing the photoactivated electrons by Pt NPs. The separation between the electron hole pairs might be further enhanced by plasmonic effects. In addition, it is reported that annealing TiO2 NRs can achieve noteworthy improvements in sensing performance. Elucidation of the performance enhancement is suggested with the investigation of the X ray diffraction patterns, which implies that the crystallinity was improved by the annealing process.", "author_names": [ "Jinhong Noh", "Soon-Hwan Kwon", "Sunghoon Park", "Kyoung-Kok Kim", "Yong-Jin Yoon" ], "corpus_id": 232258431, "doc_id": "232258431", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "TiO2 Nanorods and Pt Nanoparticles under a UV LED for an NO2 Gas Sensor at Room Temperature", "venue": "Sensors", "year": 2021 }, { "abstract": "Abstract Cu doped a Fe2O3 semiconducting nanofibers were prepared by electrospinning over a wide range of Cu molar ratios (fCu 0 0.52 for fCu fFe 1) followed then by pyrolysis in air atmosphere to remove the organic template. Cu favored to substitute some of the Fe cations in the hematite structure to form crystalline cuprospinel (CuFe2O4) phase. The nanofibers exhibited an interesting p to n type transition of semiconducting behavior when fCu was increased above 0.23, as observed from electrical resistance change against oxidative NO2 gas of ppm levels (5 50 ppm) at 300 degC. The sensing response decreased from 2.59 to 1.52 when the CuFe2O4 concentration increases; nonetheless, the presence of CuFe2O4 facilitated adsorption of the NO2 gas, resulted in a shortened response time (up to 40% as fCu was increased to 0.52.", "author_names": [ "R Wu", "Chun Wei Lin", "Wenjea J Tseng" ], "corpus_id": 98933518, "doc_id": "98933518", "n_citations": 21, "n_key_citations": 0, "score": 0, "title": "Preparation of electrospun Cu doped a Fe2O3 semiconductor nanofibers for NO2 gas sensor", "venue": "", "year": 2017 } ]

[ { "abstract": "The Electrochemical Society Interface Winter 2004 tate of the art manufacturing of semiconductor devices involves the electrodeposition of copper for on chip wiring of integrated circuits. In the Damascene process, interconnects are fabricated by first patterning trenches and vias in a dielectric medium and then filling by metal electrodeposition over the entire wafer surface. This is followed by a planarization step that leaves an array of wires and interlevel vias embedded in the dielectric matrix. The metallization process, pioneered by IBM, depends on the use of electrolyte additives that affect the local metal deposition rate, thereby resulting in superfilling, or bottom up void free filling of trenches and vias.1,2 An example of this remarkable deposition behavior is given in Fig. 1 where growth as a function of electrodeposition time and feature aspect ratio reveals preferential metal deposition at the bottom of the trenches followed by bump formation above the filled trench.3 In the early years of copper Damascene technology an understanding of the superfilling process lagged behind its implementation due to a combination of factors. The first generation of electrolytes contained numerous components and general knowledge of both the chemistry and processing conditions was significantly constrained by proprietary concerns. As a result, early modeling studies focused on traditional leveling theory where the location dependent growth rate derived from diffusion limited accumulation and consumption of an inhibiting species on the metal surface.2,4,5 In these studies it was necessary to empirically modify the area blockage leveling theory to describe feature filling.2,4 Despite these modifications, detailed studies of shape evolution and the observation of bump formation above the filled trenches made it clear that superfilling could not be rationalized by traditional transport limited leveling Superfilling and the Curvature Enhanced Accelerator Coverage Mechanism", "author_names": [ "Thomas P Moffat", "Daniel Wheeler", "Daniel Josell" ], "corpus_id": 119100674, "doc_id": "119100674", "n_citations": 19, "n_key_citations": 0, "score": 1, "title": "Superfilling and the curvature enhanced accelerator coverage mechanism", "venue": "", "year": 2004 }, { "abstract": "Abstract Superconformal electrodeposition is explained by the curvature enhanced adsorbate coverage (CEAC) mechanism. A CEAC model is used to quantitatively explain shape evolution during bottom up \"superfill\" of trenches and vias. The bottom up filling dynamic is seen to be a consequence of competitive adsorption between a rate suppressing polyethylene glycol chloride layer (PEG Cl) and a depassivating or rate accelerating species comprised of sulfonate terminated propane thiol/disulfide and chloride (SPS Cl) The SPS is the stronger surfactant and it adsorbs concurrently with displacement of the more rapidly formed PEG Cl layer; growth on non planar geometries thus leads to enrichment of SPS on advancing concave surfaces and dilution on convex sections. Because the metal deposition rate rises monotonically with the local accelerator (SPS Cl) surface coverage, this yields positive feedback that naturally gives rise to desirable bottom up superfilling. As the accelerating action of SPS can also be quenched by the addition of a cationic surfactant (LEV) additive concentrations can be optimized to allow SPS derived bottom up superfilling followed by LEV induced SPS deactivation. The LEV addition can thus be used to inhibit overshoot that otherwise would result in undesirable bump formation above the features. This paper presents a summary of electroanalytical experiments and simulations designed to determine the mechanism and rate constants of the adsorbate interactions during copper deposition in the PEG Cl SPS LEV system as well as predictions of feature filling using the CEAC shape change model.", "author_names": [ "Thomas P Moffat", "Daniel Wheeler", "Soo-Kil Kim", "Daniel Josell" ], "corpus_id": 98633561, "doc_id": "98633561", "n_citations": 107, "n_key_citations": 0, "score": 0, "title": "Curvature enhanced adsorbate coverage mechanism for bottom up superfilling and bump control in damascene processing", "venue": "", "year": 2007 }, { "abstract": "The influence of a catalyst deactivating leveling additive in electrodeposition is explored in the context of the previously developed curvature enhanced accelerator coverage model of superconformal film growth. Competitive adsorption between a rapidly adsorbed suppressor, rate accelerating catalyst, and catalyst deactivating leveler is examined. Rate equations are formulated where the leveling agent is capable of deactivating the adsorbed catalyst by either direct adsorption from the electrolyte or by deactivation/displacement during surface area reduction that accompanies advancing concave surfaces. The influence of a prototypical cationic surfactant leveler on electrochemical kinetics and feature filling is examined for copper electrodeposition from an electrolyte containing polyethylene glycol chloride bis(3 sulfopropyl)disulfide (PEG Cl SPS)", "author_names": [ "Thomas P Moffat", "Daniel Wheeler", "Soo Kyum Kim", "Daniel Josell" ], "corpus_id": 56468372, "doc_id": "56468372", "n_citations": 101, "n_key_citations": 2, "score": 0, "title": "Curvature Enhanced Adsorbate Coverage Model for Electrodeposition", "venue": "", "year": 2006 }, { "abstract": "Bottom up superconformal feature filling during electrodeposition, called \"superfilling,\" that is used for industrial processing of damascene copper interconnects has also been demonstrated during electrodeposition of silver and gold. The curvature enhanced accelerator coverage (CEAC) mechanism has been proposed to underlie all three processes and has been used to quantitatively predict observed filling of patterned features. The key feature of the CEAC mechanism is redistribution of adsorbed additives through changes of local surface area as dictated by mass conservation and the relative strengths of adsorption. Previous studies of CEAC mediated superfilling have neglected adsorbate diffusion along the surface that might arise during deposition due to the CEAC induced gradients in surface coverage. This paper extends the CEAC model to include such diffusion, applying the resulting formulation to understand differences in the geometries of experimental superfilling systems.", "author_names": [ "Daniel Josell", "Thomas P Moffat", "Daniel Wheeler" ], "corpus_id": 55955133, "doc_id": "55955133", "n_citations": 44, "n_key_citations": 1, "score": 0, "title": "Superfilling When Adsorbed Accelerators Are Mobile", "venue": "", "year": 2007 }, { "abstract": "Interesting phenomena were observed during an investigation on the accelerating effects of 3 mercapto 1 propane sulfonic acid (MPSA) i.e. different aging times of MPSA result in different filling profiles. When MPSA wasadded to the electrolyte immediately before electrodeposition, subconformal deposits appeared, whereas MPSA aged over 12 h enabled superfilling. From UV visible analysis, over 99% MPSA was converted to bis(3 sulfopropyl)disulfide (SPS) within 12 h through the reaction with Cu 2 which means that SPS was, in terms of \"visible\" superfilling, the real accelerator. This arose from the fact that SPS experienced adsorption first, while MPSA underwent Cu 2 reduction first at the trench entrance.", "author_names": [ "Soo-Kil Kim", "Jae Jeong Kim" ], "corpus_id": 62803715, "doc_id": "62803715", "n_citations": 56, "n_key_citations": 1, "score": 0, "title": "Superfilling Evolution in Cu Electrodeposition Dependence on the Aging Time of the Accelerator", "venue": "", "year": 2004 }, { "abstract": "The effects of plating process on the surface coverage of the accelerator were investigated in terms of Cu superfilling for device metallization. When a substrate having 500 nm wide trench patterns on it was immersed in an electrolyte containing poly (ethylene glycol) (PEG) chloride ion bis(3 sulfopropyl) disulfide (SPS) additives without applying deposition potential for such a time of about 100s, voids were generated inside of the electrodeposit. In time evolved electrochemical analyses, it was observed that the process (immersion without applying potential) in the electrolyte led to the build up of high initial coverage of SPS Cl on the surface, resulting in the fast saturation of the coverage. Repeated experiments suggested that the fast saturation of SPS Cl failed in superfilling while a gradual increase in the SPS Cl coverage through competition with initially adsorbed PEG Cl enabled it. Consequently, superfilling was achievable only in the case of applying the plating potential as soon as the substrate is dipped in an electrolyte to prevent rapid accumulation of SPS Cl on the surface.", "author_names": [ "Sung-Ki Cho", "Myung Jun Kim", "Hyo-Chol Koo", "Soo-Kil Kim", "Jae Jeong Kim" ], "corpus_id": 53340307, "doc_id": "53340307", "n_citations": 15, "n_key_citations": 0, "score": 0, "title": "An Empirical Relation between the Plating Process and Accelerator Coverage in Cu Superfilling", "venue": "", "year": 2012 }, { "abstract": "Electroanalytical measurements and feature filling experiments have been conducted to study the effect of dodecyltrimethylammonium chloride (DTAC) a quaternary ammonium cationic surfactant, on Cu deposition in the presence of various combinations of superfilling additives. A variety of other surfactants, cetyltrimethylammonium chloride, cetyltrimethylammonium hydrogen sulfate, and sodium dodecyl sulfate were examined to reveal the significance of head group charge, counterion, and chain length for the adsorption and interaction of levelers with the accelerator bis(3 sulfopropyl) disulfide (SPS) Dodecyltrimethylammonium chloride (DTAC) saturated surfaces yield substantial inhibition of Cu deposition that is similar in magnitude to that provided by polyethylene glycol (PEG) Cl. This suggests that such layers operate by physically limiting access of Cu 2+ to the Cu surface. However, the addition of DTAC and related cationic surfactants quench the characteristic voltammetric hysteresis of the PEG Cl SPS system. This is attributed to ion pairing between the cationic head group of the surfactants and the anionic tail group of SPS, resulting in the deactivation of SPS. Deactivation may occur either by DTAC accumulation from the electrolyte or by lateral interaction during area reduction that occurs on advancing concave surfaces in accordance with the curvature enhanced adsorbate coverage mechanism. The combined process may be optimized to enable the superfilling dynamic to be sustained while overfill bump is effectively attenuated.", "author_names": [ "Soo Kyum Kim", "Daniel Josell", "Thomas P Moffat" ], "corpus_id": 96742185, "doc_id": "96742185", "n_citations": 69, "n_key_citations": 0, "score": 0, "title": "Cationic Surfactants for the Control of Overfill Bumps in Cu Superfilling", "venue": "", "year": 2006 }, { "abstract": "To avoid complications brought about by employing organic additives, microcontact printing using a flat stamp was used in forming trench selective Cu superfilling on damascene structure. Self assembled monolayers of 1 decanethiol transferred on top surface of the trench could withstand the H 2 SO 4 electrolyte and were used as a barrier for current transfer below a certain potential that was not yet dominated by the tunneling current. Subsequent electrodeposition on the printing area was successfully inhibited. The resulting filling profile was a defect free superfilling with bumps on top. This is comparable to the three additive system consisting of accelerator and two component suppressor.", "author_names": [ "Soo-Kil Kim", "Jae Jeong Kim" ], "corpus_id": 97241336, "doc_id": "97241336", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Additive Free Superfilling in Damascene Cu Electrodeposition Using Microcontact Printing", "venue": "", "year": 2004 }, { "abstract": "Accelerator dominant bottom up copper superfilling of TSVs was demonstrated. Because of the 100 times large dimensions compared to on chip interconnections, strong inhibition on the top surface is needed and the superfilling of TSVs are generally achieved by addition of levelers in the plating bath. Recently, we reported that accelerator can be deactivated by reverse pulses and the deactivation needs solution agitation. It was expected that reverse pulses deactivate the acceleration selectively on the top surface and the acceleration around via bottoms was preserved and obvious bottom up superfilling was demonstrated by three step plating process. Some levelers, such as PEI (Polyethyleneimin) is known to suppress the deposition strongly. We verified that PEI deactivated the accelerator and explored the use of PEI to deactivate the accelerator. In this study, we demonstrated that the bottom up superfilling by the modified three step process in which a PEI bath was used instead of the reverse pulse proposed in our previous study.", "author_names": [ "Masanori Hayase", "Naoki Mizukoshi", "Masayuki Nagao" ], "corpus_id": 25082561, "doc_id": "25082561", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Copper deep via superfilling by selective accelerator deactivation", "venue": "2011 IEEE International 3D Systems Integration Conference (3DIC) 2011 IEEE International", "year": 2012 }, { "abstract": "The impact of branched polyethyleneimine (PEI) on Cu electrodeposition from an acidified cupric sulfate electtrolyte containing a combination of superfilling additives, specifically polyethylene glycol, bis(3 sulfopropyl)disulfide, and chloride (PEG Cl SPS) is examined. Electroanalytical measurements reveal that adsorption of cationic PEI leads to inhibition of the metal deposition reaction to an extent similar to that provided by PEG Cl adsorption. However, unlike the PEG Cl suppressor, PEI is shown to deactivate adsorbed SPS accelerator. As a result, addition of PEI quenches the hysteretic voltammetric response that is a signature of competitive adsorption in the PEG Cl SPS additive system. Trench filling experiments in a PEI PEG Cl SPS electrolyte demonstrate that the deactivating interaction between PEI adsorption and adsorbed SPS can be optimized to prevent overfill bump formation without substantial detrimental impact on bottom up, void free feature filling.", "author_names": [ "Soo Kyum Kim", "Daniel Josell", "Thomas P Moffat" ], "corpus_id": 55138431, "doc_id": "55138431", "n_citations": 101, "n_key_citations": 1, "score": 0, "title": "Electrodeposition of Cu in the PEI PEG Cl SPS Additive System Reduction of Overfill Bump Formation During Superfilling", "venue": "", "year": 2006 } ]

[ { "abstract": "Semiconductor technology has been scaling down at an exponential rate for many decades, yielding dramatic improvements in power, performance and cost, year after year. Today's advanced CMOS transistors have critical dimensions well below 24nm. This means that controlling the manufacturing process is increasingly difficult. Process and material fluctuations cause device and circuit characteristics to deviate from design goals, and introduce significant device to device variability due to spatial variations across silicon wafers. Accurate modeling of these spatial process variations has become critical to both foundries and circuit designers that seek optimal power/speed/area balance. To understand the nature of spatial process variations, we first carried out a comprehensive variability analysis of data measured from thousands of variability sensitized test structures, including ring oscillators, SRAM bit cells and their internal transistors. We manufactured these test chips using early stage 90nm and 45nm commercial semiconductor processes. We proposed a hierarchical variability model to capture the systematic and random components of device parameter variations across silicon wafers, and across chips. The detailed decomposition of the process variation profile reveals significant across wafer systematic component for the delay and leakage of ring oscillators, and across chip systematic component for the read/write margins of SRAM bit cells, as well as their internal transistors. The proper modeling of each hierarchical component proved to be crucial for the accurate estimation of the statistics of device performance distribution and its parametric yield.The knowledge gained about process variation from carefully designed test structures was leveraged into estimating the variation and parametric yield of new devices and circuits. This was accomplished by improved the statistical compact model parameter extraction methodology, and by proposing a stepwise parameter selection method. We used a normalized notional confidence interval and, and the sum of squares of fitting residuals as extraction and fitting quality criteria. This allowed us to determine the essential model parameters for accurate fitting over a large number of transistors. We applied this methodology to EKV and PSP with both simulated and experimental data, demonstrating its effectiveness. Finally, we combined the results from statistical parameter extraction with the hierarchical spatial variability model. This, compared to traditional methods, produced much improved estimates of device performance and manufacturing yield.", "author_names": [ "Kun Qian" ], "corpus_id": 110623669, "doc_id": "110623669", "n_citations": 8, "n_key_citations": 2, "score": 1, "title": "Variability Modeling and Statistical Parameter Extraction for CMOS Devices", "venue": "", "year": 2015 }, { "abstract": "Statistical variability is a major challenge for CMOS scaling and integration. In order to achieve variability aware design, it's critical important to reliably transfer device characteristics statistical variability information into compact models. A PCA based statistical compact modeling strategy is benchmarked against 'atomistic' device simulation and direct statistical parameter extraction strategy. The results indicate that PCA based approach may introduce considerable error in tail of distribution, which in turn may generate pessimistic or optimistic conclusions in statistical circuit simulation.", "author_names": [ "Binjie Cheng", "Negin Moezi", "Daryoosh Dideban", "Gareth Roy", "Subhasish Subhasish", "Asen Asenov" ], "corpus_id": 18147749, "doc_id": "18147749", "n_citations": 10, "n_key_citations": 1, "score": 0, "title": "Benchmarking the Accuracy of PCA Generated Statistical Compact Model Parameters Against Physical Device Simulation and Directly Extracted Statistical Parameters", "venue": "2009 International Conference on Simulation of Semiconductor Processes and Devices", "year": 2009 }, { "abstract": "As CMOS scales down to sub 50 nm, it faces critical dimensions of charge and matter granularities, leading to the drastic increase of device parameter dispersion, named statistical variability, which is one of the main contemporary challenges for further downscaling and makes each device atomistically different leading to broad dispersion of their electrical characteristics. In addition, device reliability concerns gain inertia; among them Bias Temperature Instability (BTI) shortens device lifetime by trapping charges in defect states of the insulator or at the interface. The interplay between statistical variability and BTI results in more variations on device performance and thus greatly affect circuit performance. In turn design methodologies must evolve towards variability and reliability aware design. To do so statistical compact models including both the effects of statistical variability and BTI induced ageing are required for the large scale statistical circuit simulation of variability and reliability. In this study, the application of accurate compact models, that describe performance variation in the presence of both statistical variability and reliability at arbitrary BTI induced ageing levels, to SRAM circuit simulation is described. Both SRAM cell stability and write performance are evaluated and it is seen that, due to the accurate description of device performance distributions provided by the compact models and the sensitivity of these SRAM performance metrics on device performance, the approach presented here is better suited to high sigma statistical circuit analysis than conventional approaches based upon assumed Gaussian distributions. The approach is demonstrated using a 25 nm gate length bulk MOSFET whose performance variation is obtained from statistical TCAD simulation using the GSS simulator GARAND. The simulated performance data is then used directly as the target for BSIM4 compact model extraction that ensures device figures of merit are well resolved for each device in a statistical ensemble. The distribution of compact model parameters is then generalised into an algebraic form using Generalized Lambda Distribution (GLD) methods, so that a sufficiently large number of compact models can later be generated and interpolated at arbitrary ageing levels. Finally compact models generated in this way are used to evaluate SRAM write performance and stability under the influence of statistical variability and BTI induced ageing.", "author_names": [ "Jie Ding" ], "corpus_id": 112195757, "doc_id": "112195757", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Accurate CMOS compact model and the corresponding circuit simulation in the presence of statistical variability and ageing", "venue": "", "year": 2015 }, { "abstract": "Abstract This paper presents an effective statistical compact modelling strategy that can precisely capture a statistical set of MOSFET characteristics into industrial strength statistical compact models. 3D simulation of large statistical sample of microscopically different devices is required for statistical compact model extraction when studying the impact of variability in next CMOS technology generations on circuit and system design. For a particular nominal device design the statistical 3D physical simulations needs two orders of magnitude more CPU time compared to conventional TCAD simulations. A data sampling strategy is presented to reduce the number of bias points in simulated device characteristics used as extraction targets for statistical compact model parameter extraction. We show that for a well balanced set of statistical compact model parameters carefully chosen small number of strategic bias points in the simulated I V characteristics of each microscopically different transistor is sufficient to capture accurately the statistical device behaviour. The corresponding increase in the RMS error is below 1% compared to results from comprehensive bias point set. The impact of the slight reduction of the compact model accuracy on the accuracy of statistical circuit simulation has also been investigated.", "author_names": [ "B Bindu", "Binjie Cheng", "Gareth Roy", "Xingsheng Wang", "Scott Roy", "Asen Asenov" ], "corpus_id": 94791905, "doc_id": "94791905", "n_citations": 15, "n_key_citations": 1, "score": 0, "title": "Parameter set and data sampling strategy for accurate yet efficient statistical MOSFET compact model extraction", "venue": "", "year": 2010 }, { "abstract": "Intrinsic statistical variability (SV) associated with discreteness of charge and granularity of matter is one of limiting factors for CMOS scaling and integration. There are several standard statistical parameter generation strategies to transfer SV information into compact models, and their accuracy is essential for achieving reliable variability aware design. We investigate the accuracy of these strategies based on the direct statistical compact model parameter extraction results for industry standard compact models BSIM4 and PSP. Statistical circuit simulation results indicate that the standard assumption for uncorrelated normal distribution of the statistical compact model parameters may introduce considerable errors in the statistical distribution of circuit figure of merits.", "author_names": [ "Binjie Cheng", "Daryoosh Dideban", "Negin Moezi", "Campbell Millar", "Gareth Roy", "Xingsheng Wang", "Scott Roy", "Asen Asenov" ], "corpus_id": 62183791, "doc_id": "62183791", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Benchmarking statistical compact modeling strategies for capturing device intrinsic parameter fluctuations in BSIM4 and PSP", "venue": "", "year": 2010 }, { "abstract": "One of the major limiting factors of the CMOS device, circuit and system simulation in sub 100nm regimes is the statistical variability introduced by the discreteness of charge and granularity of matter. The statistical variability cannot be eliminated by tuning the layout or by tightening fabrication process control. Since the compact models are the key bridge between technology and design, it is necessary to transfer reliably the MOSFET statistical variability information into compact models to facilitate variability aware design practice. The aim of this project is the development of a statistical extraction methodology essential to capture statistical variability with optimum set of parameters particularly in industry standard compact model BSIM. This task is accomplished by using a detailed study on the sensitivity analysis of the transistor current in respect to key parameters in compact model in combination with error analysis of the fitted Id Vg characteristics. The key point in the developed direct statistical compact model strategy is that the impacts of statistical variability can be captured in device characteristics by tuning a limited number of parameters and keeping the values for remaining major set equal to their default values obtained from the \"uniform\" MOSFET compact model extraction. However, the statistical compact model extraction strategies will accurately represent the distribution and correlation of the electrical MOSFET figures of merit. Statistical compact model parameters are generated using statistical parameter generation techniques such as uncorrelated parameter distributions, principal component analysis and nonlinear power method. The accuracy of these methods is evaluated in comparison with the results obtained from 'atomistic' simulations. The impact of the correlations in the compact model parameters has been analyzed along with the corresponding transistor figures of merit. The accuracy of the circuit simulations with different statistical compact model libraries has been studied. Moreover, the impact of the MOSFET width/length on the statistical trend of the optimum set of statistical compact model parameters and electrical figures of merit has been analyzed with two methods to capture geometry dependencies in proposed statistical models.", "author_names": [ "Negin Moezi" ], "corpus_id": 107073003, "doc_id": "107073003", "n_citations": 2, "n_key_citations": 1, "score": 0, "title": "Statistical compact model strategies for nano CMOS transistors subject of atomic scale variability", "venue": "", "year": 2012 }, { "abstract": "Combined C V/I V and RTN CMOS Variability Characterization Using An On Chip Measurement System Simeon Dimitrov Realov With the number of transistors integrated into a single integrated circuit (IC) crossing the one billion mark and complementary metal oxide semiconductor (CMOS) technology scaling pushing device dimensions ever so close to atomic scales, variability in transistor performance is becoming the dominant constraint in modern day CMOS IC design. Developing novel approaches for device characterization, which allow a detailed study of electrical transistor characteristics across large statistical sample sets, is crucial for the proper identification, characterization, and modeling of different physical sources of device variability. On chip characterization methodologies have the potential to address all of these issues by enabling the characterization of large statistical device sample sets, while also allowing for high measurement quality and throughput. In this work, a fully integrated system for on chip combined capacitance voltage (C V) and current voltage (I V) characterization of a large integrated test transistor array implemented in a 45 nm bulk CMOS process is presented. On chip I V characterization is implemented using a four point Kelvin measurement technique with 12 bit sub 10 nA current measurement resolution, 10 bit sub 1 mV voltage measurement resolution, and sampling speeds on the order of 100 kHz. C V characterization is performed using a novel leakageand parasitics insensitive charge based capacitance measurement (CBCM) technique with atto Farad resolution. The on chip system is employed in developing a comprehensive CMOS transistor variability characterization methodology, studying both random and systematic sources of quasi static device variability. For the first time, combined C V/I V characterization of circuit representative devices is demonstrated and used to extract variations in the underlying physical parameters of the device. Additionally, the fast current sampling capabilities of the system are used for the characterization of random telegraph noise (RTN) in small area devices. An automated methodology for the extraction of RTN parameters is developed, and the statistics of RTN are studied across device type, bias, and geometry.", "author_names": [ "Simeon Realov" ], "corpus_id": 117315329, "doc_id": "117315329", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Combined C V/I V and RTN CMOS Variability Characterization Using An On Chip Measurement System", "venue": "", "year": 2012 }, { "abstract": "The development of a statistical compact model strategy for nano scale CMOS transistors is presented in this thesis. Statistical variability which arises from the discreteness of charge and granularity of matter plays an important role in scaling of nano CMOS transistors especially in sub 50nm technology nodes. In order to achieve reasonable performance and yield in contemporary CMOS designs, the statistical variability that affects the circuit/system performance and yield must be accurately represented by the industry standard compact models. As a starting point, predictive 3D simulation of an ensemble of 1000 microscopically different 35nm gate length transistors is carried out to characterize the impact of statistical variability on the device characteristics. PSP, an advanced surface potential compact model that is selected as the next generation industry standard compact model, is targeted in this study. There are two challenges in development of a statistical compact model strategy. The first challenge is related to the selection of a small subset of statistical compact model parameters from the large number of compact model parameters. We propose a strategy to select 7 parameters from PSP to capture the impact of statistical variability on current voltage characteristics. These 7 parameters are used in statistical parameter extraction with an average RMS error of less than 2.5% crossing the whole operation region of the simulated transistors. Moreover, the accuracy of statistical compact model extraction strategy in reproducing the MOSFET electrical figures of merit is studied in detail. The results of the statistical compact model extraction are used for statistical circuit simulation of a CMOS inverter under different input output conditions and different number of statistical parameters. The second challenge in the development of statistical compact model strategy is associated with statistical generation of parameters preserving the distribution and correlation of the directly extracted parameters. By using advanced statistical methods such as principal component analysis and nonlinear power method, the accuracy of parameter generation is evaluated and compared to directly extracted parameter sets. Finally, an extension of the PSP statistical compact model strategy to different channel width/length devices is presented. The statistical trends of parameters and figures of merit versus channel width/length are characterized.", "author_names": [ "Daryoosh Dideban" ], "corpus_id": 109341413, "doc_id": "109341413", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Statistical modelling of nano CMOS transistors with surface potential compact model PSP", "venue": "", "year": 2012 }, { "abstract": "The implementation of a viable statistical circuit design methodology requiring detailed knowledge of the variabilities of, and correlations among, the circuit simulator model parameters utilized by designers, and the determination of the important relationships between these CAD model parameter variabilities and the process variabilities causing them is presented. This work addresses the above requirements by detailing a new framework which was adopted for a 2 /spl mu/m CMOS technology to enable realistic statistical circuit performance prediction prior to manufacture. Issues relating to MOSFET modeling, the derivation of fast \"direct\" parameter extraction methodologies suitable for rapid parameter generation, the employment of multivariate statistical techniques to analyze statistical parametric data, and the linking of the CAD model parameter variations to variabilities in process quantities are discussed. In this approach the correlated set of model parameters is reduced to a smaller and more manageable set of uncorrelated process related factors. The ensuing construction and validation of realistic statistical circuit performance procedures is also discussed. Comparisons between measured and simulated variabilities of device characteristics is utilized to demonstrate the accuracy of the techniques described. The advantages of the proposed approach over more traditional \"worst case\" design methodologies are demonstrated.", "author_names": [ "James A Power", "Brian Donnellan", "Alan Mathewson", "William A Lane" ], "corpus_id": 111083824, "doc_id": "111083824", "n_citations": 85, "n_key_citations": 4, "score": 0, "title": "Relating statistical MOSFET model parameter variabilities to IC manufacturing process fluctuations enabling realistic worst case design", "venue": "", "year": 1994 }, { "abstract": "This thesis describes the development and application of statistical circuit simulation methodologies to analyse digital circuits subject to intrinsic parameter fluctuations. The specific nature of intrinsic parameter fluctuations are discussed, and we explain the crucial importance to the semiconductor industry of developing design tools which accurately account for their effects. Current work in the area is reviewed, and three important factors are made clear: any statistical circuit simulation methodology must be based on physically correct, predictive models of device variability; the statistical compact models describing device operation must be characterised for accurate transient analysis of circuits; analysis must be carried out on realistic circuit components. Improving on previous efforts in the field, we posit a statistical circuit simulation methodology which accounts for all three of these factors. The established 3 D Glasgow atomistic simulator is employed to predict electrical characteristics for devices aimed at digital circuit applications, with gate lengths from 35 nm to 13 nm. Using these electrical characteristics, extraction of BSIM4 compact models is carried out and their accuracy in performing transient analysis using SPICE is validated against well characterised mixed mode TCAD simulation results for 35 nm devices. Static d.c. simulations are performed to test the methodology, and a useful analytic model to predict hard logic fault limitations on CMOS supply voltage scaling is derived as part of this work. Using our toolset, the effect of statistical variability introduced by random discrete dopants on the dynamic behaviour of inverters is studied in detail. As devices scaled, dynamic noise margin variation of an inverter is increased and higher output load or input slew rate improves the noise margins and its variation. Intrinsic delay variation based on CV/I delay metric is also compared using ION and IEFF definitions where the best estimate is obtained when considering ION and input transition time variations. Critical delay distribution of a path is also investigated where it is shown non Gaussian. Finally, the impact of the cell input slew rate definition on the accuracy of the inverter cell timing characterisation in NLDM format is investigated.", "author_names": [ "Noor Ain Kamsani" ], "corpus_id": 109435280, "doc_id": "109435280", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Statistical Circuit Simulations: From 'Atomistic' Compact Models to Statistical Standard Cell Characterisation", "venue": "", "year": 2012 } ]

[ { "abstract": "Silicon photodiodes with high photoconductive gain are demonstrated. The photodiodes are fabricated in a complementary metal oxide semiconductor (CMOS) compatible process. The typical room temperature responsivity at 940 nm is >20 A/W and the dark current density is 100 nA/cm2 at 5 V reverse bias, yielding a detectivity of 10(14) Jones. These photodiodes are good candidates for applications that require high detection sensitivity and low bias operation.", "author_names": [ "Xiaojian Li", "James E Carey", "Jason William Sickler", "Martin U Pralle", "Chintamani P Palsule", "Christopher J Vineis" ], "corpus_id": 23325186, "doc_id": "23325186", "n_citations": 30, "n_key_citations": 0, "score": 1, "title": "Silicon photodiodes with high photoconductive gain at room temperature.", "venue": "Optics express", "year": 2012 }, { "abstract": "Abstract For the full benefit of the silicon chip industry and to further extend the photoresponse cut off wavelength of the current Si photodetectors beyond 1100 nm, high performance silicon compatible Mg2Si/Si n p photodiodes are constructed on the bulk silicon wafer by magnetron sputtering and post annealing sequential processes. The results show that the annealing period appreciably affects microstructure, crystallite size, and roughness of the Mg2Si film sputtered on glass substrates and silicon wafers. Meanwhile, the fabricated Mg2Si/Si n p photodiodes demonstrate clear rectifying behavior and evident spectral response characteristics in the wavelength domain from 0.8 to 1.35 mm, with a maximum room temperature zero bias response of 0.1, 0.15, 0.86, and 0.47 A/W at 1.05 mm for the annealing periods of 10, 20, 40, and 60 min, respectively. The photoresponse cut off wavelength of the fabricated Mg2Si/Si n p photodiodes is 1.35 mm; however, the photosensitive cut off of the commercially available Hamamatsu Si photodiode is 1.25 mm. The fabricated Mg2Si/Si n p photodiodes at RTA period of 40 min reveal spectral response of longer cut off wavelength and higher intensity near the photon energy threshold compared to the Hamamatsu Si photodiode. In this context, the fabricated photodiodes in this study offer huge potentials to develop high performance silicon compatible photodiodes for efficiently sensing the infrared light in the wavelength domain from 0.8 to 1.35 mm.", "author_names": [ "Ahmed A M El-Amir", "Takeo Ohsawa", "Satoshi Ishii", "Masataka Imura", "Meiyong Liao", "Xiuwei Fu", "Hiroyo Segawa", "Isao Sakaguchi", "Tadaaki Nagao", "Kiyoshi Shimamura", "Naoki Ohashi" ], "corpus_id": 197181754, "doc_id": "197181754", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Silicon compatible Mg2Si/Si n p photodiodes with high room temperature infrared responsivity", "venue": "Materials Science in Semiconductor Processing", "year": 2019 }, { "abstract": "In this Letter, we report large area (600 mm diameter) 4H SiC avalanche photodiodes (APDs) with high gain and low dark current for visible blind ultraviolet detection. Based on the separate absorption and multiplication structure, 4H SiC APDs passivated with SiNx instead of SiO2 are demonstrated for the first time, to the best of our knowledge. Benefitting from the SiNx passivation, the surface leakage current is effectively suppressed. At room temperature, high multiplication gain of 6.5x105 and low dark current density of 0.88 mA/cm2 at the gain of 1000 are achieved for our devices, which are comparable to the previously reported small area SiC APDs.", "author_names": [ "Zhou Xingye", "Jia Li", "Luo Weili", "Yuangang Wang", "Song Xubo", "Shunzheng Yin", "Tan Xin", "Yuanjie Lu", "Hongyu Guo", "Guodong Gu", "Zhihong Feng" ], "corpus_id": 125183824, "doc_id": "125183824", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Large area 4H SiC avalanche photodiodes with high gain and low dark current for visible blind ultraviolet detection", "venue": "", "year": 2018 }, { "abstract": "Avalanche gain and breakdown voltage in most wide bandgap semiconductor materials are dependent on temperature and most instruments utilizing APDs rely on temperature stabilization or voltage compensation circuitry to maintain a constant avalanche gain. The complexity in operation circuitry can be reduced by incorporating material with inherently superior temperature stability in its avalanche gain and breakdown voltage. In state of the art APDs, the temperature dependence of avalanche breakdown voltage is quantified by the temperature coefficient of avalanche breakdown, Cbd. We report on the temporal and temperature stability of avalanche gain and breakdown voltage of 100 nm thick avalanche layers of Al0.85Ga0.15As0.56Sb0.44 (AlGaAsSb) The Cbd (1.60 mV/K) is smaller compared to state of art InP and InAlAs APDs for similar avalanche layer thickness. The temporal stability of avalanche gain for the AlGaAsSb APD was also evaluated in temperature ranges of 294 K to 353 K. The APD was biased at room temperature gain of 10 and maximum fluctuation of 0.7% was recorded at 294 K which increases to 1.33% when the temperature was increased to 353K. The promising temperature stability of gain indicates the potential of AlGaAsSb lattice matched to InP in achieving higher tolerance to temperature fluctuations and reduction of the operational complexity of circuitry. The dark currents are robust and do not show significant thermal degradation after gain measurements at elevated temperatures.", "author_names": [ "S Zhang", "Js S Ng" ], "corpus_id": 115602559, "doc_id": "115602559", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Al0.85Ga0.15As0.56Sb0.44 avalanche photodiodes with high immunity to temperature fluctuation", "venue": "NanoScience Engineering", "year": 2018 }, { "abstract": "A longwave infrared photodetector made of double layers of 100nm amorphous germanium (a Ge) and 25nm amorphous silicon (a Si) have been demonstrated. Under room temperature, the device shows the responsivity of 1.7 A/W, detectivity of 6x108 Jones, and noise equivalent power (NEP) of 5pW/Hz under 5V bias and at 20kHz operation. Studies of frequency dependent characteristics and device modeling indicate that, above 100Hz or beyond the bandwidth of thermal response, the device operates as a quantum detector having the photoelectrons produced by optical excitation from the bandtail states to the mobile states of a Ge. The superior device performance may be attributed to the combination of two amplification mechanisms: photoconductive gain in a Ge and cycling excitation process (CEP) in a Si, with the latter being the dominant factor. Besides its attractive performance, the device has a simple structure and is easy to fabricate at low cost, thus holding promise for night vision, sensing, autonomous driving, and many other applications.", "author_names": [ "Jiayun Zhou", "Mohammad Abu Raihan Miah", "Yugang Yu", "Alex Ce Zhang", "Zijian Zeng", "Samir Damle", "Iftikhar Ahmad Niaz", "Yanan Zhang", "Yu-hwa Lo" ], "corpus_id": 209461736, "doc_id": "209461736", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Room temperature long wave infrared detector with thin double layers of amorphous germanium and amorphous silicon.", "venue": "Optics express", "year": 2019 }, { "abstract": "Avalanche photodiodes (APD) are important components in short wave and mid wave infrared detection systems (imaging, laser radar, communications, etc. because their internal gain can improve receiver sensitivity and enables the detection of weak photon fluxes. The statistical nature of impact ionization in APDs contributes to excess shot noise, however. The excess noise factor, F(M) is related to the ratio of the electron and hole ionization coefficients, k, and multiplication, M, by F(M) ;M<;sup>2</sup>;M>;sup>2</sup> k<;M> (1 k)(2 1/;M> In the mid infrared, HgCdTe APDs represent the current state of the art; at liquid nitrogen temperatures, advanced devices offer excellent low noise characteristics with F(M) 1, gains of >1000, and excellent dark currents. Unfortunately, devices that operate at shorter wavelengths exhibit degraded noise characteristics and significantly lower maximum gains ;30. This, when combined with the growth and fabrication challenges associated with II VI compounds has motivated the search for alternative APD materials. InAs APDs, which offer a shorter wavelength cutoff wavelength of ~3 mm, have recently been found to exhibit F(M) 1, with moderately low dark current at room temperature. Increasing the multiplication region thickness increases the gains achievable at low bias, which is beneficial for integration with Read Out Integrated Circuits (ROICs) Therefore, to design a high gain InAs APD, a thick multiplication region is required. This, in turn, necessitates extremely low background doping ;1015 cm 3) or appropriate counter doping, in order to realize complete depletion and a uniform electric field profile. In this paper, we report record high gain InAs APDs employing 6 mm thick and 10 mm thick intrinsic regions with low background doping of ~4x1014 cm 3, as determined by C V profiling. An AlAsSb blocking layer was used in both structures to suppress electron diffusion current, the dominant dark current mechanism at room temperature. Significant reduction in dark current were critical to characterize these thicker multiplication regions at high gain, resulting in record high room temperature multiplication gain of ~300 at 15 V bias. This is ~6x the previous record for InAs of 50 at 15 V, as well as significantly higher than the maximum gain of 126 reported at higher biases, and represents a significant step forward in InAs APD performance.", "author_names": [ "Wenlu Sun", "Scott J Maddox", "Seth R Bank", "Joe C Campbell" ], "corpus_id": 22058870, "doc_id": "22058870", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Record high gain from InAs avalanche photodiodes at room temperature", "venue": "72nd Device Research Conference", "year": 2014 }, { "abstract": "We successfully demonstrate the high stability at room temperature of a new design of single photon detector based on multiple tunnel junctions with superior responsivity and high quantum efficiency. The single photon detector uses one dimensional (1D) multiple tunnel junctions (MTJs) with 12 islands and 13 tunnel junctions coupled with a silicon single electron box. A single electron transistor (SET) is used to read the charge state of a silicon quantum dot (Si QD) The response of the single photon detector (Si QD and SET) is directly related to the photoconductivity gain in the MTJs with associated conductance steps produced by individual photocarriers. Numerical simulations confirm the high stability at room temperature of the single photon detection. Moreover, an analytical model developed in MATLAB that takes account of the thermionic emission of charge carriers confirms the high stability of the single photon detection at room temperature.", "author_names": [ "Amine Touati", "S Chatbouri", "Adel Kalboussi" ], "corpus_id": 203141544, "doc_id": "203141544", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Room temperature high sensitivity of multiple tunnel junctions based on single charge photodetection", "venue": "Journal of Computational Electronics", "year": 2019 }, { "abstract": "We report Al_0.8In_0.2As_0.23Sb_0.77 avalanche photodiodes with high gain <inline formula> <tex math notation=\"LaTeX\"$M>1300$ /tex math>/inline formula> and low dark current at room temperature. Impact ionization coefficients for this material system are also extracted, indicating electron dominant impact ionization. Low avalanche breakdown temperature dependence is demonstrated.", "author_names": [ "Andrew H Jones", "Ann Kathryn Rockwell", "Stephen D March", "Yuan Yuan", "Seth R Bank", "Joe C Campbell" ], "corpus_id": 209460315, "doc_id": "209460315", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "High Gain, Low Dark Current Al0.8In0.2As0.23Sb0.77 Avalanche Photodiodes", "venue": "IEEE Photonics Technology Letters", "year": 2019 }, { "abstract": "Using our computer programs, numerical simulations of photoelectric and fluctuating phenomena were carried out in diode structures of the CdHgTe mesa in the P+n(p)N+ configuration operating at 230 K and 300 K. These phenomena were analyzed in structures where additional energy barriers at the absorber boundary were applied. Exclusion and extraction of charge carriers in the absorber area after biasing the structures with reverse voltage reduces their concentration by more than an order of magnitude. Reduction of carrier concentration has a positive effect on the increase of the absorption coefficient due to reduction of the Burstein Moss effect, increases the resistance and electro optical gain, and effectively suppresses generation and thermal recombination. It is possible to obtain 70% of quantum efficiency in biased photodiodes. It was shown that a non equilibrium long wave photodiode working at room temperature can have a normalized detectivity of over 109 cmHZ1/2W 1 for radiation with 10.6 mm wavelength. The results of our calculations and their analysis are illustrated by numerous figures.", "author_names": [ "Krzysztof Jozwikowski", "Alina Jozwikowska" ], "corpus_id": 182555340, "doc_id": "182555340", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Enhanced Numerical Modeling of HgCdTe Long Wavelength Infrared Radiation High Operating Temperature Non equilibrium P+n(p)N+ Photodiodes", "venue": "Journal of Electronic Materials", "year": 2019 }, { "abstract": "Abstract We report on the growth of high quality GaSb based AlInAsSb quaternary alloy by molecular beam epitaxy (MBE) to fabricate avalanche photodiodes (APDs) By means of high resolution X ray diffraction (HRXRD) and scanning transmission electron microscope (STEM) phase separation phenomenon of AlInAsSb random alloy with naturally occurring vertical superlattice configuration was demonstrated. To overcome the tendency for phase segregation while maintaining a highly crystalline film, a digital alloy technique with migration enhanced epitaxy growth method was employed, using a shutter sequence of AlSb, AlAs, AlSb, Sb, In, InAs, In, Sb. AlInAsSb digital alloy has proved to be reproducible and consistent with single phase, showing sharp satellite peaks on HRXRD rocking curve and smooth surface morphology under atomic force microscopy (AFM) Using optimized digital alloy, AlInAsSb separate absorption, grading, charge, and multiplication (SAGCM) APD was grown and fabricated. At room temperature, the device showed high performance with low dark current density of ~14.1 mA/cm 2 at 95% breakdown and maximum stable gain before breakdown as high as ~200, showing the potential for further applications in optoelectronic devices.", "author_names": [ "Lyu Yuexi", "Xi Han", "Yao-yao Sun", "Zhi Jiang", "Chun-yan Guo", "W F Xiang", "Yinan Dong", "Jie Cui", "Yuan Yao", "Dong-wei Jiang", "Guo-wei Wang", "Ying-qiang Xu", "Zhichuan Niu" ], "corpus_id": 102963350, "doc_id": "102963350", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Digitally grown AlInAsSb for high gain separate absorption, grading, charge, and multiplication avalanche photodiodes", "venue": "", "year": 2018 } ]

[ { "abstract": "Chiaverini et al. [Quantum Inf. Comput. 5, 419 (2005) recently suggested a linear Paul trap geometry for ion trap quantum computation that places all of the electrodes in a plane. Such planar ion traps are compatible with modern semiconductor fabrication techniques and can be scaled to make compact, many zone traps. In this paper we present an experimental realization of planar ion traps using electrodes on a printed circuit board to trap linear chains of tens of charged particles of $0.44\\phantom{\\rule{0.3em}{0ex}\\mathrm{\\ensuremath{\\mu}\\mathrm{m} diameter in a vacuum of $15\\phantom{\\rule{0.3em}{0ex}\\mathrm{Pa}\\phantom{\\rule{0.3em}{0ex}{10}\\ensuremath{ }1}\\phantom{\\rule{0.3em}{0ex}\\mathrm{torr} With these traps we address concerns about the low trap depth of planar ion traps and develop control electrode layouts for moving ions between trap zones without facing some of the technical difficulties involved in an atomic ion trap experiment. Specifically, we use a trap with 36 zones (77 electrodes) arranged in a cross to demonstrate loading from a traditional four rod linear Paul trap, linear ion movement, splitting and joining of ion chains, and movement of ions through intersections. We further propose an additional dc biased electrode above the trap which increases the trap depth dramatically, and a planar ion trap geometry that generates a two dimensional lattice of point Paul traps.", "author_names": [ "C E Pearson", "David R Leibrandt", "Waseem S Bakr", "William Mallard", "Kenneth R Brown", "Isaac L Chuang" ], "corpus_id": 119510129, "doc_id": "119510129", "n_citations": 129, "n_key_citations": 3, "score": 1, "title": "Experimental investigation of planar ion traps", "venue": "", "year": 2006 }, { "abstract": "", "author_names": [ "C E Pearson", "David R Leibrandt" ], "corpus_id": 117142513, "doc_id": "117142513", "n_citations": 1, "n_key_citations": 1, "score": 0, "title": "Experimental investigation of planar ion traps (12 pages)", "venue": "", "year": 2006 }, { "abstract": "The accurate characterization of eigenmodes and eigenfrequencies of two dimensional ion crystals provides the foundation for the use of such structures for quantum simulation purposes. We present a combined experimental and theoretical study of two dimensional ion crystals. We demonstrate that standard pseudopotential theory accurately predicts the positions of the ions and the location of structural transitions between different crystal configurations. However, pseudopotential theory is insufficient to determine eigenfrequencies of the two dimensional ion crystals accurately but shows significant deviations from the experimental data obtained from resolved sideband spectroscopy. Agreement at the level of 2.5x10( 3) is found with the full time dependent Coulomb theory using the Floquet Lyapunov approach and the effect is understood from the dynamics of two dimensional ion crystals in the Paul trap. The results represent initial steps towards an exploitation of these structures for quantum simulation schemes.", "author_names": [ "Henning Kaufmann", "Stefan Ulm", "Georg Jacob", "U Poschinger", "Haggai Landa", "Alex Retzker", "Martin Bodo Plenio", "Ferdinand Schmidt-Kaler" ], "corpus_id": 16425101, "doc_id": "16425101", "n_citations": 40, "n_key_citations": 2, "score": 0, "title": "Precise experimental investigation of eigenmodes in a planar ion crystal.", "venue": "Physical review letters", "year": 2012 }, { "abstract": "", "author_names": [ "Vytenis Benetis" ], "corpus_id": 107705099, "doc_id": "107705099", "n_citations": 21, "n_key_citations": 2, "score": 0, "title": "EXPERIMENTAL AND COMPUTATIONAL INVESTIGATION OF PLANAR ION DRAG MICROPUMP GEOMETRICAL DESIGN PARAMETERS", "venue": "", "year": 2005 }, { "abstract": "The uncertainty of the ac Stark shift due to thermal radiation represents a major contribution to the systematic uncertainty budget of state of the art optical atomic clocks. In the case of optical clocks based on trapped ions, the thermal behavior of the rf driven ion trap must be precisely known. This determination is even more difficult when scalable linear ion traps are used. Such traps enable a more advanced control of multiple ions and have become a platform for new applications in quantum metrology, simulation, and computation. Nevertheless, their complex structure makes it more difficult to precisely determine its temperature in operation and thus the related systematic uncertainty. We present here scalable linear ion traps for optical clocks, which exhibit very low temperature rise under operation. We use a finite element model refined with experimental measurements to determine the thermal distribution in the ion trap and the temperature at the position of the ions. The trap temperature is investigated at different rf drive frequencies and amplitudes with an infrared camera and integrated temperature sensors. We show that for typical trapping parameters for In+ Al+ Lu+ Ca+ Sr+ or Yb+ ions, the temperature rise at the position of the ions resulting from rf heating of the trap stays below 700 mK and can be controlled with an uncertainty on the order of a few 100 mK maximum. The corresponding uncertainty of the trap related blackbody radiation shift is in the low 10 19 and even 10 20 regime for 171Yb+(E3) and 115In+ respectively.", "author_names": [ "T Nordmann", "A Didier", "Miroslav Dolezal", "Petr Balling", "Tobias Burgermeister", "T E Mehlstaubler" ], "corpus_id": 224801136, "doc_id": "224801136", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Sub kelvin temperature management in ion traps for optical clocks.", "venue": "The Review of scientific instruments", "year": 2020 }, { "abstract": "Motivated by recent developments in ion trap design and fabrication, we investigate the stability of the motion of an ion in asymmetrical, planar versions of the linear Paul trap. The equations of motion of an ion in such a trap are generally coupled due to a nonzero relative angle th between the principal axes of RF and DC fields, invalidating the assumptions behind the standard stability analysis for symmetric Paul traps. Using numerical methods, we obtain stability diagrams for the coupled system for various values of th, generalizing the standard q a stability diagrams. We then use multi scale perturbation theory to obtain approximate formulas for the boundaries of the primary stability region and check our formulas against results from numerical analysis. Our results show that while the primary stability region is quite robust to changes in th, a secondary stability region is highly variable, joining the primary stability region at the special case of th=45deg, which results in a significantly enlarged sta.", "author_names": [ "Fayaz A Shaikh", "Arkadas Ozakin" ], "corpus_id": 122643325, "doc_id": "122643325", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Stability analysis of ion motion in asymmetric planar ion traps", "venue": "", "year": 2012 }, { "abstract": "In this thesis, we investigate a new geometry of Paul trap with electrodes in a plane. These planar ion traps are compatible with modern silicon microfabrication, and can be scaled up to large arrays with multiple trapping zones. We implement these designs on printed circuit boards with macroscopic ions, allowing us to study the traps while avoiding the experimental challenges of atomic ion traps. We discuss the dynamics of ions in the traps using both numerical and analytical means. Scalable traps are of interest to the quantum computing community as a potential implementation of a large scale quantum computer. However, there are concerns about the low trap depth relative to a conventional trap of the same size. We address this in three ways, first by introducing a conductive plane above the trap to increase its depth, then by using a deeper trap with a three dimensional electrode geometry to load the trap, and finally by loading the trap directly while using a buffer gas to slow down energetic ions so that the trap can capture them. Also of concern is the ability of the trap to move ions through arms and intersections. We demonstrate these movement operations, and study properties of the linear trap including the secular frequency and geometric factors between planar and four rod traps. The precision of atomic ion trap experiments makes them sensitive to background gas pressure at levels that are undetectable to conventional gauges. The capacity for integrating circuitry and optical elements with the trap could anticipate complete ion trap experiments performed by a single chip, and a new technology for an integrated pressure gauge would be immensely useful if the pressure detection can shown to be feasible and repeatable. In a point planar trap, we observe ion motion to determine background gas pressure, demonstrating an application that could bring planar ion traps into much wider use. Thesis Supervisor: Isaac L. Chuang Title: Associate Professor of Physics", "author_names": [ "C E Pearson" ], "corpus_id": 101967541, "doc_id": "101967541", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Theory and application of planar ion traps", "venue": "", "year": 2006 }, { "abstract": "", "author_names": [ "Stephen A Lammert", "James Mitchell Wells" ], "corpus_id": 98135782, "doc_id": "98135782", "n_citations": 16, "n_key_citations": 0, "score": 0, "title": "EXPERIMENTAL INVESTIGATION INTO THE PERFORMANCE OF ION TRAPS USING AIR VERSUS HELIUM AS THE BUFFER GAS", "venue": "", "year": 1996 }, { "abstract": "A hybrid model, which consists of a fluid module, a sheath module and an ion Monte Carlo module, is employed to investigate the dependence of ion energy and angular distributions (IEDs and IADs) on the inductively coupled plasma (ICP) power, pressure, gas ratio, bias power and bias frequency in Ar/O2 discharges. The results indicate that the bimodal distribution appears as bias power increases or bias frequency decreases. Moreover, the low and high energy peaks of IEDs move to higher energy with the rise of bias power and O2 content. Whereas, an opposite tendency is observed with the increase of ICP power and pressure. For IADs, it is clear that a larger percentage of ions incident on the electrode have a smaller deflection angle by increasing bias power or decreasing pressure, and a similar evolution is observed with the decline of bias frequency. Besides, the better collimation of ions is obtained at larger O2 concentration, but ICP power only has little influence on IADs. In order to validate the model, a comparison between the simulated IEDs and those measured by a retarding field energy analyzer has been done, and shows a good agreement. The results obtained in this work could help us to gain more insight into the dependence of IEDs and IADs on the discharge parameters, which is of significant importance in the improvement of the etching rate and anisotropy.", "author_names": [ "Yu-Ru Zhang", "Zhuan Zhao", "Chan Xue", "Fei Gao", "You-Nian Wang" ], "corpus_id": 155169892, "doc_id": "155169892", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Ion energy and angular distributions in planar Ar/O2 inductively coupled plasmas: hybrid simulation and experimental validation", "venue": "Journal of Physics D: Applied Physics", "year": 2019 }, { "abstract": "In order to realize the full potential of ion trap quantum computers, an improved understanding is required of the motional heating that trapped ions experience. Experimental studies of the temperature frequency and ion electrode distance dependence of the electric field noise responsible for motional heating, as well as the noise before and after ion bombardment cleaning of trap electrodes, suggest that fluctuations of adsorbate dipoles are a likely source of so called \"anomalous heating,\" or motional heating of the trapped ions at a rate much higher than the Johnson noise limit. Previous computational studies have investigated how the fluctuation of model adsorbate dipoles affects anomalous heating. However, the way in which specific adsorbates affect the electric field noise has not yet been examined, and an electric dipole model employed in previous studies is only accurate for a small subset of possible adsorbates. Here, we analyze the behavior of both in plane and out of plane vibrational modes of fifteen adsorbate electrode combinations within the independent fluctuating dipole model, utilizing accurate first principles computational methods to determine the surface induced dipole moments. We find the chemical specificity of the adsorbate can change the electric field noise by seven orders of magnitude and specifically that soft in plane modes of weakly adsorbed hydrocarbons produce the greatest noise and ion heating. We discuss the dynamics captured by the independent fluctuating dipole model, namely the adsorbate dependent turn on temperature and electric field noise magnitude, and also discuss the model's failure to reproduce the 1/\\omega} frequency scaling observed in measured noise spectra. Finally, we suggest future research directions for improved, more quantitatively predictive models based on extensions of the present framework.", "author_names": [ "Keith G Ray", "Brenda M Rubenstein", "Wenze Gu", "Vincenzo Lordi" ], "corpus_id": 53488104, "doc_id": "53488104", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "van der Waals corrected density functional study of electric field noise heating in ion traps caused by electrode surface adsorbates", "venue": "New Journal of Physics", "year": 2019 } ]

[ { "abstract": "Some special features of polaritons, quasi particles being normal modes of system of excitons interacting with photons in so called strong coupling regime, are theoretically and numerically analyze in low dimensional systems. In Chapter 1 is given a brief overview of 0D, 1D and 2D semiconductor structures with a general introduction to the polariton field. Chapter 2 is devoted to micro nano wires. The so called whispering gallery modes are studied in the general case of an anisotropic systems as well as polariton formation in ZnO wires. Theoretical model is compared with an experiment. In the Chapter 3 Josephson type dynamics with Bose Einstein condensates of polaritons is analyzed taking into account pseudospin degree of freedom. Chapter 4 start with an introduction to Aharonov Bohm effect, as the best known represent of geometrical phases. An another geometrical phase Berry phase, occurring for a wide class of systems performing adiabatic motion on a closed ring, is main subject of this section. We considered one proposition for an exciton polariton ring interferometer based on Berry phase effect. Chapter 5 concerns one 0D system strongly coupled quantum dot exciton to cavity photon. We have discussed possibility of obtaining entangled states from a quantum dot embedded in a photonic crystal in polariton regime.", "author_names": [ "Goran Pavlovic" ], "corpus_id": 115824470, "doc_id": "115824470", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "Exciton polaritons in low dimensional structures", "venue": "", "year": 2010 }, { "abstract": "Along this thesis manuscript I shall present some emergent nonlinear phenomena in spinor exciton polariton condensates. After an introductory chapter bringing the necessary background, I will in a first part focus on half integer topological defects discussing their stability, acceleration and nucleation in the presence of effective magnetic fields. We will see that these objects behave as magnetic charges being fascinating dirac's monopole analogues. Remarkably we will see as well how they can be used as stable signals allowing to seed the physics acoustic black holes analogues. In a second part I will concentrate on low dimensional structures. Especially, I'll describe the formation of gap solitons and the Bloch oscillations of exciton polaritons in periodically patterned microwires, and besides, the room temperature Josephson oscillations within pairs of coupled micropillars.", "author_names": [ "Hugo Flayac" ], "corpus_id": 124230234, "doc_id": "124230234", "n_citations": 3, "n_key_citations": 1, "score": 0, "title": "New trends in the physics of spinor exciton polariton condensates topological defects and low dimensional structures", "venue": "", "year": 2012 }, { "abstract": "A theory of the Anderson localization of light in randomly arranged ultrathin layers (quantum wells) uniform in lateral dimensions and possessing intrinsic optical resonances is put forward. To solve the multiple scattering problem, a model of layers with a d function resonance dielectric polarization is proposed. The model is an electromagnetic counterpart of the electronic model of zero radius potentials. Interlayer disorder is included under the assumption of a low average concentration of identical layers in order to calculate analytically the one and two photon characteristics of electromagnetic radiation transport, in particular, the average energy density and the Anderson localization length of light. The analysis is carried out for a structure with randomly distributed quantum wells in which quasi two dimensional excitons of different quantum wells are in resonance while their wave functions do not overlap. It is shown that the average electromagnetic field propagates through this disordered structure in the form of polaritons but are produced in exciton reemission between quantum wells. The localization length of light in the polariton spectral region decreases substantially, because the scattering (reflection) of light by individual quantum wells grows near the excitonic resonance.", "author_names": [ "Vladimir A Kosobukin" ], "corpus_id": 122028909, "doc_id": "122028909", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Exciton polaritons and their one dimensional localization in disordered quantum well structures", "venue": "", "year": 2003 }, { "abstract": "Cesium lead halide perovskite nanowires have emerged as promising low dimensional semiconductor structures for integrated photonic applications. Understanding light matter interactions in a nanowire cavity is of both fundamental and practical interest in designing low power consumption nanoscale light sources. In this work, high quality in plane aligned halide perovskite CsPbX3 (X Cl, Br, I) nanowires are synthesized by a vapor growth method on an annealed M plane sapphire substrate. Large area nanowire laser arrays have been achieved based on the as grown aligned CsPbX3 nanowires at room temperature with quite low pumping thresholds, very high quality factors, and a high degree of linear polarization. More importantly, it is found that exciton polaritons are formed in the nanowires under the excitation of a pulsed laser, indicating a strong exciton photon coupling in the optical microcavities made of cesium lead halide perovskites. The coupling strength in these CsPbX3 nanowires is dependent on the atomic composition, where the obtained room temperature Rabi splitting energy is ~210 13, 146 9, and 103 5 meV for the CsPbCl3, CsPbBr3, and CsPbI3 nanowires, respectively. This work provides fundamental insights for the practical applications of all inorganic perovskite CsPbX3 nanowires in designing light emitting devices and integrated nanophotonic systems.", "author_names": [ "Xiaoxia Wang", "Muhammad Shoaib", "Xiao Wang", "Xuehong Zhang", "Mai He", "Ziyu Luo", "Weihao Zheng", "Honglai Li", "Tiefeng Yang", "Xiaoli Zhu", "Libo Ma", "Anlian Pan" ], "corpus_id": 48355912, "doc_id": "48355912", "n_citations": 117, "n_key_citations": 0, "score": 0, "title": "High Quality In Plane Aligned CsPbX3 Perovskite Nanowire Lasers with Composition Dependent Strong Exciton Photon Coupling.", "venue": "ACS nano", "year": 2018 }, { "abstract": "Hybrid Bose Fermi systems consist of a layer of fermions, usually two dimensional electron gas (2DEG) coupled to another layer of bosons, such as excitons, exciton polaritons, or Cooper pairs. The interplay between these layers leads to various novel and fascinating phenomena, interesting from both the technological and fundamental physics perspectives. Hybrid structures are used in light absorption studies of heterostructures, designing nano devices, realization of Majorana fermions, designing optically controlled superconductivity, and others. I will report on our work where the Bose layer is made up of condensed excitons and the Fermi layer is made up of electron gas. For the latter, we considered two types of electron dispersions: parabolic (GaAs) and linear (graphene) The electrons are coupled to the Bogoliubov excitations or bogolons from the Bose layer via Coulomb interaction. We developed a microscopic theory and derived the low and high temperature dependence of the resistivity. It is shown that the presence of the condensed excitons leads to novel scattering channels and can have a dominant contribution to the resistivity. This is contrary to the conventional wisdom that impurities and phonons have dominant effect at low and high temperatures, respectively.", "author_names": [ "Kristian Hauser A Villegas" ], "corpus_id": 146011483, "doc_id": "146011483", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Electronic transport in hybrid Fermi exciton Bose gas systems", "venue": "", "year": 2019 }, { "abstract": "A computational approach is taken to studying a range of light matter interactions which are interesting in terms of their potential applications as well as from a fundamental point of view. Two different types of polariton, part light, part matter quasiparticles, namely exciton polaritons and Tamm plasmon polaritons (a type of surface plasmon polariton) are considered. The conditions required for the strong coupling of optical whisperinggallery modes and bulk excitons in submicron spheres are ascertained for the materials gallium arsenide, gallium nitride and zinc oxide. It is shown that the strong coupling regime may be accessed by optical modes with a low decay constant, typically exhibited by those modes with higher angular momentum quantum numbers. Tamm plasmon polaritons have previously been shown to exist at the boundary between a metal and a planar Bragg reflector structure. The conditions required for the formation of Tamm plasmon polaritons in cylindrical multilayer structures with a metal core, cladding or metal in both of these locations are determined. The cylindrical Tamm plasmon polaritons are shown to have low effective masses and low group velocities. It is also shown that it is possible to obtain split polariton modes in structures containing metal in both the core and the cladding. The effect of disorder on a two dimensional photonic crystal structure consisting of air holes in a slab of dielectric material is studied. It is shown that the defined threshold disorder is not significantly affected by the different relative band widths of the ideal crystal structures considered.", "author_names": [ "Claire Elspeth Little" ], "corpus_id": 209819535, "doc_id": "209819535", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Computational studies of light matter interactions in two and three dimensional systems", "venue": "", "year": 2011 }, { "abstract": "Semiconducting nanocrystals in open access microcavities are promising systems in which enhanced light matter interactions lead to quantum effects such as the modulation of the spontaneous emission process and exciton polariton formation. In this thesis I present improvements of the open cavity platform which serves to confine the electromagnetic field with mode volumes down to the l3 regime and demonstrate results in both the weak and strong coupling regimes of cavity quantum electrodynamics with a range of different low dimensional materials. I report cavity fabrication details allowing a peak finesse of 5 x 104 and advanced photonic structures such as coupled cavities in the open cavity geometry. By incorporating two dimensional materials and nanoplatelets in the cavity I demonstrate the strong coupling regime of light matter interaction with the formation of exciton polaritons, quasi particles composed of both photon and exciton, at room temperature. In the perturbative weak coupling regime I show pronounced modulation of the single photon emission from CdSe/ZnS quantum dots and the two dimensional material WSe2 and demonstrate Purcell enhancement of the spontaneous emission rate by factors of 2 at room temperature and 8 at low temperature. The findings presented in this thesis pave the way to establish open microcavities as a platform for a wide range of applications in nanophotonics and quantum information technologies.", "author_names": [ "Lucas C Flatten" ], "corpus_id": 139624228, "doc_id": "139624228", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Quantum electrodynamics of semiconducting nanomaterials in optical microcavities", "venue": "", "year": 2017 }, { "abstract": "This volume contains some of the papers presented at the Third International Conference on Physics of Light Matter Coupling in Nanostructures (PLMCN3) which took place in Acireale, Sicily, from 1 to 4 October 2003. This meeting was fourth in the series started by PLMCN (St. Nectaire, 2000) and continued by PLMCN1 (Rome, 2001) and PLMCN2 (Rithymnon, 2002) All four conferences had the same format (about 70 participants) similar subject scope (interface between fundamental physics of light matter coupling phenomena and applied research on new semiconductor materials and low dimensional structures) and the proceedings of all of them have been published in physica status solidi. During these four years, a huge progress has been achieved in the understanding of exciton polariton effects in microcavities. From the discovery of stimulated scattering of polaritons in 1999 to the first experimental reports of polariton Bose condensation and lasing, attention to this rapidly developing research area has been increased drastically. It is clear now that realization of a new generation of opto electronic devices, referred to as polariton devices, is a realistic task for the coming decade. To achieve this target, much work has to be done both in fundamental research on dynamics of exciton polaritons in microcavities and experimental realization of high quality microcavities presumably based on wide band gap semiconductors like GaN, ZnO, ZnSe, suitable for the observation of strong exciton light coupling at room temperature. Forty nine research teams from twelve European countries have created a Polariton Consortium aimed at integration of the European research effort towards fabrication of polariton devices. PLMCN3 was not only an international conference devoted, in particular, to the research on polariton devices, but also the first scientific meeting of this community. The PLMCN meetings since the very first one have been sponsored by the US Army European Research Office (ERO) This time, with the initiative of Jim Harvey from ERO, a special session has been organized on the devices of 21st century, where a number of intriguing ideas have been proposed on new light sources, polariton lasers, and quantum memory elements based on microcavities. A special prize for the most crazy but realizable idea has been won by Misha Portnoi (Exeter) for the concept of a white diode based on a microcavity. Each PLMCN meeting brings participants from new countries. This time, the traditionally strong participation from Japan, Russia, the European Union and the USA has been enforced by a representative delegation from Israel and two speakers from Mexico. We are looking forward for new comers from other countries not yet involved in the PLMCN community, to join us for the next meeting to be held in St. Petersburg on 29 June 3 July 2004. Sergey Ivanov from the A. F. Ioffe Institute chairs the local Organizing Committee of this future conference. We are going to keep a unique informal and creative atmosphere being characteristic of the PLMCN meetings. We invite all those who wish to know more about light matter coupling in solids or to present any new interesting results in this area and at the same time to enjoy the beautiful city of St. Petersburg, to contact Sergey Ivanov ([email protected]) or myself ([email protected] bpclermont.fr) We are looking forward to welcoming you in St. Petersburg!", "author_names": [ "Alexey Vitalievich Kavokin" ], "corpus_id": 122735990, "doc_id": "122735990", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Preface: phys. stat. sol. (c) 1/6", "venue": "", "year": 2004 }, { "abstract": "Semiconductor microcavities are micron scale photonic structures in which quantum wells are embedded within a high finesse Fabry Perot cavity, the whole structure being prepared by high precision, modern crystal growth techniques [1] In such structures vertical confinement of both excitons in the quantum wells and of light within the Fabry Perot cavity results in strong and controllable light matter interactions unachievable in quantum wells or bulk semiconductors. This control has opened up a new field of exciton polariton physics, where key features of the interacting exciton photon system can be tailored by sample design. Most importantly for the physics described here, the dispersion curves of the coupled two dimensional (2D) exciton photon modes, exciton polaritons (termed cavity polaritons) differ from those of their bulk analogues since the confinement of light results in a finite energy at k=0. This property, combined with the controllable dispersion and the extremely low density of polariton states [1] has recently allowed a variety of new phenomena to be observed, including final state stimulation and a new condensed phase with macroscopic coherence, which have the potential to lead to new devices including very low threshold optical parametric oscillators and a coherent light source based on stimulated polariton scattering.", "author_names": [ "M S Skolnick", "Alexander I Tartakovskii", "Raphael Butte", "R Mark Stevenson", "Jeremy J Baumberg", "D M Whittaker" ], "corpus_id": 136691938, "doc_id": "136691938", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "High Occupancy Effects and Condensation Phenomena in Semiconductor Microcavities and Bulk Semiconductors", "venue": "", "year": 2002 }, { "abstract": "Bosonic particles placed in a lattice are powerful tool for fundamental studies of quantum phenomena. The remarkable progress in this area are connected with exciton polaritons formed inside a high quality semiconductor microcavity in the regime of the strong light mater coupling. Exciton polaritons are subject to a rapid radiative decay and its population should be maintained by pumping. This nonequilibrium driven dissipative nature of polaritonic system together with the nonlinear effects substantially affects its properties. Nowadays there are several experimental proofs of the spontaneous coherency building up in the systems of polariton placed in artificial lattices [1 4] For instance, besides a conventional in phase ground state (when condensates locate in the neighboring potentials wells are in phase) a spontaneous buildup of antiphase (p state) \"superfluid\" states was observed in both weak contrast periodical lattice [2] as well as in chains of deep trapping potentials [1, 2] We consider the incoherently pumped periodical systems of exciton polaritons, which assumes that a reservoir of hot excitons is created. In particular, basing on the open dissipative Gross Pitaevskii model for wave function of coherent polaritons and exciton reservoir density we predict the existence of persistent oscillatory dynamics of polariton condensate. Such a behavior results in a persistent oscillations of the condensate density which are accompanied by periodical transitions between states located at the different bands of the condensate band structure [5] We have observed that such oscillations are developed when the condensate is both in phase and in anti phase (p states. In the latter case such oscillations resembles Josephson oscillations but it occur in the reciprocal space. Besides, we study the nonlinear modification of condensate steady states which have a structure of Bloch waves in periodical potential. It is well known that due to the presence of exciton component polaritons possess strong nonlinearities. We have demonstrated that strong Kerr like nonlinearity leads to the formation of the dynamically stable \"current state\" which are characterized by the non zero polariton flux through the lattice [6] The most intriguing feature of these states is that it exists even when the condensate quasi momentum lies at the boundaries of the Brillouin zone. According to main concepts of solid state physics the existence of a current in the Brillouin zone edge is forbidden due to Bragg scattering on the lattice. However we have shown that strongly polariton nonlinearities can effectively screen the influence of the periodic potential. An experimental scheme allowing observation of polariton nonlinear current states is also proposed. Finally, we consider the influence of the finiteness of the pump on the states formed in polariton condensation process. In we demonstrated that the formation of both in phase and anti phase states formed in finite structures can be explained in terms of the stability of such states. For this purpose we used a simple discrete model for incoherently pumped polariton condensate, which is valid in the case of strongly contrast lattices. Our analysis explains the phenomena observed in experiments within the framework of a simple phenomenological theory.", "author_names": [ "Yu A Chestnov", "A V Yulin", "Oleg A Egorov", "Alexander Alodjants" ], "corpus_id": 212735978, "doc_id": "212735978", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Dynamics of Microcavity Polaritons in Low Dimensional Lattices", "venue": "", "year": 2017 } ]

[ { "abstract": "The development of ultra efficient, sustainable, and easily accessible anode with relative non precious semiconducting metal oxides is highly significant for application in the practical treatment of organically polluted water. Herein, we report SnO2, TiO2, and Ag2O ternary semiconductor metal oxide blend grafted Ag@AgCl hybrids, prepared with the one step sol gel method and applied as a dimensionally stable anode (DSA) active layer on a SnO2 Sb/Ti electrode. Factors affecting crystal formation, including the presence or absence of O2 during calcination, the calcination temperature, and Ag@AgCl additive dosage were discussed. The micromorphology, phase composition, and photoelectrochemical activity of the newly designed anode were comprehensively characterized. The optimized preparation, which yielded a solid solution structure with flat and smooth surface and well crystallized lattice configuration, occurred in the absence of O2 during calcination at 550 with an Ag@AgCl additive dosage of 0.2 g in the sol gel precursor. The newly designed DSA displayed improved electrocatalysis (EC) and photoelectrical catalysis (PEC) capacity. The phenol and its TOC removal efficiency reached 90.65% and 58.17% for 10 mA/cm2 current density with a metal halide lamp in 3 h. The lifespan was four times that of SnO2 Sb/Ti electrode. This proposed DSA construction strategy may support improved EC and PEC reactivities toward the decomposition of organic pollutants.", "author_names": [ "Peng Li", "Zhenan Bao", "Guanghui Wang", "Pengfei Xu", "Xue-Gang Wang", "Zhipeng Liu", "Yadan Guo", "Jing Deng", "Weimin Zhang" ], "corpus_id": 52821326, "doc_id": "52821326", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Ternary semiconductor metal oxide blends grafted Ag@AgCl hybrid as dimensionally stable anode active layer for photoelectrochemical oxidation of organic compounds: Design strategies and photoelectric synergistic mechanism.", "venue": "Journal of hazardous materials", "year": 2019 }, { "abstract": "This study investigated the influence of adding peroxydisulfate (PDS) to a photoelectrocatalysis (PEC) system using self doped TiO2 nanotube arrays (bl TNAs) for organic pollutant degradation. The addition of 1.0 mM PDS increased the bisphenol A (BPA) removal efficiency of PEC (PEC/PDS) from 65.0% to 85.9% within 1 h. The enhancement could be attributed to the high formation yield of hydroxyl radicals *OH) increased charge separation, and assistance of the sulfate radicals (SO4* The PDS concentration and applied potential bias were influential operating parameters for the PEC/PDS system. In addition, the system exhibited a highly stable performance over a wide range of pH values and background inorganic and organic constituents, such as chloride ions, bicarbonate, and humic acid. Further, the degradation performance of the organic pollutant mixture, including BPA, 4 chlorophenol (4 CP) sulfamethoxazole (SMX) and carbamazepine (CBZ) was evaluated in 0.1 M (NH4)2SO4 solution and real surface water. The degradation efficiency increased in the order of CBZ SMX 4 CP BPA in the PEC and PEC/PDS systems with both water matrices. Compared with the PEC system, the PEC/PDS (1.0 mM) system showed a threefold higher pseudo first order reaction rate constant for BPA among pollutant mixtures in surface water. This was attributed to enhanced *OH production and the selective nature of SO4* The pseudo first order reaction rate constants of other pollutants, i.e. 4 CP, SMX, and CBZ increased ca. twofold in the PEC/PDS system. The results of this study showed that the PEC/PDS system with bl TNAs is a viable technology for oxidative treatment.", "author_names": [ "Aseom Son", "Jiho Lee", "Changha Lee", "Kangwoo Cho", "Jaesang Lee", "Seok Won Hong" ], "corpus_id": 231604711, "doc_id": "231604711", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Persulfate enhanced photoelectrochemical oxidation of organic pollutants using self doped TiO2nanotube arrays: Effect of operating parameters and water matrix.", "venue": "Water research", "year": 2021 }, { "abstract": "Organic metal halide perovskite material has attracted intense interest in the photovoltaic field due to its excellent optoelectronic properties, but the extreme susceptibility of organolead halide perovskite to water seriously impedes its application for photoelectrochemical (PEC) conversions in aqueous solution. In this work, we develop an organolead halide perovskite photoanode of conventional electrode structure. The perovskite photoanode was fabricated by using a facile approach and encapsulated with conductive carbon paste and silver conductive paint for waterproof function, and the PEC water splitting was carried out as a model of PEC conversion. For PEC water oxidation, the photoanode achieved a remarkable photocurrent density of 12.4 mA/cm2 at 1.23 V versus reversible hydrogen electrode in alkaline electrolyte. In addition, the as prepared photoanode of conventional structure exhibited an unprecedented stability, which could be stable in alkaline electrolyte for more than 48 h. More importantly,", "author_names": [ "Ran Tao", "Zhixia Sun", "Fengyan Li", "Wencheng Fang", "Lin Xu" ], "corpus_id": 139236505, "doc_id": "139236505", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Achieving Organic Metal Halide Perovskite into a Conventional Photoelectrode: Outstanding Stability in Aqueous Solution and High Efficient Photoelectrochemical Water Splitting", "venue": "ACS Applied Energy Materials", "year": 2019 }, { "abstract": "Solution processable organic semiconductors have potentials as visible photoelectrochemical (PEC) water splitting photoelectrodes due to their tunable small band gap and electronic energy levels, but they are typically limited by poor stability and photocatalytic activity. Here, we demonstrate the direct visible PEC water oxidation on solution processed organic semiconductor thin films with improved stability and performance by ultrathin metal oxide passivation layers. N type fullerene derivative thin films passivated by sub 2 nm ZnO via atomic layer deposition enabled the visible PEC water oxidation at wavelengths longer than 600 nm in harsh alkaline electrolyte environments with up to 30 mA/cm2 photocurrents at the thermodynamic water oxidation equilibrium potential and the photoanode half lifetime extended to ~1000 s. The systematic investigation reveals the enhanced water oxidation catalytic activity afforded by ZnO passivation and the charge tunneling governing the hole transfer through passivation l.", "author_names": [ "L Wang", "Danhua Yan", "David W Shaffer", "Xinyi Ye", "Bobby Layne", "Javier J Concepcion", "Mingzhao Liu", "Chang-Yong Nam" ], "corpus_id": 103176595, "doc_id": "103176595", "n_citations": 15, "n_key_citations": 0, "score": 0, "title": "Improved Stability and Performance of Visible Photoelectrochemical Water Splitting on Solution Processed Organic Semiconductor Thin Films by Ultrathin Metal Oxide Passivation", "venue": "", "year": 2018 }, { "abstract": "Abstract Metal organic frameworks (MOFs) are promising co catalysts for increasingenhancing the performance of photoelectrochemical (PEC) water splitting. In this work, we successfully fabricated an efficient BiVO4 photoanode for PEC water oxidation by decorating its surface with Bi based MOF as a co catalyst via an unconventional immersion process at an ambient temperature. Bi MOF exhibits a large surface area and promotes bulk charge separation and surface charge transfer in the water oxidation reaction, resulting in an enhancement in the photocurrent density, which is approximately two times larger than that of the bare BiVO4 photoanode. In addition, the operation stability of our Bi MOF/BiVO4 photoanode was dramatically improved, and more than 95% of its initial photocurrent density was retained even after 24 h, indicating that the improved charge transfer by the Bi MOF layer prohibits the dissolution of the BiVO4 layer into the solution during the water oxidation reaction.", "author_names": [ "Seungkyu Kim", "Top Archie Dela Pena", "Sehun Seo", "Jun-cheol Park", "Jong-Hoon Lee", "Jae Ha Woo", "Chang Hyuck Choi" ], "corpus_id": 236239865, "doc_id": "236239865", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Co catalytic effects of Bi based metal organic framework on BiVO4 photoanodes for photoelectrochemical water oxidation", "venue": "", "year": 2021 }, { "abstract": "Abstract The degradation of pollutants with the simultaneous promotion of hydrogen production is an attractive and promising solution for the current environmental and energy problem, but few studies have been performed concerning the trends and mechanism of this process. Two classes of typical pollutants, phenols and alkylbenzenes, are treated using a self biasing photoelectrochemical (PEC) cell to reveal the intrinsic relationships between the redox properties of the pollutants and hydrogen production. The results show that the TOC removal rates of these pollutants range from 63.5% to 93.6% The highest hydrogen production efficiency (e H2 which is the ratio of experimental and theoretical hydrogen production amounts, reaches 81.5% The degradation rate constant (k) decreases as the experimental photoelectrocatalytic oxidation potential (E PEC increases. This trend can be explained by the degradation pathway deduced from the detection of intermediate products using LC MS and the associated reaction energetics from theoretical calculations. Neither the degradation rate constant (k) nor the TOC removal amounts (DTOC) determines the hydrogen production. The e H2 value positively depends on the average oxidation current efficiency (ACE) which is the ratio of experimental to theoretical TOC removal amounts. This study reveals a significant theory for the use of wastewater for hydrogen production.", "author_names": [ "Zhongyi Wu", "Zhaoyu Zhou", "Yajun Zhang", "Jie Wang", "Huijie Shi", "Qi Shen", "Guangfeng Wei", "Guohua Zhao" ], "corpus_id": 102498409, "doc_id": "102498409", "n_citations": 18, "n_key_citations": 0, "score": 0, "title": "Simultaneous photoelectrocatalytic aromatic organic pollutants oxidation for hydrogen production promotion with a self biasing photoelectrochemical cell", "venue": "", "year": 2017 }, { "abstract": "Abstract Morphology engineering is of prime significance in designing semiconductor photoelectrodes for efficient photoelectrochemical (PEC) fuel generation. Herein, we report a strategy to fabricate nanostructured tungsten oxide films using anodic oxidation of tungsten and their performance as photoanodes for PEC water splitting. A solution of an organic compound, dimethyl sulfoxide, with hydrofluoric acid was used as the electrolyte. The anodization parameters such as voltage and electrolyte temperature were found to have a critical influence in determining the porous nature and dimensions of the resulting oxide film. Anodization conducted at a voltage ~10 V and a temperature ~40 degC led to the formation of compact tungsten oxide films due to the low strength of the electric field partially responsible for the porous morphology development. The surface of the film became porous at elevated temperatures. At higher voltages, a thin nanoporous film atop a thicker compact layer was formed; however, the structure became more disordered and less porous when the electrolyte temperature was increased. The study demonstrated that by adjusting the voltage and temperature, the oxide film morphology could be varied from a compact layer to a porous structure resembling nanotubes. The films heat treated at 500 degC attained the monoclinic phase of WO3. The PEC performance was influenced strongly by the morphology of the films. The films with nanotube like morphology yielded incident photon to current conversion efficiency values of over 40% This study would provide a practical basis for developing optimal WO3 nanostructures for efficient PEC fuel generation.", "author_names": [ "Tao Zhang", "Maggie Paulose", "Ram P Neupane", "Lillian Aurora Schaffer", "Dhan Bahadur Rana", "Jinzhan Su", "Liejin Guo", "Oomman K Varghese" ], "corpus_id": 213365422, "doc_id": "213365422", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Nanoporous WO3 films synthesized by tuning anodization conditions for photoelectrochemical water oxidation", "venue": "", "year": 2020 }, { "abstract": "Methanol is an available, small, and colorless molecule, which can be used for the photocatalytic activity evaluation without the sensitization problem associated with most dye molecules. Thus, TiO2 suspended in aqueous methanol solutions is commonly employed as a model test for the photocatalytic degradation of organic pollutants in aerobic system or for photocatalytic hydrogen production in absence of molecular oxygen. It is, hence, important to explore the mechanism of its photocatalytic and photoelectrochemical oxidation on TiO2 in aqueous solution. In this mini review, the possible mechanisms for water and methanol oxidation on TiO2 will therefore be presented and discussed.", "author_names": [ "Amira Y Ahmed", "Tarek A Kandiel", "Irina I Ivanova", "Detlef W Bahnemann" ], "corpus_id": 95950715, "doc_id": "95950715", "n_citations": 25, "n_key_citations": 0, "score": 2, "title": "Photocatalytic and photoelectrochemical oxidation mechanisms of methanol on TiO2 in aqueous solution", "venue": "", "year": 2014 }, { "abstract": "Abstract In this study, the organic solvent free 'green synthesis' of bismuth vanadate (BiVO 4 has been described for its application in photoelectrochemical (PEC) water oxidation. BiVO 4 thin films were successfully prepared through electrodeposition of Bi film on the FTO glass substrate from the aqueous bath containing Bi(NO 3 3 in presence of K Na tartrate and dextrose; followed by thermo chemical reaction with an aqueous solution of vanadium acetylacetonate (VO(acac) 2 XRD SEM EDS analyses indicated the formation of scheelite monoclinic BiVO 4 with seed like morphology. UV visible absorption spectra measured the band gap energy 2.3 eV indicating visible light activity of the photocatalyst and the Mott Schottky analysis showed n type nature of the semiconductor. Highest photocurrent of 1.3 mA cm 2 (at ~1 V vs Ag/AgCl) for water oxidation and 2 mA cm 2 (at ~0.6 V vs Ag/AgCl) for sacrificial (SO 3 2 oxidation were measured under 35 mW cm 2 illumination using the optimized thin film and the maximum incident photon to current conversion efficiency (IPCE) of 42% was obtained. The enhanced photocurrent in solar assisted water oxidation is attributed to the formation of well covered and compact film with improved electrical continuity, shown by minimum charge transfer resistance. Adsorption of an optimized amount of Co 2+ over the BiVO 4 improves its catalytic properties towards oxygen evolution reaction by approximately 2.5 times, with lowering of charge transfer resistance of the material as measured through impedance analysis.", "author_names": [ "P K Hajra", "Sukumar Kundu", "Arjun Maity", "Chinmoy Bhattacharya" ], "corpus_id": 195405371, "doc_id": "195405371", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Facile photoelectrochemical water oxidation on Co2+ adsorbed BiVO4 thin films synthesized from aqueous solutions", "venue": "Chemical Engineering Journal", "year": 2019 }, { "abstract": "Coupling semiconducting metal organic frameworks (MOFs) with metal oxide (MO) semiconductor nanowires is an efficient solution to tune the photoelectric properties of both the parties. In this report, we demonstrate a facile surfactant free growth strategy for modification of zinc oxide (ZnO) single crystal nanowire arrays (NWAs) with the MOF zinc glycolate (noted as Zn GA) that contains an embedded continuous 3D Zn O network. Due to the structural resemblance of the Zn O network between Zn GA and ZnO, the prepared ZnO@Zn GA nanowires present a tight contact at the core shell interface in a partially epitaxial manner, and the loading amount of Zn GA can be well controlled in the synthetic process. The inherent p type Zn GA in combination with the widely available n type ZnO assures the construction of tandem n p heterojunctions at the core shell interface, which is confirmed by Mott Schottky analysis. By implementation of the ZnO@Zn GA NWAs as photoanodes for photoelectrochemical oxidation of water and oxalic acid, improved photocurrent responses are obtained relative to the primary ZnO NWAs. The most significant photoresponse is observed in the ZnO nanowires shelled by a compact Zn GA particulate thin film with the largest junction region. These results are elucidated by the enhanced spatial separation efficiency of photogenerated charge carriers, which is favored by the built in electric field at the interface of the n p heterojunctions.", "author_names": [ "Qianqian Gao", "Huihui Kang", "Yun Cai", "Daxiang Xue", "Fengjiao Yu", "Jun Fang", "Yang Yang" ], "corpus_id": 174814360, "doc_id": "174814360", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Improving photoelectrochemical response of ZnO nanowire arrays by coating with p type ZnO resembling metal organic framework.", "venue": "Dalton transactions", "year": 2019 } ]

[ { "abstract": "Ultrathin two dimensional nanosheets of layered transition metal dichalcogenides (TMDs) are fundamentally and technologically intriguing. In contrast to the graphene sheet, they are chemically versatile. Mono or few layered TMDs obtained either through exfoliation of bulk materials or bottom up syntheses are direct gap semiconductors whose bandgap energy, as well as carrier type (n or p type) varies between compounds depending on their composition, structure and dimensionality. In this Review, we describe how the tunable electronic structure of TMDs makes them attractive for a variety of applications. They have been investigated as chemically active electrocatalysts for hydrogen evolution and hydrosulfurization, as well as electrically active materials in opto electronics. Their morphologies and properties are also useful for energy storage applications such as electrodes for Li ion batteries and supercapacitors.", "author_names": [ "Manish Chhowalla", "Hyeon Suk Shin", "Goki Eda", "Lain-Jong Li", "Kian Ping Loh", "Hua Zhang" ], "corpus_id": 205291228, "doc_id": "205291228", "n_citations": 5976, "n_key_citations": 50, "score": 1, "title": "The chemistry of two dimensional layered transition metal dichalcogenide nanosheets.", "venue": "Nature chemistry", "year": 2013 }, { "abstract": "Ultrathin two dimensional (2D) nanosheets of layered transition metal dichalcogenides (TMDs) such as MoS2, TiS2, TaS2, WS2, MoSe2, WSe2, etc. are emerging as a class of key materials in chemistry and electronics due to their intriguing chemical and electronic properties. The ability to prepare these TMD nanosheets in high yield and large scale via various methods has led to increasing studies on their hybridization with other materials to create novel functional composites, aiming to engineer their chemical, physical and electronic properties and thus achieve good performance for some specific applications. In this critical review, we will introduce the recent progress in hybrid nanoarchitectures based on 2D TMD nanosheets. Their synthetic strategies, properties and applications are systematically summarized and discussed, with emphasis on those new appealing structures, properties and functions. In addition, we will also give some perspectives on the challenges and opportunities in this promising research area.", "author_names": [ "Chaoliang Tan", "Hua Zhang" ], "corpus_id": 8426151, "doc_id": "8426151", "n_citations": 933, "n_key_citations": 3, "score": 0, "title": "Two dimensional transition metal dichalcogenide nanosheet based composites.", "venue": "Chemical Society reviews", "year": 2015 }, { "abstract": "Recently there have been many research breakthroughs in two dimensional (2D) materials including graphene, boron nitride (h BN) black phosphors (BPs) and transition metal dichalcogenides (TMDCs) The unique electrical, optical, and thermal properties in 2D materials are associated with their strictly defined low dimensionalities. These materials provide a wide range of basic building blocks for next generation electronics. The chemical vapor deposition (CVD) technique has shown great promise to generate high quality TMDC layers with scalable size, controllable thickness, and excellent electronic properties suitable for both technological applications and fundamental sciences. The capability to precisely engineer 2D materials by chemical approaches has also given rise to fascinating new physics, which could lead to exciting new applications. In this Review, we introduce the latest development of TMDC synthesis by CVD approaches and provide further insight for the controllable and reliable synthesis of atomically thin TMDCs. Understanding of the vapor phase growth mechanism of 2D TMDCs could benefit the formation of complicated heterostructures and novel artificial 2D lattices.", "author_names": [ "Henan Li", "Ying Li", "Areej Aljarb", "Yumeng Shi", "Lain-Jong Li" ], "corpus_id": 28453913, "doc_id": "28453913", "n_citations": 162, "n_key_citations": 1, "score": 0, "title": "Epitaxial Growth of Two Dimensional Layered Transition Metal Dichalcogenides: Growth Mechanism, Controllability, and Scalability.", "venue": "Chemical reviews", "year": 2018 }, { "abstract": "The remarkable properties of graphene have renewed interest in inorganic, two dimensional materials with unique electronic and optical attributes. Transition metal dichalcogenides (TMDCs) are layered materials with strong in plane bonding and weak out of plane interactions enabling exfoliation into two dimensional layers of single unit cell thickness. Although TMDCs have been studied for decades, recent advances in nanoscale materials characterization and device fabrication have opened up new opportunities for two dimensional layers of thin TMDCs in nanoelectronics and optoelectronics. TMDCs such as MoS(2) MoSe(2) WS(2) and WSe(2) have sizable bandgaps that change from indirect to direct in single layers, allowing applications such as transistors, photodetectors and electroluminescent devices. We review the historical development of TMDCs, methods for preparing atomically thin layers, their electronic and optical properties, and prospects for future advances in electronics and optoelectronics.", "author_names": [ "Qing Hua Wang", "Kourosh Kalantar-zadeh", "Andras Kis", "Jonathan N Coleman", "Michael S Strano" ], "corpus_id": 6261931, "doc_id": "6261931", "n_citations": 10034, "n_key_citations": 84, "score": 0, "title": "Electronics and optoelectronics of two dimensional transition metal dichalcogenides.", "venue": "Nature nanotechnology", "year": 2012 }, { "abstract": "Layered compounds such as MoS2, WS2, MoSe2, TaSe2, NbSe2, NiTe2, BN, and Bi2Te3 are exfoliated by sonication of powders of the materials in a number of solvents with varying surface tensions and deposited as individual flakes or formed into films.", "author_names": [ "Jonathan N Coleman" ], "corpus_id": 104382969, "doc_id": "104382969", "n_citations": 611, "n_key_citations": 21, "score": 0, "title": "Two Dimensional Nanosheets Produced by Liquid Exfoliation of Layered Materials.", "venue": "", "year": 2011 }, { "abstract": "Two dimensional transition metal dichalcogenides (TMDs) an emerging family of layered materials, have provided researchers a fertile ground for harvesting fundamental science and emergent applications. TMDs can contain a number of different structural defects in their crystal lattices which significantly alter their physico chemical properties. Having structural defects can be either detrimental or beneficial, depending on the targeted application. Therefore, a comprehensive understanding of structural defects is required. Here we review different defects in semiconducting TMDs by summarizing: (i) the dimensionalities and atomic structures of defects; (ii) the pathways to generating structural defects during and after synthesis and, (iii) the effects of having defects on the physico chemical properties and applications of TMDs. Thus far, significant progress has been made, although we are probably still witnessing the tip of the iceberg. A better understanding and control of defects is important in order to move forward the field of Defect Engineering in TMDs. Finally, we also provide our perspective on the challenges and opportunities in this emerging field.", "author_names": [ "Zhong Lin", "Bruno R Carvalho", "Ethan Kahn", "Ruitao Lv", "Rahul Rao", "Humberto Terrones", "Marcos A Pimenta", "Mauricio Terrones" ], "corpus_id": 3466199, "doc_id": "3466199", "n_citations": 486, "n_key_citations": 3, "score": 0, "title": "Defect engineering of two dimensional transition metal dichalcogenides", "venue": "", "year": 2016 }, { "abstract": "THE standard text books in advanced inorganic chemistry at the service of past generations presented the reader with, a gigantic jumble of disconnected data. One great unifying principle the periodic classification of the elements was indeed recognized; but it was admittedly riddled with exceptions. Small wonder that the majority of students, on reaching the research stage, preferred the severely systematic field of organic chemistry; order is always more attractive than chaos.Inorganic ChemistryBy Fritz Ephraim. English edition by Dr. P. C. L. Thorne and Dr. E. R. Roberts. Fourth edition, revised. Pp. xii 922. (London and Edinburgh: Gurney and Jackson, Ltd. 1943. 28s. net.", "author_names": [ "James I Kendall" ], "corpus_id": 4007211, "doc_id": "4007211", "n_citations": 2281, "n_key_citations": 152, "score": 0, "title": "Inorganic Chemistry", "venue": "Nature", "year": 1944 }, { "abstract": "We report free standing atomic crystals that are strictly 2D and can be viewed as individual atomic planes pulled out of bulk crystals or as unrolled single wall nanotubes. By using micromechanical cleavage, we have prepared and studied a variety of 2D crystals including single layers of boron nitride, graphite, several dichalcogenides, and complex oxides. These atomically thin sheets (essentially gigantic 2D molecules unprotected from the immediate environment) are stable under ambient conditions, exhibit high crystal quality, and are continuous on a macroscopic scale.", "author_names": [ "Kostya S Novoselov", "Da Jiang", "Fred Schedin", "Timothy J Booth", "V V Khotkevich", "S V Morozov", "Andre K Geim" ], "corpus_id": 7683253, "doc_id": "7683253", "n_citations": 8498, "n_key_citations": 122, "score": 0, "title": "Two dimensional atomic crystals.", "venue": "Proceedings of the National Academy of Sciences of the United States of America", "year": 2005 }, { "abstract": "Two dimensional (2D) layered transition metal dichalcogenides (TMDs) are a fascinating class of nanomaterials that have the potential for application in catalysis, electronics, photonics, energy storage, and sensing. TMDs are rather inert, and thus pose problems for chemical derivatization. However, to further modify the properties of TMDs and fully harness their capabilities, routes towards their chemical functionalization must be identified. Herein, recent efforts toward the chemical (bond forming) functionalization of 2D TMDs are critically reviewed. Recent successes are highlighted, along with areas where further detailed analyses and experimentation are required. This burgeoning field is very much in its infancy but has already provided several important breakthroughs.", "author_names": [ "Xu-Dong Chen", "Aidan R McDonald" ], "corpus_id": 11650150, "doc_id": "11650150", "n_citations": 126, "n_key_citations": 2, "score": 0, "title": "Functionalization of Two Dimensional Transition Metal Dichalcogenides.", "venue": "Advanced materials", "year": 2016 }, { "abstract": "In this report, we have developed a rapid and versatile ultrasonication enhanced lithium intercalation (ULI) method to prepare single layer transition metal dichalcogenide nanosheets (TMDC NSs, including MoS2, WS2, and TiS2) by using n butyllithium (n BuLi)", "author_names": [ "Lihui Yuwen", "Huan Yu", "Xiangrong Yang", "Jiajia Zhou", "Qi-ming Zhang", "Yuqian Zhang", "Zhimin Luo", "Shao Su", "Lianhui Wang" ], "corpus_id": 205944490, "doc_id": "205944490", "n_citations": 80, "n_key_citations": 0, "score": 0, "title": "Rapid preparation of single layer transition metal dichalcogenide nanosheets via ultrasonication enhanced lithium intercalation.", "venue": "Chemical communications", "year": 2016 } ]

[ { "abstract": "Electrochemical impedance spectroscopy has become a mature and well understood technique. It is now possible to acquire, validate, and quantitatively interpret the experimental impedances. This chapter has been addressed to understanding the fundamental processes of diffusion and faradaic reaction at electrodes. However, the most difficult problem in EIS is modeling the electrode processes, which is where most of the problems and errors arise. There is an almost infinite variety of different reactions and interfaces that can be studied (corrosion, coatings, conducting polymers, batteries and fuel cells, semiconductors, electrocatalytic reactions, chemical reactions coupled with faradaic processes, etc. and the main effort is now being applied to understanding and analyzing these processes. These applications will be the subject of a second review in a forthcoming volume in this series.", "author_names": [ "Andrzej Lasia" ], "corpus_id": 93191784, "doc_id": "93191784", "n_citations": 961, "n_key_citations": 41, "score": 1, "title": "Electrochemical Impedance Spectroscopy and its Applications", "venue": "", "year": 2014 }, { "abstract": "", "author_names": [ "" ], "corpus_id": 139559449, "doc_id": "139559449", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Recent Advances in Electrochemical Impedance Spectroscopy and Its Applications", "venue": "", "year": 2018 }, { "abstract": "Electrochemical techniques have been widely employed to detect and/or quantify molecules of medical, environmental and industrial interests. Among traditional techniques such as potentiometry, amperometry and conductometry, the Electrochemical Impedance Spectroscopy (EIS) has gained great attention as an analytical tool for a broad range of analytes, mainly because it can be performed as a non destructive method and it enables in situ measurements.1,2 Moreover, EIS exempt the use of special reagents, which makes it suitable for label free applications, which significantly diminishes its cost in relation to other techniques and makes it easier to perform.3 In common, all the electrochemical sensors consist on relating a measurable output electrical signal to the changes in the structure (usually the surface) of an electrode because of the recognition of a target analyte. The in depth understanding of the mechanisms and fundaments involving the sensing phenomena is a challenge in electroanalytical techniques and can lead to the improvement of the main desirable characteristics of a sensor: the selectivity, stability and sensibility.4 In this sense, this minireview presents the main aspects regarding the EIS as a technique for application in sensors based on its two categories of performance: the Faradaic and non faradaic EIS.", "author_names": [ "Ricardo Adriano Dorledo de Faria", "Luiz Guilherme Dias Heneine", "Tulio Matencio", "Younes Messaddeq" ], "corpus_id": 109936655, "doc_id": "109936655", "n_citations": 13, "n_key_citations": 1, "score": 0, "title": "Faradaic and non faradaic electrochemical impedance spectroscopy as transduction techniques for sensing applications", "venue": "International Journal of Biosensors Bioelectronics", "year": 2019 }, { "abstract": "We report an extraction reconstruction strategy for obtaining a novel voltammogram for a specific electrochemical process. While a conventional voltammogram is obtained from potentiodynamic currents, our voltammogram is obtained from a large body of potentiodynamic electrochemical impedance spectra by taking advantage of their highly resolvable power. As a proof of concept, construction of a mass transfer admittance voltammogram (MTAV) is demonstrated, which is made up of purely mass transfer admittances plotted vs. potential, excluding effects from other interfering electrochemical components. We also compare the MTAV with the AC voltammogram to show its enhanced accuracy and apply the novel voltammetry to clearly determine the number of electrons transferred and diffusion coefficients, which may vary depending on experimental conditions, for a complex electrochemical reaction.", "author_names": [ "Byoung-Yong Chang", "Hyo Joong Lee", "Su-Moon Park" ], "corpus_id": 96810376, "doc_id": "96810376", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Mass Transfer Admittance Voltammetry from Electrochemical Impedance Spectroscopy and Its Applications", "venue": "", "year": 2011 }, { "abstract": "As research on secondary batteries becomes important, interest in analytical methods to examine the condition of secondary batteries is also increasing. Among these methods, the electrochemical impedance spectroscopy (EIS) method is one of the most attractive diagnostic techniques due to its convenience, quickness, accuracy, and low cost. However, since the obtained spectra are complicated signals representing several impedance elements, it is necessary to understand the whole electrochemical environment for a meaningful analysis. Based on the understanding of the whole system, the circuit elements constituting the cell can be obtained through construction of a physically sound circuit model. Therefore, this mini review will explain how to construct a physically sound circuit model according to the characteristics of the battery cell system and then introduce the relationship between the obtained resistances of the bulk (Rb) charge transfer reaction (Rct) interface layer (RSEI) diffusion process (W) and battery characteristics, such as the state of charge (SOC) temperature, and state of health (SOH)", "author_names": [ "Woosung Choi", "Heon-Cheol Shin", "Ji Man Kim", "Jaeyoung Choi", "Won-Sub Yoon" ], "corpus_id": 211570579, "doc_id": "211570579", "n_citations": 70, "n_key_citations": 1, "score": 0, "title": "Modeling and Applications of Electrochemical Impedance Spectroscopy (EIS) for Lithium ion Batteries", "venue": "", "year": 2020 }, { "abstract": "A critical review of electrochemical impedance techniques in corrosion research is presented. Electrochemical impedance spectroscopy (EIS) is a powerful in situ technique used in corrosion research owing to its promise in providing information on various fundamental/complex electrochemistry processes that occur at the metal/electrolyte interface. EIS has played a pivotal role in defining new information in corrosion research and materials characterization. Using EIS in combination with new surface analytical and imaging tools, it is now possible to characterize the structure, growth kinetics and electronic properties of passive oxide films at the nanoscale level. Successful use of EIS as a corrosion monitoring tool has been demonstrated in many recent studies. The power of EIS in characterizing a wide range of electrochemical corrosion systems and use of various new impedance techniques, including those of combined electrochemical, microscopic and mechanical techniques for studying physico electrochemical systems are briefly described. The purpose of this paper is to critically review the recent advances of EIS in unraveling the response mechanisms of electrochemical nature of corrosion. More importantly, the various advantages offered by EIS over other electrochemical techniques are discussed. The paper also provides a brief review of EIS, with emphasis on those developments that have propelled the impedance technique into the forefront of corrosion research in India. Corresponding author: Tel No: +91 44 27480121; Fax: +91 44 27480301; E mail: [email protected] (Prof.Dr.U.Kamachi Mudali)", "author_names": [ "S Ningshen", "Uthandi Kamachi Mudali", "Baldev Raj" ], "corpus_id": 102153006, "doc_id": "102153006", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY AND ITS APPLICATIONS IN CORROSION RESEARCH", "venue": "", "year": 2009 }, { "abstract": "", "author_names": [ "Andrzej Lasia" ], "corpus_id": 199492448, "doc_id": "199492448", "n_citations": 72, "n_key_citations": 0, "score": 0, "title": "Electrochemical Impedance Spectroscopy and its Applications", "venue": "", "year": 2014 }, { "abstract": "Electrochemical impedance spectroscopy (EIS) is a nondestructive technique often used to understand the interfacial behavior in electrochemical systems. The ability of the technique to segregate various processes, i.e. ohmic conduction, charge transfer interfacial charging, mass transfer etc, makes it an elegant technique for electrochemical systems. Its applicability to lithium ion cells is further enhanced by the fact that surface films cover both the electrodes and especially the carbon anode. This paper describes the EIS response of individual electrodes in the lithium. ion cells under a variety of experimental conditions, i.e. temperature, high temperature storage and cycling.", "author_names": [ "Bugga V Ratnakumar", "Marshall C Smart", "Subbarao Surampudi" ], "corpus_id": 55100541, "doc_id": "55100541", "n_citations": 15, "n_key_citations": 0, "score": 0, "title": "Electrochemical impedance spectroscopy and its applications to lithium ion cells", "venue": "Seventeenth Annual Battery Conference on Applications and Advances. Proceedings of Conference (Cat. No.02TH8576)", "year": 2002 }, { "abstract": "The application of electrochemical impedance spectroscopy (EIS) has increased dramatically in the past few years due to its ability to elucidate a plethora of physical and electronic properties of electrochemical systems such as diffusion coefficients, electron transfer rate constants, adsorption mechanisms, charge transfer resistances, capacitances and pore sizes. This review provides a short introduction to the fundamental principles of EIS before exploring the many exciting and pertinent analytical applications regarding the numerous methods in biosensing, the application of EIS with graphene based materials and last, the use of EIS with screen printed electrodes.", "author_names": [ "Edward P Randviir", "Craig E Banks" ], "corpus_id": 97605813, "doc_id": "97605813", "n_citations": 296, "n_key_citations": 5, "score": 0, "title": "Electrochemical impedance spectroscopy: an overview of bioanalytical applications", "venue": "", "year": 2013 }, { "abstract": "Abstract Considering transport applications, there is worldwide an increasing interest in the use of hydrogen energy for supplying electric powertrains. In order to extend the fuel cell lifespan and to increase its reliability and efficiency, the following features are essential to a fuel cell stack connected DC/DC boost converter: low input current ripple, high voltage gain ratio, high efficiency, high compactness, and high redundancy. Moreover, in order to assess in real time the state of health of the fuel cell stack, on line Electrochemical Impedance Spectroscopy (EIS) functionality integrated with the fuel cell stack connected DC/DC boost converter is a real promising solution requiring no additional measurement equipment. From these points of view, this paper presents a comparison analysis of high voltage gain DC/DC boost converters for fuel cell electric vehicles applications. In addition, some comments and guidelines regarding integration issues are also provided.", "author_names": [ "Hanqing Wang", "Arnaud Gaillard", "Daniel Hissel" ], "corpus_id": 133495201, "doc_id": "133495201", "n_citations": 51, "n_key_citations": 0, "score": 0, "title": "A review of DC/DC converter based electrochemical impedance spectroscopy for fuel cell electric vehicles", "venue": "Renewable Energy", "year": 2019 } ]

[ { "abstract": "We review the physical properties of diluted magnetic semiconductors (DMS) of the type AII1 xMnxBVI (e.g. Cd1 xMnxSe, Hg1 xMnxTe) Crystallographic properties are discussed first, with emphasis on the common structural features which these materials have as a result of tetrahedral bonding. We then describe the band structure of the AII1 xMnxBVI alloys in the absence of an external magnetic field, stressing the close relationship of the sp electron bands in these materials to the band structure of the nonmagnetic AIIBVI 'parent' semiconductors. In addition, the characteristics of the narrow (nearly localized) band arising from the half filled Mn 3d5 shells are described, along with their profound effect on the optical properties of DMS. We then describe our present understanding of the magnetic properties of the AII1 xMnxBVI alloys. In particular, we discuss the mechanism of the Mn+ Mn+ exchange, which underlies the magnetism of these materials; we present an analytic formulation for the magnetic susc.", "author_names": [ "Jacek K Furdyna" ], "corpus_id": 96287182, "doc_id": "96287182", "n_citations": 2480, "n_key_citations": 14, "score": 1, "title": "Diluted magnetic semiconductors", "venue": "", "year": 1988 }, { "abstract": "Diluted magnetic semiconductors (DMSs) i.e. semiconducting crystals whose lattice is made up in part of substitutional magnetic ions (e.g. Cd/sub 1 x/Mn/sub x/Te, Hg/sub 1 x/Fe/sub x/Se, Zn/sub 1 x/Co/sub x/S) are reviewed. The focus is on materials of the type A/sub 1 x//sup II/ Mn/sub x/B/sup VI/ which are the most thoroughly understood. However, the similarities and differences between these materials and the A/sub 1 x//sup II/Fe/sub x/B/sup VI/ and A/sub 1 /sup II/Co/sub x/B/sup VI/ systems are discussed wherever information on the latter system is available. The band structure of the materials, which determines their basic semiconducting properties, is examined. Special attention is given to exchange interactions between the magnetic ions themselves (the d d interaction) and the interaction between the magnetic ions and band electrons (the sp d interaction) Magnetic phenomena in DMS alloys are considered. Special attention is given to the physics of layered structures, such as quantum wells and superlattices, involving DMS materials. The prospects of device applications made possible by the properties of DMS alloys are assessed.", "author_names": [ "Nitin Samarth", "Jacek K Furdyna" ], "corpus_id": 97897057, "doc_id": "97897057", "n_citations": 174, "n_key_citations": 16, "score": 0, "title": "Diluted magnetic semiconductors", "venue": "", "year": 1990 }, { "abstract": "Thin epitaxial films of the diluted magnetic semiconductor (DMS) GaMnAs have been studied by low energy muon spin rotation and relaxation (LE microSR) as well as by transport and magnetization measurement techniques. LE microSR allows measurements of the distribution of magnetic field on the nanometer scale inaccessible to traditional macroscopic techniques. The spatial inhomogeneity of the magnetic field is resolved: although homogeneous above Tc, below Tc the DMS consists of ferromagnetic and paramagnetic regions of comparable volumes. In the ferromagnetic regions the local field inhomogeneity amounts to 0.03 T.", "author_names": [ "Vyacheslav G Storchak", "Dmitry G Eshchenko", "Elvezio Morenzoni", "Thomas Prokscha", "Andreas Suter", "Xinyu Liu", "Jacek K Furdyna" ], "corpus_id": 20219394, "doc_id": "20219394", "n_citations": 23, "n_key_citations": 0, "score": 0, "title": "Spatially resolved inhomogeneous ferromagnetism in (Ga,Mn)as diluted magnetic semiconductors: a microscopic study by muon spin relaxation.", "venue": "Physical review letters", "year": 2008 }, { "abstract": "This paper reviews the electrical, magnetic, and optical properties of diluted magnetic semiconductors (sometimes also referred to as 'semimagnetic' semiconductors) These materials are ternary semiconductor alloys whose lattice is made up in part of substitutional magnetic ions. Cd1 xMnxTe and Hg1 xMnxTe are examples of such systems. As semiconductors, these alloys display interesting and important properties, such as the variation of the energy gap and of effective mass with composition. They also exhibit magnetic properties which are interesting in their own right, e.g. a low temperature spin glass transition and magnon excitations. Most importantly, however, the presence of substitutional magnetic ions in these alloys leads to spin spin exchange interaction between the localized magnetic moments and the band electrons. This in turn has rather important consequences on band structure and on donor and acceptor states, leading to dramatic effects in quantum transport, impurity conduction, and magneto optics. Specifically, the presence of exchange interaction results in extremely large and temperature dependent g factors of electrons and holes; in gigantic values of Faraday rotation; in anomalously large negative magnetoresistance; and in the formation of the bound magnetic polaron.", "author_names": [ "Jacek K Furdyna" ], "corpus_id": 117989022, "doc_id": "117989022", "n_citations": 338, "n_key_citations": 0, "score": 0, "title": "DILUTE MAGNETIC SEMICONDUCTORS: OTHER SPIN GLASSES C. Stassis, Chairperson Diluted magnetic semiconductors: An interface of semiconductor physics and magnetism (invited)", "venue": "", "year": 1982 }, { "abstract": "The spin of the carriers has so far played a minor role in semiconductor devices mainly because the semiconductors used for industrial applications, such as Si and GaAs, are nonmagnetic. On the other hand, the enhanced spin related phenomena have been realized in diluted magnetic semiconductors (DMS) to offer applications known as spintronics. Discovery of ferromagnetism (FM) in the canonical DMS GaMnAs films which have the benefit of being compatible with GaAs technology has led to intense studies of the FM in these materials for spintronics applications. Although there is an emerging consensus that the FM in DMS originates from the interaction between itinerant carriers and localized magnetic moments, the microscopic theory of FM in these materials is the subject of considerable debate [1] Theoretical models encounter major difficulties caused by the absence of experimental data on the distribution of the magnetic field in DMS on the nanometer scale because so far the FM properties of DMS have been studied mainly using traditional macroscopic integral techniques unable to produce spatially resolved information. Here we present direct experimental evidence for the inhomogeneous nature of the FM state in GaMnAs DMS. Using low energy positive muons as a local magnetic probe we are able to resolve spatial inhomogeneity of the magnetic field in the thin film: although homogeneous above Tc, DMS clearly consists of ferromagnetic and paramagnetic regions of the comparable volumes in the FM state.", "author_names": [ "Vyacheslav G Storchak", "Dmitry G Eshchenko", "Elvezio Morenzoni", "Thomas Prokscha", "Andreas Suter", "Xianghua Liu", "Jacek K Furdyna" ], "corpus_id": 201040033, "doc_id": "201040033", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "P 74 Poster II Magnetic Semiconductors Spatially Resolved Inhomogeneous Ferromagnetism in Ga Mn As Diluted Magnetic Semiconductors", "venue": "", "year": 2008 }, { "abstract": "Diluted magnetic semiconductors (DMS) are semiconducting alloys containing a random distribution of substitutional magnetic ions (e.g. Mn+ in Cd1 xMnxSe) Magnetic properties of DMS such as spin glass behavior due to lattice frustration, magnon excitations in a random system of spins, superexchange, and short range antiferromagnetic order are of considerable interest in their own right. In addition, understanding these properties is important because they strongly influence the electronic phenomena in DMS via the sp d exchange interaction between the band electrons and the localized magnetic moments. We review the most recent results concerning magnetic susceptibility, Mn+ Mn+ nearest neighbor exchange, and magnetic short range order in these materials. On this basis, we can present a fairly complete and unified picture of magnetic properties of DMS. In addition, we point out some of the issues and challenges that lie ahead.", "author_names": [ "Jacek K Furdyna", "Nitin Samarth" ], "corpus_id": 96347566, "doc_id": "96347566", "n_citations": 105, "n_key_citations": 0, "score": 0, "title": "Magnetic properties of diluted magnetic semiconductors: A review (invited)", "venue": "", "year": 1987 }, { "abstract": "We review the crystallography, band structure, and optical, electrical, and magnetic properties of diluted magnetic semiconductors (DMS) with emphasis on ternary alloys of the type AII1 xMnxBVI (e.g. Hg1 xMnxTe) Considerable attention in the review is given to spectacular novel effects which arise from the selective enhancement of spin dependent properties due to exchange interaction between the localized magnetic moments (Mn+2) and band electrons. We then identify the major issues currently facing the field of DMS, and we discuss the major opportunities which these materials hold in store, both in the area of further scientific discoveries and in technological applications. In particular, we stress the need for a systematic concerted effort in the area of controlling impurities and defects in DMS, and we argue that exchange interaction in these materials offers an additional tool for studies in this area. We then describe, as examples of important future opportunities, the emerging field of Fe based D.", "author_names": [ "Jacek K Furdyna" ], "corpus_id": 95261320, "doc_id": "95261320", "n_citations": 73, "n_key_citations": 0, "score": 0, "title": "Diluted magnetic semiconductors: Issues and opportunities", "venue": "", "year": 1986 }, { "abstract": "Publisher Summary This chapter discusses the crystal structure, composition, and materials preparation of diluted magnetic semiconductors. It reviews the crystal structure and composition of the various AII1 xMnxBVI alloys. It shows that this can be done in a unified way for both the zinc blende and wurtzite members of this group of materials. The chapter also describes the methods of preparation of bulk diluted magnetic semiconductors (DMS) crystals, including materials purification, the synthesis of starting binary compounds, and crystal growth. It discusses recent developments in the field of DMS, such as AII1 xMnxBVI epitaxial films and superlattices, AII1 xFexBVI alloys, and AIVBVI based DMS containing substitutional manganese or rare earth ions. Both crystal structures of the DMS zinc blende and wurtzite are very closely related in spite of the differences in symmetry, they are both formed with tetrahedral (s p3) bonding, involving the two valence s electrons of the group VI element and the six valence p electrons of the group VI element. Manganese is a transition metal with valence electrons corresponding to the 4s2 orbital. Although manganese differs from the group II elements by the fact that its 3d shell is only half filled, it can contribute its 4s2 electrons to the s p3 bonding and can, therefore, substitutionally replace the group II elements in the AIIBVI wurtzite or zinc blende structures.", "author_names": [ "Witold Giriat", "Jacek K Furdyna" ], "corpus_id": 93479471, "doc_id": "93479471", "n_citations": 44, "n_key_citations": 0, "score": 0, "title": "Chapter 1 Crystal Structure, Composition, and Materials Preparation of Diluted Magnetic Semiconductors", "venue": "", "year": 1988 }, { "abstract": "We report measurements of EPR in the magnetic semiconductors Cd1 xMnxTe and reanalyze earlier data. Experimentally we find (i) the room temperature linewidth increases as x is increased, (ii) the g value, obtained by reference to the zero of the derivative curve, is almost independent of x, (iii) each resonance line has a symmetric lineshape, and (iv) for each x the linewidth increases as T is reduced. These facts suggest that the resonances are not relaxation broadened but are, instead, inhomogeneously broadened. We model this inhomogeneity in terms of a Gaussian distribution of internal fields and show that there is a sharp change in the x dependence of the corresponding Gaussian widths at the percolation threshold. We also note that the temperature dependence of the linewidths follows an empirical form proposed earlier for metallic spin glasses.", "author_names": [ "David J Webb", "S M Bhagat", "Jacek K Furdyna" ], "corpus_id": 96999475, "doc_id": "96999475", "n_citations": 31, "n_key_citations": 0, "score": 0, "title": "Electron paramagnetic resonance linewidths in diluted magnetic semiconductors: Cd1 xMnxTe", "venue": "", "year": 1984 }, { "abstract": "Abstract Localization of exciton wavefunctions in self assembled quantum dots (QDs) has been investigated using CdSe QDs embedded in ZnMnSe. This system was chosen so as to make use of the giant Zeeman splitting in the diluted magnetic semiconductor (DMS) ZnMnSe, which enables one to map how the exciton wavefunction is distributed between the QDs and the surrounding matrix. Two series of CdSe QDs in ZnMnSe were prepared for this investigation by molecular beam epitaxy (MBE) either by varying the CdSe coverage while keeping a constant Mn concentration in ZnMnSe; or by varying the Mn concentration in the matrix while maintaining a constant CdSe coverage. Photoluminescence (PL) experiments show a systematic evolution of the CdSe QDs with increasing CdSe coverage; and also reveal the role of Mn in nucleating \"seeding\" the self assembly of the QDs. By simultaneously measuring the Zeeman shifts of the PL peaks from both the CdSe QDs and their ZnMnSe matrix, we are able to extract information on exciton localization in the QDs and its dependence on the degree of development of the self assembled CdSe QDs with increasing CdSe coverage.", "author_names": [ "Sang Hoon Lee", "Margaret Dobrowolska", "Jacek K Furdyna" ], "corpus_id": 96278323, "doc_id": "96278323", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Zeeman mapping of exciton localization in self assembled CdSe quantum dots using diluted magnetic semiconductors", "venue": "", "year": 2007 } ]

[ { "abstract": "Machine learning models of materials1 5 accelerate discovery compared to ab initio methods: deep learning models now reproduce density functional theory (DFT) calculated results at one hundred thousandths of the cost of DFT6. To provide guidance in experimental materials synthesis, these need to be coupled with an accurate yet effective search algorithm and training data consistent with experimental observations. Here we report an evolutionary algorithm powered search which uses machine learned surrogate models trained on highthroughput hybrid functional DFT data benchmarked against experimental bandgaps: Deep Adaptive Regressive Weighted Intelligent Network (DARWIN) The strategy enables efficient search over the materials space of ~108 ternaries and 1011 quaternaries7 for candidates with target properties. It provides interpretable design rules, such as our finding that the difference in the electronegativity between the halide and B site cation being a strong predictor of ternary structural stability. As an example, when we seek UV emission, DARWIN predicts K2CuX3 (X Cl, Br) as a promising materials family, based on its electronegativity difference. We synthesized and found these materials to be stable, direct bandgap UV emitters. The approach also allows knowledge distillation for use by humans. Introduction Inverse materials design, i.e. prediction of a structure and composition with targeted properties, is used to accelerate materials discovery for light emission, sensing, lasing, energy harvesting and energy storage. Recently, deep learning models have advanced in predicting the materials properties of molecular and inorganic crystal structures8 10. However, even with a deep learning acceleration of 105, such brute force exploration of the compositional and structural space remains infeasible: there are ~108 inorganic ternary, ~1011 quaternary compounds, and even more variations for alloyed and multinary compositions. An efficient and interpretable search algorithm is required to complement accurate property evaluation. This combinatorial space may have multiple local optima, hindering the efficiency of gradient based methods. Searching within a lower dimensional latent space has been suggested previously11,12, yet the continuous nature of the latent space distinct from the discrete nature of chemical elements leads to multiple predictions based on artificial elements, which when discretized to true elements do not present the optimal solutions due to the sampling methods involved in prediction. Evolutionary algorithms (EA) are a gradient free bias free approach that allow for the rapid exploration of a space13,14. They are particularly well suited to search when the evaluation cost per instance is small compared to the size of the space15,16. The evolutionary algorithm approach assesses an entire population at each specific time step, giving rise to multiple local solutions while iterating towards the global minima17. Furthermore, the approach is highly flexible, allowing for the multi objective optimization of mixed variables (discrete and continuous) thereby enabling efficient space exploration in which typical gradient based approaches suffer from18,19. Discussion Several studies have discussed machine learning (ML) algorithms for accelerated discovery of novel materials, but a major hurdle in actually discovering a new material is the availability of high fidelity training data. All the open source material databases20 22 report Perdew Burke Ernzerhof (PBE)23 exchange correlation based calculated Density Functional Theory (DFT) bandgaps which are known to severely and inconsistently underestimate24 the bandgaps of the materials. ML models trained on such data will yield error prone and unreliable predictions unable to guide the experiments. This has made most studies6,25 on accelerated materials discovery focus only on the stability of the materials, ignoring the optical properties (bandgap and nature of bandgaps) Using a generated high throughput hybrid exchange correlation based bandgaps database (Supplementary Figures 1 3) we bridge this gap between theory and experiments (Figure 1 where we compare ML predictions with experimental bandgap values) We design a machine learned framework DARWIN: Deep Adaptive Regressive Weighted Intelligent Network. It enables efficient search over a large chemical space using our ML based models and proposes a diverse set of candidates with specific target properties. We develop a graph convolutional neural network (GCNN) architecture6,10 that incorporates a unique edge attribute, which enables efficient learning on a smaller dataset. This specific reciprocal distance edge attribute helps capture the strength of the relative atomic properties for the varied elements in the crystal system. GCNN generates a global representation of the crystal structure from the chemical features representative of each element at a given node and edge feature that scales as the reciprocal distance between the atoms to reproduce the predictions of accurate ab initio calculations (Figure 1a, see Methods for details) Using data from the Materials Project database14,26, we trained a total energy regressor and a classifier for predicting the direct/indirect nature of bandgaps (Supplementary Figures 4 8 for loss and classification curves) We train our bandgap regressor (Supplementary Figure 9, 10) on a newly generated dataset of 1800 samples (which we release as part of this paper) calculated using HSE functional, known to correlate well with experimental values. We report an original performance comparison between ML predictions and experimental values of the bandgaps (Figure 1b) Despite training on DFT values, ML predicted bandgaps show good agreement with measured values on a test set of experimentally confirmed compounds. The trained and optimized GCNN models predict HSE06 bandgaps with mean absolute errors (MAE) of 0.53 eV on test data, 0.45 eV on validation data, and energies above hull with MAE of 0.06 eV/atom (Figure 1b, c) Furthermore, we build an accurate classifier for predicting the directindirect nature of the materials and obtain an F1 score of 0.8 (Figure 1d) This value is close to previously reported (0.89) study on the direct indirect classification that was limited only to the Kesterite family of compounds27. Using GCNNs allowed going beyond a single crystal family and developing a dependable and accurate classifier for all 7 crystal systems. (Figure 1e for a comparison between ML predictions and DFT)", "author_names": [ "Hitarth Choubisa", "Petar Todorovi'c", "Joao M Pina", "Darshan H Parmar", "Ziliang Li", "Oleksandr Voznyy", "Isaac Tamblyn", "Edward Sargent Department of Electrical", "Computer Engineering", "University of Toronto", "", "National Research Council Canada", "Vector Institute for Artificial Intelligence", "Department of Physical", "Environmental Sciences" ], "corpus_id": 231583109, "doc_id": "231583109", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Interpretable discovery of new semiconductors with machine learning", "venue": "ArXiv", "year": 2021 }, { "abstract": "MicroRNAs are small non coding RNA found in many different species. They play crucial roles in cancer such as biological processes of apoptosis and proliferation. The identification of microRNA target genes can be an essential first step towards to reveal the role of microRNA in various cancer types. In this paper, we predict miRNA target genes for lung cancer by integrating prediction scores from miRanda and PITA algorithms used as a feature vector of miRNA target interaction. Then, machine learning algorithms were implemented for making a final prediction. The approach developed in this study should be of value for future studies into understanding the role of miRNAs in molecular mechanisms enabling lung cancer formation. Keywords MicroRNA, miRNAs, lung cancer, machine learning, Naive Bayes, SVM.", "author_names": [ "Nilubon Kurubanjerdjit", "Nattakarn Iam-On", "Ka-Lok Ng" ], "corpus_id": 10065171, "doc_id": "10065171", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Prediction of MicroRNA Target Gene by Machine Learning Algorithms in Lung Cancer Study", "venue": "", "year": 2016 }, { "abstract": "Massive Multiple Input Multiple Output (MIMO) is widely considered a pivotal communication technology for future generations of wireless networks. Massive MIMO uses a large number of antennas at the base station, which offers better effectiveness in spectral and energy use. However, a Frequency Division Duplex (FDD) system is challenging in reciprocity since it is difficult to estimate channels and requires feeding back channel state information. Joint Spatial Division and Multiplexing (JSDM) is a simplified FDD technique to provide massive MIMO gains. The main idea of JSDM is related to grouping users with approximately similar channel covariance. Many machine learning algorithms have been applied to conduct user grouping. In this paper, to improve the user grouping, we employ Reinforcement Guided Competitive Learning (RGCL) to the user grouping and then compare it with clustering techniques, including K means, and sequential K means to achieve the appropriate user grouping. The experimental results show that the RGCL technique represents better performance in computational time and system throughput than the other two above mentioned techniques, since RGCL can avoid being trapping in local minima.", "author_names": [ "Tanyaluk Deeka", "Boriboon Deeka", "Surajate On-rit" ], "corpus_id": 233250318, "doc_id": "233250318", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "A Study of a Competitive Reinforcement Learning Approach for Joint Spatial Division and Multiplexing in Massive MIMO", "venue": "", "year": 2021 }, { "abstract": "The performance of different machine learning algorithms for detecting the nature of change was compared. To choose the best algorithms for a specific task, users are advised to consider not only classification accuracy, but also comprehensibility, compactness, and robustness in training and classification. The purpose of this paper is to provide information to users so that they can choose the best algorithms for specific tasks. To alleviate the problem of obtaining enough training data, simulated training data were generated from single date images. A one pass classification with four machine learning algorithms, namely, Multi Layer Perceptrons (MLP) Learning Vector Quantization (LVQ) Decision Tree Classifiers (DTC) and the Maximum Likelihood Classifier (MLC) were tested. Recognition rates, ease of use, and degree of automation of the four algorithms were assessed. The results showed that the incorporation of cross combined simulated training data enhanced the detection of nature of change. Compared to conventional post classification comparison methods, LVQ and DTC did better in terms of overall accuracy. In terms of average accuracy of the change classes, LVQ was the best performer. DTC was the easiest to use and the most robust in training. MLP procedures were the most difficult to replicate.", "author_names": [ "Jonathan Cheung-Wai Chan", "Kwok-Ping Chan", "Anthony Gar-on Yeh" ], "corpus_id": 129996510, "doc_id": "129996510", "n_citations": 151, "n_key_citations": 6, "score": 0, "title": "Detecting the nature of change in an urban environment A comparison of machine learning algorithms", "venue": "", "year": 2001 }, { "abstract": "ABSTRACT Urban villages (UVs) are commonly found in many Asian cities. These villages contain many closely packed buildings constructed decades ago without proper urban planning. There is a need for those buildings to be identified and put into statistics. In this paper, we present a segmentation framework that invokes multiple machine learning techniques and point cloud/image processing algorithms to segment individual closely packed buildings from large urban scenes. The presented framework consists of two major segmentation processes. The framework first filters out the non ground objects from the point cloud, then it classified them by using the Random Forest classifier to isolate buildings from the entire scene. After that, the building point clouds will be segmented based on several building attribute analysis methods. This is followed by using the Random Sample Consensus (RANSAC) plane filtering method to expand the space between two closely packed buildings, so that the Density Based Spatial Clustering of Applications with Noise (DBSCAN) clustering technique can be used to more accurately segment each individual building from the closely packed building areas. Two airborne Light Detection and Ranging (LiDAR) datasets collected in two different cities with some typical closely packed buildings were used to verify the proposed framework. The results show that the framework can effectively identify the closely packed buildings with unified structures from large airborne LiDAR datasets. The overall segmentation accuracy reaches 84% for the two datasets. The proposed framework can serve as a basis for analysis and segmentation of closely packed buildings with a more complicated structure.", "author_names": [ "Xinsheng Wang", "Ting On Chan", "Kai Liu", "Jun Pan", "Ming Luo", "Wenkai Li", "Chunzhu Wei" ], "corpus_id": 216434544, "doc_id": "216434544", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "A robust segmentation framework for closely packed buildings from airborne LiDAR point clouds", "venue": "", "year": 2020 }, { "abstract": "Pedagogy with learning analytics is shown to facilitate the teaching learning process through analyzing student's behaviours. In this paper, we explored the possibility of using learning analytics tools Coh Metrix and Lightside for analyzing and improving writing skills of students in a technological common core curriculum course. In this study, we i) investigated linguistic characteristics of student's essays, and ii) applied a machine learning algorithm for giving instant sketch feedback to students. Results illustrated the necessity of improving student's writing skills in their university learning through elearning technologies, so that students can effectively circulate their ideas to the public in the future.", "author_names": [ "Chi-Un Lei", "Ka Lok Man", "Tiew On Ting" ], "corpus_id": 21502522, "doc_id": "21502522", "n_citations": 8, "n_key_citations": 1, "score": 0, "title": "Using Learning Analytics to Analyze Writing Skills of Students A Case Study in a Technological Common Core Curriculum Course", "venue": "", "year": 2014 }, { "abstract": "Feature Ordering is a unique preprocessing step in Incremental Attribute Learning (IAL) where features are gradually trained one after another. In previous studies, feature ordering derived based upon each individual feature's contribution is time consuming. This study attempts to develop an efficient feature ordering algorithm by some evolutionary approaches. The feature ordering algorithm presented in this paper is based on a criterion of maximum mean of feature discriminability. Experimental results derived by ITID, a neural IAL algorithm, show that such a feature ordering algorithm has a higher probability to obtain the lowest classification error rate with datasets from UCI Machine Learning Repository.", "author_names": [ "Ting Wang", "Steven Guan", "Tiew On Ting", "Ka Lok Man", "Fei Liu" ], "corpus_id": 41338623, "doc_id": "41338623", "n_citations": 9, "n_key_citations": 1, "score": 0, "title": "Evolving Linear Discriminant in a Continuously Growing Dimensional Space for Incremental Attribute Learning", "venue": "NPC", "year": 2012 }, { "abstract": "Discretization plays a major role as a data preprocessing technique used in machine learning and data mining. Recent studies have focused on multivariate discretization that considers relations among attributes. The general goal of this method is to obtain the discrete data, which preserves most of the semantics exhibited by original continuous data. However, many techniques generate the final discrete data that may be less useful with natural groups of data not being maintained. This paper presents a novel graph clustering based discretization algorithm that encodes different similarity measures into a graph representation of the examined data. The intuition allows more refined data wise relations to be obtained and used with the effective graph clustering technique based on normalized association to discover nature graphs accurately. The goodness of this approach is empirically demonstrated over 30 standard datasets and 20 imbalanced datasets, compared with 11 well known discretization algorithms using 4 classifiers. The results suggest the new approach is able to preserve the natural groups and usually achieve the efficiency in terms of classifier performance, and the desired number of intervals than the comparative methods.", "author_names": [ "Kittakorn Sriwanna", "Tossapon Boongoen", "Natthakan Iam-on" ], "corpus_id": 27454989, "doc_id": "27454989", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Graph clustering based discretization of splitting and merging methods (GraphS and GraphM)", "venue": "Human centric Computing and Information Sciences", "year": 2017 }, { "abstract": "Feature selection (FS) plays a crucial role in machine learning to build a robust model for either learning or classification from a large amount of data. Among feature selection techniques, the Relief algorithm is one of the most common due to its simplicity and effectiveness. The performance of the Relief algorithm, however, could be dramatically affected by the consistency of the data patterns. For instance, Relief F could become less accurate in the presence of noise. The accuracy would decrease further if an outlier sample was included in the dataset. Therefore, it is very important to select the samples to be included in the dataset carefully. This paper presents an effort to improve the effectiveness of Relief algorithm by filtering samples before selecting features. This method is termed Sample Filtering Relief Algorithm (SFRA) The main idea of this method is to discriminate outlier samples out of the main pattern using self organizing map (SOM) and then proceed with feature selection using the Relief algorithm. We have tested SFRA with a gene expression dataset of interferon (IFN response of Hepatitis B patients that contains outlier data. SFRA could successfully remove outlier samples that have been verified by visual inspection by experts. Also, it has better accuracy in separating the relevant and irrelevant features than other feature selection methods considered.", "author_names": [ "Thammakorn Saethang", "Santitham Prom-on", "Asawin Meechai", "Jonathan H Chan" ], "corpus_id": 33980508, "doc_id": "33980508", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Sample Filtering Relief Algorithm: Robust Algorithm for Feature Selection", "venue": "ICONIP", "year": 2008 }, { "abstract": "The paper presents a novel search algorithm named adaptive tabu search (ATS) The algorithm has been applied to enhance the learning process of neural networks. The paper presents a new neuro tabu fuzzy (NTF) control structure to demonstrate the capability of the ATS algorithm. The algorithm is general and can be applied to various problems including machine learning, optimization, etc. Our proposed algorithm and controller nicely stabilize the single and double inverted pendulum systems.", "author_names": [ "Sarawut Sujitjorn", "Sudarat Khwan-on" ], "corpus_id": 37166697, "doc_id": "37166697", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Learning Control Via Neuro Tabu Fuzzy Controller", "venue": "KES", "year": 2006 } ]

[ { "abstract": "Whole eras of technical progress and economic growth appear to be driven by a few key technologies, which we call General Purpose Technologies (GPT's) Thus the steam engine and the electric motor may have played such a role in the past, whereas semiconductors and computers may be doing as much in our era. GPT's are characterized by pervasiveness (they are used as inputs by many downstream sectors) inherent potential for technical improvements, and innovational complementarities' meaning that the productivity of RD on the other hand this phenomenon makes it difficult for a decentralized economy to fully exploit the growth opportunities offered by evolving GPT's. In particular; if the relationship between the GPT and its users is limited to arms length market transactions, there will be \"too little, too late\" innovation in both sectors. Likewise, difficulties in forecasting the technological developments of the other side may lower the rate of technical advance of all sectors. Lastly, we show that the analysis of GPT's has testable implications in the context of R&D and productivity equations, that can in principle be estimated.", "author_names": [ "Timothy F Bresnahan", "Manuel Trajtenberg" ], "corpus_id": 221989035, "doc_id": "221989035", "n_citations": 91, "n_key_citations": 10, "score": 1, "title": "General Purpose Technologies \"Engines of Growth?\"", "venue": "", "year": 1992 }, { "abstract": "Since Bresnahan and Trajitenberg's original 1995 article on 'General Purpose Technology (GPT) Engines of Growth' the concept of GPT has slowly but steadily influenced the literature on business ICT (information and communication technology) adoption. In considering business ICT, within the framework of GPT allows to focus on the externalities in ICT adoption which poses challenges for policy and society as a whole. In the literature, these externality benefits of business ICT have rarely been examined. In this context, the article provides a survey of recently published empirical studies (from 2004 to 2013) citing the original article of Bresnahan and Trajenberg. In using the science citation index and citations derived from Google Scholar, we found 1090 articles fulfilling these criteria; from these articles just 57 studies provided some empirical estimation of the productivity impact of ICT. Our survey indicates if GPT refers to whole range of ICT, this might generate misleading results. In general, our results indicate a shift in the discussion on GPT focusing on business ICT. The literature demonstrates that with the availability of better data increasingly a better distinction between infrastructure technologies and applications should be used. While infrastructure technologies are uniformly adopted among small and large enterprises, the adoption of applications is a more complex phenomenon. Although some authors argue that there is a productivity impact of ICT, this impact is mediated by employment, wage and size variables. In particular, the adoption of business ICT within small and medium sized enterprises (SMEs) has rarely been examined.", "author_names": [ "S Sadaf Bashir", "Bm Bert Sadowski" ], "corpus_id": 58917894, "doc_id": "58917894", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "General Purpose Technologies: A Survey, a Critique and Future Research Directions", "venue": "", "year": 2014 }, { "abstract": "This dissertation tackles the different aspects of the creation and transmission of (new) knowledge in the context of the characteristics of a general purpose technology (GPT) Particular emphasis is put on the role of the composition of knowledge as well as the corresponding (presumed) knowledge spillovers on the one hand and on the concrete impact of collaboration and knowledge sharing in innovator networks on the other hand. The thesis offers a coherent literature review in its first part, analysing the theoretical role of knowledge for innovation and growth as well as the role of knowledge diffusion and sharing. Although the development of GPTs is particularly knowledgeand innovation intensive and GPTs are found to be 'engines of growth' the role of knowledge for innovation in GPTs has not been distinctive subject to investigation yet. Therefore, the two mentioned sets of research questions were tackled empirically in this thesis using the showcase example of nanotechnology. Nanotechnology is argued to be the key technology of the future, and empirical analyses in this thesis using patent and publication data provided evidence that there is sensible reason to consider nanotechnology as GPT. The first array of research questions is concerned with the role of local knowledge composition and spillovers for the development of nanotechnology. Two different approaches capture these issues. The first one investigates how the characteristics of the regional technological nano knowledge base as approximated (mainly) by patents influence the creation of new nanoknowledge. Panel negative binomial regression analyses are employed to disentangle the effects. The second approach captures the performance of nano firms depending on the local endowment with knowledge as investigated by means of OLS and fixed effects panel analyses. The central finding is that the regional endowment with knowledge impacts the development of nanotechnology. Concerning the composition of the knowledge bases, evidence suggests that specialisation and diversity are positively impacting innovation in nanotechnology. More particularly both are necessary to support nanotechnology's characteristics both as high technology and as GPT. Focusing on the role of collaboration and knowledge sharing in networks, the second array of research questions is tackled by another two analyses. One analysis focuses on the development of the role of collaboration and networking. The means of social network analysis of German nanotechnology patents' co contributorship networks shed light on the relationship between collaboration, the efficiency of the networks and the technological overlap (and hence the potential for cooperation) and the development of nanotechnology. The second analysis more particularly puts an emphasis on the factors that impact the generality of a patent. Therefore variables such as intensity of collaboration, access to knowledge, experience and overlap of technological background are included into fractional logit analyses. Findings include that the performance of a GPT can be enhanced through collaboration by offering efficient means for the organisation and coordination of knowledge sharing and knowledge spillovers and by fostering an increase in the technology's generality level due to knowledge sharing in teams and networks.", "author_names": [ "Nina Teichert" ], "corpus_id": 65124642, "doc_id": "65124642", "n_citations": 5, "n_key_citations": 2, "score": 0, "title": "Innovation in General Purpose Technologies How Knowledge Gains when It Is Shared", "venue": "", "year": 2013 }, { "abstract": "Since Bresnahan and Trajitenberg's original 1995 article on 'General Purpose Technology (GPT) Engines of Growth' the concept of GPT has slowly but steadily influenced the literature on business ICT (information and communication technology) adoption. In considering business ICT, within the framework of GPT allows to focus on the externalities in ICT adoption which poses challenges for policy and society as a whole. In the literature, these externality benefits of business ICT have rarely been examined. In this context, the article provides a survey of recently published empirical studies (from 2004 to 2013) citing the original article of Bresnahan and Trajenberg. In using the science citation index and citations derived from Google Scholar, we found 1090 articles fulfilling these criteria; from these articles just 57 studies provided some empirical estimation of the productivity impact of ICT. Our survey indicates if GPT refers to whole range of ICT, this might generate misleading results. In general, our results indicate a shift in the discussion on GPT focusing on business ICT. The literature demonstrates that with the availability of better data increasingly a better distinction between infrastructure technologies and applications should be used. While infrastructure technologies are uniformly adopted among small and large enterprises, the adoption of applications is a more complex phenomenon. Although some authors argue that there is a productivity impact of ICT, this impact is mediated by employment, wage and size variables. In particular, the adoption of business ICT within small and medium sized enterprises (SMEs) has rarely been examined. 1 Corresponding author: [email protected]", "author_names": [ "S Sadaf Bashir", "Bert M Sadowski" ], "corpus_id": 89606933, "doc_id": "89606933", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "1 General Purpose Technologies A survey a critique and future research directions", "venue": "", "year": 2014 }, { "abstract": "This paper presents a critique of the General Purpose Technology (GPT) framework. It argues that the GPT framework is fundamentally flawed as an approach to understanding growth as it focuses on what are input production technologies (hereafter input technologies) and not on the associated primary inputs and resulting outputs. Computers don't produce output; rather, they produce information which is necessary for the production of output. Dynamos don't produce output, rather they transform prime movers (steam, hydraulics, fossil fuels) into electricity which is transmitted to machines that ultimately produce output. Steam engines don't produce output; rather, they too transmit prime movers (fossil fuels) into output. The problem with the GPT framewoek lies with the implicit assumption that there exists a one to one relationship between the intermediate input and the primary input. We will show that this assumption was violated in all three classic GPT cases, which explains what Paul Davd referred to as the \"electricity paradox\" and what Robert Solow referred to as the \"information paradox.\" We then proceed to present an alternative framework based on the concept of enabling technologies.", "author_names": [ "Bernard C Beaudreau" ], "corpus_id": 114646187, "doc_id": "114646187", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A Critique of the General Purpose Technology Framework", "venue": "", "year": 2016 }, { "abstract": "We present a dynamic, non scale general equilibrium model with two human capital types where Schumpeterian R&D and human capital accumulation are the engines of growth and wage inequality. In particular, wage inequality is encouraged by relative changes in supply and demand of both human capital types. Relative supply restricts employed human capital levels. Relative demand is instantly affected by a new general purpose technology and, as in the skill biased technological change literature, by technological knowledge bias. By considering substitutability between technologies and complementarity between inputs, the bias is driven by the price channel (not by the market size channel) and is affected by human capital accumulation.", "author_names": [ "Oscar Afonso" ], "corpus_id": 154992780, "doc_id": "154992780", "n_citations": 3, "n_key_citations": 1, "score": 0, "title": "Growth and Wage Inequality in a Scale Independent Model with R&D and Human Capital Accumulation", "venue": "", "year": 2010 }, { "abstract": "Google is an American multinational technology company which specializes in internet related services and products. The products and services offered by Google include online advertising technologies, search, cloud computing, and software. Google's ownership structure consists of 95% equity and 5% debt. Google's board of directors have authorized three classes of stock Class A, Class B common stock, and Class C capital stock. The continuing shift from an offline to online world has contributed to the growth of Google's business. Google generate revenue primarily by delivering both performance advertising and brand advertising. Google have many competitors in different industries, including general purpose search engines and information services, vertical search engines and e commerce websites, social networks, providers of online products and services, other forms of advertising. Acquisition is an important strategy of growth for Google. Google has emerged as the one of the biggest and most successful acquirers in the technology industry. Google went public on August 19, 2004.", "author_names": [ "Rajesh Kumar" ], "corpus_id": 168560116, "doc_id": "168560116", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Wealth creation analysis of Google", "venue": "", "year": 2017 }, { "abstract": "The model we propose in this paper is an extension of the one described in Freeman et al. [Freeman, S. Hong, D. and Peled, D. (1999) Endogenous Cycles and Growth with Indivisible Technological Developments. Review of Economics Dynamics, 2, 403 432] In our model, we incorporate the process of diffusion of major innovations and analyze macroeconomic effects on consumption, capital and aggregate output. Following Bresnahan and Trajtenberg [Bresnahan, T. and Trajtenberg, M. (1995) General Purpose Technologies: Engines of Growth? Journal of Econometrics, 65, 83 108. Helpman [Helpman, E. (ed. (1998) General Purpose Technologies and Economic Growth. MIT Press] and Lipsey et al. [Lipsey, R.G. Carlaw, K. and Bekar, C. (2005) Economic Transformations: General Purpose Technologies and Long Term Economic Growth. Oxford University Press. we assimilate major innovations with the emergence of certain GPTs, and we suggest that the diffusion process for these technologies, at a large scale, might follow an S shaped pattern. The proposed model presents optimum stationary solutions which are cyclical and have a wave dynamic within each cycle. The cycles are characterized by certain co movements in consumption, R&D investment, capital accumulation and output. Consideration of the innovation diffusion process highlights new aspects of endogenous cycles and long run growth.", "author_names": [ "Julio Sanchez-Choliz", "Francisco Fatas-Villafranca", "Gloria Jarne", "Isabel Perez-Grasa" ], "corpus_id": 154073375, "doc_id": "154073375", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "ENDOGENOUS CYCLICAL GROWTH WITH A SIGMOIDAL DIFFUSION OF INNOVATIONS", "venue": "", "year": 2008 }, { "abstract": "This paper presents the latest update for historical scaling dynamics research including new technoloies such as general purpose technologies (e.g. steam engines) and small end use technologies (e.g.,cellphones, e bikes) Scaling refers to technology growth that is rapid and extensive, occurring at different levels, both unit and industry. It also studies the importance of the formative phase in the historical diffusion of energy technologies. So, what are the characteristics of the formative phase in the case of fast and intense adoptions? What is the infuence of the formative phase in the overall diffusion? Empirical analysis uses logistic models to exlore the growth of energy technologies observed historically. The formative phase is defined here as the early stage of diffusion before technology up scales at unit level; the operational critera adoped is that formative phase ends when diffusion reaches 10% of cumulative total unit numbers. The hisorical evidence confirms that larger transitions require more time for experimentation and maturation in the formative periods, especially in the case of complex innovations with high infrastrcture needs. In addition, small size technologies with high turnover rates present the fastest diffusion. Moreresearch is needed to refine the definition of the moment when the technology completes the formativ phase and acquires enough maturity to pass on to mass commercialization. KEYWRODS: technological change; innovation; economies of scale; logistic growth; formative phases", "author_names": [ "Nuno Bento" ], "corpus_id": 112128372, "doc_id": "112128372", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "New Evidence in Technology Scaling Dynamics and the Role of the Formative Phase", "venue": "", "year": 2013 }, { "abstract": "BackgroundWith the growth of biological data in volume and heterogeneity, web search engines become key tools for researchers. However, general purpose search engines are not specialized for the search of biological data.DescriptionHere, we present an approach at developing a biological web search engine based on the Semantic Web technologies and demonstrate its implementation for retrieving gene and protein centered knowledge. The engine is available at http:/www.integromedb.org.ConclusionsThe IntegromeDB search engine allows scanning data on gene regulation, gene expression, protein protein interactions, pathways, metagenomics, mutations, diseases, and other gene and protein related data that are automatically retrieved from publicly available databases and web pages using biological ontologies. To perfect the resource design and usability, we welcome and encourage community feedback.", "author_names": [ "Michael Baitaluk", "Sergey Kozhenkov", "Yulia Dubinina", "Julia V Ponomarenko" ], "corpus_id": 15615120, "doc_id": "15615120", "n_citations": 12, "n_key_citations": 2, "score": 0, "title": "IntegromeDB: an integrated system and biological search engine", "venue": "BMC Genomics", "year": 2011 } ]

[ { "abstract": "Engineering the electromagnetic environment of a nanometre scale light emitter by use of a photonic cavity can significantly enhance its spontaneous emission rate, through cavity quantum electrodynamics in the Purcell regime. This effect can greatly reduce the lasing threshold of the emitter, providing a low threshold laser system with small footprint, low power consumption and ultrafast modulation. An ultralow threshold nanoscale laser has been successfully developed by embedding quantum dots into a photonic crystal cavity (PCC) However, several challenges impede the practical application of this architecture, including the random positions and compositional fluctuations of the dots, extreme difficulty in current injection, and lack of compatibility with electronic circuits. Here we report a new lasing strategy: an atomically thin crystalline semiconductor that is, a tungsten diselenide monolayer is non destructively and deterministically introduced as a gain medium at the surface of a pre fabricated PCC. A continuous wave nanolaser operating in the visible regime is thereby achieved with an optical pumping threshold as low as 27 nanowatts at 130 kelvin, similar to the value achieved in quantum dot PCC lasers. The key to the lasing action lies in the monolayer nature of the gain medium, which confines direct gap excitons to within one nanometre of the PCC surface. The surface gain geometry gives unprecedented accessibility and hence the ability to tailor gain properties via external controls such as electrostatic gating and current injection, enabling electrically pumped operation. Our scheme is scalable and compatible with integrated photonics for on chip optical communication technologies.", "author_names": [ "Sanfeng Wu", "Sonia M Buckley", "John R Schaibley", "Liefeng Feng", "Jiaqiang Yan", "David G Mandrus", "Fariba Hatami", "Wang Yao", "Jelena Vuckovic", "Arka Majumdar", "Xiaodong Xu" ], "corpus_id": 4457688, "doc_id": "4457688", "n_citations": 546, "n_key_citations": 4, "score": 1, "title": "Monolayer semiconductor nanocavity lasers with ultralow thresholds", "venue": "Nature", "year": 2015 }, { "abstract": "Engineering the electromagnetic environment of a nanoscale light emitter by a photonic cavity can significantly enhance its spontaneous emission rate through cavity quantum electrodynamics in the Purcell regime. This effect can greatly reduce the lasing threshold of the emitter, providing the ultimate low threshold laser system with small footprint, low power consumption and ultrafast modulation. A state of the art ultra low threshold nanolaser has been successfully developed though embedding quantum dots into photonic crystal cavity (PhCC) However, several core challenges impede the practical applications of this architecture, including the random positions and compositional fluctuations of the dots, extreme difficulty in current injection, and lack of compatibility with electronic circuits. Here, we report a new strategy to lase, where atomically thin crystalline semiconductor, i.e. a tungsten diselenide (WSe2) monolayer, is nondestructively and deterministically introduced as a gain medium at the surface of a pre fabricated PhCC. A new type of continuous wave nanolaser operating in the visible regime is achieved with an optical pumping threshold as low as 27 nW at 130 K, similar to the value achieved in quantum dot PhCC lasers. The key to the lasing action lies in the monolayer nature of the gain medium, which confines direct gap excitons to within 1 nm of the PhCC surface. The surface gain geometry allows unprecedented accessibilities to multi functionalize the gain, enabling electrically pumped operation. Our scheme is scalable and compatible with integrated photonics for on chip optical communication technologies.", "author_names": [ "Sanfeng Wu", "Sonia M Buckley", "John R Schaibley", "Liefeng Feng", "Jiaqiang Yan", "David G Mandrus", "Fariba Hatami", "Wang Yao", "Jelena Vuckovic", "Arka Majumdar", "Xiaodong Xu" ], "corpus_id": 27863958, "doc_id": "27863958", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Ultra Low Threshold Monolayer Semiconductor Nanocavity Lasers", "venue": "", "year": 2015 }, { "abstract": "Two dimensional (2D) semiconductors are opening a new platform for revitalizing widely spread optoelectronic applications. The realisation of room temperature vertical 2D lasing from monolayer semiconductors is fundamentally interesting and highly desired for appealing on chip laser applications such as optical interconnects and supercomputing. Here, we present room temperature low threshold lasing from 2D semiconductor activated vertical cavity surface emitting lasers (VCSELs) under continuous wave pumping. 2D lasing is achieved from a 2D semiconductor. Structurally, dielectric oxides were used to construct the half wavelength thick cavity and distributed Bragg reflectors, in favour of single mode operation and ultralow optical loss; in the cavity centre, the direct bandgap monolayer WS2 was embedded as the gain medium, compatible with the planar VCSEL configuration and the monolithic integration technology. This work demonstrates 2D semiconductor activated VCSELs with desirable emission characteristics, which represents a major step towards practical optoelectronic applications of 2D semiconductor lasers.Two dimensional materials have recently emerged as interesting materials for optoelectronic applications. Here, Shang et al. demonstrate two dimensional semiconductor activated vertical cavity surface emitting lasers where both the gain material and the lasing characteristics are two dimensional.", "author_names": [ "Jingzhi Shang", "Chunxiao Cong", "Zilong Wang", "Namphung Peimyoo", "LiShu Wu", "Chenji Zou", "Yu Zong Chen", "Xin Yu Chin", "Jianpu Wang", "C Soci", "Wei Huang", "Ting Yu" ], "corpus_id": 205547254, "doc_id": "205547254", "n_citations": 61, "n_key_citations": 1, "score": 0, "title": "Room temperature 2D semiconductor activated vertical cavity surface emitting lasers", "venue": "Nature Communications", "year": 2017 }, { "abstract": "Nanoscrolls are a class of nanostructures where atomic layers of 2D materials are stacked consecutively in a coaxial manner to form a 1D spiral topography. Self assembly of chemical vapor deposition grown 2D WS2 monolayer into quasi 1D van der Waals scroll structure instigates a plethora of unique physiochemical properties significantly different from its 2D counterparts. The physical properties of such nanoscrolls can be greatly manipulated upon hybridizing them with high quantum yield colloidal quantum dots, forming 0D/2D structures. The efficient dissociation of excitons at the heterojunctions of QD/2D hybridized nanoscrolls exhibits a 3000 fold increased photosensitivity compared to the pristine 2D material based nanoscroll. The synergistic effects of confined geometry and efficient QD scatterers produce a nanocavity with multiple feedback loops, resulting in coherent lasing action with an unprecedentedly low lasing threshold. Predominant localization of the excitons along the circumference of this helical scroll results in a 12 fold brighter emission for the parallel polarized transition compared to the perpendicular one, as confirmed by finite difference time domain simulation. The versatility of hybridized nanoscrolls and their unique properties opens up a powerful route for not yet realized devices toward practical applications.", "author_names": [ "Rapti Ghosh", "Hung-I Lin", "Yu-Siang Chen", "Mukesh Singh", "Zhi-Long Yen", "Sheng-Kuei Chiu", "Hsia-Yu Lin", "Krishna Prasad Bera", "Yu-Ming Liao", "Mario Hofmann", "Y P Hsieh", "Yang-Fang Chen" ], "corpus_id": 224808594, "doc_id": "224808594", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "QD/2D Hybrid Nanoscrolls: A New Class of Materials for High Performance Polarized Photodetection and Ultralow Threshold Laser Action.", "venue": "Small", "year": 2020 }, { "abstract": "Confining photons in a small space is a difficult task. Recent nanotechnology advances now enable their confinement in a cubic wavelength volume for as long as 1 nanosecond in semiconductors when using 2D photonic crystal (PhC) structures. As shown in Figure 1, a PhC is a periodic optical structure whose periodicity is on the order of the wavelength of light. PhCs are designed to affect the motion of photons1 because they have the optical equivalent of the energy gap of conventional semiconductors. The possibility to manipulate photons in solid materials offers many attractive applications such as nanocavity lasers, tunable slow light devices, and optical integrated circuits. The PhC nanocavity laser is considered one of the best candidates to achieve ultra low threshold lasing due to its small mode volume and high quality factor (Q, which expresses the ability of an oscillating system to keep oscillating before running out of energy) The first reported PhC laser (1999) used multiple quantumwells (QWs) as the gain material at low temperature in pulsed operation.2 Recently, continuous wave (CW) laser operation at low temperature was also reported. However, CW lasing is inherently difficult to achieve at room temperature due to fast non radiative losses that translate into very high Q nanocavity requirements. Our group was the first to demonstrate room temperature operation of a high Q PhC nanocavity CW laser.3 Further improvement of the cavity Q reduced the optical pumping threshold down to the microwatt level.4 3D photon confinement can be achieved by fabricating the PhC slab structure with a nanocavity (see Figure 1) The 2D triangular lattice confines photons in the plane of the slab. The excitation beam generates excitons in quantum dots (QDs) embedded into the slab layer and the excitons recombine with photon emission. Our PhC nanocavity was designed to have its resonant wavelength at the excitonic photoluminescence (PL) peak, allowing CW lasing at 1.33mm at room temperature with Figure 1. Scanning electron micrographs of a photonic crystal nanocavity structure. Top (a) and cross sectional (b) views. QD: quantum dot.", "author_names": [ "Masahiro Nomura" ], "corpus_id": 54654928, "doc_id": "54654928", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "A photonic crystal nanocavity laser with ultralow threshold", "venue": "", "year": 2007 }, { "abstract": "A room temperature polariton nanolaser is demonstrated using quantum heterostructure nanocavities to boost exciton properties. Ultralow threshold coherent light emitters can be achieved through lasing from exciton polariton condensates, but this generally requires sophisticated device structures and cryogenic temperatures. Polaritonic nanolasers operating at room temperature lie on the crucial path of related research, not only for the exploration of polariton physics at the nanoscale but also for potential applications in quantum information systems, all optical logic gates, and ultralow threshold lasers. However, at present, progress toward room temperature polariton nanolasers has been limited by the thermal instability of excitons and the inherently low quality factors of nanocavities. Here, we demonstrate room temperature polaritonic nanolasers by designing wide gap semiconductor heterostructure nanocavities to produce thermally stable excitons coupled with nanocavity photons. The resulting mixed states of exciton polaritons with Rabi frequencies of approximately 370 meV enable persistent polariton lasing up to room temperature, facilitating the realization of miniaturized and integrated polariton systems.", "author_names": [ "Jang-Won Kang", "Bokyung Song", "Wenjing Liu", "Seong-Ju Park", "Ritesh Agarwal", "Chang-Hee Cho" ], "corpus_id": 119015233, "doc_id": "119015233", "n_citations": 22, "n_key_citations": 0, "score": 0, "title": "Room temperature polariton lasing in quantum heterostructure nanocavities", "venue": "Science Advances", "year": 2019 }, { "abstract": "Reliable technologies for the monolithic integration of lasers onto silicon represent the holy grail for chip level optical interconnects. In this context, nanowires (NWs) fabricated using III V semiconductors are of strong interest since they can be grown site selectively on silicon using conventional epitaxial approaches. Their unique one dimensional structure and high refractive index naturally facilitate low loss optical waveguiding and optical recirculation in the active NW core region. However, lasing from NWs on silicon has not been achieved to date, due to the poor modal reflectivity at the NW silicon interface. We demonstrate how, by inserting a tailored dielectric interlayer at the NW Si interface, low threshold single mode lasing can be achieved in vertical cavity GaAs AlGaAs core shell NW lasers on silicon as measured at low temperature. By exploring the output characteristics along a detection direction parallel to the NW axis, we measure very high spontaneous emission factors comparable to nanocavity lasers (b 0.2) and achieve ultralow threshold pump energies =11 pJ/pulse. Analysis of the input output characteristics of the NW lasers and the power dependence of the lasing emission line width demonstrate the potential for high pulsation rates =250 GHz. Such highly efficient nanolasers grown monolithically on silicon are highly promising for the realization of chip level optical interconnects.", "author_names": [ "Benedikt F Mayer", "Lisa Janker", "Bernhard Loitsch", "Julian Treu", "T Kostenbader", "Stefan Lichtmannecker", "Thorsten Reichert", "Stefanie Morkotter", "Michael Kaniber", "Gerhard Abstreiter", "Cheryl Gies", "Gregor Koblmuller", "Jonathan J Finley" ], "corpus_id": 11677879, "doc_id": "11677879", "n_citations": 94, "n_key_citations": 3, "score": 0, "title": "Monolithically Integrated High b Nanowire Lasers on Silicon.", "venue": "Nano letters", "year": 2016 }, { "abstract": "Recently, rolled up semiconductor tubes, formed when a coherently strained semiconductor bilayer is selectively released from the host substrate, have emerged as a promising technique to realize high performance optical micro and nanocavity devices [1 6] Combining the advantages of both top down and bottom up fabrication processes, this approach offers an exceptional flexibility for achieving semiconductor micro and nanotube structures with an epitaxially smooth surface and well controlled diameters and wall thicknesses using a single photolithography step. However, lasing in such tube structures has hitherto not been demonstrated. In this context, we have performed a detailed investigation of the fabrication and characterization of rolled up micro and nanotubes, with the incorporation of self organized InGaAs/GaAs quantum dots as the gain media. We have achieved, for the first time, lasing in rolled up semiconductor tubes at room temperature. The devices are characterized an ultralow threshold power 4 mW) an intrinsic lasing linewidth of 0.2 0.3 nm, and a linear polarization with the electric field parallel to the tube surface.", "author_names": [ "Zetian Mi", "F Li" ], "corpus_id": 26201215, "doc_id": "26201215", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Rolled up InGaAs/GaAs quantum dot micro and nanotube lasers", "venue": "2010 IEEE Photonics Society Winter Topicals Meeting Series (WTM)", "year": 2010 }, { "abstract": "ZnO microspheres fabricated via laser ablation in superfluid helium were found to have bubble like voids. Even a microsphere demonstrating clear whispering gallery mode resonances in the luminescence had voids. Our analysis confirmed that the voids are located away from the surface and have negligible or little effect on the whispering gallery mode resonances since the electromagnetic energy localizes near the surface of these microspheres. The existence of the voids indicates that helium gas or any evaporated target material was present within the molten microparticles during the microsphere formation. (c) 2018 Optical Society of America OCIS codes: (220.4000) Microstructure fabrication; (140.3945) Microcavities. References and links 1. J. R. Buck and H. J. Kimble, \"Optimal sizes of dielectric microspheres for cavity QED with strong coupling,\" Physical Review A 67, 033806 (2003) 2. S. M. Spillane, T. J. Kippenberg, and K. J. Vahala, \"Ultralow threshold Raman laser using a spherical dielectric microcavity,\" Nature 415, 621 623 (2002) 3. F. Treussart, V. S. Ilchenko, J. F. Roch, J. Hare, V. Lefevre Seguin, J. M. Raimond, and S. Haroche, \"Evidence for intrinsic Kerr bistability of high Q microsphere resonators in superfluid helium,\" The European Physical Journal D Atomic, Molecular, Optical and Plasma Physics 1, 235 238 (1998) 4. G. W. 't Hooft, W. A. J. A. van der Poel, L. W. Molenkamp, and C. T. Foxon, \"Giant oscillator strength of free excitons in GaAs,\" Physical Review B 35, 8281 8284 (1987) 5. M. Nagai, F. Hoshino, S. Yamamoto, R. Shimano, and M. Kuwata Gonokami, \"Spherical cavity mode laser with self organized CuCl microspheres,\" Optics Letters 22, 1630 1632 (1997) 6. T. H. B. Ngo, C. H. Chien, S. H. Wu, and Y. C. Chang, \"Size and morphology dependent evolution of resonant modes in ZnO microspheres grown by hydrothermal synthesis,\" Optics Express 24, 16010 16015 (2016) 7. W. Stober, A. Fink, and E. Bohn, \"Controlled growth of monodisperse silica spheres in the micron size range,\" Journal of Colloid and Interface Science 26, 62 69 (1968) 8. M. L. Gorodetsky, A. A. Savchenkov, and V. S. Ilchenko, \"Ultimate Q of optical microsphere resonators,\" Optics Letters 21, 453 455 (1996) 9. N. G. Semaltianos, \"Nanoparticles by Laser Ablation,\" Critical Reviews in Solid State and Materials Sciences 35, 105 124 (2010) 10. S. Okamoto, S. Ichikawa, Y. Minowa, and M. Ashida, \"Optical Fabrication of Semiconductor Single Crystalline Microspheres in Superfluid Helium,\" MRS Online Proceedings Library Archive 1635, 103 108 (2014) 11. S. Okamoto, K. Inaba, T. Iida, H. Ishihara, S. Ichikawa, andM. Ashida, \"Fabrication of single crystalline microspheres with high sphericity from anisotropic materials,\" Scientific Reports 4, 5186 (2014) 12. S. Okamoto, Y. Minowa, and M. Ashida, \"White light lasing in ZnO microspheres fabricated by laser ablation,\" in \"SPIE OPTO,\" (International Society for Optics and Photonics, 2012) pp. 82630K 82630K. 13. E. B. Gordon, A. V. Karabulin, V. I. Matyushenko, V. D. Sizov, and I. I. Khodos, \"Stability of micron sized spheres formed by pulsed laser ablation of metals in superfluid helium and water,\" High Energy Chemistry 48, 206 212 (2014) 14. K. Inaba, K. Imaizumi, K. Katayama, M. Ichimiya, M. Ashida, T. Iida, H. Ishihara, and T. Itoh, \"Optical manipulation of CuCl nanoparticles under an excitonic resonance condition in superfluid helium,\" physica status solidi (b) 243, 3829 3833 (2006) 15. D. Nakamura, T. Smogaki, K. Okazaki, M. Higashihata, H. Ikenoue, and T. Okada, \"Synthesis of Various Sized ZnO Microspheres by Laser Ablation and Their Lasing Characteristics,\" Journal of Laser Micro/Nanoengineering 8, 296 299 (2013) 16. U. Ozgur, Y. I. Alivov, C. Liu, A. Teke, M. Reshchikov, S. Dogan, V. Avrutin, S. J. Cho, and H. Morkoc, \"A comprehensive review of ZnO materials and devices,\" Journal of applied physics 98, 11 (2005) 17. C. F. Bohren and D. R. Huffman, Absorption and scattering of light by small particles (Wiley, 1983) 18. T. Nobis and M. Grundmann, \"Low order optical whispering gallery modes in hexagonal nanocavities,\" Physical Review A 72, 063806 (2005) ar X iv :1 70 3. 01 17 8v 1 co nd m at .m tr lsc i] 1 M ar 2 01 7 19. V. V. Datsyuk, \"Some characteristics of resonant electromagnetic modes in a dielectric sphere,\" Applied Physics B 54, 184 187 (1992) 20. A. N. Oraevsky, \"Whispering gallery waves,\" Quantum Electronics 32, 377 (2002) 21. V. V. Datsyuk and I. A. Izmailov, \"Optics of microdroplets,\" Physics Uspekhi 44, 1061 (2001) 22. H. Miura, E. Yokoyama, K. Nagashima, K. Tsukamoto, and A. Srivastava, \"A new constraint for chondrule formation: condition for the rim formation of barred olivine textures,\" Earth, Planets and Space 63, 8 (2011) 23. T. Ihara, H. Wagata, T. Kogure, K. Katsumata, K. Okada, and N. Matsushita, \"Template free solvothermal preparation of ZnO hollow microspheres covered with c planes,\" RSC Advances 4, 25148 25154 (2014) 24. K. T. Gahagan and G. A. Swartzlander, \"Optical vortex trapping of particles,\" Optics Letters 21, 827 829 (1996)", "author_names": [ "" ], "corpus_id": 199535364, "doc_id": "199535364", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Inner structure of ZnO microspheres fabricated via laser ablation in superfluid helium", "venue": "", "year": 2018 }, { "abstract": "Summary form only given. Miniaturization of semiconductor lasers holds the key to the development of compact, low threshold, and fast coherent on chip light sources/amplifiers, which are critically important for emerging applications in nanophotonics, integrated optics, and information technology. However, on chip integration of nanoscale electronic components with conventional semiconductor lasers utilizing dielectric optical cavities is impeded by the diffraction limit i.e. (l/2n)3 for three dimensional (3D) cavities, where l is the free space wavelength and n is the refractive index of the dielectric. The recent advent of nanoplasmonics based on metallodielectric structures has led to the design of optical components and optoelectronic devices in the deep subwavelength regime. In particular, a new class of lasers based on surface plasmon amplification by stimulated emission of radiation (SPASER) has recently been proposed and experimentally demonstrated (16 19) In the SPASER operation, surface plasmons excited in noble metal structures adjacent to gain media dramatically increase the optical mode density, shrink the optical mode volume, and provide the necessary feedback mechanism. Among the available plasmonic cavity materials in the visible and near infrared ranges, silver (Ag) is the best choice due to minimal plasmonic damping. However, so far, most plasmonic devices are based on granular polycrystalline Ag films where strong surface roughness and grain boundaries lead to strong scattering losses of surface plasmon polaritons (SPPs) Thus, atomically smooth or single crystalline plasmonic structures are desirable building blocks for low loss applications. In polycrystalline metallic materials the lasing threshold of plasmonic nanolasers remains impractically high and the continuous wave (CW) operation of a plasmonic laser has yet to be demonstrated. Having developed epitaxially grown, atomically smooth Ag films as a new plasmonic platform, we report a SPASER under CW operation with an ultralow lasing threshold at liquid nitrogen temperature and mode volume well below the 3D diffraction limit. The device is based on the plasmonic nanocavity formed between epitaxial Ag film and a single nanorod consisting of a gallium nitride (GaN) shell and an indium gallium nitride (InGaN) core acting as gain medium. The nanolaser emits in the green spectral region with perfectly polarized far field radiation at the main lasing mode. In comparison with other semiconductor gain media, the large gain coefficient of InGaN plays a critical role in the ultralow lasing threshold observed for our experiment with a 3D subdiffraction cavity. The development of atomically smooth epitaxial Ag on Si as a new platform for plasmonics not only allows us to demonstrate the SPASER enabled nanolaser, it should also promote the development of monolithically integrated plasmonics and Si based electronics on a single platform.", "author_names": [ "Yu-Jung Lu", "Jisun Kim", "Hung-Ying Chen", "Chihhui Wu", "Charlotta E Sanders", "Chun-Yuan Wang", "Wen-Hao Chang", "Gennady Shvets", "Shangjr Gwo", "Chih-Kang Shih" ], "corpus_id": 33358269, "doc_id": "33358269", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Nanolasers employing epitaxial plasmonic layers", "venue": "CLEO: 2013", "year": 2013 } ]

[ { "abstract": "Engineering the spectral properties of fluorophores, such as the enhancement of luminescence intensity, can be achieved through coupling with surface plasmons in metallic nanostructures1,2,3,4,5,6,7,8,9,10,11. This process, referred to as metal enhanced fluorescence, offers promise for a range of applications, including LEDs, sensor technology, microarrays and single molecule studies. It becomes even more appealing when applied to colloidal semiconductor nanocrystals, which exhibit size dependent optical properties, have high photochemical stability, and are characterized by broad excitation spectra and narrow emission bands12. Other approaches have relied upon the coupling of fluorophores (typically organic dyes) to random distributions of metallic nanoparticles or nanoscale roughness in metallic films1,2,3,4,6,8. Here, we develop a new strategy based on the highly reproducible fabrication of ordered arrays of gold nanostructures coupled to CdSe/ZnS nanocrystals dispersed in a polymer blend. We demonstrate the possibility of obtaining precise control and a high spatial selectivity of the fluorescence enhancement process.", "author_names": [ "Pier Paolo Pompa", "Luigi Martiradonna", "Antonio Della Torre", "F Della Sala", "Liberato Manna", "Massimo de Vittorio", "Franco Calabi", "Roberto Cingolani", "Rosaria Rinaldi" ], "corpus_id": 667517, "doc_id": "667517", "n_citations": 512, "n_key_citations": 4, "score": 1, "title": "Metal enhanced fluorescence of colloidal nanocrystals with nanoscale control", "venue": "Nature nanotechnology", "year": 2006 }, { "abstract": "Nanocrystals (NCs) discussed in this Review are tiny crystals of metals, semiconductors, and magnetic material consisting of hundreds to a few thousand atoms each. Their size ranges from 2 3 to about 20 nm. What is special about this size regime that placed NCs among the hottest research topics of the last decades? The quantum mechanical coupling To whom correspondence should be addressed. E mail: [email protected]. The University of Chicago. Argonne National Lab. Chem. Rev. 2010, 110, 389 458 389", "author_names": [ "Dmitri V Talapin", "Jong-Soo Lee", "Maksym V Kovalenko", "Elena V Shevchenko" ], "corpus_id": 206903168, "doc_id": "206903168", "n_citations": 3163, "n_key_citations": 31, "score": 0, "title": "Prospects of colloidal nanocrystals for electronic and optoelectronic applications.", "venue": "Chemical reviews", "year": 2010 }, { "abstract": "Colloidal metal nanoparticles are emerging as key materials for catalysis, plasmonics, sensing, and spectroscopy. Within these applications, control of nanoparticle shape lends increasing functionality and selectivity. Shape controlled nanocrystals possess well defined surfaces and morphologies because their nucleation and growth are controlled at the atomic level. An overall picture of shaped metal particles is presented, with a particular focus on solution based syntheses for the noble metals. General strategies for synthetic control are discussed, emphasizing key factors that result in anisotropic, nonspherical growth such as crystallographically selective adsorbates and seeding processes.", "author_names": [ "Andrea R Tao", "Susan E Habas", "Peidong Yang" ], "corpus_id": 1444360, "doc_id": "1444360", "n_citations": 1937, "n_key_citations": 12, "score": 0, "title": "Shape Control of Colloidal Metal Nanocrystals", "venue": "", "year": 2008 }, { "abstract": "We present an experimental and theoretical study of the fluorescence rate of a single molecule as a function of its distance to a laser irradiated gold nanoparticle. The local field enhancement leads to an increased excitation rate whereas nonradiative energy transfer to the particle leads to a decrease of the quantum yield (quenching) Because of these competing effects, previous experiments showed either fluorescence enhancement or fluorescence quenching. By varying the distance between molecule and particle we show the first experimental measurement demonstrating the continuous transition from fluorescence enhancement to fluorescence quenching. This transition cannot be explained by treating the particle as a polarizable sphere in the dipole approximation.", "author_names": [ "Pascal Anger", "Palash Bharadwaj", "Lukas Novotny" ], "corpus_id": 29654692, "doc_id": "29654692", "n_citations": 2365, "n_key_citations": 38, "score": 0, "title": "Enhancement and quenching of single molecule fluorescence.", "venue": "Physical review letters", "year": 2006 }, { "abstract": "Nanometre size inorganic dots, tubes and wires exhibit a wide range of electrical and optical properties that depend sensitively on both size and shape, and are of both fundamental and technological interest. In contrast to the syntheses of zero dimensional systems, existing preparations of one dimensional systems often yield networks of tubes or rods which are difficult to separate. And, in the case of optically active II VI and III V semiconductors, the resulting rod diameters are too large to exhibit quantum confinement effects. Thus, except for some metal nanocrystals, there are no methods of preparation that yield soluble and monodisperse particles that are quantum confined in two of their dimensions. For semiconductors, a benchmark preparation is the growth of nearly spherical II VI and III V nanocrystals by injection of precursor molecules into a hot surfactant. Here we demonstrate that control of the growth kinetics of the II VI semiconductor cadmium selenide can be used to vary the shapes of the resulting particles from a nearly spherical morphology to a rod like one, with aspect ratios as large as ten to one. This method should be useful, not only for testing theories of quantum confinement, but also for obtaining particles with spectroscopic properties that could prove advantageous in biological labelling experiments and as chromophores in light emitting diodes.", "author_names": [ "Xiaogang Peng", "Liberato Manna", "Weidong Yang", "Juanita Wickham", "Erik C Scher", "Andreas V Kadavanich", "A Paul Alivisatos" ], "corpus_id": 4390767, "doc_id": "4390767", "n_citations": 3412, "n_key_citations": 16, "score": 0, "title": "Shape control of CdSe nanocrystals", "venue": "Nature", "year": 2000 }, { "abstract": "Abstract Solution phase syntheses and size selective separation methods to prepare semiconductor and metal nanocrystals, tunable in size from ~1 to 20 nm and monodisperse to =5% are presented. Preparation of monodisperse samples enables systematic characterization of the structural, electronic, and optical properties of materials as they evolve from molecular to bulk in the nanometer size range. Sample uniformity makes it possible to manipulate nanocrystals into close packed, glassy, and ordered nanocrystal assemblies (superlattices, colloidal crystals, supercrystals) Rigorous structural characterization is critical to understanding the electronic and optical properties of both nanocrystals and their assemblies. At inter particle separations 5 100 A, dipole dipole interactions lead to energy transfer between neighboring nanocrystals, and electronic tunneling between proximal nanocrystals gives rise to dark and photoconductivity. At separations <5 A, exchange interactions cause otherwise insulating ass.", "author_names": [ "Christopher B Murray", "Cherie R Kagan", "Moungi G Bawendi" ], "corpus_id": 53589018, "doc_id": "53589018", "n_citations": 3300, "n_key_citations": 27, "score": 0, "title": "Synthesis and Characterization of Monodisperse Nanocrystals and Close Packed Nanocrystal Assemblies", "venue": "", "year": 2000 }, { "abstract": "The development of nanocrystals has been intensively pursued, not only for their fundamental scientific interest, but also for many technological applications1,2,3. The synthesis of monodisperse nanocrystals (size variation <5% is of key importance, because the properties of these nanocrystals depend strongly on their dimensions. For example, the colour sharpness of semiconductor nanocrystal based optical devices is strongly dependent on the uniformity of the nanocrystals3,4,5,6, and monodisperse magnetic nanocrystals are critical for the next generation multi terabit magnetic storage media7,8,9. For these monodisperse nanocrystals to be used, an economical mass production method needs to be developed. Unfortunately, however, in most syntheses reported so far, only sub gram quantities of monodisperse nanocrystals were produced. Uniform sized nanocrystals of CdSe (refs 10,11) and Au (refs 12,13) have been produced using colloidal chemical synthetic procedures. In addition, monodisperse magnetic nanocrystals such as Fe (refs 14,15) Co (refs 16 18) g Fe2O3 (refs 19,20) and Fe3O4 (refs 21,22) have been synthesized by using various synthetic methods23. Here, we report on the ultra large scale synthesis of monodisperse nanocrystals using inexpensive and non toxic metal salts as reactants. We were able to synthesize as much as 40 g of monodisperse nanocrystals in a single reaction, without a size sorting process. Moreover, the particle size could be controlled simply by varying the experimental conditions. The current synthetic procedure is very general and nanocrystals of many transition metal oxides were successfully synthesized using a very similar procedure.", "author_names": [ "Jongnam Park", "Kwang Jun An", "Yosun Hwang", "Je-Guen Park", "H J Noh", "Jae-Young Kim", "Jae-hoon Park", "Nong-Moon Hwang", "Taeghwan Hyeon" ], "corpus_id": 38000870, "doc_id": "38000870", "n_citations": 3116, "n_key_citations": 54, "score": 0, "title": "Ultra large scale syntheses of monodisperse nanocrystals", "venue": "Nature materials", "year": 2004 }, { "abstract": "Due to their interesting properties, research on colloidal nanocrystals has moved in the last few years from fundamental research to first applications in materials science and life sciences. In this review some recent biological applications of colloidal nanocrystals are discussed, without going into biological or chemical details. First, the properties of colloidal nanocrystals and how they can be synthesized are described. Second, the conjugation of nanocrystals with biological molecules is discussed. And third, three different biological applications are introduced: (i) the arrangement of nanocrystal oligonucleotide conjugates using molecular scaffolds such as single stranded DNA, (ii) the use of nanocrystal protein conjugates as fluorescent probes for cellular imaging, and (iii) a motility assay based on the uptake of nanocrystals by living cells.", "author_names": [ "Wolfgang J Parak", "Daniele Gerion", "Teresa Pellegrino", "Daniela Zanchet", "Christine M Micheel", "Shara C Williams", "Rosanne Boudreau", "Mark A Le Gros", "Carolyn A Larabell", "A Paul Alivisatos" ], "corpus_id": 56211942, "doc_id": "56211942", "n_citations": 676, "n_key_citations": 3, "score": 0, "title": "Biological applications of colloidal nanocrystals", "venue": "", "year": 2003 }, { "abstract": "Metallic particles and surfaces display diverse and complex optical properties. Examples include the intense colors of noble metal colloids, surface plasmon resonance absorption by thin metal films, and quenching of excited fluorophores near the metal surfaces. Recently, the interactions of fluorophores with metallic particles and surfaces (metals) have been used to obtain increased fluorescence intensities, to develop assays based on fluorescence quenching by gold colloids, and to obtain directional radiation from fluorophores near thin metal films. For metal enhanced fluorescence it is difficult to predict whether a particular metal structure, such as a colloid, fractal, or continuous surface, will quench or enhance fluorescence. In the present report we suggest how the effects of metals on fluorescence can be explained using a simple concept, based on radiating plasmons (RPs) The underlying physics may be complex but the concept is simple to understand. According to the RP model, the emission or quenching of a fluorophore near the metal can be predicted from the optical properties of the metal structures as calculated from electrodynamics, Mie theory, and/or Maxwell's equations. For example, according to Mie theory and the size and shape of the particle, the extinction of metal colloids can be due to either absorption or scattering. Incident energy is dissipated by absorption. Far field radiation is created by scattering. Based on our model small colloids are expected to quench fluorescence because absorption is dominant over scattering. Larger colloids are expected to enhance fluorescence because the scattering component is dominant over absorption. The ability of a metal's surface to absorb or reflect light is due to wavenumber matching requirements at the metal sample interface. Wavenumber matching considerations can also be used to predict whether fluorophores at a given distance from a continuous planar surface will be emitted or quenched. These considerations suggest that the so called \"lossy surface waves\" which quench fluorescence are due to induced electron oscillations which cannot radiate to the far field because wavevector matching is not possible. We suggest that the energy from the fluorophores thought to be lost by lossy surface waves can be recovered as emission by adjustment of the sample to allow wavevector matching. The RP model provides a rational approach for designing fluorophore metal configurations with the desired emissive properties and a basis for nanophotonic fluorophore technology.", "author_names": [ "Joseph R Lakowicz" ], "corpus_id": 23236607, "doc_id": "23236607", "n_citations": 1085, "n_key_citations": 20, "score": 0, "title": "Radiative decay engineering 5: metal enhanced fluorescence and plasmon emission.", "venue": "Analytical biochemistry", "year": 2005 }, { "abstract": "Since the use of magnetic nanocrystals as probes for biomedical system is attractive, it is important to develop optimal synthetic protocols for high quality magnetic nanocrystals and to have the systematic understanding of their nanoscale properties. Here we present the development of a synthetically controlled magnetic nanocrystal model system that correlates the nanoscale tunabilities in terms of size, magnetism, and induced nuclear spin relaxation processes. This system further led to the development of high performance nanocrystal antibody probe systems for the diagnosis of breast cancer cells via magnetic resonance imaging.", "author_names": [ "Young-wook Jun", "Yong-Min Huh", "Jin-Sil Choi", "Jae-Hyun Lee", "Ho-Taek Song", "Sungjun Kim", "Sarah Yoon", "Kyung-sup Kim", "Jeon-Soo Shin", "Jin-Suck Suh", "Jinwoo Cheon" ], "corpus_id": 34870584, "doc_id": "34870584", "n_citations": 984, "n_key_citations": 15, "score": 0, "title": "Nanoscale size effect of magnetic nanocrystals and their utilization for cancer diagnosis via magnetic resonance imaging.", "venue": "Journal of the American Chemical Society", "year": 2005 } ]

[ { "abstract": "Solar cell theory, materials, fabrication, design, modules, and systems are discussed. The solar source of light energy is described and quantified, along with a review of semiconductor properties and the generation, recombination, and the basic equations of photovoltaic device physics. Particular attention is given to p n junction diodes, including efficiency limits, losses, and measurements. Si solar cell technology is described for the production of solar quality crystals and wafers, and design, improvements, and device structures are examined. Consideration is given to alternate semiconductor materials and applications in concentrating systems, storage, and the design and construction of standalone systems and systems for residential and centralized power generation. Bibtex entry for this abstract Preferred format for this abstract", "author_names": [ "Martin A Green" ], "corpus_id": 53458999, "doc_id": "53458999", "n_citations": 1691, "n_key_citations": 137, "score": 0, "title": "Solar Cells Operating Principles, Technology and System Applications", "venue": "", "year": 1981 }, { "abstract": "The advantages and limitations of photovoltaic solar modules for energy generation are reviewed with their operation principles and physical efficiency limits. Although the main materials currently used or investigated and the associated fabrication technologies are individually described, emphasis is on silicon based solar cells. Wafer based crystalline silicon solar modules dominate in terms of production, but amorphous silicon solar cells have the potential to undercut costs owing, for example, to the roll to roll production possibilities for modules. Recent developments suggest that thin film crystalline silicon (especially microcrystalline silicon) is becoming a prime candidate for future photovoltaics.", "author_names": [ "" ], "corpus_id": 11342870, "doc_id": "11342870", "n_citations": 1065, "n_key_citations": 13, "score": 0, "title": "Photovoltaic technology: the case for thin film solar cells", "venue": "Science", "year": 1999 }, { "abstract": "About the Editors. List of Contributors. Preface to the 2nd Edition. 1 Achievements and Challenges of Solar Electricity from Photovoltaics (Steven Hegedus and Antonio Luque) 1.1 The Big Picture. 1.2 What is Photovoltaics? 1.3 Photovoltaics Today. 1.4 The Great Challenge. 1.5 Trends in Technology. 1.6 Conclusions. 2 The Role of Policy in PV Industry Growth: Past, Present and Future (John Byrne and Lado Kurdgelashvili) 2.1 Introduction. 2.2 Policy Review of Selected Countries. 2.3 Policy Impact on PV Market Development. 2.4 Future PV Market Growth Scenarios. 2.5 Toward a Sustainable Future. 3 The Physics of the Solar Cell (Jeffery L. Gray) 3.1 Introduction. 3.2 Fundamental Properties of Semiconductors. 3.3 Solar Cell Fundamentals. 3.4 Additional Topics. 3.5 Summary. 4 Theoretical Limits of Photovoltaic Conversion and New generation Solar Cells (Antonio Luque and Antonio Marti) 4.1 Introduction. 4.2 Thermodynamic Background. 4.3 Photovoltaic Converters. 4.4 The Technical Efficiency Limit for Solar Converters. 4.5 Very high efficiency Concepts. 4.6 Conclusions. 5 Solar Grade Silicon Feedstock (Bruno Ceccaroli and Otto Lohne) 5.1 Introduction. 5.2 Silicon. 5.3 Production of Silicon Metal/Metallurgical Grade Silicon. 5.4 Production of Polysilicon/Silicon of Electronic and Photovoltaic Grade. 5.5 Current Silicon Feedstock to Solar Cells. 5.6 Requirements of Silicon for Crystalline Solar Cells. 5.7 Routes to Solar Grade Silicon. 5.8 Conclusions. 6 Bulk Crystal Growth and Wafering for PV (Hugo Rodriguez, Ismael Guerrero, Wolfgang Koch, Arthur L. Endros, Dieter Franke, Christian Hassler, Juris P. Kalejs and H. J. Moller) 6.1 Introduction. 6.2 Bulk Monocrystalline Material. 6.3 Bulk Multicrystalline Silicon. 6.4 Wafering. 6.5 Silicon Ribbon and Foil Production. 6.6 Numerical Simulations of Crystal Growth Techniques. 6.7 Conclusions. 7 Crystalline Silicon Solar Cells and Modules (Ignacio Tobias, Carlos del Ca\"nizo and Jesus Alonso) 7.1 Introduction. 7.2 Crystalline Silicon as a Photovoltaic Material. 7.3 Crystalline Silicon Solar Cells. 7.4 Manufacturing Process. 7.5 Variations to the Basic Process. 7.6 Other Industrial Approaches. 7.7 Crystalline Silicon Photovoltaic Modules. 7.8 Electrical and Optical Performance of Modules. 7.9 Field Performance of Modules. 7.10 Conclusions. 8 High efficiency III V Multijunction Solar Cells (D. J. Friedman, J. M. Olson and Sarah Kurtz) 8.1 Introduction. 8.2 Applications. 8.3 Physics of III V Multijunction and Single junction Solar Cells. 8.4 Cell Configuration. 8.5 Computation of Series connected Device Performance. 8.6 Materials Issues Related to GaInP/GaAs/Ge Solar Cells. 8.7 Epilayer Characterization and Other Diagnostic Techniques. 8.8 Reliability and Degradation. 8.9 Future generation Solar Cells. 8.10 Summary. 9 Space Solar Cells and Arrays (Sheila Bailey and Ryne Raffaelle) 9.1 The History of Space Solar Cells. 9.2 The Challenge for Space Solar Cells. 9.3 Silicon Solar Cells. 9.4 III V Solar Cells. 9.5 Space Solar Arrays. 9.6 Future Cell and Array Possibilities. 9.7 Power System Figures of Merit. 9.8 Summary. 10 Photovoltaic Concentrators (Gabriel Sala and Ignacio Anton) 10.1 What is the Aim of Photovoltaic Concentration and What Does it Do? 10.2 Objectives, Limitations and Opportunities. 10.3 Typical Concentrators: an Attempt at Classification. 10.4 Concentration Optics: Thermodynamic Limits. 10.5 Factors of Merit for Concentrators in Relation to the Optics. 10.6 Photovoltaic Concentration Modules and Assemblies. 10.7 Tracking for Concentrator Systems. 10.8 Measurements of Cells, Modules and Photovoltaic Systems in Concentration. 10.9 Summary. 11 Crystalline Silicon Thin Film Solar Cells via High temperature and Intermediate temperature Approaches (Armin G. Aberle and Per I. Widenborg) 11.1 Introduction. 11.2 Modelling. 11.4 Crystalline Silicon Thin Film Solar Cells on Intermediate T Foreign Supporting Materials. 11.5 Conclusions. 12 Amorphous Silicon based Solar Cells (Eric A. Schiff, Steven Hegedus and Xunming Deng) 12.1 Overview. 12.2 Atomic and Electronic Structure of Hydrogenated Amorphous Silicon. 12.3 Depositing Amorphous Silicon. 12.4 Understanding a Si pin Cells. 12.5 Multijunction Solar Cells. 12.6 Module Manufacturing. 12.7 Conclusions and Future Projections. 13 Cu(InGa)Se2 Solar Cells (William N. Shafarman, Susanne Siebentritt and Lars Stolt) 13.1 Introduction. 13.2 Material Properties. 13.3 Deposition Methods. 13.4 Junction and Device Formation. 13.5 Device Operation. 13.6 Manufacturing Issues. 13.7 The Cu(InGa)Se2 Outlook. 14 Cadmium Telluride Solar Cells (Brian E. McCandless and James R. Sites) 14.1 Introduction. 14.2 Historical Development. 14.3 CdTe Properties. 14.4 CdTe Film Deposition. 14.5 CdTe Thin Film Solar Cells. 14.6 CdTe Modules. 14.7 Future of CdTe based Solar Cells. 15 Dye sensitized Solar Cells (Kohjiro Hara and Shogo Mori) 15.1 Introduction. 15.2 Operating Mechanism of DSSC. 15.3 Materials. 15.4 Performance of Highly Efficient DSSCs. 15.5 Electron transfer Processes. 15.6 New Materials. 15.7 Stability. 15.8 Approach to Commercialization. 15.9 Summary and Prospects. 16 Sunlight Energy Conversion Via Organics (Sam Shajing Sun and Hugh O'Neill) 16.1 Principles of Organic and Polymeric Photovoltaics. 16.2 Evolution and Types of Organic and Polymeric Solar Cells. 16.3 Organic and Polymeric Solar Cell Fabrication and Characterization. 16.4 Natural Photosynthetic Sunlight Energy Conversion Systems. 16.5 Artificial Photosynthetic Systems. 16.6 Artificial Reaction Centers. 16.7 Towards Device Architectures. 16.8 Summary and Future Perspectives. 17 Transparent Conducting Oxides for Photovoltaics (Alan E. Delahoy and Sheyu Guo) 17.1 Introduction. 17.2 Survey of Materials. 17.3 Deposition Methods. 17.4 TCO Theory and Modeling: Electrical and Optical Properties and their Impact on Module Performance. 17.5 Principal Materials and Issues for Thin Film and Wafer based PV. 17.6 Textured Films. 17.7 Measurements and Characterization Methods. 17.8 TCO Stability. 17.9 Recent Developments and Prospects. 18 Measurement and Characterization of Solar Cells and Modules (Keith Emery) 18.1 Introduction. 18.2 Rating PV Performance. 18.3 Current Voltage Measurements. 18.4 Spectral Responsivity Measurements. 18.5 Module Qualification and Certification. 18.6 Summary. 19 PV Systems (Charles M. Whitaker, Timothy U. Townsend, Anat Razon, Raymond M. Hudson and Xavier Vallve) 19.1 Introduction: There is gold at the end of the rainbow. 19.2 System Types. 19.3 Exemplary PV Systems. 19.4 Ratings. 19.5 Key System Components. 19.6 System Design Considerations. 19.7 System Design. 19.8 Installation. 19.9 Operation and Maintenance/Monitoring. 19.10 Removal, Recycling and Remediation. 19.11 Examples. 20 Electrochemical Storage for Photovoltaics (Dirk Uwe Sauer) 20.1 Introduction. 20.2 General Concept of Electrochemical Batteries. 20.3 Typical Operation Conditions of Batteries in PV Applications. 20.4 Secondary Electrochemical Accumulators with Internal Storage. 20.5 Secondary Electrochemical Battery Systems with External Storage. 20.6 Investment and Lifetime Cost Considerations. 20.7 Conclusion. 21 Power Conditioning for Photovoltaic Power Systems (Heribert Schmidt, Bruno Burger and Jurgen Schmid) 21.1 Charge Controllers and Monitoring Systems for Batteries in PV Power Systems. 21.2 Inverters. 22 Energy Collected and Delivered by PV Modules (Eduardo Lorenzo) 22.1 Introduction. 22.2 Movement between Sun and Earth. 22.3 Solar Radiation Components. 22.4 Solar Radiation Data and Uncertainty. 22.5 Radiation on Inclined Surfaces. 22.6 Diurnal Variations of the Ambient Temperature. 22.7 Effects of the Angle of Incidence and of Dirt. 22.8 Some Calculation Tools. 22.9 Irradiation on Most Widely Studied Surfaces. 22.10 PV Generator Behaviour Under Real Operation Conditions. 22.11 Reliability and Sizing of Stand alone PV Systems. 22.12 The Case of Solar Home Systems. 22.13 Energy Yield of Grid connected PV Systems. 22.14 Conclusions. 23 PV in Architecture (Tjerk H. Reijenga and Henk F. Kaan) 23.1 Introduction. 23.2 PV in Architecture. 23.3 BIPV Basics. 23.4 Steps in the Design Process with PV. 23.5 Concluding Remarks. 24 Photovoltaics and Development (Jorge M. Huacuz, Jaime Agredano and Lalith Gunaratne) 24.1 Electricity and Development. 24.2 Breaking the Chains of Underdevelopment. 24.3 The PV Alternative. 24.4 Examples of PV Rural Electrification. 24.5 Toward a New Paradigm for Rural Electrification. References. Index.", "author_names": [ "Antonio Luque", "Steven Hegedus" ], "corpus_id": 109095275, "doc_id": "109095275", "n_citations": 2409, "n_key_citations": 160, "score": 0, "title": "Handbook of photovoltaic science and engineering", "venue": "", "year": 2011 }, { "abstract": "A polymer solar cell based on a bulk hetereojunction design with an internal quantum efficiency of over 90% across the visible spectrum (425 nm to 575 nm) is reported. The device exhibits a power conversion efficiency of 6% under standard air mass 1.5 global illumination tests.", "author_names": [ "Sung Heum Park", "Anshuman Vijay Roy", "Serge Beaupre", "Shinuk Cho", "Nelson E Coates", "Ji Sun Moon", "Daniel Moses", "Mario Leclerc", "Kwanghee Lee", "Alan J Heeger" ], "corpus_id": 122649389, "doc_id": "122649389", "n_citations": 3687, "n_key_citations": 47, "score": 0, "title": "Bulk heterojunction solar cells with internal quantum efficiency approaching 100", "venue": "", "year": 2009 }, { "abstract": "Abstract We review the technical progress made in the past several years in the area of mono and polycrystalline thin film photovoltaic (PV) technologies based on Si, III V, II VI, and I III VI2 semiconductors, as well as nano PV. PV electricity is one of the best options for sustainable future energy requirements of the world. At present, the PV market is growing rapidly at an annual rate of 35 40% with PV production around 10.66 GW in 2009. Si and GaAs monocrystalline solar cell efficiencies are very close to the theoretically predicted maximum values. Mono and polycrystalline wafer Si solar cells remain the predominant PV technology with module production cost around $1.50 per peak watt. Thin film PV was developed as a means of substantially reducing the cost of solar cells. Remarkable progress has been achieved in this field in recent years. CdTe and Cu(In,Ga)Se2 thin film solar cells demonstrated record efficiencies of 16.5% and almost 20% respectively. These values are the highest achieved for thin film solar cells. Production cost of CdTe thin film modules is presently around $0.76 per peak watt.", "author_names": [ "T M Razykov", "Christos S Ferekides", "Don L Morel", "Elias K Stefanakos", "Harin S Ullal", "Hari M Upadhyaya" ], "corpus_id": 55540244, "doc_id": "55540244", "n_citations": 821, "n_key_citations": 27, "score": 0, "title": "Solar photovoltaic electricity: Current status and future prospects", "venue": "", "year": 2011 }, { "abstract": "The Sandia Photovoltaic Program conducted research in crystalline silicon solar cells between 1986 and 2000 for the U.S. Department of Energy. This period saw rapid improvements in the fundamental understanding of c Si materials and devices, improvements in c Si PV manufacturing and control, and a rapid expansion of c Si PV manufacturing capacity. Crystalline silicon technology has provided the basis for PV to emerge as a serious option for global energy needs. The c Si cell research at Sandia examined c Si materials, devices, processing, and process integration. This report summarizes research conducted in this program over the past 15 years.", "author_names": [ "Douglas Scott W Ruby", "James M Gee" ], "corpus_id": 73596361, "doc_id": "73596361", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "History of the Crystalline Silicon Photovoltaic Cell Research Program at Sandia National Laboratories", "venue": "", "year": 2001 }, { "abstract": "We study the femtosecond laser ablation properties of borosilicate glass using atomic force microscopy and laser pulses of 200 fs duration, centered at 780 nm wavelength. We show that both single shot and multishot ablation threshold fluences can be determined by studying the diameter and the depth of single shot ablated craters. The linear relationship between the square of the crater diameter and the logarithm of the laser fluence in the form of D2=2w02ln(F0/FthN=1) provides the single shot ablation threshold, FthN=1, whereas the linear relationship between the ablation depth and the logarithm of laser fluence in the form of ha=aeff 1ln(F0/FthN>1) provides the multishot ablation threshold, FthN>1. The results depict a multishot ablation threshold of 1.7J/cm2 independent of the atmospheric conditions. The slopes of the linear fits also provide a precise estimate of the beam radius at the surface, w05.9mm, and the \"effective optical penetration depth,\" aeff 1238nm in air. The method is systematic, prov.", "author_names": [ "Adela Ben-Yakar", "Robert L Byer" ], "corpus_id": 55477797, "doc_id": "55477797", "n_citations": 218, "n_key_citations": 6, "score": 0, "title": "Femtosecond laser ablation properties of borosilicate glass", "venue": "", "year": 2004 }, { "abstract": "Monolithic series interconnection is a key advantage of thin film PV. The standard approach is to alternate layer deposition and laser scribing. Here the M Solv patented One Step Interconnect (OSI) process is introduced as an alternative to the conventional all laser interconnect. OSI interconnects TF PV modules in a single step after all deposition is complete with considerable advantages: reduced capital expenditure; better process control; less vacuum/air interfaces, reduced line footprint and faster panel transit. OSI employs a combination of laser scribing and inkjet printing of functional materials. OSI mini modules have been fabricated on CdTe with good electrical performance. Although the focus here has been CdTe, OSI is applicable to all thin film technologies. The laser and inkjet processes presented are fully scalable for industrial production.", "author_names": [ "Mickey Crozier", "Adam N Brunton", "Ali Abbas", "Jake W Bowers", "Piotr Kaminski", "John M Walls", "Jonathan D Shephard" ], "corpus_id": 39706747, "doc_id": "39706747", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "One step thin film PV interconnection process using laser and inkjet", "venue": "2013 IEEE 39th Photovoltaic Specialists Conference (PVSC)", "year": 2013 }, { "abstract": "Thin film solar cells offer the most promising options for substantially reducing the cost of photovoltaic systems. A multiplicity of options, in terms of materials and devices, are currently being developed worldwide. Some of the leading contenders are: amorphous and polycrystalline silicon, compound semiconductor thin films such as CuInSe2 based alloys, and CdTe thin film solar cells. Enormous progress in device performance has been made in most of these technologies, and considerable effort is devoted to commercialization of these technologies. Exciting new developments are happening in some relatively new materials and devices.", "author_names": [ "Satyen K Deb" ], "corpus_id": 110203578, "doc_id": "110203578", "n_citations": 206, "n_key_citations": 11, "score": 0, "title": "Thin film solar cells: An overview", "venue": "", "year": 1996 }, { "abstract": "Laser Surface Texturing, Crystallization and Scribing of Thin Films in Solar Cell Applications Hongliang Wang Thin films have been considered for use in terrestrial solar cell applications because of their significantly reduced cost compared with bulk crystalline silicon. However, their overall efficiency and stability are less than that of their bulk crystalline counterpart. The work presented in this thesis seeks to investigate these issues via a series of experimental and numerical analysis of the influences of laser processing on microstructure, optical and electrical properties of two absorber materials, a Si:H (hydrogenated amorphous silicon) and CdTe (cadmium telluride) a Si:H thin film solar cells suffer from disadvantages of low efficiencies and light induced degradation. A one step laser processing is investigated for introducing light trapping structure and crystallization on a Si:H thin films, which can potentially simultaneously alleviate the two weaknesses of a Si:H. The nanoscale conical and pillar shaped spikes formed on the surface of a Si:H films by irradiation of both femtosecond (fs) infrared and nanosecond (ns) excimer lasers enhanced light absorption, while the formation of a mixture of hydrogenated nanocrystalline silicon (nc Si:H) and a Si:H after crystallization suggests that the overall material stability can potentially improve. It is shown that growth is a more dominant spike formation mechanism in excimer laser processing, rather than ablation which is dominant during fs laser texturing. Experimental and analytical approaches are also developed revealing the effect of hydrogen on texturing behavior and crystallization during excimer laser irradiation, and a step by step crystallization process is proposed to prevent the hydrogen from diffusing out in order to reduce the defect density. In addition, a comparison of absorptance spectra for various surface morphologies and crystallinity is developed and the absorptance across the solar spectrum shows that the combination of surface texturing and crystallization induced by laser processing is very promising for a Si:H thin film solar cell applications. CdTe thin film solar cells are the basis of a significant technology with major commercial impact on terrestrial photovoltaic production, since CdTe leads to substantial cost reduction. Laser scribing is a key process used to increase thin film solar panel efficiency through the formation of serial interconnections to reduce photocurrent and resistance losses. Currently, scribing is performed using glass side laser processes which have led to increased scribe quality. Defects formed during scribing such as micro cracks, film delamination, thermal effect and tapered sidewall geometries, however, still keep solar panels from reaching their theoretical efficiencies. In this study, a ns Nd:YAG laser operating at the fundamental (1064nm) or frequency doubled (532nm) wavelengths is employed for pattern 1 (P1) and 2 (P2) scribing on CdTe thin film solar cells. The experimental investigation shows that film removal mechanisms for different materials are due to laser induced ablation, thermal stress and micro explosion processes. The formation mechanisms and mitigation techniques of the defects during micro explosion process are studied. A fully coupled thermal and mechanical finite element model is developed to analyze the laserinduced spatio temporal temperature and thermal stress distribution responsible for SnO2:F film removal, and a plasma expansion model is also investigated to simulate the film removal of CdTe/Cds multilayer due to the micro explosion process. The characterization of removal qualities will enable the process optimization and design required to enhance solar module efficiency.", "author_names": [ "Hongliang Wang" ], "corpus_id": 135853309, "doc_id": "135853309", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Laser Surface Texturing, Crystallization and Scribing of Thin Films in Solar Cell Applications", "venue": "", "year": 2013 } ]

[ { "abstract": "Future opportunities of gigascale integration are governed by a hierarchy of limits of which system limits are the most numerous, constraining, and difficult to define. A generic system simulator, GENESYS, is proposed as the most promising approach to identifying future system limits and opportunities. The GENESYS analysis tool assimilates the entire hierarchical description of a chip through a concise set of input parameters and projects its key performance metrics by engaging a set of interrelated models incorporating both physical principles and empirical knowledge. This research enables simultaneous consideration of both the implementation technology and architecture of future microprocessors through the unique integration of phenomena from each level of the hierarchy as well as the utilization of novel cycle time, generic on chip memory, and instructions per cycle models. GENESYS and its core models are verified by simulating commercial microprocessors and comparing the predictions with the actual areas, power dissipations, and throughputs. Based on the technology and integration levels projected by the National Technology Roadmap for Semiconductors (NTRS) and optimal multi level interconnect architectures and memory hierarchies identified by GENESYS, throughput is projected across the NTRS roadmap. Simulations indicate that the clock frequency and throughput become limited by global interconnects after 2006. For a given technology, GENESYS identifies the optimal zone of synchrony at which throughput reaches a maximum. Cellular array architectures or alternative novel architectures that ensure short wires will be required to sustain current rates of performance growth. This dissertation provides the first systematic approach to predicting the throughput of gigascale integration systems and elucidates the tradeoffs and physical limits as well as the opportunities of these systems.", "author_names": [ "John C Eble", "Scott Wills", "James D Meindl" ], "corpus_id": 108603992, "doc_id": "108603992", "n_citations": 44, "n_key_citations": 6, "score": 1, "title": "A generic system simulator with novel on chip cache and throughput models for gigascale integration", "venue": "", "year": 1998 }, { "abstract": "The growing complexity of embedded multiprocessor architectures for digital media processing will soon require highly scalable communication infrastructures. Packet switched networks on chip (NoC) have been proposed to support the trend for systems on chip integration. In this paper, an advanced NoC architecture, called Xpipes, targeting high performance and reliable communication for on chip multi processors is introduced. It consists of a library of soft macros (switches, network interfaces and links) that are design time composable and tunable so that domain specific heterogeneous architectures can be instantiated and synthesized. Links can be pipelined with a flexible number of stages to decouple link throughput from its length and to get arbitrary topologies. Moreover, a tool called XpipesCompiler, which automatically instantiates a customized NoC from the library of soft network components, is used in this paper to test the Xpipes based synthesis flow for domain specific communication architectures.", "author_names": [ "Davide Bertozzi", "Luca Benini" ], "corpus_id": 24709911, "doc_id": "24709911", "n_citations": 489, "n_key_citations": 30, "score": 0, "title": "Xpipes: a network on chip architecture for gigascale systems on chip", "venue": "IEEE Circuits and Systems Magazine", "year": 2004 }, { "abstract": "The continuous advances in semiconductor technology enable the integration of increasing numbers of IP blocks in a single SoC. Interconnect infrastructures, such as buses, switches, and networks on chips (NoCs) combine the IPs into a working SoC. Moreover, the industry expects platform based SoC design to evolve to communication centric design, with NoCs as a central enabling technology. In this article, we introduce the AEthereal NoC. The tenet of the AEthereal NoC is that guaranteed services (GSs) such as uncorrupted, lossless, ordered data delivery; guaranteed throughput; and bounded latency are essential for the efficient construction of robust SoCs. To exploit the NoC capacity unused by the GS traffic, we provide best effort services.", "author_names": [ "Kees G W Goossens", "John Dielissen", "Andrei Radulescu" ], "corpus_id": 206459081, "doc_id": "206459081", "n_citations": 957, "n_key_citations": 74, "score": 0, "title": "AEthereal network on chip: concepts, architectures, and implementations", "venue": "IEEE Design Test of Computers", "year": 2005 }, { "abstract": "On chip micronetworks, designed with a layered methodology, will meet the distinctive challenges of providing functionally correct, reliable operation of interacting system on chip components. A system on chip (SoC) can provide an integrated solution to challenging design problems in the telecommunications, multimedia, and consumer electronics domains. Much of the progress in these fields hinges on the designers' ability to conceive complex electronic engines under strong time to market pressure. Success will require using appropriate design and process technologies, as well as interconnecting existing components reliably in a plug and play fashion. Focusing on using probabilistic metrics such as average values or variance to quantify design objectives such as performance and power will lead to a major change in SoC design methodologies. Overall, these designs will be based on both deterministic and stochastic models. Creating complex SoCs requires a modular, component based approach to both hardware and software design. Despite numerous challenges, the authors believe that developers will solve the problems of designing SoC networks. At the same time, they believe that a layered micronetwork design methodology will likely be the only path to mastering the complexity of future SoC designs.", "author_names": [ "Luca Benini", "Giovanni De Micheli" ], "corpus_id": 6459657, "doc_id": "6459657", "n_citations": 3906, "n_key_citations": 150, "score": 0, "title": "Networks on Chips: A New SoC Paradigm", "venue": "Computer", "year": 2002 }, { "abstract": "We define Quality of Service (QoS) and cost model for communications in Systems on Chip (SoC) and derive related Network on Chip (NoC) architecture and design process. SoC inter module communication traffic is classified into four classes of service: signaling (for inter module control signals) real time (representing delay constrained bit streams) RD/WR (modeling short data access) and block transfer (handling large data bursts) Communication traffic of the target SoC is analyzed (by means of analytic calculations and simulations) and QoS requirements (delay and throughput) for each service class are derived. A customized Quality of Service NoC (QNoC) architecture is derived by modifying a generic network architecture. The customization process minimizes the network cost (in area and power) while maintaining the required QoS.The generic network is based on a two dimensional planar mesh and fixed shortest path (X Y based) multiclass wormhole routing. Once communication requirements of the target SoC are identified, the network is customized as follows: The SoC modules are placed so as to minimize spatial traffic density, unnecessary mesh links and switching nodes are removed, and bandwidth is allocated to the remaining links and switches according to their relative load so that link utilization is balanced. The result is a low cost customized QNoC for the target SoC which guarantees that QoS requirements are met.", "author_names": [ "Evgeny Bolotin", "Israel Cidon", "Ran Ginosar", "Avinoam Kolodny" ], "corpus_id": 2614065, "doc_id": "2614065", "n_citations": 601, "n_key_citations": 44, "score": 0, "title": "QNoC: QoS architecture and design process for network on chip", "venue": "J. Syst. Archit.", "year": 2004 }, { "abstract": "Single chip multiprocessors are an important research direction for future microprocessors. The stigma of this approach is that many important applications cannot be automatically parallelized. This chapter presents a single chip multiprocessor that engages aggressive speculation techniques to enable dynamic parallelization of irregular, sequential binaries. Thread speculation (multiscalar execution) and data value prediction are combined to enable the processor to execute dependent threads in parallel. The architecture performs a novel form of dynamic thread partitioning and includes an aggressive correlated value predictor. Several new microarchitectural structures manage inter thread dependencies. On an eight processor system, simulated execution of SPECint95 binaries delivers a speedup of 3.4 over uniprocessor performance. This improvement is due entirely to the exploitation of dynamically extracted thread level parallelism. Introduction As semiconductor technology pushes towards billions of fast transistors on a chip, interconnect delay and design complexity become critical issues [56][23][84] The processor architectures popular today exploit Instruction Level Parallelism (ILP) The fundamental ILP techniques in use today were developed in an era when transistor size", "author_names": [ "Lucian Codrescu", "D Scott Wills", "James D Meindl" ], "corpus_id": 39486974, "doc_id": "39486974", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Atlas: a dynamically parallelizing chip multiprocessor for gigascale integration", "venue": "", "year": 2000 }, { "abstract": "Using on chip interconnection networks in place of ad hoc global wiring structures the top level wires on a chip and facilitates modular design. With this approach, system modules (processors, memories, peripherals, etc. communicate by sending packets to one another over the network. The structured network wiring gives well controlled electrical parameters that eliminate timing iterations and enable the use of high performance circuits to reduce latency and increase bandwidth. The area overhead required to implement an on chip network is modest, we estimate 6.6% This paper introduces the concept of on chip networks, sketches a simple network, and discusses some challenges in the architecture and design of these networks.", "author_names": [ "William J Dally", "Brian Towles" ], "corpus_id": 195858813, "doc_id": "195858813", "n_citations": 2539, "n_key_citations": 122, "score": 0, "title": "Route packets, not wires: on chip interconnection networks", "venue": "Proceedings of the 38th Design Automation Conference (IEEE Cat. No.01CH37232)", "year": 2001 }, { "abstract": "Multiprocessor system on chip (MP SoC) platforms are emerging as an important trend for SoC design. Power and wire design constraints are forcing the adoption of new design methodologies for system on chip (SoC) namely, those that incorporate modularity and explicit parallelism. To enable these MP SoC platforms, researchers have recently pursued scaleable communication centric interconnect fabrics, such as networks on chip (NoC) which possess many features that are particularly attractive for these. These communication centric interconnect fabrics are characterized by different trade offs with regard to latency, throughput, energy dissipation, and silicon area requirements. In this paper, we develop a consistent and meaningful evaluation methodology to compare the performance and characteristics of a variety of NoC architectures. We also explore design trade offs that characterize the NoC approach and obtain comparative results for a number of common NoC topologies. To the best of our knowledge, this is the first effort in characterizing different NoC architectures with respect to their performance and design trade offs. To further illustrate our evaluation methodology, we map a typical multiprocessing platform to different NoC interconnect architectures and show how the system performance is affected by these design trade offs.", "author_names": [ "Partha Pratim Pande", "Cristian Grecu", "Michael Jones", "Andre Ivanov", "Resve A Saleh" ], "corpus_id": 14577240, "doc_id": "14577240", "n_citations": 901, "n_key_citations": 67, "score": 0, "title": "Performance evaluation and design trade offs for network on chip interconnect architectures", "venue": "IEEE Transactions on Computers", "year": 2005 }, { "abstract": "Traditionally, design space exploration for systems on chip (SoCs) has focused on the computational aspects of the problem at hand. However, as the number of components on a single chip and their performance continue to increase, a shift from computation based to communication based design becomes mandatory. As a result, the communication architecture plays a major role in the area, performance, and energy consumption of the overall system. This article presents a comprehensive evaluation of three on chip communication architectures targeting multimedia applications. Specifically, we compare and contrast the network on chip (NoC) with point to point (P2P) and bus based communication architectures in terms of area, performance, and energy consumption. As the main contribution, we present complete P2P, bus and NoC based implementations of a real multimedia application (i. e. the MPEG 2 encoder) and provide direct measurements using an FPGA prototype and actual video clips, rather than simulation and synthetic workloads. We also support the experimental findings through a theoretical analysis. Both experimental and analysis results show that the NoC architecture scales very well in terms of area, performance, energy, and design effort, while the P2P and bus based architectures scale poorly on all accounts except for performance and area, respectively.", "author_names": [ "Hyung Gyu Lee", "Naehyuck Chang", "Umit Y Ogras", "Radu Marculescu" ], "corpus_id": 15259434, "doc_id": "15259434", "n_citations": 256, "n_key_citations": 9, "score": 0, "title": "On chip communication architecture exploration: A quantitative evaluation of point to point, bus, and network on chip approaches", "venue": "TODE", "year": 2008 }, { "abstract": "Based on physical models, distributed circuit models are presented for single walled carbon nanotubes (SWCNs) and SWCN bundles that are valid for all voltages and lengths. These models can be used for circuit simulations and compact modeling. It is demonstrated that by customizing SWCN interconnects at the local, semiglobal, and global levels, several major challenges facing gigascale integrated systems can potentially be addressed. For local interconnects, monolayer or multilayer SWCN interconnects can offer up to 50% reduction in capacitance and power dissipation with up to 20% improvement in latency if they are short enough <20 mum) For semiglobal interconnects, either latency or power dissipation can be substantially improved if bundles of SWCNs are used. The improvements increase as the cross sectional dimensions scale down. For global interconnects, bandwidth density can be improved by 40% if there is at least one metallic SWCN per 3 nm2 cross sectional area", "author_names": [ "A Naeemi", "James D Meindl" ], "corpus_id": 37222672, "doc_id": "37222672", "n_citations": 235, "n_key_citations": 20, "score": 0, "title": "Design and Performance Modeling for Single Walled Carbon Nanotubes as Local, Semiglobal, and Global Interconnects in Gigascale Integrated Systems", "venue": "IEEE Transactions on Electron Devices", "year": 2007 } ]

[ { "abstract": "Abstract We consider situations where the observed data is of categorical type and the underlying parameters are subject to abrupt changes of unpredictable magnitude at unknown points in time. We derive change point detection schemes based on generalized likelihood ratio tests and develop procedures for their design and analysis. We also discuss problems related to parameter estimation for categorical data in the presence of abrupt changes. We illustrate use of the proposed methodology for fault characterization and monitoring in the semiconductor industry.", "author_names": [ "Emmanuel Yashchin" ], "corpus_id": 123949805, "doc_id": "123949805", "n_citations": 23, "n_key_citations": 0, "score": 1, "title": "On Detection of Changes in Categorical Data", "venue": "", "year": 2012 }, { "abstract": "Remotely sensed datasets are increasingly being used to model habitat suitability for a variety of taxa. We review habitat suitability models (HSMs) developed for both plants and animals that include remote sensing predictor variables to determine how these variables could affect model projections. For models focused on plant species habitat, we find several instances of unintentional bias in HSMs of vegetation due to the inclusion of remote sensing variables. Notably, studies that include continuous remote sensing variables could be inadvertently mapping actual species distribution instead of potential habitat due to unique spectral or temporal characteristics of the target species. Additionally, HSMs including categorical classifications are rarely explicit about assumptions of habitat suitability related to land cover, which could lead to unintended exclusion of potential habitat due to current land use. Although we support the broader application of remote sensing in general, we caution developers of HSMs to be aware of introduced model bias. These biases are more likely to arise when remote sensing variables are added to models simply because they improve accuracy, rather than considering how they affect the model results and interpretation. When including land cover classifications as predictors, we recommend that modellers provide more explicit descriptions of how habitat is defined (e.g. is deforested land considered suitable for trees? Further, we suggest that continuous remote sensing variables should only be included in habitat models if authors can demonstrate that their inclusion characterizes potential habitat rather than actual species distribution. Use of the term 'habitat suitability model' rather than 'species distribution model' could reduce confusion about modelling goals and improve communication between the remote sensing and ecological modelling communities. (c) 2012 Elsevier B.V. All rights reserved.", "author_names": [ "ethany A Bradleya", "Aaryn D Olssonb", "Ophelia Wangb", "Brett G Dicksonb", "Lori Pelecha", "E Sesnieb", "Luke J Zachmannb" ], "corpus_id": 15566101, "doc_id": "15566101", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "eview pecies detection vs habitat suitability Are we biasing habitat suitability models ith remotely sensed data", "venue": "", "year": 2012 }, { "abstract": "Proceedings: AACR 103rd Annual Meeting 2012 Mar 31 Apr 4, 2012; Chicago, IL Background: Mammographic density is an independent risk factor for breast cancer associated with a large relative and attributable risk for the disease. Given the prevalence of women with increased breast density, the attributable risk may be as high as 33% The largest factor influencing density is heredity, but various lines of evidence suggest that modification of breast density is associated with a decrease in breast cancer risk. Studies have found vitamin D levels to be inversely related to breast density. Here we present a cross sectional analysis of vitamin D and breast density in women enrolled in the Vermont Cancer Centers High Risk Breast Program. Longitudinal associations and correlations of vitamin D and breast density were evaluated. Methods: The High Risk Breast Program database, for women with strong family history, BRCA mutations, high risk pathology or prior chemoradiotherapy for Hodgkins Disease, was initiated in 2003 and contains over 500 women. A subset of 51 women ranging in age from 31 69 with a mean lifetime Gail risk of 21% is the subject of this analysis. Data collected included mammograms, a medical and dietary history, BMI, and serum Vitamin D levels. Breast density was interpreted (at baseline, 2 years and 4 years) from mammograms using a visual analogue scale and reliability was evaluated. Univariate and multivariate analyses were performed using SAS statistical software. Results: The intra observer variability for density determination using a visual analogue scale was comparable to published studies (R=0.82) Baseline BMI showed an inverse univariate trend with percent of dense tissue at both time points (p=0.001) No correlation was found between any determinant and change in breast density measured at the 2 year time point. A subset of patients (n=37) was followed for 2 additional years. A model for change in percent dense tissue was obtained for this subset of patients using multivariate analysis that included baseline BMI and change in serum Vitamin D level (R2=0.23) The other factors with a univariate relationship were not found to contribute to the multivariate model. Conclusions: The HRBP database has become an invaluable resource, significantly reducing the financial resources necessary to complete this study and aiding the expansion of the study when needed. Information has been gained with high potential impact on prevention and early detection of breast cancer; first is the reproducibility of the visual analogue scale, a method of quantifying density which is readily available to clinicians and research staff with little training and minimal resources. Second, this study illuminates the importance of a longer follow up period for the detection of changes in mammographic breast density. Third, this study validates the association between serum vitamin D levels and percent breast density, and more importantly the inverse relationship between change in vitamin D levels and change in breast density. Citation Format: {Authors} {Abstract title} [abstract] In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31 Apr 4; Chicago, IL. Philadelphia (PA) AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 575. doi:1538 7445.AM2012 575", "author_names": [ "Shaleen K Theiler", "Farrah B Khan", "Chelsea A Thompson", "Brian L Sprague", "Kim L Dittus", "Betsy L Sussman", "Marie E Wood" ], "corpus_id": 72779470, "doc_id": "72779470", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Abstract 575: Correlation of serum vitamin D levels and changes in breast density", "venue": "", "year": 2012 }, { "abstract": "Monitoring gene activation and repression in cellular signaling pathways requires specific tools. Reporter gene assays use a technique of attaching a genetic regulatory element, or promoter, to a gene encoding for a protein with enzymatic, chromophoric or fluorescent properties. Cloned into a plasmid vector, these sequences can be transfected or transduced into animal, plant or tissue culture cells. Reporter gene expression can be measured via bioluminescent, chemiluminescent or fluorescent output to quantify the element or protein activity in the pathway affecting the regulatory element. Bioluminescent output is formed through the catalysis of a substrate and the natural enzyme luciferase. Present in many terrestrial and marine metazoans, bioluminescence is a powerful instrument for mutational analysis of gene promoters, transcription factor dynamics, and protein protein interactions. Our study confirmed the beneficial use of sensitive bioluminescent enzymes in reporter gene assays with wide dynamic ranges and flexibility in signal identification. Mutation of several of the luciferase genes resulted in spectral shifting and narrowing of the photon reaction products relative to the wavelength of the natural state. The mutations provide the ability to spectrally resolve the modified luciferases in a single reaction. In addition, multiplex assays relying on sequential addition of substrates can be achieved through manipulation of the enzyme substrate reaction conditions. Marine copepod and ostracod luciferase enzymes are naturally secreted, and reporter assays using these genes can capture real time or time course data by sampling the media of transfected cells or blood from transgenic animals and assaying for luciferase. The distinct advantage of these assays is that they are not destructive to the cells or animals. Our study used spectral separation using Gaussia/firefly and multiplex assays relying on sequential addition of substrates and Gaussia/Cypridina to monitor changes in NFkB activity in response to small molecule agonists. Our results demonstrate the usefulness of dual secreted luciferase assays for sensitive real time monitoring of NFkB activity in media. Furthermore, these assays enable simultaneous detection of spectrally resolvable luciferases using filter based detection. Citation Format: {Authors} {Abstract title} [abstract] In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31 Apr 4; Chicago, IL. Philadelphia (PA) AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3207. doi:1538 7445.AM2012 3207", "author_names": [ "Megan Dobbs", "Douglas E Hughes", "Janaki Narahari", "Jae Seong Choi", "Atul S Deshpande", "Brian Webb" ], "corpus_id": 85028579, "doc_id": "85028579", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Abstract 3207: Monitoring changes in NF kB pathway regulation using highly sensitive multiplex bioluminescent reporter assays", "venue": "", "year": 2012 }, { "abstract": "Abstract Hydrological data may be temporally autocorrelated requiring autoregressive process parameters to be estimated. Current statistical methods for hydrological change detection in paired watershed studies rely on prediction intervals, but the current form of prediction intervals does not include all appropriate sources of variation. Corrected prediction intervals for the analysis of paired watershed study data that include variation associated with covariance and linear model parameter estimation are presented. We provide an example of their application to data from the Hinkle Creek Paired Watershed Study located in the western Cascade foothills of Southern Oregon, USA. Research implications of using the correct prediction limits and incorporating the estimation uncertainty of autoregressive process parameters are discussed. Editor D. Koutsoyiannis Citation Som, N.A. Zegre, N.P. Ganio, L.M. and Skaugset, A.E. 2012. Corrected prediction intervals for change detection in paired watershed studies. Hydrological Sciences Journal, 57 (1) 134 143.", "author_names": [ "Nicholas A Som", "Nicolas Zegre", "Lisa M Ganio", "Arne E Skaugset" ], "corpus_id": 129431815, "doc_id": "129431815", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Corrected prediction intervals for change detection in paired watershed studies", "venue": "", "year": 2012 }, { "abstract": "Security issues in communication environment pose a special challenge. At the same time challenges are increased from the illegal users.in the communication environment, a good security policy and its proper implementation go a long way in ensuring adequate security management practices. But violations of policies on access information are handles through intrusion. Intrusion detection and prevention systems are learning from attacks either before or after its success and used to detect unauthorised intrusions into computer system and network. It focused on identifying possible threats, user's information about them, attempting to stop them, and reporting them to security administrators.as technology has developed, and a new industry based on intrusion detection has sprung up. Security firms are growing up everywhere to offer individual and property security. IDPS have been made to configure changes, compare user actions against known attack scenarios, and able to predict changes in activities that indicate and can lead to suspicious activities.in this paper describes about protocol sequences which is used to detect the intrusion on upgrade network and its attributes and recommend the standardized ARP protocol for the intrusion detection process and another alternatives to improves efficiencies for security. 1.0 INTRODUCTION In the communication environment, a good security policy and its proper implementation go a long way in ensuring adequate security management practices. But violations of policies on access information are handles through intrusion. Intrusion prevention is mostly impossible to achieve at all times. Hence focus is on intrusion detection.it can help to collect more information about intrusions, strengthening the intrusion prevention method and act as good deterrents to intruders.Security are needed to protect data during their transmission, in last two decades multimedia data are increased on the internet, in fact ,in term network security is somewhat important, because all business, government and academic organizations interconnect their data processing equipment with a collection of interconnected networks. Many applications are available over the internet to secure overall important data. The networks are usually secured by anti key logger, cryptographic software, firewall, sandbox etc. Since it has been proven that attacker can always find a way to attack a network. These systems are known as Intrusion Detection System (IDS) and are placed inside the secured network, looking for potential threats in network traffic and or audit data recorded by host [1].Protocols are set of rules that governing how data is transferred, compressed and presented over networks. Network layer security is a main aspect of the internet base security mechanism [7] The network layers protocols generally used to send and receive messages in the form of packets to route them from source to destination. By using a routing algorithm and also perform fragmentation and reassembly, and report delivery errors However, new security requirements demand that even the lower level data units should be protected. With this view in mind network layer security mechanism have emerged and are being used quite extensively in real life. In network layer protocols are widely used. Besides Internet Protocol (IP),higher level protocols TCP, UDP, HTTP, and FTP all integrate with IP to provide additional capabilities. Similarly, lowerlevel Protocols like ARP and ICMP also co exist with IP. These higher level protocols interact more with applications like Web browsers while lowerlevel protocols interact with network adapters and other computer hardware. The following part of the paper provides more details on ARP protocol and its functional services. [1] 2.0 LITERATURE REVIEW Initially intruder attempts to break into an information system or performs an action not legally allowed; we refer to this activity as an intrusion [8] Intruders can be divided into two groups, external and internal. The former refers to those who do not have authorized access to the system and who attack by using various penetration techniques. The latter refers to those with access permission who wish to perform unauthorized activities. Intrusion techniques may include exploiting software bugs and system misconfigurations, password cracking, sniffing unsecured traffic, or exploiting the design flaw of specific protocols [8].An Intrusion Detection System is a system for detecting intrusions and reporting them accurately to the proper authority. Intrusion Detection Systems are usually specific to the operating system that they operate in and are an important tool in the overall implementation an organization\"s information security policy [8] which reflects an organization's statement by Mr.D.Y.Thorat International Journal of Engineering Research and Applications (IJERA) ISSN: 2248 9622 www.ijera.com Vol. 2, Issue5, SeptemberOctober 2012, pp.1490 1494 1491 P a g e defining the rules and practices to provide security, handle intrusions, and recover from damage caused by security breaches. There are two generally accepted categories of intrusion detection techniques: misuse detection and anomaly detection. Misuse detection refers to techniques that characterize known methods to penetrate a system. These penetrations are characterized as a ,pattern\" or a ,signature\" that the IDS looks for. The pattern/signature might be a static string or a set sequence of actions. System responses are based on identified penetrations. Anomaly detection refers to techniques that define and characterize normal or acceptable behaviours of the system (e.g. CPU usage, job execution time, system calls) Behaviours that deviate from the expected normal behaviour are considered intrusions [5] 3.0 ADDRESS RESOLUTION PROTOCOL (ARP) The ARP is a protocol in the network layer. The ARP associated with its physical address. On a typical physical network such as a LAN, each device on the link is identified by a physical or station address usually imprinted on the network interface card (NIC).The function of ARP is to map IPaddresses onto hosts hardware addresses within a local area network [2] As such, its correctness is essential to proper functioningof the network. However, otherprotocol within IP, ARP is subject to a range of serious and continuing security vulnerabilities.In a local area network, however, addresses for attached devices are 48 bits long[1] A table, usually called the ARP cache, is used to maintain a relation between each MAC address and its corresponding IP address. ARP supports the protocol rules for making this relation and providing address conversion in both directions. This is used to identify and monitor packet communication across the network. These parts of the work try to optimize and construct the ARP sequence to detect the Intrusion [1].The communication network consist of wireless and wire specification with LAN and wan architectures connected intranet, internet extranet to support the services for the faculties, scholars, and student. This network used for NETBIOS, Print server, file transfer protocol(FTP) Active Directory Services(DNS) PING ICMP, IP telephony (Internal),Wireless Fidelity, Bluetooth, Remote access(TELNET) VPN,Email(IMAP) SMTP, E Learning(Web server HTTP),etc. services. While supporting the above services with the network bandwidth, reply and its quality of services differ due to the protocols which are used for the service. To reach the large service utilization, existing services are observed based on its protocol in and between the networks. There are many protocols working over the network to support various requests and services. In this study we considered few services and its related protocol for the practical observation and analyse to construct the packet sequence to detect the intrusion.The Network architecture of academic network which connects two academic department and three nonacademic departments. This network provides educational management and Teachinglearning.It provides Services 2000 students and the faculties in the campus. This consists of LAN and the following technological configurations this academic network is framed as two clusters to provide the educational services. For the effective administration and maintenance of this network services, the classification and cluster made in the department level. In this study, the academic network structure and its laboratories setup data communication and transformation architecture is adopted [1] The network architecture constructed with modern technological equipment\"s such as ciscoswitches,cisco routers,Firewall CISCO ASA 5510, this also integrated with High end servers\" such as HP, IBM,and Xeon.SAN SWITCHA device that routes data between servers and disk arrays in a storage area network. Its\" 800 nodes are typically Conduit with UTP CAT 5, CAT 5E, CAT 6 and fiber Channel switch made up of fiber multimode channels. The established infrastructure integrated with wireless fidelity of various manufacturers. Video conferencing is supported for inter and intra conferencing facility in this network. There are many protocols are analysed for the intrusion detection process to frame the sequence generation. But in this paper we are going to discuss the common sequence formation of the ARP protocol. 4.0 WORKING ANALYSIS OF FUNCTIONAL ARP In the networking process, ahost, or a router/gateway, needs to find the physical address of the another host on its network.it sends an ARP query packet that includes the physical and IP addresses of the sender and the IP address of the receiver .since the sender does not know the physical address of the receiver the query broadcast over the network [1] Every host, or router/gateway on the network receives the processes the ARP query packet, but only the intended recipient recognizes its IP address and sends back a ARP response packet,", "author_names": [ "" ], "corpus_id": 15684857, "doc_id": "15684857", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Secure Arp Protocol For Intrusion Detection System Mr", "venue": "", "year": 2012 }, { "abstract": "Conservation and management programs use populations of sentinel taxa, such as stream associated amphibians, as indicator species due to their perceived sensitivity to environmental change. Estimating population size with traditional tools such as mark recapture estimators may be impractical for forestdwelling stream associated amphibians, many of which are cryptic and have low detection probabilities. In addition, sampling techniques can alter habitat conditions, particularly with repeat sampling, and compromise inferences about management impacts. We used simulated and empirical data and N mixture models to estimate detection probabilities and abundances for two amphibian genera, giant Dicamptodon and torrent Rhyacotriton salamanders, sampled with a less invasive approach than other methods. We surveyed forested headwater streams located in western Washington, USA, for salamanders 7 July 27 August 2008. We assessed model sensitivity to changes in animal abundance (5 and 15) and detection probability (0.05 0.5) as well as study design alternatives including number of sample plots (50 150) and number of sampling visits (2 4) We also evaluated the effects of stream temperature and stream order on detection probability using data collected from forested streams in Washington, USA. Precision of detection probability estimates improved as the number of plots and sampling occasions increased. Variability of estimated population sizes decreased with higher detection probability, although species abundance had little effect on precision of detection probability estimates. Detection probability estimated from empirical data ranged from 0.07 to 0.65 for giant salamanders and 0.06 0.67 for torrent salamanders. Giant salamander detection probability was positively associated with stream temperature regardless of stream order, and was higher in second and third order streams than first order streams. Detection probability for torrent salamanders varied with stream temperature, order, and the interaction of those covariates, with detection increasing with temperature for second and third order streams but showing a flat or decreasing trend for first order streams. N mixture models, paired with careful consideration of study design alternatives, can produce robust estimates of abundance and obviate the traditional reliance on indices of relative abundance for many rare and sensitive taxa. Use of a less invasive technique for sampling stream associated amphibians resulted in sufficient animal captures for suitable model performance. Our simulation results can inform study design and direct efficient allocation of field effort. 2012 Elsevier B.V. All rights reserved.", "author_names": [ "Aimee P Mcintyre", "Jay E Jones", "Eric M Lund", "Frithiof T Waterstrat", "Jack N Giovanini", "Steven D Duke", "Marc P Hayes", "Timothy Quinn", "Andrew J Kroll" ], "corpus_id": 84677483, "doc_id": "84677483", "n_citations": 12, "n_key_citations": 2, "score": 0, "title": "Empirical and simulation evaluations of an abundance estimator using unmarked individuals of cryptic forest dwelling taxa", "venue": "", "year": 2012 }, { "abstract": "Change detection An image enhancement technique that compares two images of same area from different time periods. Identical picture elements are eliminated leaving signature that have undergone change. As used here, the term change detection pertains to the visual process involved in first noticing a change. It denotes not only detection (the observer reporting on the existence of the change) but also identification (reporting what the change is) and also specifies localization (reporting where it is) Classification It is the process of classifying something according to shared qualities, some common characteristics and affinities. In supervised classification, it approaches the classification that is created and is based on all samples being created from domain (user) knowledge. This method require a significant number of pre labeled sample in order to determine accurate classifiers of an image where as unsupervised approaches to classification clutters data points together to produce the data sheet classifier. Study area It covers Industrial area Kundli which is located near NH1and between 28o53' 17\" N to 28o52' 3\" N and 77o 5'56\"E to 77o8'44\"E in Sonipat, Haryana. The study area is characterized by vegetal cover and industrial building between the year 2004 to 2012.", "author_names": [ "Harshita Singh", "Rohit Dahiya" ], "corpus_id": 130929947, "doc_id": "130929947", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Change detection and Classification of Industrial Area Kundli", "venue": "", "year": 2012 }, { "abstract": "Nowadays wireless technology plays an important role in public and personal communication. However, the growth of wireless networking has confused the traditional boundaries between trusted and un trusted networks. Wireless networks are subject to a variety of threats and attacks at present. An attacker has the ability to listen to all network traffic which becoming a potential intrusion. Intrusion of any kind may lead to a chaotic condition. In addition, improperly configured access points also contribute the risk to wireless network. To overcome this issue, a security solution that includes an intrusion detection and prevention system needs to be implemented. The intrusion detection system is one of the security defense tools for computer networks. In recent years this research has lacked in direction and focus. In this paper we present a survey on the recent progression of multi agent intrusion detection systems. We survey the existing types, techniques and architectures of Intrusion Detection Systems in the literature. Finally we outline the present research challenges and issues. In addition to examining the challenges of providing intrusion detection in this environment, this paper reviews current efforts to detect attacks against the ad hoc routing infrastructure, as well as detecting attacks directed against the mobile nodes. KeywordsIntrusion Detection System, DIDS, SNORT 1. Wireless Ad hoc Networks The proliferation of mobile computing and communication devices (e.g. cell phones, laptops, handheld digital devices, personal digital assistants, or wearable computers) is driving a revolutionary change in our information society. We are moving from the Personal Computer age (i.e. a one computing device per person) to the Ubiquitous Computing age in which a user utilizes, at the same time, several electronic platforms through which he can access all the required information whenever and wherever needed. The nature of ubiquitous devices makes wireless networks the easiest solution for their interconnection and, as a consequence, the wireless arena has been experiencing exponential growth in the past decade. Mobile users can use their cellular phone to check email, browse internet; travelers with portable computers can surf the internet from airports, railway stations, Starbucks and other public locations. Wireless ad hoc networks do not rely on a preexisting network infrastructure, and are characterized by wireless multi hop communication. Wireless ad hoc networks are vulnerable to additional threats above those for a fixed wired network, due to the wireless communication link and the dynamic and cooperative nature of the ad hoc routing infrastructure. The wireless nature of communication and lack of any security infrastructure raises several security problems. There are two different types of wireless networks: The easiest network topology is where each node is able to reach all the other nodes with a traditional radio relay system with a big range. There is no use of routing protocols with this kind of network because all nodes \"can see\" the others. The second kind uses also the radio relay system but each node has a smaller range, therefore one node has to use neighboring nodes to reach another node that is not within its transmission range. Then, the intermediate nodes are the routers. The focus is mainly on the security of the routing protocols used in the second kind of ad hoc network described above. Any routing protocol must encapsulate an essential set of security mechanisms. These are mechanisms that help prevent, detect, and respond to security attacks. There are five major security goals that need to be addressed in order to maintain a reliable and secure ad hoc network environment. They are mainly: Confidentiality: Protection of any information from being exposed to unintended entities. In ad hoc networks this is more difficult to achieve because intermediates nodes (that act as routers) receive the packets for other recipients, so they can easily eavesdrop the information being routed. Manish Kumar,Dr. M. Hanumanthappa,Dr. T. V. Suresh Kumar/ International Journal of Engineering Research and Applications (IJERA) ISSN: 2248 9622 www.ijera.com Vol. 2, Issue 1, Jan Feb 2012, pp.274 280 275 P a g e Availability: Services should be available whenever required. There should be an assurance of survivability despite a Denial of Service (DOS) attack. On physical and media access control layer attacker can use jamming techniques to interfere with communication on physical channel. On network layer the attacker can disrupt the routing protocol. On higher layers, the attacker could bring down high level services e.g. key management service. Authentication: Assurance that an entity of concern or the origin of a communication is what it claims to be or from. Without which an attacker would impersonate a node, thus gaining unauthorized access to resource and sensitive information and interfering with operation of other nodes. Integrity: Message being transmitted is never altered. Non repudiation: Ensures that sending and receiving parties can never deny ever sending or receiving the message. All the above security mechanisms must be implemented in any ad hoc networks so as to ensure the security of the transmissions along that network. Thus whenever considering any security issues with respect to a network, we always need to ensure that the above mentioned security goals have been put into effect and none (most) of them are flawed. Broadly there are two major categories of attacks when considering any network Attacks from external sources and attacks from within the network. The second attack is more severe and detection and correction is difficult. Routing protocol should be able to secure themselves against both of these attacks. As there is no infrastructure in mobile ad hoc networks, the nodes have to cooperate in order to communicate. Intentional non cooperation is mainly caused by two types of nodes: selfish ones that, e.g. want to save power and malicious nodes that are not primarily concerned with power saving but that are interested in attacking the network. Use of wireless links renders an ad hoc network susceptible to link attacks ranging from passive eavesdropping to active impersonation, message replay and message distortion. Nodes roaming freely in a hostile environment with relatively poor physical protection have non negligible probability of being compromised. Hence, we need to consider malicious attacks not only from outside but also from within the network from compromised nodes. Eavesdropping might give an attacker access to secret information thus violating confidentiality. Active attacks could range from deleting data, injecting erroneous messages; impersonate a node etc. thus violating availability, integrity, authentication and non repudiation. Most of the security measures surrounding ad hoc networks in general and their routing solutions are, as yet, incomplete and mostly inefficient. 2. Intrusion Detection in Wireless Ad hoc Networks Security mechanisms must be deployed in order to counter threats against wireless ad hoc networks. While cryptographic mechanisms provide protection against some types of attacks from external nodes, cryptography will not protect against malicious inside nodes, which already have the required cryptographic keys. Therefore, intrusion detection mechanisms are necessary to detect these Byzantine nodes. Intrusion Detection Systems (IDS) may be classified based on the data collection mechanism, as well as the technique used to detect events. While the requirement of intrusion detection for both fixed wired and wireless ad hoc networks are the same, wireless ad hoc networks impose additional challenges. In general, the effectiveness of solutions designed for fixed wired networks are limited for wireless ad hoc networks. 2.1. Classifications of IDS Two distinct types of intrusion detection systems exist. Pattern based intrusion detection system has the capability to identify all the known intrusions, while anomaly based intrusion detection mechanisms have the intelligence to identify and respond to new intrusions which are not known. IDS are further classified as Stand alone IDS, Distributed and Cooperative IDS, and Hierarchical IDS [22] Standalone IDS operates on each node independently to determine intrusions by monitoring the internal events which are recorded in the system logs. In distributed and cooperative IDS, every node participate in intrusion detection and response, while in hierarchical IDS, the cluster heads monitor all of its child nodes, and respond in case of intrusion is detected. 2.2. Components of IDS Broadly speaking, IDS has two main components [5] i.e. the features and the modeling algorithm. Features include attributes or measures which are mostly concern with the functionalities the IDS would provide. Algorithm is the core component and the efficiency and accuracy of detecting and responding intrusion is totally dependent on the underlying algorithm. IDS may have many components depend on the nature and characteristics of the network and possible intrusions. Most of the IDS have some common components such as: Monitoring Component, this is used for local events monitoring as well as neighbors monitoring. Intrusion database, which contains the records of recent misbehaviors and reputation value for the neighbors. Response component, which is used to respond in case of intrusion, is detected. The response may be to raise an alarm to alert the administrator or to Manish Kumar,Dr. M. Hanumanthappa,Dr. T. V. Suresh Kumar/ International Journal of Engineering Research and Applications (IJERA) ISSN: 2248 9622 www.ijera.com Vol. 2, Issue 1, Jan Feb 2012, pp.274 280 276 P a g e broadcast the information to its neighbor nodes about the misbehaving node. However, the components and the response nature of IDS are ma", "author_names": [ "Munendra Kumar", "M Hanumanthappa", "T V Suresh Kumar" ], "corpus_id": 14396188, "doc_id": "14396188", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "INTRUSION DETECTION SYSTEMS CHALLENGES FOR WIRELESS NETWORK", "venue": "", "year": 2012 }, { "abstract": "Objective: to identify the profile sociodemographic and academic graduate students in nursing. Method: a descriptive transversal study with a quantitative approach, conducted with nursing students from a public university of Rio Grande do Sul RS, Brazil. The population consisted of 130 academic students. Data were collected through a form, between April and May 2011, and then we created a database in Excel spreadsheet program, programs analyzed by Statistical Analysis System (SAS) and statistics. For continuous variables, we used measures of central tendency and dispersion, for categorical variables: relative frequency and absolute (n) The research project was approved by the Research Ethics Committee of UFSM under CAEE No 0380.0.243.00010. Results: There was a predominance of female students (86.92% aged between 20 and 24 years old (69.23% unmarried (86.92% without children (93.08% living with family (60% do not practice sport (70.77% perform leisure activity (68.46% participate in group research study (64.62% did not receive a paid scholarship (64.62% not work (93.08% do not have professional experience in healthcare (89.23% did not attend another college (97.69% are satisfied with the course (86.92% and thought to give up the same (34.62% Conclusion: knowledge of sociodemographic and academic of nursing students, allows us to understand the reality and the needs of, and assist the course coordinator and constitute an important tool to propose actions in interventional Education Program Course. Descriptors: nursing; nursing students; institutions of superior teaching. RESUMO Objetivo: identificar o perfil sociodemografico e academico de estudantes de graduacao em enfermagem. Metodo: estudo descritivo, transversal com abordagem quantitativa, realizado com discentes de enfermagem de uma universidade publica do Rio Grande do Sul RS, Brasil. A populacao foi constituida por 130 academicos. Os dados foram coletados por meio de um formulario, entre abril e maio de 2011; em seguida, foi constituido um banco de dados em planilha do Programa Excel, analisados pelos programas Statistical Analisys System (SAS) e estatistica. Para as variaveis continuas, foram utilizadas medidas de tendencia central e dispersao; para as variaveis categoricas: frequencia relativa e absoluta (n) O projeto de pesquisa teve a aprovacao do Comite de Etica em Pesquisa da UFSM sob o CAEE no 0380.0.243.000 10. Resultados: houve predominio de discentes do sexo feminino (86,92% com idade entre 20 e 24 anos (69,23% solteiros (86,92% sem filhos (93,08% residem com familiares (60% nao praticam esporte (70,77% realizam atividade de lazer (68,46% participam de grupo de pesquisa/estudo (64,62% nao recebem bolsa remunerada (64,62% nao trabalham (93,08% nao possuem experiencia profissional na area da saude (89,23% nao frequentaram outro curso superior (97,69% estao satisfeitos com o curso (86,92% e pensaram em desistir do mesmo (34,62% Conclusao: o conhecimento das caracteristicas sociodemograficas e academicas dos alunos de enfermagem, permite compreender a realidade e as necessidades desses, alem de auxiliar a coordenacao do curso e constituir se em uma importante ferramenta para proposicao de acoes interventivas no Projeto Pedagogico do Curso. Descritores: enfermagem; estudantes de enfermagem; instituicoes de ensino superior. RESUMEN Objetivo: identificar a los estudiantes graduados sociodemograficas y academicas de enfermeria. Metodo: estudio descriptivo transversal, con abordaje cuantitativo, realizado con estudiantes de enfermeria de una universidad publica de Rio Grande do SulRS, Brasil. La poblacion de estudio estuvo constituida por 130 estudiantes. Los datos fueron recolectados a traves de un formulario, entre abril y mayo de 2011, y entonces se creo una base de datos en el programa de hoja de calculo Excel, programas analizados por el Sistema de Analisis Estadistico (SAS) y las estadisticas. Para las variables continuas, se utilizaron medidas de tendencia central y dispersion, para las variables categoricas: frecuencia relativa y absoluta (n) El proyecto de investigacion fue aprobado por el Comite Etico de Investigacion de UFSM bajo CAEE No 0380.0.243.000 10. Resultados: se observo un predominio de estudiantes mujeres (86,92% con edades comprendidas entre los 20 y los 24 anos (69,23% solteros (86,92% sin hijos (93,08% viviendo con la familia (60% no practican deporte (70,77% realizar actividades de ocio (68,46% participar en el grupo de investigacion estudio (64,62% no recibio una beca pagada (64,62% no funciona (93,08% no tiene experiencia profesional en el sector sanitario (89,23% no asistir a otra universidad (97.69% estan satisfechos con el curso (86,92% y el pensamiento a renunciar a los mismos (34,62% Conclusion: el conocimiento de variables sociodemograficas y academicas de los estudiantes de enfermeria, nos permite comprender la realidad y las necesidades de los y ayudar al coordinador del curso y constituyen una herramienta importante para proponer acciones de intervencion en el Curso del Programa de Educacion. Descriptores: enfermeria; estudiantes de enfermeria; IES. Nurse, Master in Nursing Program by the Program of Post Graduation in Nursing/Federal University of Santa Maria/RS. Santa Maria (RS) Brazil. E mail: [email protected]; Nurse, Mastering in Nursing by the Program of Post Graduation in Nursing Federal University of Santa Maria/RS. Santa Maria (RS) Brazil. E mail: [email protected]; Nurse, Ph.D in Nursing by the College of Nursing Anna Nery, of the Federal University of Rio de Janeiro, Associate Professor of the Department of Nursing and Permanent Professor of the Post Graduation Program in Nursing, of the Federal University of Santa Maria/UFSM, Coordinator of the Graduation Course in Nursing CCS/Federal University of Santa Maria/RS. Santa Maria (RS) Brazil. E mail: [email protected]; Nurse, Ph.D in Nursing by the School of Nursing of the University of Sao Paulo, Associate Professor of the Department of Nursing of the Federal University of Santa Maria/RS. Santa Maria (RS) Brazil. E mail: [email protected] Article compiled from the dissertation Stress, Coping, Burnout, and Depressive Symptoms among nursing students Hardiness presented to the Graduate Program in Nursing, the Center for Health Sciences, Federal University of Santa Maria UFSM. Santa Maria (RS) Brazil. in 2012 ORIGINAL ARTICLE Freitas EO, Bublitz S, Neves ET et al. Sociodemographic and academic profile of. English/Portuguese J Nurs UFPE on line. 2012 Oct;6(10):2455 62 2456 DOI: 10.5205/reuol.3111 24934 1 LE.0610201217 ISSN: 1981 8963 The changes occurring in the political economy, technological and social, during the last years, have influenced changes in the health and education of future professionals who will work in this particular industry. In this sense, the training of nurses, was directed to a more critical and general education in order to adapt to the social reality and the new organization of the health sector. It is noteworthy that these changes have provided growth and enhancement of the profession and especially the recognition of users and managers of health services. 3 It is believed that this recognition is mainly due to professional training centers, which prepare students for that when nurses meet the demands required by the labor market. In this context, is the Undergraduate Nursing, Federal University of Santa Maria (UFSM) in Rio Grande do Sul, whose Political Pedagogical Project aims at training contemporary, contextual and dynamic, based on the inseparability of teaching, research and extension, which aims to train the generalist nurse, critical, able to work in all dimensions of care and health in various scenarios as a promoter of citizen's health, family and community. The graduate course in nursing, of UFSM, in the context of external evaluations in favor of quality, has been outstanding, with excellent assessment by the National Assessment of Higher Education (SINAES MEC) getting top marks in the National Survey of Student Performance (ENADE) and four in the overall concept, having been among the top five nursing courses in the country in 2011 and first in the Rio Grande do Sul in 2010, the course was selected for obtaining the quality seal of System ARCU SOUTH accreditation of undergraduate MERCOSUR, ongoing process. However, until then, had not been any study on the profile of nursing students of this institution, data essential to the ongoing process of assessment and curriculum restructuring that may contribute to the development of strategies that address the needs of students. Thus, with a view to the continuous improvement of training in Nursing Course UFSM, and believing that this becomes more appropriate in that the teacher knows and (re) meets the characteristics of learners, this study aims to: Identify the sociodemographic profile and academic graduate students in Nursing. This is a descriptive, exploratory, crosssectional quantitative approach, developed with the students of Nursing, Federal University of Santa Maria (UFSM) Rio Grande do Sul, Brazil. It included students from 1st to 8th semester, enrolled in Undergraduate Nursing, aged equal or over 18 years old. We excluded students who were not enrolled in vocational disciplines cycle (specific to nursing) and those who, during the period of data collection, would not complete the curriculum for exceeding the time limit training graduation (12 semesters) The completion of data collection took place in classrooms, at time previously scheduled with students and faculty and with consent of course coordinator. The students who were not in the classroom were subsequently searched and scheduled time for delivery of the questionnaire. The collection took place between April and May 2011 by means of a questionnaire for sociodemographic and academic o", "author_names": [ "Etiane de Oliveira Freitas", "Susan Bublitz", "Eliane Tastch Neves", "Laura de Azevedo Guido" ], "corpus_id": 74822086, "doc_id": "74822086", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Sociodemographic and academic profile of nursing students of a public university", "venue": "", "year": 2012 } ]

[ { "abstract": "Reducing the heat generated in traditional electronics is a chief motivation for the development of spin based electronics, called spintronics. Spin based transistors that do not strictly rely on the raising or lowering of electrostatic barriers can overcome scaling limits in charge based transistors. Spin transport in semiconductors might also lead to dissipation less information transfer with pure spin currents. Despite these thermodynamic advantages, little experimental literature exists on the thermal aspects of spin transport in solids. A recent and surprising exception was the discovery of the spin Seebeck effect, reported as a measurement of a redistribution of spins along the length of a sample of permalloy (NiFe) induced by a temperature gradient. This macroscopic spatial distribution of spins is, surprisingly, many orders of magnitude larger than the spin diffusion length, which has generated strong interest in the thermal aspects of spin transport. Here, the spin Seebeck effect is observed in a ferromagnetic semiconductor, GaMnAs, which allows flexible design of the magnetization directions, a larger spin polarization, and measurements across the magnetic phase transition. This effect is observed even in the absence of longitudinal charge transport. The spatial distribution of spin currents is maintained across electrical breaks, highlighting the local nature of this thermally driven effect.", "author_names": [ "Christopher M Jaworski", "Jianbo Yang", "Shawn Mack", "David D Awschalom", "Joseph P Heremans", "Robert C Myers" ], "corpus_id": 205404770, "doc_id": "205404770", "n_citations": 522, "n_key_citations": 9, "score": 0, "title": "Observation of the spin Seebeck effect in a ferromagnetic semiconductor.", "venue": "Nature materials", "year": 2010 }, { "abstract": "The generation of electric voltage by placing a conductor in a temperature gradient is called the Seebeck effect. Its efficiency is represented by the Seebeck coefficient, S, which is defined as the ratio of the generated electric voltage to the temperature difference, and is determined by the scattering rate and the density of the conduction electrons. The effect can be exploited, for example, in thermal electric power generators and for temperature sensing, by connecting two conductors with different Seebeck coefficients, a device called a thermocouple. Here we report the observation of the thermal generation of driving power, or voltage, for electron spin: the spin Seebeck effect. Using a recently developed spin detection technique that involves the spin Hall effect, we measure the spin voltage generated from a temperature gradient in a metallic magnet. This thermally induced spin voltage persists even at distances far from the sample ends, and spins can be extracted from every position on the magnet simply by attaching a metal. The spin Seebeck effect observed here is directly applicable to the production of spin voltage generators, which are crucial for driving spintronic devices. The spin Seebeck effect allows us to pass a pure spin current, a flow of electron spins without electric currents, over a long distance. These innovative capabilities will invigorate spintronics research.", "author_names": [ "Kazuhito Uchida", "S Takahashi", "Kazuya Harii", "Jun'ichi Ieda", "Wataru Koshibae", "Kazuya Ando", "Sadamichi Maekawa", "Eiji Saitoh" ], "corpus_id": 1680530, "doc_id": "1680530", "n_citations": 1275, "n_key_citations": 17, "score": 1, "title": "Observation of the spin Seebeck effect", "venue": "Nature", "year": 2008 }, { "abstract": "We report the experimental observation of the spin Seebeck effect in magnetite thin films. The signal observed at temperatures above the Verwey transition is a contribution from both the anomalous Nernst (ANE) and spin Seebeck (SSE) effects. The contribution from the ANE of the Fe3O4 layer to the SSE is found to be negligible due to the resistivity difference between Fe3O4 and Pt layers. Below the Verwey transition, the SSE is free from the ANE of the ferromagnetic layer and it is also found to dominate over the ANE due to magnetic proximity effect on the Pt layer.", "author_names": [ "Rafael Ramos", "Takashi Kikkawa", "Kazuhito Uchida", "Hiroto Adachi", "Irene Lucas", "Myriam H Aguirre", "Pedro Antonio Algarabel", "Luis Morellon", "Sadamichi Maekawa", "Eiji Saitoh", "Manuel Ricardo Ibarra" ], "corpus_id": 52226280, "doc_id": "52226280", "n_citations": 120, "n_key_citations": 1, "score": 0, "title": "Observation of the spin Seebeck effect in epitaxial Fe3O4 thin films", "venue": "", "year": 2013 }, { "abstract": "We have developed a vectorial type of measurement for the spin Seebeck effect (SSE) in epitaxial NiFe$_2$O$_4$ thin films which have been grown by pulsed laser deposition on MgGa$_2$O$_4$ (MGO) with (001) and (011) orientation as well as CoGa$_2$O$_4$ (011) (CGO) thus varying the lattice mismatch. We confirm that a large lattice mismatch leads to strain anisotropy in addition to the magnetocrystalline anisotropy in the thin films using vibrating sample magnetometry and ferromagnetic resonance measurements. Moreover, we show that the existence of a magnetic strain anisotropy in NiFe$_2$O$_4$ thin films significantly impacts the shape and magnitude of the magnetic field dependent SSE voltage loops. We further demonstrate that bidirectional field dependent SSE voltage curves can be utilized to reveal the complete magnetization reversal process, which establishes a new vectorial magnetometry technique based on a spin caloric effect.", "author_names": [ "Zhong Li", "Jan Krieft", "Amit Vikram Singh", "Sudhir Regmi", "Ankur Rastogi", "Abhishek Srivastava", "Zbigniew Galazka", "Tim Mewes", "Arunava Gupta", "Timo Kuschel" ], "corpus_id": 119067421, "doc_id": "119067421", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Vectorial observation of the spin Seebeck effect in epitaxial NiFe2O4 thin films with various magnetic anisotropy contributions", "venue": "Applied Physics Letters", "year": 2019 }, { "abstract": "", "author_names": [ "Ken-ichi Uchida", "Saburo Takahashi", "Kazuya Harii", "Jun'ichi Ieda", "Wataru Koshibae", "Kazuya Ando", "Sadamichi Maekawa", "Eiji Saitoh" ], "corpus_id": 197318521, "doc_id": "197318521", "n_citations": 99, "n_key_citations": 14, "score": 0, "title": "Observation of the Spin Seebeck Effect.", "venue": "", "year": 2009 }, { "abstract": "", "author_names": [ "I S Yoon", "Sangeun Cho", "Sh U Yuldashev" ], "corpus_id": 214544087, "doc_id": "214544087", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Observation of the Spin Seebeck Effect in Bi 2 Te 3 Topological Insulator without an External Magnetic Field", "venue": "", "year": 2020 }, { "abstract": "", "author_names": [ "Sergio M Rezende", "Jose Holanda", "O Alves Santos", "J B S Mendes", "Matheus Gomes", "R O Cunha", "R L Rodriguez-Suarez", "Antonio Azevedo" ], "corpus_id": 102680151, "doc_id": "102680151", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Spin current transport in an insulating antiferromagnet makes possible the observation of the spin Seebeck effect in permalloy separated from the anomalous Nernst effect", "venue": "", "year": 2018 }, { "abstract": "Understanding the transfer of spin angular momentum is essential in modern magnetism research. A model case is the generation of magnons in magnetic insulators by heating an adjacent metal film. Here, we reveal the initial steps of this spin Seebeck effect with <27 fs time resolution using terahertz spectroscopy on bilayers of ferrimagnetic yttrium iron garnet and platinum. Upon exciting the metal with an infrared laser pulse, a spin Seebeck current js arises on the same ~100 fs time scale on which the metal electrons thermalize. This observation highlights that efficient spin transfer critically relies on carrier multiplication and is driven by conduction electrons scattering off the metal insulator interface. Analytical modeling shows that the electrons' dynamics are almost instantaneously imprinted onto js because their spins have a correlation time of only ~4 fs and deflect the ferrimagnetic moments without inertia. Applications in material characterization, interface probing, spin noise spectroscopy and terahertz spin pumping emerge.Probing spin pumping in the terahertz regime allows one to reveal its initial elementary steps. Here, the authors show that the formation of the spin Seebeck current in YIG/Pt critically relies on hot thermalized metal electrons because they impinge on the metal insulator interface with maximum noise.", "author_names": [ "Tom S Seifert", "Samridh Jaiswal", "Joseph Barker", "Sebastian T Weber", "Ilya Razdolski", "Joel Cramer", "Oliver Gueckstock", "Sebastian F Maehrlein", "Lukas Nadvornik", "Shun Watanabe", "Chiara Ciccarelli", "Alexey A Melnikov", "Gerhard Jakob", "Markus Munzenberg", "Sebastian T B Goennenwein", "Georg Woltersdorf", "Baerbel Rethfeld", "Piet W Brouwer", "Martin Wolf", "Mathias Klaui", "Tobias Kampfrath" ], "corpus_id": 50767427, "doc_id": "50767427", "n_citations": 63, "n_key_citations": 1, "score": 0, "title": "Femtosecond formation dynamics of the spin Seebeck effect revealed by terahertz spectroscopy", "venue": "Nature Communications", "year": 2018 }, { "abstract": "Abstract Rhodium (Rh) is a 4d metal possessing a large spin orbit coupling strength and spin Hall conductivity with a very small magnetic susceptibility, implying an insignificant magnetic proximity effect (MPE) We report here the observation of longitudinal spin Seebeck effect (LSSE) using Rh as a normal metal. A Rh film was sputtered on nanometer thick YIG films of highly crystalline nature and extremely low magnetic damping to obtain Rh/YIG hybrid structure. A clear thermal voltage Vth (SSE voltage) was obtained when a temperature gradient was applied on the Rh/YIG hybrid. The Rh film showed a very weak anomalous Hall resistance and the magneto resistive testing clearly ruled out the magnetization of the Rh films via MPE. The anisotropic magnetoresistance (AMR) revealed a clear spin hall magnetoresistance (SMR) signal in Rh film implying a purely intrinsic spin current generation, free from any parasitic magnetic effects. The work can open a new window in the study of pure and uncontaminated spin current, generated in ferromagnetic insulators, using Rh as spin current detector.", "author_names": [ "Fida Mohmed", "Yuanhua Lin" ], "corpus_id": 104361055, "doc_id": "104361055", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "The observation of inherent spin Seebeck effect in Rh/YIG hybrid structure", "venue": "Current Applied Physics", "year": 2019 }, { "abstract": "Abstract We report on the observation of the spin Seebeck effect in Ni Zn ferrites slabs with different Zn concentration. All samples have a spinel structure confirmed by XRD and TEM. We fully characterize the magnetic properties by VSM and Mossbauer spectroscopy. Samples exhibit a nonmonotonic magnetization behavior depending on the structural inversion parameter, however we found a spin Seebeck response voltage of about 25.5 nV/K independent of the magnetization and the inversion degree.", "author_names": [ "J D Arboleda", "O Arnache", "Myriam H Aguirre", "Rafael Ramos", "Alberto Anadon", "Manuel Ricardo Ibarra" ], "corpus_id": 125405036, "doc_id": "125405036", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Evidence of the spin Seebeck effect in Ni Zn ferrites polycrystalline slabs", "venue": "", "year": 2018 } ]

[ { "abstract": "A significant broad bandwidth near shot noise limited intensity noise suppression of a single frequency fiber laser is demonstrated based on a semiconductor optical amplifier (SOA) with optoelectronic feedback. By exploiting the gain saturation effect of the SOA and the intensity feedback loop, a maximum noise suppression of over 50 dB around the relaxation oscillation frequencies and a suppression bandwidth of up to 50 MHz are obtained. The relative intensity noise of 150 dB/Hz in the frequency range from 0.8 kHz to 50 MHz is achieved, which approaches the shot noise limit. The obtained optical signal to noise ratio is more than 70 dB. This near shot noise limited laser source shows important implications for the advanced fields of high precision frequency stabilization, quantum key distribution, and gravitational wave detection.", "author_names": [ "Qilai Zhao", "Shanhui Xu", "Kaijun Zhou", "Changsheng Yang", "Can Li", "Zhouming Feng", "Mingying Peng", "Huaqiu Deng", "Zhongmin Yang" ], "corpus_id": 30745039, "doc_id": "30745039", "n_citations": 31, "n_key_citations": 0, "score": 0, "title": "Broad bandwidth near shot noise limited intensity noise suppression of a single frequency fiber laser.", "venue": "Optics letters", "year": 2016 }, { "abstract": "An all optical frequency and intensity noise suppression technique of a single frequency fiber laser is demonstrated. By exploiting the recursive noise reduction effect of a semiconductor optical amplifier (SOA) in a self injection locked fiber laser, the frequency and intensity noise of the laser are remarkably suppressed in a significantly wide frequency range. In addition to the linewidth suppression from 3.5 kHz to 700 Hz, the frequency noise has been reduced by ~25 dB. After suppression, the relative intensity noise (RIN) is within 5 dB of the shot noise limit at frequencies from 1.5 to 3 MHz, and the frequency range of the suppression reaches about 30 MHz. The relaxation oscillation peak is observed to shift to lower frequencies and is reduced by about 35 dB from 90 dB/Hz to 125 dB/Hz. It is believed that the achieved low noise makes the fiber laser a promising candidate in applications such as ultra long haul coherent optical communication and LIDAR.", "author_names": [ "Can Li", "Shanhui Xu", "Xiang Huang", "Yu Xiao", "Zhouming Feng", "Changsheng Yang", "Kaijun Zhou", "Wei Lin", "Jiulin Gan", "Zhongmin Yang" ], "corpus_id": 19329878, "doc_id": "19329878", "n_citations": 40, "n_key_citations": 0, "score": 0, "title": "All optical frequency and intensity noise suppression of single frequency fiber laser.", "venue": "Optics letters", "year": 2015 }, { "abstract": "The frequency and intensity noise of an Yb3+ doped single frequency distributed Bragg reflector (DBR) fiber laser are effectively reduced by a simple, passive optical feedback loop (POFL) which consists of only two optical couplers. The feedback loop, which has resonance with the high reflective grating of the DBR laser and relative long optical path compared to the DBR cavity, results in narrower linewidth and lower relative intensity noise (RIN) in the feedback signal. The RIN of relaxation oscillation is reduced by 20dB from 99.9dB/Hz 993 kHz to 119.4dB/Hz 192 kHz, and the frequency noise was suppressed at frequencies higher than 1 kHz, with a maximum reduction of about 30 dB from 10 kHz to 100 kHz, which results in a spectral linewidth compression from 3.96 kHz to 540 Hz. Even after one fiber amplification stage, the noise did not increase significantly, and a spectral linewidth well below 1 kHz were also achieved at output power of 10W.", "author_names": [ "Yubin Hou", "Qian Zhang", "Pu Wang" ], "corpus_id": 27534294, "doc_id": "27534294", "n_citations": 6, "n_key_citations": 0, "score": 1, "title": "Frequency and intensity noise suppression in Yb3+ doped single frequency fiber laser by a passive optical feedback loop.", "venue": "Optics express", "year": 2016 }, { "abstract": "The suppression of the low frequency intensity noise of a 1083 nm single frequency Yb3+ doped phosphate fiber laser is reported. The noise suppression scheme is to use a liquid crystal device as a variable attenuator to modulate the laser power to close to the desired level. The achieved long term (12 h) laser instability is less than 0.2% while the relative intensity noise (RIN) has been decreased to lower than 140 dB Hz 1 at frequencies from 250 Hz to 1 kHz. Moreover, the laser linewidth value remains the same as before suppression, while the degree of polarization (DOP) declined slightly.", "author_names": [ "Zhouming Feng", "Can Li", "Shanhui Xu", "Changsheng Yang", "Shupei Mo", "Dongdan Chen", "Mingying Peng", "Z M Yang" ], "corpus_id": 122330537, "doc_id": "122330537", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Suppression of the low frequency intensity noise of a single frequency Yb3+ doped phosphate fiber laser at 1083 nm", "venue": "", "year": 2014 }, { "abstract": "Significant suppression of the intensity noise of single frequency fiber laser is demonstrated with a cascading semiconductor optical amplifier (SOA) Based on the nonlinear amplification dynamics of the SOA, intensity noise reduction would take place in every transmission of the laser signal. By cascading two SOAs, a maximum noise suppression of 30 dB at around the resonant relaxation oscillation (RRO) frequency as well as a suppression bandwidth of up to 50 MHz is realized. Moreover, the RRO peak is restricted to a significant narrow frequency band, outside of which the laser noise approaches the noise floor of the measurement. The remarkable amplified spontaneous emission (ASE) introduced by the SOA is entirely filtered out with a fiber Bragg grating (FBG) Furthermore, no noticeable degradation of laser frequency noise has been observed.", "author_names": [ "Zhouming Feng", "Can Li", "Shanhui Xu", "Xiang Huang", "Changsheng Yang", "Kaijun Zhou", "Jiulin Gan", "Huaqiu Deng", "Zhongmin Yang" ], "corpus_id": 123760130, "doc_id": "123760130", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Significant intensity noise suppression of single frequency fiber laser via cascading semiconductor optical amplifier", "venue": "", "year": 2015 }, { "abstract": "Low intensity noise laser sources are a fundamental prerequisite for demanding fundamental research such as interferometric gravitational wave detection (GWD) [1] precision spectroscopy, LIDAR, and ultra cold atom/molecular optical lattices. Besides, high power lasers with low intensity noise also attract great interest in the industry applications. Direct pump current control is the simplest method to suppress the laser intensity noise. However, the modulation of high current multi mode pump diodes is not straightforward and achieving wide feedback control bandwidth beyond 200 kHz is challenging. For the laser sources used in GWD, the intensity noise could be suppressed down to 140 dBc/Hz (1 kHz 10 kHz) for an output power of 160 W. However, this approach requires a quite complex setup and the feedback bandwidth is limited to ~10 kHz [1]", "author_names": [ "Jian Zhao", "Germain Guiraud", "Florian Floissat", "Benoit Gouhier", "Sergio Rota-Rodrigo", "Nicholas Traynor", "Giorgio Santarelli" ], "corpus_id": 32044806, "doc_id": "32044806", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Gain dynamics and intensity noise suppression of a clad pumped Yb fiber amplifier", "venue": "2017 Conference on Lasers and Electro Optics Europe European Quantum Electronics Conference (CLEO/Europe EQEC)", "year": 2017 }, { "abstract": "The supermode noise in an actively mode locked fiber laser is suppressed for the first time by a so called pulse intensity feed forward technique. In this novel scheme, the optical pulse is firstly converted into an electronic signal, and then fed forward to a dual drive Mach Zehnder modulator (MZM) where the optical pulse is modulated by the reversed intensity profile of itself. In a 12.5 m long actively mode locked fiber ring laser experiment, the resulting power limiting shows a stable 10 GHz optical pulse train with a supermode suppression ratio larger than 81 dB. The phase noise and pulse to pulse timing jitter are below 141 dBc Hz 1 at 10 MHz and 22.1 fs, respectively. Compared with the conventional fiber nonlinearity based power limiting schemes, our proposal is compact and stable.", "author_names": [ "Kun Xu", "Ruixin Wang", "Yitang Dai", "Feifei Yin", "Jianqiang Li", "Yuefeng Ji", "Jintong Lin" ], "corpus_id": 123168060, "doc_id": "123168060", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Supermode noise suppression in an actively mode locked fiber laser with pulse intensity feed forward and a dual drive MZM", "venue": "", "year": 2013 }, { "abstract": "Abstract A feasible approach is theoretically demonstrated that suppresses the relative intensity noise (RIN) transfer from pump sources to the proposed Raman fiber laser (RFL) output at the first order Stokes line. The technique is accomplished by injecting a modulated signal at second order Stokes shift from the pump wavelength according to the monitored RFL output, which indirectly consumes the pump power fluctuations and results in suppression of the RIN transfer to the RFL output. With the RFL used as a pump source for co pumped Raman fiber amplifiers, further calculation results show that the Q factor penalty due to RIN transfer can be dramatically reduced.", "author_names": [ "Ying Wu Zhou", "Guoyong Sun" ], "corpus_id": 119524093, "doc_id": "119524093", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Suppression of pump to Stokes relative intensity noise transfer in Raman fiber laser by injection of modulated signal", "venue": "", "year": 2011 }, { "abstract": "We proposed an experimental investigation into the low frequency intensity noise characteristics of erbium doped distributed feedback fiber lasers (DFB FL) And the paper presented a simple self injection locking (SIL) configuration of DFB fiber laser to suppress the intensity noise. One of the reasons caused intensity noise is the existence of multimode in the DFB FL. SIL inhibits other modes while enhances dominant mode. Process of locking mode occurred in the DFB FL was measured in this paper. Comparison of the output powers with and without injection gives a sufficient proof, that it can realize the stable lasing by injecting the feedback laser into the cavity again. When the current of 980nm pump is about 175mA, the intensity noise is suppressed about 25 dB, and relaxation oscillation frequency decreased from 126.5 KHz to 60 KHz in this paper. The results have potential application in high sensitive fiber sensors and optical communication.", "author_names": [ "Yanjie Zhao", "Chang Wang", "Jiasheng Ni", "Jun Chang", "Pengpeng Wang", "Gangding Peng", "Tong-yu Liu", "Qingpu Wang" ], "corpus_id": 108567151, "doc_id": "108567151", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Study of DFB fiber laser intensity noise and its suppression", "venue": "Asia Pacific Optical Sensors Conference", "year": 2012 }, { "abstract": "We demonstrate suppression of relative intensity noise by ;25 dB for the primary output of a stimulated Brillouin fiber laser by operating above the threshold for second order stimulated Brillouin scattering.", "author_names": [ "Michael L Dennis", "Patrick T Callahan", "Michael C Gross" ], "corpus_id": 9229361, "doc_id": "9229361", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Suppression of relative intensity noise in a Brillouin fiber laser by operation above second order threshold", "venue": "2010 IEEE Photinic Society's 23rd Annual Meeting", "year": 2010 } ]

[ { "abstract": "Graphene has shown promising perspectives in optical active components due to the large active control of its permittivity variation. This paper systematically reviews the recent developments of graphene based optical modulators, including material property, different integration schemes, single layer graphene based modulator, multi layer and few layer graphene based modulators, corresponding figure of merits, wavelength/temperature tolerance, and graphene based fiber optic modulator. The different treatments for graphene's isotropic and anisotropic property were also discussed. The results showed graphene is an excellent material for enhancing silicon's weak modulation capability after it is integrated into the silicon platform, and has great potentials for complementary metal oxide semiconductor (CMOS) compatible optical devices, showing significant influence on optical interconnects in future integrated optoelectronic circuits.", "author_names": [ "Ran Hao", "Jiamin Jin", "Xinchang Wei", "Xiaofeng Jin", "Xianmin Zhang", "Erping Li" ], "corpus_id": 136547956, "doc_id": "136547956", "n_citations": 10, "n_key_citations": 0, "score": 1, "title": "Recent developments in graphene based optical modulators", "venue": "", "year": 2014 }, { "abstract": "Significant achievements have been made on the development of next generation filtration and separation membranes using graphene materials, as graphene based membranes can afford numerous novel mass transport properties that are not possible in state of art commercial membranes, making them promising in areas such as membrane separation, water desalination, proton conductors, energy storage and conversion, etc. The latest developments on understanding mass transport through graphene based membranes, including perfect graphene lattice, nanoporous graphene and graphene oxide membranes are reviewed here in relation to their potential applications. A summary and outlook is further provided on the opportunities and challenges in this arising field. The aspects discussed may enable researchers to better understand the mass transport mechanism and to optimize the synthesis of graphene based membranes toward large scale production for a wide range of applications.", "author_names": [ "Pengzhan Sun", "Kunlin Wang", "Hongwei Zhu" ], "corpus_id": 205262327, "doc_id": "205262327", "n_citations": 373, "n_key_citations": 4, "score": 0, "title": "Recent Developments in Graphene Based Membranes: Structure, Mass Transport Mechanism and Potential Applications.", "venue": "Advanced materials", "year": 2016 }, { "abstract": "DOI: 10.1002/admt.201700248 intelligence, healthcare monitoring, artificial prosthesis, and human machine interaction electronics.[1 4] Human skin, served as the largest sensory organ in human body, can help us communicate with surroundings such as the contacted pressures, changed temperatures, shapes, and textures of touched objects, via the specialized sense receptors.[5,6] For an intact haptic system, the collected information will be sent to the central nervous systems for comprehending and processing the meaning of the received information, and then our body will be guided to respond to the physical contact successfully. To imitate the sophisticated perception of human skin, various kinds of functional electronic devices which can sense and distinguish external physical, chemical, and biological signals simultaneously are integrated in a flexible or elastic system likes human skin. The functional electronic devices including pressure sensor, temperature sensor, and humidity sensor[7 9] have the ability to transfer the generated information from physical signals into electrical signals that electronic devices can recognize.[10 12] However, there remains enormous challenges to construct E skins with multimodal detection, fleet response, high sensitivity and resolution, even though much research has been reported on the imitation of human skin behaviors recently. The rise of E skins in early years may be resulted from the inspiration of science fiction and movies, which builds a bridge between virtual imagination and scientific reality. Since a prosthetic hand with tactile feedback was demonstrated by Clippinger et al. in 1974,[13] several studies have been followed to explore the potential application of tactile bionics.[14 16] Especially, flexible electronics achieved significant progress which served as a foundation to construct E skins, due to the particular importance of mechanical compliance and highly sensitive characteristics in mimicking human skin.[17 21] For examples, Rogers and co workers developed flexible electronics technologies to transfer traditional Si electronic devices onto 100 nm ultrathin films connected by stretchable interconnects.[22,23] Someya and co workers integrated a large scale organic fieldeffect transistors (FETs) based on flexible pentacene which showed excellent pressure sensitivity.[24] Bao and coworkers developed novel self healing and mechanical force sensing E skins with microstructured elastomeric dielectrics.[25 27] In addition, piezoresistive, capacitive, and piezoelectric sensors are deemed as three major transduction mechanisms for the Human skin, the largest organ of human body, can perceive tactile sensations, temperature, humidity, and other complex environmental stimulations. To mimic the capabilities of human skin, graphene provides great potential in building wearable electronic skins (E skins) which hold broad applications in advanced robotics, healthcare monitoring, artificial intelligence, human machine interfaces, etc. Herein, the recent progress in flexible tactile sensors and E skins based on graphene material is presented. A brief introduction of the main approaches to prepare graphene nanosheets is provided. The main developments on the functions and mechanisms of bionic functional devices in E skins including tactile sensors, temperature sensors, and humidity sensors are then highlighted. The current and future applications for graphenebased E skins, such as multifunctional biomimetic E skins, healthcare monitoring, and interactive human machine interface, are also described. Finally, the existing challenges and future development trends for graphenebased E skins are discussed.", "author_names": [ "Shuai Chen", "Kai Jiang", "Zheng Lou", "Di Chen", "Guozhen Shen" ], "corpus_id": 139758099, "doc_id": "139758099", "n_citations": 78, "n_key_citations": 1, "score": 0, "title": "Recent Developments in Graphene Based Tactile Sensors and E Skins", "venue": "", "year": 2018 }, { "abstract": "Optical modulators (OMs) are a key device in modern optical systems. Due to its unique optical properties, graphene has been recently utilized in the fabrication of optical modulators, which promise high performance such as broadband response, high modulation speed, and high modulation depth. In this paper, the latest experimental and theoretical demonstrations of graphene optical modulators (GOMs) with different structures and functions are reviewed. Particularly, the principles of electro optical and all optical modulators are illustrated. Additionally, the limitation of GOMs and possible methods to improve performance and practicability are discussed. At last, graphene terahertz modulators (GTMs) are introduced.", "author_names": [ "Siyuan Luo", "Yanan Wang", "Xin Tong", "Zhiming M Wang" ], "corpus_id": 17779898, "doc_id": "17779898", "n_citations": 34, "n_key_citations": 0, "score": 0, "title": "Graphene based optical modulators", "venue": "Nanoscale Research Letters", "year": 2015 }, { "abstract": "The optical loss of graphene can be tuned by shifting its Fermi level. We demonstrated that this tuning can be used for in a high speed optical modulator at telecommunication wavelength.", "author_names": [ "Ming Liu", "Xiang Zhang" ], "corpus_id": 35503327, "doc_id": "35503327", "n_citations": 55, "n_key_citations": 0, "score": 0, "title": "Graphene based optical modulators", "venue": "OFC/NFOEC", "year": 2012 }, { "abstract": "Tiny active components will enable a new generation of integrated photonics for communications and sensing. This paper discusses highlights from ongoing programs that seek to reduce the footprint of optical modulators using strong light matter interaction.", "author_names": [ "Gordon Arthur Keeler" ], "corpus_id": 49183579, "doc_id": "49183579", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Nanoscale Optical Modulators: Application Drivers and Recent Developments", "venue": "2018 Optical Fiber Communications Conference and Exposition (OFC)", "year": 2018 }, { "abstract": "Abstract The majority of the most successful optical modulators in silicon demonstrated in recent years operate via the plasma dispersion effect and are more specifically based upon free carrier depletion in a silicon rib waveguide. In this work we overview the different types of free carrier depletion type optical modulators in silicon. A summary of some recent example devices for each configuration is then presented together with the performance that they have achieved. Finally an insight into some current research trends involving silicon based optical modulators is provided including integration, operation in the mid infrared wavelength range and application in short and long haul data transmission links.", "author_names": [ "Graham T Reed", "Goran Z Mashanovich", "Frederic Y Gardes", "Milos S Nedeljkovic", "Youfang Hu", "David J Thomson", "Ke Li", "Peter Wilson", "Shen-Wen Chen", "Shawn S H Hsu" ], "corpus_id": 51998037, "doc_id": "51998037", "n_citations": 162, "n_key_citations": 5, "score": 0, "title": "Recent breakthroughs in carrier depletion based silicon optical modulators", "venue": "", "year": 2013 }, { "abstract": "Optical modulators are commonly used in communication and information technology to control intensity, phase, or polarization of light. Electro optic, electroabsorption, and acousto optic modulators based on semiconductors and compound semiconductors have been used to control the intensity of light. Because of gate tunable optical properties, graphene introduces new potentials for optical modulators. The operation wavelength of graphene based modulators, however, is limited to infrared wavelengths due to inefficient gating schemes. Here, we report a broadband optical modulator based on graphene supercapacitors formed by graphene electrodes and electrolyte medium. The transparent supercapacitor structure allows us to modulate optical transmission over a broad range of wavelengths from 450 nm to 2 mm under ambient conditions. We also provide various device geometries including multilayer graphene electrodes and reflection type device geometries that provide modulation of 35% The graphene supercapacitor structure together with the high modulation efficiency can enable various active devices ranging from plasmonics to optoelectronics.", "author_names": [ "Emre O Polat", "Coskun Kocabas" ], "corpus_id": 14960475, "doc_id": "14960475", "n_citations": 148, "n_key_citations": 0, "score": 0, "title": "Broadband optical modulators based on graphene supercapacitors.", "venue": "Nano letters", "year": 2013 }, { "abstract": "Abstract Graphene, a monolayer of graphite sheet consisting of sp2 hybridized carbon atoms covalently bonded to three other atoms (discovered in 2004) has recently attracted the attention of chemical sensor researchers owing to its unprecedented structural, mechanical and electrical properties. Excellent mechanical strength (Young modulus ~0.05 TPa) potentiality of ultrafast electron transport (highest mobility ~200,000 cm 2 /V s) along with the best surface to volume ratio has opened up the opportunity to use the material for future gas and vapor sensors with ultra fast speed and long term durability. Since it is a two dimensional material, every atom of graphene may be considered a surface atom and as a result every atom site may be involved in the gas interactions. This feature of graphene can eventually be responsible for its ultra sensitive sensor response with the lowest detection capability approaching even a single molecule. Further, the ease of functionalization of the material either by chemical means (absorption of many molecules like oxygen or hydrogen) or by application of voltage or pressure, facilitates bandgap engineering which in turn may lead to a possible solution to the selectivity issues, the perennial problems of chemical sensors. In this review, the latest advancement and new perspectives of graphene based gas and vapor sensors have been discussed critically.", "author_names": [ "S Basu", "Partha Bhattacharyya" ], "corpus_id": 93210482, "doc_id": "93210482", "n_citations": 524, "n_key_citations": 10, "score": 0, "title": "Recent developments on graphene and graphene oxide based solid state gas sensors", "venue": "", "year": 2012 }, { "abstract": "Research and development in graphene synthesis has been rapidly growing in the past few years because of its extraordinary physical, mechanical, thermal, electrical and optical properties. Graphene flakes, one of the most popular forms of graphene, can be used for many applications such as conductive inks, nanofluids, supercapacitors, composites, etc. Synthesis of graphene flakes is indeed a path to reach large scale production even if the cost of production and efficiency are required to be further improved. This review sheds light on the recent advancements of graphene flake synthesis and it gives a comprehensive analysis of the synthesis methods. Keys for further improvements are proposed based on the mechanisms involved in the graphene flake formation.", "author_names": [ "Muhammad Izhar Kairi", "Sebastian Dayou", "Nurul Izni Kairi", "Suriani Abu Bakar", "Brigitte Vigolo", "Abdul Rahman Mohamed" ], "corpus_id": 105127935, "doc_id": "105127935", "n_citations": 35, "n_key_citations": 0, "score": 0, "title": "Toward high production of graphene flakes a review on recent developments in their synthesis methods and scalability", "venue": "", "year": 2018 } ]

[ { "abstract": "The energy distribution profile of the interface states (N\"s\"s) and their relaxation time @t) and capture cross section @s\"p) of metal insulator semiconductor (Al/SiO\"2/p Si) Schottky diodes have been investigated by using the high low frequency capacitance and conductance methods. The capacitance voltage (C V) and conductance voltage (G/@w V) characteristics of these devices were investigated by considering series resistance (R\"s) effects in a wide frequency range (5kHz 1MHz. It is shown that the capacitance of the Al/SiO\"2/p Si Schottky diode decreases with increasing frequency. The increase in capacitance especially at low frequencies results form the presence of interface states at Si/SiO\"2 interface. The energy distributions of the interface states and their relaxation time have been determined in the energy range of (0.362 E\"v) (0.512 E\"v)eV by taking into account the surface potential as a function of applied bias obtained from the measurable C V curve (500Hz) at the lowest frequency. The values of the interface state density (N\"s\"s) ranges from 2.34x10^1^2 to 2.91x 10^1^2eV^ ^1/cm^2, and the relaxation time @t) ranges from 1.05x10^ ^6 to 1.58x10^ ^4s, showing an exponential rise with bias from the top of the valance band towards the mid gap.", "author_names": [ "Semsettin Altindal", "Halide Esra Kanbur", "Ibrahim Yucedag", "Adem Tataroglu" ], "corpus_id": 98549366, "doc_id": "98549366", "n_citations": 62, "n_key_citations": 1, "score": 1, "title": "On the energy distribution of interface states and their relaxation time and capture cross section profiles in Al/SiO2/p Si (MIS) Schottky diodes", "venue": "", "year": 2008 }, { "abstract": "A modified form of deep level transient spectroscopy (DLTS) has been employed to perform energy resolved measurements of Si SiO2 interface states. Decreasing the height of the trap filling pulse from the order of volts, as in the usual DLTS procedure, to tens of millivolts allows trap filling measurements to be made, rendering possible the use of Shockley Read Hall theory to show that the degeneracy factor of interface states is around unity. The energy dependence of the capture cross section in the upper band gap is also calculated from Shockley Read Hall theory and is contrasted for oxidation ambients with and without added HCl.", "author_names": [ "Wendell D Eades", "Richard M Swanson" ], "corpus_id": 95136956, "doc_id": "95136956", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "Determination of the capture cross section and degeneracy factor of Si SiO2 interface states", "venue": "", "year": 1984 }, { "abstract": "P/sub b/ centers dominate radiation induced interface defects. On the (100) Si/SiO/sub 2/ interface, the P/sub b0/ center dominates radiation damage, but another center, the P/sub b1/ plays a secondary role. Neither the electronic density of states nor the capture cross section of this center are well established. This study provides information about both the density of states and capture cross section of P/sub b1/ The study also shows that some refinement is required in techniques utilized to separate interface trap space charge from space charge in the oxide.", "author_names": [ "Patrick M Lenahan", "N A Bohna", "J P Campbell" ], "corpus_id": 122799065, "doc_id": "122799065", "n_citations": 20, "n_key_citations": 2, "score": 0, "title": "Radiation induced interface traps in MOS devices: capture cross section and density of states of P/sub b1/ silicon dangling bond centers", "venue": "", "year": 2002 }, { "abstract": "The evolution of the capture cross section of the Si SiO2 interface states is analyzed when metal oxide semiconductor capacitors are stressed by Fowler Nordheim injection of electrons from the n type substrate. The capture cross sections of the energy distribution of the states are measured by a trap filling method using deep level transient spectroscopy. We found that the capture cross sections of near midgap states increase by a factor 10, while they remain unchanged for the states localized near the conduction band edge. The capture cross sections are temperature dependent and their associated activation energies increase with the stress from 30 to 100 meV. The exponential prefactor in the temperature dependence law of the capture cross section is increased from 10 16 to 10 14 cm2 and we suggest that the Fowler Nordheim degradation induces new interface states of donor type in the upper part of the silicon band gap.", "author_names": [ "Dominique Vuillaume", "Rachid Bouchakour", "M Jourdain", "Jacques C Bourgoin" ], "corpus_id": 98735306, "doc_id": "98735306", "n_citations": 16, "n_key_citations": 0, "score": 0, "title": "Capture cross section of Si SiO2 interface states generated during electron injection", "venue": "", "year": 1989 }, { "abstract": "A modified transient capacitance technique is introduced which is capable of characterizing continuously distributed semiconductor/insulator interface states. Using this technique, Si/SiO2 interface states located in the upper half of the Si bandgap have been studied in n type MOS structures. In agreement with previous reports, it was found that the interface state density continuously increase towards the conduction band edge. The interface state density close to mid gap was about 1010 eV 1 cm 2. For the first time, it was experimentally shown that the electron capture cross section, sn, of the interface states located in the upper half of the bandgap is thermally activated, i.e. described by the formula sn so exp( DE/kT) where so?3x10 17 cm2 is independent of temperature and the energy location of the interface states. The observed decrease of the activation energy DE(10 40 meV in the energy range 0.3 0.1 eV below the conduction band) The observed interface states are shown to be indentical with th.", "author_names": [ "Emil Kamieniecki", "N S Gomma", "Agnieszka Kloc", "Ryszard Nitecki" ], "corpus_id": 96662782, "doc_id": "96662782", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Transient capacitance spectroscopy of semiconductor/insulator interface states: Thermally activated capture cross section of Si/SiO2 interface states", "venue": "", "year": 1981 }, { "abstract": "The capture cross section of interface states induced by Fowler Nordheim tunneling electron injection in (100) n and p Si metal/oxide/semiconductor (MOS) capacitors has been measured as a function of interface state density by means of the ac conductance method. In n Si MOS capacitors two interface states are generated in the upper half of the Si gap, while in p Si MOS capacitors only one interface state is observed in the lower half of the gap. The capture cross section for electrons (upper half of the gap) and for holes (lower half of the gap) tends to decrease when the interface state densities exceed about 1.5x1011 cm 2eV 1. This behavior is explained by taking the occurrence of additional tunneling to defect states in the oxide into account. Moreover, the difference in the slopes of the descending characteristics of electron and hole capture cross sections is used to estimate the effective mass ratio of an electron and a hole in the SiO2 gap.", "author_names": [ "Masataka Inoue", "Akihiro Shimada", "Junji Shirafuji" ], "corpus_id": 95757900, "doc_id": "95757900", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Capture Cross Section of Electric Stress Induced Interface States in (100) Si Metal/Oxide/Semiconductor Capacitors", "venue": "", "year": 1996 }, { "abstract": "The interfacial properties between silicon and hafnium oxide (HfO2) are explored by the gated diode method and the subthreshold measurement. The density of interface trapped charges, the current induced by surface defect centers, the surface recombination velocity, and the surface state capture cross section are obtained in this work. Among the interfacial properties, the surface state capture cross section is approximately constant even if the postdeposition annealing condition is changed. This effective capture cross section of surface states is about 2.4 x 10 15 cm2, which may be an inherent nature in the HfO2/Si interface.", "author_names": [ "Fu-Chien Chiu" ], "corpus_id": 54770529, "doc_id": "54770529", "n_citations": 4, "n_key_citations": 1, "score": 0, "title": "Surface State Capture Cross Section at the Interface between Silicon and Hafnium Oxide", "venue": "", "year": 2013 }, { "abstract": "Abstract The capacitance and conductance of a metal nitride oxide semiconductor (MNOS) capacitor was measured as a function of voltage at various frequencies between 10 Hz and 200 kHz using a \"lock in\" amplifier. The capacitance as a function of voltage was also measured at a frequency of 1 MHz as well as under quasi static conditions. All the measurements were made at a temperature of 298degK. The high frequency C V measurements were used to establish the relation between the surface potential and gate voltage. The experimental data was analysed in terms of the theoretical models of Lehovec and of Deuling et al. to determine the energy density distribution of the interface states. The interface states density calculated from the quasi static capacitance measurements agreed with those obtained from the low frequency capacitance results analysed in terms of Lehovec's model. However, in the energy range between 0.5 and 0.9 eV, the vlaues of the interface states energy density calculated from fitting the conductance data to the model of Deuling et al. differ from those obtained by the other two methods by as much as a factor of two due to the high density of interface states in the MNOS device. The analysis of conductance data also furnished the values of electron capture cross section which decreases approximately exponentially with interface states energy, varying from 10 13 cm 2 at 0.4 eV to 10 19 cm 2 at 0.86 eV.", "author_names": [ "A Singh", "J G Simmons" ], "corpus_id": 97077133, "doc_id": "97077133", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Determination of energy density distribution and capture cross section of interface states in the metal nitride oxide semiconductor (MNOS) structure", "venue": "", "year": 1982 }, { "abstract": "We employed a high temperature conductance method to investigate the interface state properties of the Al2O3/B doped diamond MOS structure by considering the surface potential fluctuation. Based on Gaussian approximation of Nicollian's model and Brew's graphical approach, we analyzed the frequency dependent characteristics of parallel conductance (Gp/o f) at various gate voltages and extracted the energy distribution of interface state density (Dit) capture cross section (sp) time constant (tit) and the standard deviation of surface potential fluctuation (ss) The Dit extracted by the conductance method exhibited good agreement with that by the high low method, whereas there exist large errors when surface potential fluctuation was not considered by using the conductance method. The capture cross section extracted by the conductance method was on the order of 10 17 cm2. From the energy dependence of the interface state time constant, the hole capture and emission follow the Shockley Read Hall statistics. ss decreases with the energy position away from the valence band edge (Ev) of diamond, indicating that donor like traps are distributed in the Ev side of diamond.", "author_names": [ "Xufang Zhang", "Tsubasa Matsumoto", "Ukyo Sakurai", "Toshiharu Makino", "Masahiko Ogura", "Mitsuru Sometani", "Satoshi Yamasaki", "Christoph E Nebel", "Takao Inokuma", "Norio Tokuda" ], "corpus_id": 225313224, "doc_id": "225313224", "n_citations": 5, "n_key_citations": 1, "score": 0, "title": "Insight into Al2O3/B doped diamond interface states with high temperature conductance method", "venue": "", "year": 2020 }, { "abstract": "Au/graphene oxide (GO) doped PrBaCoO nanoceramic/n Si capacitors were fabricated and their admittance measurements were carried out between 1 kHz and 1 MHz at room temperature. Experimental results showed that the capacitance (C) and conductance (G/w) values are strong functions of frequency and applied bias voltage. C V plot revealed two distinctive peaks at low frequencies which are located at about 0 and 2 V, such that the first peak disappears towards high frequencies. The energy density distribution profile of the interface/surface states (Dit/Nss) and their relaxation time (t) and capture cross section (sp) of the sample were obtained by using the admittance method. In addition, the voltage dependent profile of Nss and resistance were obtained by using low high frequency capacitance and Nicollian Brews method, respectively, and they also reveal two distinctive peaks, respectively. Two peaks' behavior in the forward bias C V, Nss V and Ri V plots confirmed the existence of two different localized regions of Nss between Si and interfacial layer. The series resistance (Rs) of the device decreased with increasing frequency from 175 O at 1 kHz to 72 O at 1 MHz. As a result, the mean value of Dit was found about 5 x 1013 eV 1 cm 2 which is reasonable for an electronic device.", "author_names": [ "Selcuk Demirezen", "Ahmet Kaya", "Semsettin Altindal", "I Uslu" ], "corpus_id": 135971481, "doc_id": "135971481", "n_citations": 10, "n_key_citations": 1, "score": 0, "title": "The energy density distribution profile of interface traps and their relaxation times and capture cross sections of Au/GO doped PrBaCoO nanoceramic/n Si capacitors at room temperature", "venue": "Polymer Bulletin", "year": 2017 } ]

[ { "abstract": "The basic diode charge control model used in SPICE is extended to include reverse recovery. The model is derived from the semiconductor charge transport equations. The diode charge transport equations are simplified using the lumped charged concept of Linvill, and the model is demonstrated on the Saber simulator for simple inductive and resistive load circuits. The two model parameters, diode lifetime and diffusion transit time, can easily be determined from a switching waveform.", "author_names": [ "Peter O Lauritzen", "C L Ma" ], "corpus_id": 110290064, "doc_id": "110290064", "n_citations": 211, "n_key_citations": 6, "score": 1, "title": "A simple diode model with reverse recovery", "venue": "", "year": 1991 }, { "abstract": "The diode model presented is a simplified physical model for a high voltage p i n structure operating in high level injection, as is typical for most power diodes. The model is an extension of the basic charge control diode model using the lumped charge concept. The equations for both forward and reverse recovery as well as the emitter recombination are derived from simplified semiconductor charge transport equations. The complete model requires only seven simple equations and three additional device parameters beyond the generic SPICE diode model.", "author_names": [ "C L Ma", "Peter O Lauritzen" ], "corpus_id": 110067390, "doc_id": "110067390", "n_citations": 105, "n_key_citations": 3, "score": 0, "title": "A simple power diode model with forward and reverse recovery", "venue": "", "year": 1991 }, { "abstract": "The diode model presented is a simplified physical model for a high voltage p i n structure operating in high level injection, as is typical for most power diodes. The model is an extension of the basic charge control diode model using the lumped charge concept. The equations for both forward and reverse recovery as well as the emitter recombination are derived from simplified semiconductor charge transport equations. The complete model requires only seven simple equations and three additional device parameters beyond the generic SPICE diode model.<ETX>", "author_names": [ "Cliff L Ma", "Peter O Lauritzen" ], "corpus_id": 195841057, "doc_id": "195841057", "n_citations": 65, "n_key_citations": 5, "score": 0, "title": "A simple power diode model with forward and reverse recovery", "venue": "PESC '91 Record 22nd Annual IEEE Power Electronics Specialists Conference", "year": 1991 }, { "abstract": "In the quest for higher power density in switching converters, the use of SiC MOSFETs provides increased switching speed, which allows higher switching frequencies and smaller filtering elements. In order to accurately estimate switching losses in these fast high voltage devices, a detailed analytical loss model considering parasitic effects and parasitic elements is required. In this paper, a simple and accurate analytical loss model is presented which considers the device junction capacitances, parasitic inductances and reverse recovery of the high voltage SiC MOSFET body diode. The reverse recovery time is calculated and used in the model. The proposed model provides easy to use closed form mathematical equations and gives insight into the switching process and the parameters that affect it. Analytical equations are validated by experimental results.", "author_names": [ "Soheila Eskandari", "Kang Peng", "Bo Tian", "Enrico Santi" ], "corpus_id": 54452511, "doc_id": "54452511", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Accurate Analytical Switching Loss Model for High Voltage SiC MOSFETs Includes Parasitics and Body Diode Reverse Recovery Effects", "venue": "2018 IEEE Energy Conversion Congress and Exposition (ECCE)", "year": 2018 }, { "abstract": "The basic diode chargecontrol model used in SPICE is extended by employing the lumped charge concept of Linvill to derive a set of model equations from simplified device physics. Both forward and reverse recovery phenomena are included as well as emitter recombination. The complete model requires only 7 relative simple equations and three additional device parameters beyond the generic SPICE diode model. +t", "author_names": [ "Cliff L Ma" ], "corpus_id": 228717601, "doc_id": "228717601", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "A SIMPLE POWER DIODE MODEL WITH FORWARD AND REVERSE RECOVERY", "venue": "", "year": 2004 }, { "abstract": "Super junction technology has pushed the silicon limits to new heights. The CoolMOS/spl trade/ device is based on the super junction technology and provides high on state conductivity with ultra fast switching speed. However, the dynamic behavior of the intrinsic body diode may limit its usage in converter topologies where the body junction diode conducts. In this paper, we report on the static blocking and reverse recovery charge dynamics of the CoolMOS body junction diode. An explanation of the diode reverse recovery mechanism is provided and a model for its charge dynamics is presented and validated with the measured results.", "author_names": [ "Rajni K Burra", "Krishna Shenai" ], "corpus_id": 70524739, "doc_id": "70524739", "n_citations": 17, "n_key_citations": 1, "score": 0, "title": "CoolMOS integral diode: a simple analytical reverse recovery model", "venue": "IEEE 34th Annual Conference on Power Electronics Specialist, 2003. PESC '03.", "year": 2003 }, { "abstract": "A practical parameter extraction method for physics based lumped charge silicon carbide (SiC) merged PiN Schottky (MPS) diode model is presented. The physical parameters of a device model are necessary for accurate simulation but are usually not provided as these parameters are the core business profits of the manufacturers. The values of SiC MPS diode parameters are often based on assumptions or given in a wide range, thus the accuracy of the model simulation is compromised and the application of the model is also limited. The proposed method includes semiconductor physical and structural parameters and only some basic experiments are needed, such as reverse recovery and static characteristic experiments. Based on the lumped charge SiC MPS diode model, reasonable assumptions are used and simple mathematical formulas are derived for the extraction of the parameters. Finally, the method is validated by two different SiC MPS diodes from CREE and CETC having the ratings of 1200 V/300 A and 3300 V/60 A.", "author_names": [ "Fei Xiao", "Yifei Luo", "Yaoqiang Duan" ], "corpus_id": 225765274, "doc_id": "225765274", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Parameter extraction method for a physics based lumped charge SiC MPS diode model", "venue": "", "year": 2020 }, { "abstract": "Abstract A new numerical reverse recovery model of silicon pin diode is proposed by the approximation of the reverse recovery waveform as a simple shape. This is the first model to calculate the reverse recovery characteristics using numerical equations without adjusted by fitting equations and fitting parameters. In order to verify the validity and the accuracy of the numerical model, the calculation result from the model is verified through the device simulation result.", "author_names": [ "Yusuke Yamashita", "Hiroshi Tadano" ], "corpus_id": 104276152, "doc_id": "104276152", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Numerical modeling of reverse recovery characteristic in silicon pin diodes", "venue": "", "year": 2018 }, { "abstract": "A method called the HYBRID method, which solves the differential equations describing the semiconductor partly analytically and partly numerically, is presented. The advantages of this model compared with other ones are: continuous description of the switching process; simple simulator equations (no convergence problems) accurate solution of the ambipolar diffusion equation; and adaptability of the method to other devices. Important effects such as conductivity modulation and field dependence of charge carrier velocity are considered as well as the effect of mobile charge carriers in the space charge region. The model is programmed in FORTRAN 77 and implemented in the SABER circuit simulator, and has been verified for different ranges of operation.<ETX>", "author_names": [ "Holger Goebel", "Kurt Hoffmann" ], "corpus_id": 110118102, "doc_id": "110118102", "n_citations": 18, "n_key_citations": 1, "score": 0, "title": "Power diode HYBRID model with forward and reverse recovery for use in circuit simulators", "venue": "[Proceedings] APEC '92 Seventh Annual Applied Power Electronics Conference and Exposition", "year": 1992 }, { "abstract": "A simplified behavioral model of diode reverse recov ery, which is based on the lumped charge control concept, is proposed and tested experimentally. The model can be imple mented in discrete transition simulators that do not apply full physical models of devices and it does not require heavy compu tational resources. The parameters of the model can be easily extracted from a simple single measurement. The model is dem onstrated in the PSIM platform and is verified experimentally for various turn off conditions.", "author_names": [ "Natan Krihely", "Sam Ben-Yaakov" ], "corpus_id": 114692948, "doc_id": "114692948", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Simulation Bits: Adding the Reverse Recovery Feature to a Generic Diode", "venue": "", "year": 2011 } ]

[ { "abstract": "BGA (ball grid array) one of the structures used for semiconductor packages, involves a laminated structure. BGA inevitably involves significant warpage, owing to differences in shrinkage among constituent materials. The extent of warpage is governed by total shrinkage cure shrinkage thermal shrinkage of the epoxy molding compound that encapsulates the IC chip. In particular, the cure shrinkage exerts great influence on warpage. Cure shrinkage has been understood as the decrease in free volume at the time of curing. However, the cure shrinkage rate cannot be sufficiently explained by the free volume of the cured epoxy resin. We have developed an evaluation method based on the epoxy group reaction ratio, and have eventually confirmed that cure shrinkage depends on the reaction ratio of the epoxy group after curing, and on epoxy group density.", "author_names": [ "Ken Oota", "Masumi Saka" ], "corpus_id": 136540473, "doc_id": "136540473", "n_citations": 43, "n_key_citations": 3, "score": 1, "title": "Cure shrinkage analysis of epoxy molding compound", "venue": "", "year": 2001 }, { "abstract": "Finite element analysis (FEA) is widely used throughout the electronics industry to understand the thermal and thermo mechanical behavior of electronic packages and interconnect during their manufacture and lifetime. After encapsulation, thermo mechanical stress builds up within the package due to temperature coefficient of expansion mismatch between the respective materials within the package as it cools to room temperature. Due to the complexity and time consuming of the calculation, it is almost impossible for industry to carry out the numerical simulation using viscoelastic property which is the most close to the real material property of polymer material. However, FEA using temperature dependent elastic property, temperature dependent thermal expansion coefficient and accurate chemical cure shrinkage can help to improve the accuracy on the stress and warpage prediction. This study has developed an evaluation method for the chemical cure shrinkage based on the measurement of the warpage of bimaterial model. The results show that FEA simulations without chemical cure shrinkage fail to accurately predict the package warpage. On the other hand. FEA simulations with chemical cure shrinkage is outlined which show fair agreement with experimental measurements of package warpage over a range of temperatures.", "author_names": [ "Guojun Hu", "Spencer Chew", "B Singh" ], "corpus_id": 25852854, "doc_id": "25852854", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Cure Shrinkage Analysis of Green Epoxy Molding Compound with Application to Warpage Analysis in a Plastic IC Package", "venue": "2007 8th International Conference on Electronic Packaging Technology", "year": 2007 }, { "abstract": "After encapsulation, thermomechanical deformation builds up within the electronic packages due to the temperature coefficient of expansion mismatch between the respective materials within the package as it cools to room temperature. At the same time, the chemical cure shrinkage exerts important influence on the total deformation. Due to the complexity and time consuming of the calculation, it is almost impossible for an industry to carry out the numerical simulation using viscoelastic property, which is the most close to the real material property of polymer material. However, finite element analysis (FEA) using temperature dependent elastic property, temperature dependent thermal expansion coefficient, and accurate chemical cure shrinkage can help to improve the accuracy on the stress and warpage prediction. This study has developed an evaluation method for the chemical cure shrinkage based on the measurement of the warpage of bimaterial model. The results show that FEA simulations without chemical cure shrinkage fail to accurately predict the package warpage. On the other hand, FEA simulations with chemical cure shrinkage are outlined, which show fair agreement with experimental measurements of package warpage over a range of temperatures. Furthermore, this study has evaluated the effect of silica filler percentage on the chemical cure shrinkage and confirmed that the chemical cure shrinkage decreases with the increase in silica filler percentage.", "author_names": [ "Guojun Hu", "Jing-en Luan", "Spencer Chew" ], "corpus_id": 111368002, "doc_id": "111368002", "n_citations": 30, "n_key_citations": 1, "score": 0, "title": "Characterization of Chemical Cure Shrinkage of Epoxy Molding Compound With Application to Warpage Analysis", "venue": "", "year": 2009 }, { "abstract": "One of the most prominent failure modes in microelectronics devices is the delamination of epoxy materials (adhesives, molding compounds) The thermal mismatch at the interface between materials leads to stresses that build up during processing steps at different temperatures and in the following thermal cycling through use of the device or reliability testing. These stresses are well understood and are commonly investigated by finite element modeling. Epoxy molding compounds undergo a chemical reaction during processing called curing. Here the two components epoxy and hardener react to form a 3D network giving the molding compound its final material properties. During this process, the volume of the compound decreases, a phenomenon called cure shrinkage. The shrinkage itself can be experimentally determined, e.g. using volumetric measurements. However, due to relaxation processes that take place at higher temperatures and the changing thermal mechanical properties during the curing process, the stresses that build up due to chemical shrinkage are more complex to consider. In this work, the mechanically relevant cure shrinkage was investigated by a combination of experiments and finite clement simulations. Samples of molding compound on Cu leadframe material were manufactured using standard procedures. Thermal expansion experiments were performed at several temperatures recording the warpage of the samples. To extract the mechanically relevant shrinkage FE simulations were performed mimicking the process temperatures. The resulting data was evaluated and discussed with respect to: qualitative behaviour for five different molding compounds; qualitative agreement between simulation and experiment; error margins of simulation results with respect to material properties input data; and error margins of experimental data due to processing variations and experimental setup.", "author_names": [ "Marcelo Fraga de Sousa", "Ole Holck", "Tanja Braun", "Jorg Bauer", "Hans Walter", "Olaf Wittler", "Klaus-D Lang" ], "corpus_id": 2210263, "doc_id": "2210263", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Mechanically relevant chemical shrinkage of epoxy molding compounds", "venue": "2013 14th International Conference on Thermal, Mechanical and Multi Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE)", "year": 2013 }, { "abstract": "In this paper, both isothermal and dynamic differential scanning calorimetry (DSC) are employed to characterize the thermal properties of two commercial epoxy molding compounds designated as EMC A and EMC B respectively. In dynamic curing, the heat flow of uncured powder samples weighting 10+ 0.5 mg are measured at the heating rates of 5, 10 and 15 degC /min from room temperature to 220 degC. The isothermal curing tests are performed under the constant temperatures of 130, 140 and 150 degC for 30 min. The experimental results show that compared with EMC B, EMC A has smaller average curing reaction enthalpy and activation energy showing a better moldability. The parameters of autocatalytic Kamal equation for these two EMCs are obtained by the isothermal curing tests and the curing kinetic model exhibits good agreement with the experimental data generally.", "author_names": [ "Shen Hui-qiang", "Qin Fei", "Xia Guofeng", "Bie Xiaorui" ], "corpus_id": 2164824, "doc_id": "2164824", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Characterization of thermal and curing behaviors of epoxy molding compounds", "venue": "2014 15th International Conference on Electronic Packaging Technology", "year": 2014 }, { "abstract": "Warpage is an important issue for IC packages after molding. Due to laminated structure of IC packages, significant warpage occurs owing to differences in shrinkage among constituent materials. Thermal shrinkage is usually considered as the main cause for IC warpage. However, cure induced warpage is also important during the molding process. Analysis without considering cure induced shrinkage can not predict the amount of warpage well. In this paper, TSOP LOC54L package product, which is manufactured by ChipMos Corporation, is used as the simulation model. The P V T C (Pressure, Volume, Temperature, and Conversion) relation and CTE (Coefficients of Thermal Expansion) of an encapsulation material are used to predict the amount of warpage and experimentally verifying the results in this study. By comparing the simulations with the experiments, the preliminary results of the study indicate this approach is capable of estimating warpage in IC packages without prohibitive computational effort.Copyright (c) 2005 by ASME", "author_names": [ "Shiang-Yu Teng", "Sheng-Jye Hwang" ], "corpus_id": 135645089, "doc_id": "135645089", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Simulation of Warpage Considering Both Thermal and Cure Induced Shrinkage During Molding in IC Packaging", "venue": "", "year": 2005 }, { "abstract": "The rubbery (equilibrium) modulus of thermosetting polymers dominates the mechanical behavior at elevated temperature or at long times. It also plays a major role in the residual stress induced during the curing process. In this paper, ai extensive study on the cure dependent rubbery moduli of silica spheres filled epoxy resin is carried out both experimentally and theoretically. DSC measurements were used for characterization of the cure kinetics and T/sub g/ conversion relationship. Low frequency DMA was used to measure the rubbery modulus build up during cure. A model based on scaling analysis was applied to describe the evolution of the rubbery shear modulus. A similar model was proposed for the cure dependent rubbery bulk modulus. Models from the theory of particulate filled composites were used to predict the rubbery moduli of the molding compound with different filler concentration. The effect of the filler percentage on the rubbery moduli was discussed.", "author_names": [ "D G Yang", "Kaspar M B Jansen", "Leo J Ernst", "G -Q Zhang", "H J L Bressers", "J H J Janssen" ], "corpus_id": 5743557, "doc_id": "5743557", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Measuring and modeling the cure dependent rubbery moduli of epoxy molding compound", "venue": "EuroSimE 2005. Proceedings of the 6th International Conference on Thermal, Mechanial and Multi Physics Simulation and Experiments in Micro Electronics and Micro Systems, 2005.", "year": 2005 }, { "abstract": "This paper is to study the warpage impact of filler content and special additives on BGA packages. The special additives have significant impact on the warpage. The additive A has great influence on the warpage at different temperature; the warpage will flatten when more additive A is added. From the warpage study of single unit from room temperature to 260degC, all the warpage is in 50um when additive A is about 1% The additive A can flatten the warpage of the package and keep the warpage at same level even with different silicon occupation in the package. The filler content shows great impact on the warpage by control the shrinkage after cured, the lower shrinkage; the package will move to more crying.", "author_names": [ "Wei Tan", "Fang Zhou", "Xingming Cheng", "D H Ding", "Juan Wu" ], "corpus_id": 8173685, "doc_id": "8173685", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "The warpage control method in epoxy molding compound", "venue": "2009 International Conference on Electronic Packaging Technology High Density Packaging", "year": 2009 }, { "abstract": "The isothermal and isobaric volume shrinkage is measured by a single plunger type dilatometer for epoxy molding compound (EMC) This device has been found suitable for measuring volume change of thermosetting materials such as commercial EMC under isothermal and isobaric conditions. Moreover, the degree of cure (conversion) was determined by a differential scanning calorimetry (DSC) Combining volume change and conversion, a mathematic pressure volume temperature cure (P V T C) model is proposed to describe the relationship between volume shrinkage, pressure, temperature and conversion. The P V T C equation can be simply expressed as VS(P,T,C)=F/sub 1/(P,T)/spl middot/C/sup F2(P,T) This equation can well describe historical profiles of volume shrinkage under specified isothermal and isobaric states. From the predicted results, volume shrinkage under different pressure levels in any specified temperature can be approximated as and it obeys the principle of linearity. With the help of this model, together with three dimensional mold filling simulation, engineers will be able to predict warpage and residual stresses for a package after molding.", "author_names": [ "Sheng-Jye Hwang", "Yi-San Chang" ], "corpus_id": 37155716, "doc_id": "37155716", "n_citations": 32, "n_key_citations": 5, "score": 0, "title": "P V T C equation for epoxy molding compound", "venue": "IEEE Transactions on Components and Packaging Technologies", "year": 2006 }, { "abstract": "The cure process of epoxy prepreg used as composite pipe joints was studied by means of differential scanning calorimetry (DSC) Bohlin Rheometer and other techniques. Isothermal DSC measurements were conducted between 110 and 220 C, at 10 C intervals. The results show that the complete cure reaction could be achieved at 220 C. The isothermal cure process was simulated with the four parameter autocatalytic model. Except in the late stage of cure reaction, the model agrees well with the experimental data, especially at high temperatures. To account for the effect of diffusion on the cure rate, a diffusion factor was introduced into the model. The modified model greatly improved the predicated data at the late stage of cure reaction. The dynamic cure process was different from the isothermal cure process in that it is composed of two cure reactions. For dynamic cure process, a three parameter autocatalytic model was used. The parameters in the model were determined by two methods. One was based on Kissinger and Ozawa approach. The whole curing process was modeled with two reactions. Another method was based on Borchardt and Daniels kinetic approach with the whole curing process modeled with one reaction. The fitted results by the first and second methods agreed well with the experimental values in the late and early cure stages, respectively. Rheological properties of epoxy prepreg are closely related to the cure process. With the development of the cure reaction, gelation occurs and epoxy prepreg becomes difficult to process. As the temperature increases, the gel time decreases. Viscosity profiles were described by different models. Except for the first and nth order viscosity", "author_names": [ "Liangfeng Sun" ], "corpus_id": 137044173, "doc_id": "137044173", "n_citations": 36, "n_key_citations": 6, "score": 0, "title": "Thermal rheological analysis of cure process of epoxy prepreg", "venue": "", "year": 2002 } ]

[ { "abstract": "The interfacial charge transfer still limits the photoactivity of artificial Z scheme photocatalysts although they showed complementary light absorption and a strong photoredox ability. In this study, layered metallene is designed as an efficient electron mediator for constructing a C3N4/bismuthene/BiOCl 2D/2D/2D Z scheme system. This bismuthene serves as a bridge processing superior charge conductibility, abundant metal semiconductor contact sites, and the shortened charge diffusion distance, enhancing the photocatalytic CO2 reduction reaction activity and stability. Density functional theory calculations show that the bismuthene creates a built in electric field and congregates interfacial electrons, which is confirmed by the stable and consistent emission of the ultrafast transient absorption spectra. This work gives new insight into the interface design of Z scheme photocatalysts by selecting a novel metallene electron mediator.", "author_names": [ "Dan Zhang", "Xiaoqiang Cui", "Lulu Liu", "Yanchao Xu", "Jianhui Han" ], "corpus_id": 233483231, "doc_id": "233483231", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "2D Bismuthene Metal Electron Mediator Engineering Super Interfacial Charge Transfer for Efficient Photocatalytic Reduction of Carbon Dioxide.", "venue": "ACS applied materials interfaces", "year": 2021 }, { "abstract": "Abstract Designing hetero junction photo catalysts with high separation efficiency of photo generated charge carriers has been recognized as an optimistic route to water purification and hydrogen generation. The interfacial interaction and band potential fluctuation in forming hetero junction play important roles in photo catalytic activity. In this work, a series of highly active layer structured g C3N4/BiOCl (C3N4/BOC) hetero junction have been successfully synthesized through a two step calcination hydrothermal method. The hetero junction photo catalysts exhibit 8.15 times higher degradation rate for Rhodamine B (RhB) and 6.97 times higher H2 evolution rate than those of pristine g C3N4. For comprehensively understand the charge transfer mechanism, experimental characterization and theoretical Density functional theory (DFT) calculations are adopted in the single phase semiconductor and hetero junction system. The superior photo induced electron holes separation ability and band potential fluctuation of present photo catalysts are confirmed. This work provides insightful understanding for the formation mechanism of hetero junction photo catalysts.", "author_names": [ "Ruoyu Zhang", "Siying Niu", "Jinmeng Xiang", "Jiming Zheng", "Zhenyi Jiang", "Chongfeng Guo" ], "corpus_id": 233060623, "doc_id": "233060623", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Band potential fluctuation in C3N4/BiOCl hetero junction for boosting photo catalytic activity", "venue": "", "year": 2021 }, { "abstract": "Abstract Photocatalytic degradation of noxious pollutants is an efficacious approach to combat water pollution. The heterojunction photocatalysts having low band gap and recombination rate have immense significance in this respect. Herein, a series of composites (various weight ratios of g C3N4@BiOCl) are constructed by conglomerating g C3N4 nanosheets with BiOCl nanoplates by a wet chemical process. XRD, XPS, EDX, and TGA analysis verified the successful formation, uniform distribution, and thermal stability of the catalysts. FESEM and HRTEM images exhibited that BiOCl platelets are well covered with g C3N4 nanosheets. The UV DRS and PL spectroscopy confirmed that the hybrid had a low bandgap and a low recombination rate facilitating charge separation. BET assay revealed that 3:1 g C3N4@BiOCl had the highest surface area (107 m2/g) with mesopores. To assess the catalyst's photocatalytic performance, MB and IC were degraded in natural sunlight. Kinetic studies showed that the 3:1 g C3N4@BiOCl hybrid manifested the best performance (degrading 94.8% of MB and 73.4% of IC) and rate constant (0.0301 min 1 and 0.0085 min 1 for MB and IC, respectively) An effect of pH and catalyst concentration on the photodegradation was also investigated. Trapping experiments revealed that O2* was the major reactive species in the photodegradation mechanism. The successful IC degradation confirmed the occurrence of indirect photocatalysis. The catalyst was reused for MB degradation showing 75% efficiency even after 5 sequential cycles. Considering the simplistic preparation and excellent properties, g C3N4@BiOCl can be used as a promising and competitive solar light driven photocatalyst for environmental remediation.", "author_names": [ "Aayushi Kundu", "Surbhi Sharma", "Soumen Basu" ], "corpus_id": 233638991, "doc_id": "233638991", "n_citations": 6, "n_key_citations": 0, "score": 1, "title": "Modulated BiOCl nanoplates with porous g C3N4 nanosheets for photocatalytic degradation of color/colorless pollutants in natural sunlight", "venue": "Journal of Physics and Chemistry of Solids", "year": 2021 }, { "abstract": "BiOCl/g C3N4 (BC) heterojunctions were constructed successfully through a novel in situ hydrolysis method by taking metallic Bi nanospheres as Bi source. The TEM and HRTEM images showed the heterogeneous nanostructures at the interface between BiOCl and g C3N4. The combination of BiOCl and g C3N4 enlarged the light adsorption range of the BC heterojunctions, which extended to visible region. Besides, the contact of the two semiconductors at the heterointerfaces improved the separation efficiency of photoinduced charge carriers, thus endowing the BC samples with superior visible light driven (VLD) photocatalytic performance in degrading organic pollutants. Notably, the BC12% sample exhibited the optimized photocatalytic activity in which 97.3% of RhB was decomposed within 30 min, achieving 13.87 and 4.26 times improvement than the bare BiOCl and pristine g C3N4, respectively. Moreover, the trapping experiments revealed that .O2 and h+ were the dominant active species during the degradation processes of RhB. Meanwhile, the possible degradation pathway of RhB was proposed on the basis of the intermediate products detected by LC MS, and the appearance photocatalytic mechanisms were also discussed in detail. As an original strategy to obtain samples with highly dispersed heterointerface, this work provides a facile route for the surface modification of g C3N4 via a facile hydrolysis process of metallic particles to form heterostructures and very promising for practical application.", "author_names": [ "Zikang Zeng", "Kai Li", "Tao Yuan", "Yujun Liang", "Jian Yang", "Guie Yang", "Kun Wang", "Zhuoran Xiong" ], "corpus_id": 232215629, "doc_id": "232215629", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Facile synthesis of BiOCl/g C3N4 heterojunction via in situ hydrolysis of Bi nanospheres: a high efficiency visible light driven photocatalyst", "venue": "Journal of Materials Science: Materials in Electronics", "year": 2021 }, { "abstract": "Abstract Advanced analytical instrumentations and improved analytical techniques have paved the way to detect many chemicals in natural waters. These chemicals, collectively termed emerging contaminants (ECs) include drugs, disinfectants, plasticizers, detergents, surfactants, pesticides, dyes, paints, preservatives, food additives, and personal care products released into the environment by chemical and pharmaceutical industries, hospitals, households, wastewater treatment plants, and land runoff. The effectiveness of EC removal by traditional methods, that is, biodegradation, coagulation, and sedimentation, is often low or very low. In recent years, advanced oxidation processes (AOP) such as photocatalysis, photo Fenton, and ozonation, have been effectively used to remove these contaminants. Among these AOPs, solar photocatalysis has drawn major attention in treating ECs due to its low cost and ease of operation. Solar photocatalysis utilizes the absorption of sunlight by the semiconductor catalyst for its activation. Upon irradiation with light (photon energy) greater than or equal to its bandgap energy, the semiconductor photocatalyst generates an electron (e and hole (h+ pair (EHP) These photogenerated EHPs would promote different redox reactions, facilitating pollutant degradation. The semiconductor photocatalysts used in the photocatalysis process include TiO2, ZnO, WO3, Cds, Fe2O3, Cu2O, CdSe, etc. However, the higher bandgap energy of these catalysts necessitates ultraviolet irradiation for the excitation. On the other hand, to reduce the bandgap energy and to cause visible light (sunlight) excitation, several modifications are carried out such as metal/nonmetal doping, coupling, structural modification, and noble metal deposition on the surface. Some of the modified catalysts such as TiO2/Cu2O, Bi2O3/g C3N4, Ag/TiO2, Au/TiO2, Pt/TiO2, C TiO2, N TiO2, and BiOCl/Bi24O31Cl10 showed good efficiency in pollutant degradation by solar photocatalysis. Solar photocatalysis has been successfully employed for EC degradation from wastewater. For example, TiO2/Cu2O and WO3 catalysts resulted in 100% and 99.39% degradation of the pharmaceuticals sulfamethazine and amoxicillin, respectively, from wastewater within 3 h. However, the solar photocatalytic performance depends on different parameters such as pH, oxidant dosage, and natural organic matter in wastewater. This study will summarize the solar photocatalytic treatment employed for the removal of ECs from wastewater with an emphasis on the catalyst modification.", "author_names": [ "Venkatesan Prashanth", "P K Jayasree", "P R Rajput", "Neelancherry Remya" ], "corpus_id": 224838938, "doc_id": "224838938", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Solar photocatalysis and its application for emerging contaminant removal from wastewater", "venue": "", "year": 2021 }, { "abstract": "In this work, g C3N4 x/BiOCl/WO2.92 heterojunction with \"N O\" vacancies was prepared using NaBiO3 and WCl6 as raw materials and non metal plasma of WO2.92 grew in situ on the surface of BiOCl, resulting in the enhanced photocatalytic NO deep oxidation. XPS tests and DFT calculation indicated the formation of internal electric fields from g C3N4 x to BiOCl, BiOCl to WO2.92, which induced the transition from II II type to double Z scheme hetero structure. High separation efficiency, prolong lifetime and strong redox ability of photo generated electron hole pairs were simultaneously achieved due to the charge capture effect of defects and double Z scheme mechanism. Therefore, g C3N4 x/BiOCl/WO2.92 exhibited the significantly increased NO removal rates from 21.17% (BiOCl/WO2.92) and 36.52% (g C3N4 x) to 68.70% and the main oxidation product of NO was NO3 This study revealed that the carrier dynamics of heterojunction photocatalysts could be optimized by the synergistic effect of defects and internal electric fields to achieve photocatalytic NO deep oxidization.", "author_names": [ "Mozhen Wang", "Guoqiang Tan", "Shuaijun Feng", "Mingyue Dang", "Bixin Zhang", "Huijun Ren", "Long Lv", "Ao Xia", "Wenlong Liu", "Yun Liu" ], "corpus_id": 229694301, "doc_id": "229694301", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Defects and internal electric fields synergistically optimized g C3N4 x/BiOCl/WO2.92 heterojunction for photocatalytic NO deep oxidation.", "venue": "Journal of hazardous materials", "year": 2020 }, { "abstract": "Abstract A Z scheme of 2D/2D BiOCl/g C3N4 nanosheet like composite was prepared by hydrothermal method. The properties of prepared samples were well tested by XRD, FT IR, PL, EIS, SEM equipped with EDS, XPS, UV Vis DRS analysis. After the BiOCl nanosheets anchored on g C3N4 nanosheets, the BiOCl/g C3N4 3 composite exhibited a remarkable photocatalytic efficiency and antimicrobial activity for tetracycline (TC) About 97.1% of TC degraded within 60 min and the TOC removal rate of TC reached to 76.3% in 180 min. Moreover, the E.coli reduction of antimicrobial activity reached to 96.5% after 40 min illumination. Those excellent photocatalytic efficiency of BiOCl/g C3N4 3 composite was contribution of the rapid charge transfer in Z scheme system. Finally, 4 cycles of photocatalytic experiments revealed an excellent stability and reusability of BiOCl/g C3N4 3 composite.", "author_names": [ "Yuwei Sun", "Xin Qi", "Qiang Tang", "Baixiang Ren" ], "corpus_id": 224854185, "doc_id": "224854185", "n_citations": 12, "n_key_citations": 0, "score": 1, "title": "Hydrothermal synthesis of 2D/2D BiOCl/g C3N4 Z scheme: For TC degradation and antimicrobial activity evaluation", "venue": "", "year": 2020 }, { "abstract": "Abstract In this paper, a novel heterojunction material was synthesized of C3N4 via doping with p deficient conjugated pyridine ring molecules (2,6 diaminopyridine) and BiOCl by ultrasound assisted method. First, doping C3N4 with 2,6 diaminopyridine can reduce the structural integrity and orderliness of C3N4, and reduce the number of structural fragments, Which makes C3N4 have more reactive sites. And then BiOCl nanosheets were grown on the surface of the modified C3N4 nanosheets to obtain a new heterojunction material composed of modified C3N4 doped with p deficient pyridine ring molecules and BiOCl by the co precipitation method. At last, the degradation of methyl orange (MO) by BiOCl, C3N4, modified C3N4 doped with 2,6 diaminopyridine, and a series of C3N4 doped with 2,6 diaminopyridine and BiOCl composite heterojunction materials under visible light was studied. X ray diffraction (XRD) scanning electron microscope (SEM) high resolution transmission electron microscopy (HRTEM) X ray photoelectron spectroscopy (XPS) Brunauer Emmett Teller (BET) ultraviolet visible diffuse reflection (UV Vis DRS) and transient photocurrent densities, and electrochemical impedance spectroscopy (EIS) were used to analyze the structure, morphology, and photogenerated charge transfer characteristics of samples. The experimental results show that the new heterojunction composite materials has better photocatalytic activity compared with pure BiOCl, C3N4, and modified C3N4 doped with 2,6 diaminopyridine. In addition, the degradation performance of methyl orange with different mass ratios of composite materials is also different. When the mass ratio of C3N4 doped with 2,6 diaminopyridine to BiOCl is 1:2, The composite material exhibits the best photocatalytic performance, which may be related to the synergistic effect of the modified C3N4 doped with 2,6 diaminopyridine and BiOCl. Based on the band structure and active species experiments, the reasons for the enhanced photocatalytic activity are discussed, and the possible degradation mechanisms are proposed. The research in this paper provides an effective new way to construct new heterojunction materials.", "author_names": [ "Wei Yang", "Xinyao Shan", "Ying Chen", "Yanhua Gao" ], "corpus_id": 219761641, "doc_id": "219761641", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Enhanced photocatalytic performance of C3N4 via doping with p deficient conjugated pyridine ring and BiOCl composite heterogeneous materials", "venue": "", "year": 2020 }, { "abstract": "Abstract Bismuth oxychloride (BiOCl) limited by a wide band gap, makes it poor perform in visible light driven photodegradation. The novel semiconductor composites of BiOCl/g C3N4@UiO 66 composites were first prepared through the facile solvothermal approach. BiOCl/g C3N4@UiO 66 photocatalysts were characterized and BiOCl nanoplates and g C3N4 nanosheets were successful constructed and further decorated on the surface with UiO 66. In comparison with the binary composites and the pure materials, BiOCl/g C3N4@UiO 66 exhibits the higher RhB photocatalytic degradation under visible light irradiation. The enhanced photocatalytic activity of BiOCl/g C3N4@UiO 66 composites can be attributed to the lower recombination probability of electron hole pair of the heterojunction, increased surface area for RhB adsorption accomplished with photodegradation process.", "author_names": [ "Yu Zhu", "Mengying Zhu", "Hua Lv", "Su Rui Zhao", "Qiyuan Zhang", "Wen Kun Zhu", "Bingdong Li" ], "corpus_id": 225417551, "doc_id": "225417551", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Coating BiOCl@g C3N4 nanocomposite with a metal organic framework: Enhanced visible light photocatalytic activities", "venue": "", "year": 2020 }, { "abstract": "In this work, fibrous TiO2@g C3N4 nanocomposites (FTGCNCs) were used for dispersive micro solid phase extraction of Co and Ni prior to their determination by inductively coupled plasma mass spectrometry. As a new adsorbent, the surface on FTGCNCs have rich functional groups such as NH2, NH and =N which can selectively adsorb target ions. The adsorption behaviors of Co and Ni on FTGCNCs were investigated. The results indicated that the analytes were quantitatively retained on FTGCNCs in the pH range of 5.0 8.0 and eluted completely with 1.0 mL of 0.5 mol L HNO3 solution. The main factors influencing the preconcentration and determination of the analytes were investigated in detail, including the pH of the sample solution, dosage of adsorbent, extraction/elution time, elution parameters and sample volumes. Under the optimum conditions, the detection limits of this method were 0.12 pg mL and 1.34 pg mL for Co and Ni, respectively. The relative standard deviations were 3.9% for Co and 4.8% for Ni (n=9, c=1.0 ng mL) This method was used for the determination of trace/ultra trace Co and Ni in environmental water samples with satisfactory results. In order to verify this method, three certified reference materials of stream sediment, human hair and mussel were analyzed using the proposed method, and the determined results were in agreement with the certified values.", "author_names": [ "Shizhong Chen", "Yuxiu Liu", "Juntao Yan", "Chunlei Wang", "Deng-bo Lu" ], "corpus_id": 221093950, "doc_id": "221093950", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Dispersive Micro solid Phase Extraction with Fibrous TiO2@g C3N4 Nanocomposites Coupled with ICP MS for the Determination of Cobalt and Nickel in Environmental and Biological Samples", "venue": "", "year": 2020 } ]

[ { "abstract": "The electron transport properties of atomically thin semiconductors such as MoS2 have attracted significant recent scrutiny and controversy. In this work, the scattering mechanisms responsible for limiting the mobility of single layer semiconductors are evaluated. The roles of individual scattering rates are tracked as the 2D electron gas density is varied over orders of magnitude at various temperatures. From a comparative study of the individual scattering mechanisms, we conclude that all current reported values of mobilities in atomically thin transition metal dichalcogenide semiconductors are limited by ionized impurity scattering. When the charged impurity densities are reduced, remote optical phonon scattering will determine the ceiling of the highest mobilities attainable in these ultrathin materials at room temperature. The intrinsic mobilities will be accessible only in clean suspended layers, as is also the case for graphene. Based on the study, we identify the best choices for surrounding dielectrics that will help attain the highest mobilities.", "author_names": [ "N Ma", "Debdeep Jena" ], "corpus_id": 2432766, "doc_id": "2432766", "n_citations": 191, "n_key_citations": 9, "score": 1, "title": "Charge Scattering and Mobility in Atomically Thin Semiconductors", "venue": "", "year": 2014 }, { "abstract": "The transition metal dichalcogenides have attracted a lot of attention as a possible stepping stone toward atomically thin and flexible field effect transistors. One key parameter to describe the charge transport is the time between two successive scattering events the transport scattering time. In a recent report, we have shown that it is possible to use density functional theory to obtain the band structure of two dimensional semiconductors in presence of field effect doping. Here, we report a simple method to extract the scattering time from the experimental conductivity and from the knowledge of the band structure. We apply our approach to monolayers and multilayers of MoS$_2$ MoSe$_2$ MoTe$_2$ WS$_2$ and WSe$_2$ in presence of a gate. In WS$_2$ for which accurate measurements of mobility have been published, we find that the scattering time is inversely proportional to the density of states at the Fermi level. Finally, we show that it is possible to identify the critical doping at which different valleys start to be occupied from the doping dependence of the conductivity.", "author_names": [ "Thomas Brumme", "Matteo Calandra", "Francesco Mauri" ], "corpus_id": 119267677, "doc_id": "119267677", "n_citations": 12, "n_key_citations": 1, "score": 0, "title": "Determination of scattering time and of valley occupation in transition metal dichalcogenides doped by field effect", "venue": "", "year": 2016 }, { "abstract": "Incorporation of tetramethylammonium iodide into conjugated D A polymer thin film leads to remarkable enhancement of charge mobility. Organic semiconductors with high charge carrier mobilities are crucial for flexible electronic applications. Apart from designing new conjugated frameworks, different strategies have been explored to increase charge carrier mobilities. We report a new and simple approach to enhancing the charge carrier mobility of DPP thieno[3,2 b]thiophene conjugated polymer by incorporating an ionic additive, tetramethylammonium iodide, without extra treatments into the polymer. The resulting thin films exhibit a very high hole mobility, which is higher by a factor of 24 than that of thin films without the ionic additive under the same conditions. On the basis of spectroscopic grazing incidence wide angle x ray scattering and atomic force microscopy studies as well as theoretical calculations, the remarkable enhancement of charge mobility upon addition of tetramethylammonium iodide is attributed primarily to an inhibition of the torsion of the alkyl side chains by the presence of the ionic species, facilitating a more ordered lamellar packing of the alkyl side chains and interchain p p interactions.", "author_names": [ "Hewei Luo", "Chenmin Yu", "Zitong Liu", "Guanxin Zhang", "Hua Geng", "Yuanping Yi", "Katharina Broch", "Yuanyuan Hu", "Aditya Sadhanala", "Lang Jiang", "Penglin Qi", "Zhengxu Cai", "Henning Sirringhaus", "Deqing Zhang" ], "corpus_id": 18228802, "doc_id": "18228802", "n_citations": 104, "n_key_citations": 0, "score": 0, "title": "Remarkable enhancement of charge carrier mobility of conjugated polymer field effect transistors upon incorporating an ionic additive", "venue": "Science Advances", "year": 2016 }, { "abstract": "Clean interface and low contact resistance are crucial requirements in two dimensional (2D) materials to preserve their intrinsic carrier mobility. However, atomically thin 2D materials are sensitive to undesired Coulomb scatterers such as surface/interface adsorbates, metal to semiconductor Schottky barrier (SB) and ionic charges in the gate oxides, which often limits the understanding of the charge scattering mechanism in 2D electronic systems. Here, we present the effects of hafnium dioxide (HfO2) high k passivation and SB height on the low frequency (LF) noise characteristics of multilayer molybdenum ditelluride (MoTe2) transistors. The passivated HfO2 passivation layer significantly suppresses the surface reaction and enhances dielectric screening effect, resulting in an excess electron n doping, zero hysteresis, and substantial improvement in carrier mobility. After the high k HfO2 passivation, the obtained LF noise data appropriately demonstrates the transition of the Coulomb scattering mechanism from the SB contact to the channel, revealing the significant SB noise contribution to the 1/f noise. The substantial excess LF noise in the subthreshold regime is mainly attributed to the excess metal to MoTe2 SB noise and is fully eliminated at the high drain bias regime. This study provides a clear insight into the origin of electronic signal perturbation in 2D electronic systems.", "author_names": [ "Min-Kyu Joo", "Yoojoo Yun", "Hyunjin Ji", "Dongseok Suh" ], "corpus_id": 53568616, "doc_id": "53568616", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Coulomb scattering mechanism transition in 2D layered MoTe2: effect of high k passivation and Schottky barrier height.", "venue": "Nanotechnology", "year": 2019 }, { "abstract": "Simultaneously achieving higher carriers concentration and mobility is a technical challenge against up scaling the transparent conductive performances of transparent conductive oxides. Utilizing one order higher dense ~1 x 1011 cm 3) plasmas (in comparison to the conventional direct current plasmas) highly c axis oriented Al doped ZnO films have been prepared with precise control over relative composition and chemical states of constituting elements. Tailoring of intrinsic (O vacancies) and extrinsic (ionic Al and zero valent Al) dopants provide simultaneous enhancement in mobility and concentration of charge carriers. Room temperature resistivity as low as 4.89 x 10 4 O cm along the carrier concentration 5.6 x 1020 cm 3 is obtained in 200 nm thick transparent films. Here, the control of atomic Al reduces the charge trapping at grain boundaries and subdues the effects of grain boundary scattering. A mechanism based on the correlation between electron hole interaction and carrier mobility is proposed for degenerately doped wide band gap semiconductors.", "author_names": [ "Manish Kumar", "Long Wen", "Bibhuti Bhusan Sahu", "Jeon Geon Han" ], "corpus_id": 116939160, "doc_id": "116939160", "n_citations": 43, "n_key_citations": 0, "score": 0, "title": "Simultaneous enhancement of carrier mobility and concentration via tailoring of Al chemical states in Al ZnO thin films", "venue": "", "year": 2015 }, { "abstract": "In this work, we have applied the Airy Function Transfer Matrix Method to provide a numerical description of the charge scattering mechanisms taking place at the grain boundaries in polycrystalline, degenerately Al doped ZnO (ZnO:Al) films, one of the most studied Transparent Conductive Oxides (TCOs) By discretizing the potential barrier at the grain boundary into linear segments, an accurate calculation of the electron tunneling probability through the grain boundaries has been obtained. Conversely to analytical models based on the Wentzel Kramers Brillouin (WKB) approximation, our new approach is valid for any doping level. We thus provide a complete model that allows a comprehensive explanation of carrier transport in highly doped semiconductors, for which charge tunneling across grain boundaries cannot be neglected. We have tested our model with ZnO:Al thin films prepared by different physical and chemical deposition techniques, namely, sputtering, atomic layer deposition and atmospheric pressure spatial atomic layer deposition. A linear relationship between the trap density at the grain boundaries and carrier density has been extracted by fitting our model to Hall mobility data for the different samples. Our results provide guidance on how to adapt the deposition conditions to obtain high quality materials, with an optimum ratio between optical and electrical properties as required for specific applications.", "author_names": [ "V Nguyen", "Ulrich Gottlieb", "Anthony Valla", "Delfina Munoz", "Daniel Bellet", "David Munoz-Rojas" ], "corpus_id": 139290915, "doc_id": "139290915", "n_citations": 29, "n_key_citations": 1, "score": 0, "title": "Electron tunneling through grain boundaries in transparent conductive oxides and implications for electrical conductivity: the case of ZnO:Al thin films", "venue": "", "year": 2018 }, { "abstract": "High molecular symmetry is always observed in high performance organic semiconductors. However, whether it is an essential factor for molecular design is unclear. In this work, we designed and synthesized three quinoidal isomers, QBTT o, QBTT i, and QBTT s, with different sulfur orientations and a stable E configuration to investigate the relationship between the structure symmetry and organic thin film transistor performance. We found that QBTT o and QBTT i with high C2h symmetry exhibit electron mobilities of 0.02 and 0.15 cm2 V 1 s 1, respectively, while QBTT s exhibits an unexpectedly high electron mobility of 0.32 cm2 V 1 s 1 with Ion/Ioff ratios of =106. The enhanced electron mobilities from QBTT o and QBTT i to QBTT s can be attributed to the different sulfur orientations, especially, molecular symmetry. The thin film microstructures of three QBTTs were systematically investigated by grazing incidence wide angle X ray scattering, near edge X ray absorption fine structure spectroscopy, atomic force", "author_names": [ "Longbin Ren", "Dafei Yuan", "Eliot Gann", "Yuan Guo", "Lars Thomsen", "Christopher R McNeill", "Chong-an Di", "Yuanping Yi", "Xiaozhang Zhu", "Daoben Zhu" ], "corpus_id": 99688143, "doc_id": "99688143", "n_citations": 18, "n_key_citations": 0, "score": 0, "title": "Critical Role of Molecular Symmetry for Charge Transport Properties: A Paradigm Learned from Quinoidal Bithieno[3,4 b]thiophenes", "venue": "", "year": 2017 }, { "abstract": "The design and synthesis of new dye/pigment based semiconductors have made a significant contribution to the development of organic electronics. However, there are few detailed studies on the comparison of isomeric dye/pigment molecules, which play an important role in revealing the molecular structure property device performance relationships. In this study, we, for the first time, compared the thermal stability, optical, electrochemical, molecular assembling and charge transport properties of isomeric angular and linear shaped carbazoledioxazine derivatives, namely Ang CZ and Lin CZ, respectively. While the molecular shapes hardly affect the optical bandgaps and energy levels, they dramatically alter the charge transport characteristics. Accordingly, Lin CZ exhibited a two orders of magnitude higher mobility than Ang CZ, evaluated by thin film transistors (TFTs) Further studies suggested that Lin CZ tends to adopt a denser molecular packing motif and a higher molecular orbital overlapping than Ang CZ which is revealed by grazing incidence wide angle X ray scattering (GIWAXS) atomic force microscopy (AFM) and density functional theory calculations (DFT) More importantly, Lin CZ T, a p extended derivative of Lin CZ, showed a relatively high and stable TFT mobility of over 0.1 cm2 V 1 s 1, which was revealed by using an environmentally benign solvent and a pre aggregation method. Our findings will provide direction for developing more promising molecular semiconductors and organic TFT technology.", "author_names": [ "Yang Wang", "Hiroki Tatsumi", "Rikuo Otsuka", "Takehiko Mori", "Tsuyoshi Michinobu" ], "corpus_id": 139222453, "doc_id": "139222453", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Highly stable, green solvent processable organic thin film transistors: angular vs. linear shaped carbazoledioxazine derivatives", "venue": "", "year": 2018 }, { "abstract": "Thin film transistors based on regioregular poly(3 hexylthiophene) (PHT) and poly(3 decylthiophene) (PDT) and their binary blends were investigated and the blend composition dependence of the charge carrier mobility was determined. The field effect mobility of holes (mh) in a series of 10 binary blends of poly(3 hexylthiophene) (mh 0.02 cm2/(V s) and poly(3 decylthiophene) (mh 8 x 10 5 cm2/(V s) was found to be relatively high (2 x 10 3 cm2/(V s) and constant over a broad composition range (5 80 wt PDT) Above 80% PDT, the hole mobility decreased exponentially with composition. Atomic force microscopy of the homopolymers and blends confirmed the absence of phase separation in the blends. A similar interlayer d spacing that is intermediate between those of the homopolymers is implied by the constant hole mobility in the single phase crystalline blends of 5 80 wt PDT. These results demonstrate that blends of conjugated polymers are alloy semiconductors in which high and tunable charge carrier mob.", "author_names": [ "Amit Babel and", "Samson A Jenekhe" ], "corpus_id": 95636081, "doc_id": "95636081", "n_citations": 67, "n_key_citations": 0, "score": 0, "title": "Field Effect Mobility of Charge Carriers in Blends of Regioregular Poly(3 alkylthiophene)s", "venue": "", "year": 2003 }, { "abstract": "We report structural and electrical transport properties of a family of p stacking soluble organic semiconductors, N,N' dialkyl 3,4,9,10 perylene tetracarboxylic diimides (alkyl pentyl [1] octyl [2] and dodecyl [3] The structures of evaporated polycrystalline films of 1 3 were studied using X ray diffraction and atomic force microscopy. Films of 1 3 pack similarly with the direction of p p overlap in the substrate plane. Organic thin film transistors (OTFTs) based on 1 3 deposited on SiO2 gate dielectric showed linear regime electron mobilities of 0.1, 0.6, and 0.2 cm2/(V s) respectively, corrected for contact resistance. OTFTs of 2 had saturation electron mobilities as high as 1.7 cm2/(V s) with on to off current ratios of 107. Variable temperature measurements were used to examine the charge transport kinetics in the range 80 300 K and revealed (1) thermally activated electron mobilities with activation energies dependent on gate voltage and (2) the presence of well defined isokinetic points, i.e.", "author_names": [ "Reid John Chesterfield", "John C Mckeen", "Christopher R Newman", "Paul C Ewbank", "Demetrio Antonio da Silva Filho", "Jean-Luc Bredas", "Larry L Miller", "and Kent R Mann", "C Daniel Frisbie" ], "corpus_id": 97508590, "doc_id": "97508590", "n_citations": 355, "n_key_citations": 2, "score": 0, "title": "Organic Thin Film Transistors Based on N Alkyl Perylene Diimides: Charge Transport Kinetics as a Function of Gate Voltage and Temperature", "venue": "", "year": 2004 } ]

[ { "abstract": "Raman spectroscopy can be used to measure the chemical composition of a sample, which can in turn be used to extract biological information. Many materials have characteristic Raman spectra, which means that Raman spectroscopy has proven to be an effective analytical approach in geology, semiconductor, materials and polymer science fields. The application of Raman spectroscopy and microscopy within biology is rapidly increasing because it can provide chemical and compositional information, but it does not typically suffer from interference from water molecules. Analysis does not conventionally require extensive sample preparation; biochemical and structural information can usually be obtained without labeling. In this protocol, we aim to standardize and bring together multiple experimental approaches from key leaders in the field for obtaining Raman spectra using a microspectrometer. As examples of the range of biological samples that can be analyzed, we provide instructions for acquiring Raman spectra, maps and images for fresh plant tissue, formalin fixed and fresh frozen mammalian tissue, fixed cells and biofluids. We explore a robust approach for sample preparation, instrumentation, acquisition parameters and data processing. By using this approach, we expect that a typical Raman experiment can be performed by a nonspecialist user to generate high quality data for biological materials analysis.", "author_names": [ "Holly J Butler", "Lorna Ashton", "Benjamin Bird", "Gianfelice Cinque", "Kelly Curtis", "Jennifer Dorney", "Karen Esmonde-White", "Nigel J Fullwood", "Benjamin Gardner", "Pierre P L Martin-Hirsch", "Michael J Walsh", "Martin Robert McAinsh", "Nicholas Stone", "Francis L Martin" ], "corpus_id": 12315122, "doc_id": "12315122", "n_citations": 523, "n_key_citations": 18, "score": 1, "title": "Using Raman spectroscopy to characterize biological materials", "venue": "Nature Protocols", "year": 2016 }, { "abstract": "Raman spectroscopy is a non destructive, label free, highly specific approach which provides the chemical information of materials. Thus, it is suitable to be used as an effective analytical tool to characterize biological samples. Here we introduce a novel method which uses artificial intelligence to analyze biological Raman spectra and identify the microbes at a single cell level. The combination of a framework of convolutional neural network (ConvNet) and Raman spectroscopy allows the extraction of the Raman spectral features of a single microbial cell and then categorizes cells according to their spectral features. As the proof of concept, we measured Raman spectra of 14 microbial species at a single cell level and constructed an optimal ConvNet model using the Raman data. The average accuracy of classification by ConvNet is 95.64+ 5.46% Meanwhile, we introduced an occlusion based Raman spectra feature extraction (ORSFE) to visualize the weights of Raman features for distinguishing different species.", "author_names": [ "W Lu", "Xiuqiang Chen", "Li-li Wang", "Hanfei Li", "Yu Vincent Fu" ], "corpus_id": 215751183, "doc_id": "215751183", "n_citations": 18, "n_key_citations": 0, "score": 0, "title": "The combination of an artificial intelligence approach and laser tweezers Raman spectroscopy for microbial identification.", "venue": "Analytical chemistry", "year": 2020 }, { "abstract": "A condom can be described as a protective sheath used as a contraceptive or to protect against sexually transmitted diseases. However, individuals also use condoms during the commission of sexual assaults to prevent identification through deposited biological material. Raman spectroscopy offers a novel approach to identifying the presence of condom lubricant components. Furthermore, Raman chemical imaging expands on conventional Raman spectroscopy to characterize multiple condom lubricant components simultaneously in a manner that effectively demonstrates heterogeneous sample mixtures both spectrally and spatially. Known reference materials, liquid and solid lubricant components of common condom brands were successfully characterized using Raman dispersive spectroscopy and Raman chemical imaging without extensive sample preparation inherent to other analytical methods. The characterization of these materials demonstrates the potential of this technique to become a routine screening method for condom lubricants. This preliminary investigation provides a basis for future studies to determine the feasibility of Raman spectroscopy and Raman chemical imaging for condom lubricant trace detection in case type samples.", "author_names": [ "Julianne Wolfe", "David L Exline" ], "corpus_id": 25570515, "doc_id": "25570515", "n_citations": 29, "n_key_citations": 0, "score": 0, "title": "Characterization of condom lubricant components using Raman spectroscopy and Raman chemical imaging.", "venue": "Journal of forensic sciences", "year": 2003 }, { "abstract": "A wet chemical approach to synthesize Au graphene (Au G) Ag G and Ag@Au G hybrid nanocomposites in the water vitamin C system using graphene oxide and noble metal nanoparticles (NPs) is reported in this paper. AFM, TEM, UV vis absorption, Raman spectroscopy and XRD are employed to characterize the morphology, optical properties and analyze crystal characteristics. Ag@Au G nanocomposites have stronger surface enhanced Raman scattering (SERS) activity than that of pure Au G and Ag G. So the Ag@Au G nanocomposites can be used not only for SERS, but also to exhibit good compatibility in biological detection. It is expected that these hybrid materials can be used as new functional building blocks to assemble novel three dimensional (3D) complex multicomponent nanostructures, which are believed to be useful for nanodevices.", "author_names": [ "Liang Zhou", "Huai-min Gu", "Canchen Wang", "Juling Zhang", "Meng Lv", "Ruoyu He" ], "corpus_id": 96255673, "doc_id": "96255673", "n_citations": 29, "n_key_citations": 0, "score": 0, "title": "Study on the synthesis and surface enhanced Raman spectroscopy of graphene based nanocomposites decorated with noble metal nanoparticles", "venue": "", "year": 2013 }, { "abstract": "An approach binary spectronephelometry (BSN) to perform real time simultaneous noninvasive in situ physical and chemical analysis of bacterial cultures in fluid media is described. We choose to characterize cultures of Escherichia coli (NC) Pseudomonas aeruginosa (PA) and Shewanella oneidensis (SO) in the specific case of complex media whose Raman spectrum cannot be unambiguously assigned. Nevertheless, organism number density and a measure of the chemical makeup of the fluid medium can be monitored noninvasively, simultaneously, and continuously, despite changing turbidity and medium chemistry. The method involves irradiating a culture in fluid medium in an appropriate vessel (in this case a standard 1 cm cuvette) using a near infrared laser and collecting all the backscattered light from the cuvette, i.e. the Rayleigh Mie line and the inelastically emitted light which includes unresolved Raman scattered light and fluorescence. Complex \"legacy\" media contain materials of biological origin whose chemical composition cannot be fully delineated. We independently calibrate this approach to a commonly used reference, optical density at 600 nm (OD600) for characterizing the number density of organisms. We suggest that the total inelastically emitted light could be a measure of the chemical state of a biologically based medium, e.g. lysogeny broth (LB) This approach may be useful in a broad range of basic and applied studies and enterprises that utilize bacterial cultures in any medium or container that permits optical probing in the single scattering limit.", "author_names": [ "Steve Ortiz", "Ricky McDonough", "Paul Dent", "Jerry Goodisman", "Joseph Chaiken" ], "corpus_id": 199507252, "doc_id": "199507252", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Coupled Turbidity and Spectroscopy Problems: A Simple Algorithm for Volumetric Analysis of Optically Thin or Dilute, In Vitro Bacterial Cultures in Various Media", "venue": "Applied spectroscopy", "year": 2019 }, { "abstract": "Abstract A System has been developed to simulate biofouling of metal surfaces under a range of physical, chemical, and biological conditions. Items of equipment to eliminate and concentrate organic constituents from seawater and to analyze for proteins, glycoproteins, and carbohydrates have been acquired. Teflon fouling chambers have been developed to characterize surface properties of metals in seawater, i.e. adsorption of organic materials, using optical and electrochemical spectroscopic probes. Preliminary studies using these chambers and surface enhanced Raman spectroscopy demonstrated ability to detect thin layers of pyridine, tryptophan, and phenylalanine adsorbed to silver electrodes. A system to perform waveguide Internal Reflectance Raman Spectroscopy (WIRRS) on thin films adsorbed to a substratum was developed and tested. During preliminary studies, an excellent Raman spectrum was obtained from a 1 micrometer layer of polystyrene. For Electrochemical Impedance Spectroscopy (EIS) electronic hardware was acquired and software was developed to determine the impedance attributes of fouled metal coupons. Preliminary EIS studies using the enzyme, Ribulose Biphosphate Carboxylase, demonstrated the ability to detect adsorption of this protein to a silver electrode.", "author_names": [ "Gordon T Taylor" ], "corpus_id": 137137549, "doc_id": "137137549", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Examination of Chemical Adsorption and Marine Biofouling on Metal Surfaces Using Raman Scattering Techniques and Electrochemical Impedance Spectroscopy", "venue": "", "year": 1991 }, { "abstract": "In the latest literature search, the technology based on graphite oxide (GO) nanomaterials exhibits a great potential in many aspects of wastewater treatment involving adsorption, photocatalysis, disinfection and membrane process. In this study experimental data involving the carbon element in different forms such as active carbon (AC) graphite and graphene oxide (GO) applied as the active reagents in wastewater treatment are summarized and discussed. The first step was to characterize the aforementioned carbon materials and nanoparticles using various complementary techniques. These include optical microscopy, scanning electron microscopy (SEM) energy dispersive spectroscopy (EDS) Raman spectrophotometry and zeta potential measurements. The second issue was to design the relatively simple experiment enabling us to observe the physicochemical and biological effects of carbon nanoparticles in the presence of sewage water and/or active sludge. Obtained experimental data have been inspected using univariate and multivariate (principal component analysis, PCA) approaches confirming the complex interaction of GO nanoparticles with microorganisms that are present in activated sludge. This experiment enabled the collection of an initial data set to design different large scale investigations focusing on active nanoparticles affecting wastewater purification. PCA calculations clearly revealed that GO strongly affects the wastewater technological processes investigated. It is hoped that the described results will allow the design of smart environmental protection systems in the future.", "author_names": [ "Krzysztof Piaskowski", "Pawel Zarzycki" ], "corpus_id": 221236216, "doc_id": "221236216", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Carbon Based Nanomaterials as Promising Material for Wastewater Treatment Processes", "venue": "International journal of environmental research and public health", "year": 2020 }, { "abstract": "Breast cancer is the most malignant type of cancer in women and is a global health problem, with mortality by metastasis being the main factor among others. Currently, detection and diagnosis of breast cancer is achieved through a variety of procedures, such as clinical examination, medical imaging, biopsy, and histopathological analysis. In contrast, spectroscopic analysis has a variety of advantages such as being noninvasive, not destroying biological materials, and not requiring additional histological analysis. In this study, various approaches using Raman spectroscopy, atomic force microscopy (AFM) and optical microscopy were used together to differentiate between and characterize normal breast cell lines (MCF 10A) and breast cancer cell lines (MDA MB 231, MDA MB 453) Raman spectra of normal breast cell and breast cancer cell lines confirmed visual differences in the concentrations of various compounds. These spectra were also analyzed using principle component analysis (PCA) and the PCA results showed reliable separation of the three cell lines and the cancer cell lines (MDA MB 231, MDA MB 453) With these results, optically synchronizing the AFM morphology, the Raman spectroscopy, and the visible RGB optical transmission intensity provided contrasts for not only conformational differences but also intracellular variation between the normal and cancer cell lines. We observed the inherent characteristic that there is no local difference in cancer cells regardless of morphology in a wide range of optical properties such as absorption, scattering and inelastic scattering.", "author_names": [ "Seung Ho Lee", "Ok-Kyun Kim", "Sanghwa Lee", "Jun Ki Kim" ], "corpus_id": 51647371, "doc_id": "51647371", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Local dependency of morphological and optical properties between breast cancer cell lines.", "venue": "Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy", "year": 2018 }, { "abstract": "Raman spectroscopy has become an essential tool for chemists, physicists, biologists and materials scientists. In this article, we present the challenges in unravelling the molecule specific Raman spectral signatures of different biomolecules like proteins, nucleic acids, lipids and carbohydrates based on the review of our work and the current trends in these areas. We also show how Raman spectroscopy can be used to probe the secondary and tertiary structural changes occurring during thermal denaturation of protein and lysozyme as well as more complex biological systems like bacteria. Complex biological systems like tissues, cells, blood serum etc. are also made up of such biomolecules. Using mice liver and blood serum, it is shown that different tissues yield their unique signature Raman spectra, owing to a difference in the relative composition of the biomolecules. Additionally, recent progress in Raman spectroscopy for diagnosing a multitude of diseases ranging from cancer to infection is also presented. The second part of this article focuses on applications of Raman spectroscopy to materials. As a first example, Raman spectroscopy of a melt cast explosives formulation was carried out to monitor the changes in the peaks which indicates the potential of this technique for remote process monitoring. The second example presents various modern methods of Raman spectroscopy such as spatially offset Raman spectroscopy (SORS) reflection, transmission and universal multiple angle Raman spectroscopy (UMARS) to study layered materials. Studies on chemicals/layered materials hidden in non metallic containers using the above variants are presented. Using suitable examples, it is shown how a specific excitation or collection geometry can yield different information about the location of materials. Additionally, it is shown that UMARS imaging can also be used as an effective tool to obtain layer specific information of materials located at depths beyond a few centimeters.", "author_names": [ "Nikki Kuhar", "S Sil", "Taru Verma", "Siva Umapathy" ], "corpus_id": 105749228, "doc_id": "105749228", "n_citations": 62, "n_key_citations": 1, "score": 0, "title": "Challenges in application of Raman spectroscopy to biology and materials", "venue": "", "year": 2018 }, { "abstract": "Abstract The ability of Raman spectroscopy to characterize amorphous materials makes this technique ideal to study alkali silica reaction (ASR) gels. The structure of several synthetic ASR gels was thoroughly characterized using Raman Spectroscopy. The results were validated with additional techniques such as Fourier transmission infrared spectroscopy, X ray powder diffraction and thermogravimetric analysis. The Raman spectra were found to have two broad bands in the 800 to 1200 cm 1 range and the 400 to 700 cm 1 range indicating the amorphous nature of the gel. Important information regarding the silicate polymerization was deduced from both of these spectral regions. An increase in alkali content of the gels caused a depolymerization in the silicate framework which manifested in the Raman spectra as a gradual shift of predominant peaks in both regions. The trends in silicate depolymerization were in agreement with results from a NMR spectroscopy study on similar synthetic ASR gels.", "author_names": [ "Chandni Balachandran", "Jose Luis Fernandez Munoz", "Terry S Arnold" ], "corpus_id": 102407233, "doc_id": "102407233", "n_citations": 25, "n_key_citations": 1, "score": 0, "title": "Characterization of alkali silica reaction gels using Raman spectroscopy", "venue": "", "year": 2017 } ]

[ { "abstract": "In this study, a transition from metallic to semiconducting like behavior has been demonstrated in two dimensional (2D) transition metal carbides by replacing titanium with molybdenum in the outer transition metal (M) layers of M3C2 and M4C3 MXenes. The MXene structure consists of n 1 layers of near close packed M layers with C or N occupying the octahedral site between them in an [MX]nM arrangement. Recently, two new families of ordered 2D double transition metal carbides MXenes were discovered, M'2M''C2 and M'2M''2C3 where M' and M' are two different early transition metals, such as Mo, Cr, Ta, Nb, V, and Ti. The M' atoms only occupy the outer layers and the M' atoms fill the middle layers. In other words, M' atomic layers sandwich the middle M' C layers. Using X ray atomic pair distribution function (PDF) analysis on Mo2TiC2 and Mo2Ti2C3 MXenes, we present the first quantitative analysis of structures of these novel materials and experimentally confirm that Mo atoms are in the outer layers of the [MC]nM structures. The electronic properties of these Mo containing MXenes are compared with their Ti3C2 counterparts, and are found to be no longer metallic like conductors; instead the resistance increases mildly with decreasing temperatures. Density functional theory (DFT) calculations suggest that OH terminated Mo Ti MXenes are semiconductors with narrow band gaps. Measurements of the temperature dependencies of conductivities and magnetoresistances have confirmed that Mo2TiC2Tx exhibits semiconductor like transport behavior, while Ti3C2Tx is a metal. This finding opens new avenues for the control of the electronic and optical applications of MXenes and for exploring new applications, in which semiconducting properties are required.", "author_names": [ "Babak Anasori", "Chenyang Shi", "Eun Ju Moon", "Yu Xie", "Cooper A Voigt", "Paul R C Kent", "Steven J May", "Simon J L Billinge", "Michel W Barsoum", "Yury Gogotsi" ], "corpus_id": 101080633, "doc_id": "101080633", "n_citations": 158, "n_key_citations": 0, "score": 1, "title": "Control of electronic properties of 2D carbides (MXenes) by manipulating their transition metal layers.", "venue": "Nanoscale horizons", "year": 2016 }, { "abstract": "Abstract In 2011, a new family of two dimensional (2D) carbides, carbonitrides and nitrides labeled MXenes was discovered. Since then the number of papers on these materials has increased exponentially for several reasons amongst them: their hydrophilic nature, excellent electronic conductivities and ease of synthesizing large quantities in water. This unique combination of properties and ease of processing has positioned them as enabling materials for a large, and quite varied, host of applications from energy storage to electromagnetic shielding, transparent conductive electrodes, electrocatalysis, to name a few. Since the initial synthesis of Ti3C2 in hydrofluoric acid, many more compositions were discovered, and different synthesis pathways were explored. Most of the work done so far has been conducted on top down synthesis where a layered parent compound is etched and then exfoliated. Three bottom up synthesis methods, chemical vapor deposition, a template method and plasma enhanced pulsed laser deposition have been reported. The latter methods enable the synthesis of not only high quality ultrathin 2D transition metal carbide and nitride films, but also those that could not be synthesized by selective etching. This article reviews and summarizes the most important breakthroughs in the synthesis of MXenes and high quality ultrathin 2D transition metal carbide and nitride films.", "author_names": [ "Louisiane Verger", "Chuan Xu", "Varun Natu", "Hui-Ming Cheng", "Wencai Ren", "Michel W Barsoum" ], "corpus_id": 140014706, "doc_id": "140014706", "n_citations": 111, "n_key_citations": 2, "score": 0, "title": "Overview of the synthesis of MXenes and other ultrathin 2D transition metal carbides and nitrides", "venue": "Current Opinion in Solid State and Materials Science", "year": 2019 }, { "abstract": "MXenes are 2D transition metal carbides with high potential for overcoming limitations of conventional two dimensional electronics. In this context, various MXenes have shown magnetic properties suitable for applications in spintronics, yet the number of MXenes reported so far is far smaller than their parental MAX phases. Therefore, we have studied the structural, electronic and magnetic properties of bimetallic and vacancy ordered MXenes derived from a new (V2/3Zr1/3)2AlC MAX phase to assess whether MXene exfoliation would return stable magnetic materials. In particular, we have investigated the properties of pristine and surface functionalized (V2/3Zr1/3)2CX2 bimetallic and (V2/3#1/3)2CX2 (where denotes the vacancies) vacancy ordered MXenes (X O, F and OH) Our density functional theory (DFT) calculations showed that modifying the MXene stoichiometry and/or MXene surface functionalization changes MXene properties. After testing all possible combinations of metallic motifs and functionalization, we identified (V2/3Zr1/3)2CX2, (V2/3#1/3)2CF2 and (V2/3#1/3)2C(OH)2 as stable structures. Among them, (V2/3Zr1/3)2CO2 MXene is predicted to be an FM intrinsic half semiconductor with a remarkably high Curie temperature (TC) of 270 K. The (V2/3Zr1/3)2C(OH)2 MXene exhibits a rather low work function (WF) (1.37 eV) and is thus a promising candidate for ultra low work function electron emitters. Conversely, the (V2/3#1/3)2CF2 MXene has a rather high WF and hence can be used as a hole injector for Schottky barrier free contact applications. Overall, our proof of concept study shows that theoretical predictions of MXene exfoliation and properties support further experimental research towards developing spintronics devices.", "author_names": [ "Shuo Li", "Junjie He", "Petr Nachtigall", "Luk'avs Grajciar", "Federico Brivio" ], "corpus_id": 203641751, "doc_id": "203641751", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Control of spintronic and electronic properties of bimetallic and vacancy ordered vanadium carbide MXenes via surface functionalization.", "venue": "Physical chemistry chemical physics PCCP", "year": 2019 }, { "abstract": "With the development of electronic devices such as integrated circuits toward the continual increase in power density and consumption, the efficient heat dissipation and low thermal expansion of materials become one of the most important issue. However, conventional polymers have the problem of poor thermal dissipation performance, which hinder application for electronic devices. In this work, the two dimensional material, MXene (Ti3C2) is used as the reinforcement additive to optimize the thermal properties of polymers. We reported the preparation of multilayer Ti3C2 MXene by HF etching method and obtained few layer Ti3C2 MXene by simple ultrasonication. Meanwhile, Ti3C2/epoxy composites were prepared by a solution blending method. The results show that the thermal properties of the composites are improved in comparison with the neat epoxy. Thermal conductivity value (0.587 W/mK) of epoxy composite with only 1.0 wt% Ti3C2 MXene fillers, is increased by 141.3% compared with that of neat epoxy. In addition, the composite presents an increased glass transition temperature, high thermal stability and lower coefficient of thermal expansion. This work is of great significance for the research of high performance composite materials.", "author_names": [ "Ruiyang Kang", "Zhenyu J Zhang", "Liangchao Guo", "Junfeng Cui", "Yapeng Chen", "Xiao Hou", "Bo Wang", "Cheng-Te Lin", "Nan Jiang", "Jinhong Yu" ], "corpus_id": 195329703, "doc_id": "195329703", "n_citations": 39, "n_key_citations": 1, "score": 0, "title": "Enhanced Thermal Conductivity of Epoxy Composites Filled with 2D Transition Metal Carbides (MXenes) with Ultralow Loading", "venue": "Scientific Reports", "year": 2019 }, { "abstract": "Strain engineering appears as an effective way to modulate physical and chemical properties of two dimensional (2D) materials. In contrast to their three dimensional counterparts, 2D materials can withstand high strain before rapture, which promises unique opportunities to control and tune their electronic, optical, and magnetic properties. Recently predicted Hf 2 MnC 2 O 2 and Hf 2 VC 2 O 2 double transition metal ferromagnetic semiconductor MXenes show robust ferromagnetic ground state with high Curie temperature. In this study, we investigated the structural, electronic, and magnetic properties of those 2D materials under the biaxial strain using density functional theory. Both strain free monolayers are indirect bandgap semiconductors. Strain engineering can be exploited to turn semiconductor monolayers into metallic or semi metallic ones depending on the size and type of the applied strain. For instance, a semiconductor to metal transition occurs at 3 compression and 8% tension in Hf 2 MnC 2 O 2 and also at 2 compression and 9% tension in Hf 2 VC 2 O 2. Electron and hole effective masses are able to be tuned significantly. The ferromagnetic phase becomes stronger (weaker) as compared to the anti ferromagnetic phase of both types of monolayers by applying the biaxial tensile (compressive) strain. Our calculations indicated that the Curie temperature T C) is highly sensitive to the size and type of strain. T C increases (decreases) with the tensile (compressive) strain. While T C is 444 K at a compressive strain of 4% it becomes 1577 K at a tensile strain of 8% for Hf 2 MnC 2 O 2.Strain engineering appears as an effective way to modulate physical and chemical properties of two dimensional (2D) materials. In contrast to their three dimensional counterparts, 2D materials can withstand high strain before rapture, which promises unique opportunities to control and tune their electronic, optical, and magnetic properties. Recently predicted Hf 2 MnC 2 O 2 and Hf 2 VC 2 O 2 double transition metal ferromagnetic semiconductor MXenes show robust ferromagnetic ground state with high Curie temperature. In this study, we investigated the structural, electronic, and magnetic properties of those 2D materials under the biaxial strain using density functional theory. Both strain free monolayers are indirect bandgap semiconductors. Strain engineering can be exploited to turn semiconductor monolayers into metallic or semi metallic ones depending on the size and type of the applied strain. For instance, a semiconductor to metal transition occurs at 3 compression and 8% tension", "author_names": [ "Edirisuriya M D Siriwardane", "Deniz Cakir" ], "corpus_id": 127362358, "doc_id": "127362358", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Strain engineering of electronic and magnetic properties of double transition metal ferromagnetic semiconductor MXenes", "venue": "Journal of Applied Physics", "year": 2019 }, { "abstract": "MXenes have demonstrated high performance as negative electrodes in supercapacitors with aqueous electrolytes due to their high redox capacitance. However, oxidation limits their use under positive potential, requiring asymmetric devices with positive electrodes made of other materials which are usually less capacitive compared to MXenes and therefore limit the device performances. Here, we report the synthesis of two dimensional molybdenum vanadium carbides (MoxV4 xC3) previously unexplored double transition metal MXenes, by selective etching of aluminum from MoxV4 xAlC3 MAX phase precursors. Unlike the ordered double transition metal MXenes reported previously, MoxV4 xC3 exhibits a Mo V solid solution in the transition metal layers. We have synthesized and characterized four different compositions of MoxV4 xC3 with x 1, 1.5, 2, and 2.7. We showed that by changing the Mo V ratio, the surface terminations (O F ratio) and electrical and electrochemical properties of the resulting MXenes can be tuned. The Mo2.7V1.3C3 composition showed a remarkable volumetric capacitance (up to 860 F cm 3) and high electrical conductivity (830 S cm 1) at room temperature. Moreover, these solid solution MXenes have demonstrated the ability to operate in a wider range of positive potentials compared to other MXenes. Following this discovery, we coupled a Mo2.7V1.3C3 positive electrode with a well studied Ti3C2 MXene negative electrode to create an all MXene supercapacitor, as a proof of concept.", "author_names": [ "David Pinto", "Babak Anasori", "Hemesh Avireddy", "Christopher Eugene Shuck", "Kanit Hantanasirisakul", "Grayson Deysher", "Joan Ramon Morante", "William Porzio", "Husam N Alshareef", "Yury Gogotsi" ], "corpus_id": 218778531, "doc_id": "218778531", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "Synthesis and electrochemical properties of 2D molybdenum vanadium carbides solid solution MXenes", "venue": "", "year": 2020 }, { "abstract": "The family of 2D transition metal carbides, carbonitrides and nitrides (collectively referred to as MXenes) has expanded rapidly since the discovery of Ti3C2 in 2011. The materials reported so far always have surface terminations, such as hydroxyl, oxygen or fluorine, which impart hydrophilicity to their surfaces. About 20 different MXenes have been synthesized, and the structures and properties of dozens more have been theoretically predicted. The availability of solid solutions, the control of surface terminations and a recent discovery of multi transition metal layered MXenes offer the potential for synthesis of many new structures. The versatile chemistry of MXenes allows the tuning of properties for applications including energy storage, electromagnetic interference shielding, reinforcement for composites, water purification, gas and biosensors, lubrication, and photo electro and chemical catalysis. Attractive electronic, optical, plasmonic and thermoelectric properties have also been shown. In this Review, we present the synthesis, structure and properties of MXenes, as well as their energy storage and related applications, and an outlook for future research. More than twenty 2D carbides, nitrides and carbonitrides of transition metals (MXenes) have been synthesized and studied, and dozens more predicted to exist. Highly electrically conductive MXenes show promise in electrical energy storage, electromagnetic interference shielding, electrocatalysis, plasmonics and other applications.", "author_names": [ "Babak Anasori", "Maria R Lukatskaya", "Yury Gogotsi" ], "corpus_id": 136258520, "doc_id": "136258520", "n_citations": 2560, "n_key_citations": 13, "score": 0, "title": "2D metal carbides and nitrides (MXenes) for energy storage", "venue": "", "year": 2017 }, { "abstract": "Growing interest in the potential applications of two dimensional (2D) materials has fueled advancement in the identification of 2D systems with exotic properties. Increasingly, the bottleneck in this field is the synthesis of these materials. Although theoretical calculations have predicted a myriad of promising 2D materials, only a few dozen have been experimentally realized since the initial discovery of graphene. Here, we adapt the state of the art positive and unlabeled (PU) machine learning framework to predict which theoretically proposed 2D materials have the highest likelihood of being successfully synthesized. Using elemental information and data from high throughput density functional theory calculations, we apply the PU learning method to the MXene family of 2D transition metal carbides, carbonitrides, and nitrides, and their layered precursor MAX phases, and identify 18 MXene compounds that are highly promising candidates for synthesis. By considering both the MXenes and their precursors, we further propose 20 synthesizable MAX phases that can be chemically exfoliated to produce MXenes.", "author_names": [ "Nathan C Frey", "Jin Wang", "Gabriel Ivan Vega Bellido", "Babak Anasori", "Yury Gogotsi", "Vivek B Shenoy" ], "corpus_id": 73483176, "doc_id": "73483176", "n_citations": 60, "n_key_citations": 0, "score": 0, "title": "Prediction of Synthesis of 2D Metal Carbides and Nitrides (MXenes) and Their Precursors with Positive and Unlabeled Machine Learning.", "venue": "ACS nano", "year": 2019 }, { "abstract": "Summary In 2011, a new and growing family of two dimensional (2D) transition metal carbides, nitrides, and carbonitrides (MXenes) was discovered. Benefitting from intriguing electronic and structural properties, MXenes have received increasing attention and emerged as next generation nanomaterials for the exploration of environmentally friendly energy resources for catalysis in energy and environmental technologies. In this review, we systematically highlight the expeditious advances and achievements in design strategies, physico chemical properties, and catalytic applications of 2D layered MXenes and their nanocomposites in environmental science and renewable energy. In addition, we unravel the structural, optical, and electronic properties of MXenes to elucidate their key roles of ameliorating the niche areas of photo(electro)catalytic hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, carabon dioxide reduction reaction, nitrogen reduction reaction, and pollutant degradation. This review concludes with invigorating perspectives, outlooks, and formidable challenges in the future development of MXene based materials for sustainable applications.", "author_names": [ "Jiahe Peng", "Xingzhuo Chen", "Wee-Jun Ong", "Xiujian Zhao", "Neng Li" ], "corpus_id": 186398625, "doc_id": "186398625", "n_citations": 253, "n_key_citations": 0, "score": 0, "title": "Surface and Heterointerface Engineering of 2D MXenes and Their Nanocomposites: Insights into Electro and Photocatalysis", "venue": "", "year": 2019 }, { "abstract": "The ability in experiments to control the relative twist angle between successive layers in two dimensional (2D) materials offers an approach to manipulating their electronic properties; we refer to this approach as `twistronics. A major challenge to theory is that, for arbitrary twist angles, the resulting structure involves incommensurate (aperiodic) 2D lattices. Here, we present a general method for the calculation of the electronic density of states of aperiodic 2D layered materials, using parameter free Hamiltonians derived from ab initio density functional theory. We use graphene, a semimetal, and \\mathrm{MoS}}_{2} a representative of the transition metal dichalcogenide family of 2D semiconductors, to illustrate the application of our method, which enables fast and efficient simulation of multilayered stacks in the presence of local disorder and external fields. We comment on the interesting features of their density of states as a function of twist angle and local configuration and on how these features can be experimentally observed.", "author_names": [ "Stephen Carr", "Daniel Massatt", "Shiang Fang", "Paul Cazeaux", "Mitchell Luskin", "Efthimios Kaxiras" ], "corpus_id": 27148700, "doc_id": "27148700", "n_citations": 138, "n_key_citations": 2, "score": 0, "title": "Twistronics: Manipulating the electronic properties of two dimensional layered structures through their twist angle", "venue": "", "year": 2017 } ]

[ { "abstract": "Tunneling field effect transistors (TFETs) have created excitement for their potential to overcome the 60 mV/decade thermal limit of the subthreshold swing for conventional devices enabling lower power electronics. However, as shown in the TFET review by Seabaugh and Zhang [1] experimental subthreshold characteristics have not achieved the steepness of theoretical predictions. Possible explanations for the non abrupt turn on of experimental devices include long band tails (exacerbated by doping) that extend into the semiconductor band gap, mid gap and interface trap states, inhomogeneity of the semiconductor composition, strain and/or thickness, and non optimal electrostatic design of the transistor structure. This paper focuses on improving the electrostatic design of vertical tunneling structures (where tunneling occurs vertically toward the gate) in order to better experimental turn on characteristics.", "author_names": [ "James T Teherani", "Tao Yu", "Dimitri A Antoniadis", "Judy L Hoyt" ], "corpus_id": 11038377, "doc_id": "11038377", "n_citations": 5, "n_key_citations": 0, "score": 1, "title": "Electrostatic design of vertical tunneling field effect transistors", "venue": "2013 Third Berkeley Symposium on Energy Efficient Electronic Systems (E3S)", "year": 2013 }, { "abstract": "Abstract Total ionizing dose (TID) and transient dose rate (TDR) effects on planar and vertical ferroelectric tunneling field effect transistors (TFET) are investigated using TCAD simulations. First, two types of TFET structures are constructed numerically. Then the electrical properties of these devices are studied under different irradiation doses, demonstrating that they are slightly affected by TID effects, especially for the vertical transistor. The maximum photocurrents under different operation voltage (VD) and dose rate are extremely small with respect to the conventional bulk transistors. Physical mechanisms of device performance degradation are investigated in detail. The results suggest that the vertical ferroelectric TFET, which shows better electrical performance and radiation hard characteristics compared with the planar one, is useful for the design of very large scale logic circuits for applications in harsh radiation environments.", "author_names": [ "Gangping Yan", "Gaobo Xu", "Jinshun Bi", "Guoliang Tian", "Qiuxia Xu", "Huaxiang Yin", "Yongliang Li" ], "corpus_id": 228986618, "doc_id": "228986618", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Accumulative total ionizing dose (TID) and transient dose rate (TDR) effects on planar and vertical ferroelectric tunneling field effect transistors (TFET)", "venue": "", "year": 2020 }, { "abstract": "Tunneling field effect transistors (TFETs) have been proposed as energy efficient switches for low power integrated circuits. In this letter, we present the first reconfigurable black phosphorus vertical TFET. The device exhibits a record high ON current <inline formula> <tex math notation=\"LaTeX\"{I}_{\\text {ON} /tex math>/inline formula> among all 2D TFETs of <inline formula> <tex math notation=\"LaTeX\"$15.2~\\mu \\text{A}\\mu \\text{m} /tex math>/inline formula> at <inline formula> <tex math notation=\"LaTeX\"{V}_{\\text {DS} {1} /tex math>/inline formula> V and a subthreshold swing (SS) of 187 mV/dec at <inline formula> <tex math notation=\"LaTeX\"$V_{\\text {DS} {0.3} /tex math>/inline formula> V. By tuning the electrostatic doping with multiple gates, the device can be reconfigured to operate in the TFET mode or the MOSFET mode and can be tuned to behave like an n type or p type FET. Moreover, negative differential resistance (NDR) is observed in the forward bias of the TFET at room temperature, providing unambiguous evidence of band to band tunneling in our devices.", "author_names": [ "Peng Wu", "Joerg Appenzeller" ], "corpus_id": 132452023, "doc_id": "132452023", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Reconfigurable Black Phosphorus Vertical Tunneling Field Effect Transistor With Record High ON Currents", "venue": "IEEE Electron Device Letters", "year": 2019 }, { "abstract": "Dear editor, Ferroelectric tunneling FETs (FeTFETs) are the increasingly significant research topics on novel low power electronic devices [1, 2] because ferroelectric materials' negative capacitance effect is helpful to boost the channel potential and increase the on state current in TFETs. Ferroelectric materials show radiation hard performance against radiation, which is helpful for devices based on this type of material utilized in harsh environment [3, 4] Single event transient (SET) effects are caused by high energy particles in space or terrestrial radiation environment, which may increase the probability of soft error or even lead to catastrophic accidents in the spacecraft [5, 6] Research on the irradiation effects of FeTFETs under heavy ion strike is therefore extremely important to evaluate use of these devices for potential missions in space environments. In order to boost the devices' performance, we propose a new silicon oninsulator double gate FeTFET (SOI DG FeTFET) with the Si:HfO2 ferroelectric gate dielectric. The single event transient effects in SOI DG FeTFET were investigated using a synopsys sentaurus technology computer aided design (TCAD) simulator [7] Device structure and simulation setup. The two dimensional (2D) architecture of the SOI DGFeTFET considered in the simulation is shown in Figure 1(a) In this structure, 10 nm thick Si:HfO2 ferroelectric layer is used as the gate dielectric, and amorphous HfO2 film with 2 nm thickness is used as a gate insulator between the poly crystalline Si:HfO2 layer and Si substrate. The detailed geometry parameters for SOI DG FeTFET are given in Figure 1(b) Complete device structure was built in the simulation, with left and right drains part of the same node. Because the structure is symmetrical, the right half of the device is chosen as the incident position of heavy ions. Ions strike in the middle of the body in the right half of the device with linear energy transfer (LET) ranges from 10 to 100 MeV*cm/mg. Collection charge in the complete device structure is taken into consideration. The ion trajectories have a Gaussian radial distribution with characteristic radius of 5 nm. The SOI DG FeTFET in TCAD simulation is biased to off state (Vg 0 V) with the drain terminal at 0.5 V, while the substrate and source electrodes are grounded. Results and discussion. Figure 1(c) shows the SET drain current for SOI DG FeTFET with different LETs at Vd 0.5 V. The drain transient leakage current gradually increases to a max", "author_names": [ "Guoliang Tian", "Jinshun Bi", "Gaobo Xu", "Kai Xi", "Xueqin Yang", "Majumdar Sandip", "Huaxiang Yin", "Qiuxia Xu", "Wenwu Wang" ], "corpus_id": 227138905, "doc_id": "227138905", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Single event transient effects in silicon on insulator ferroelectric double gate vertical tunneling field effect transistors", "venue": "", "year": 2020 }, { "abstract": "We demonstrate improved performance due to enhanced electrostatic control achieved by diameter scaling and gate placement in vertical InAs GaSb tunneling field effect transistors integrated on Si substrates. The best subthreshold swing, 68 mV/decade at VDS 0.3 V, was achieved for a device with 20 nm InAs diameter. The ON current for the same device was 35 mA/mm at VGS 0.5 V and VDS 0.5 V. The fabrication technique used allow downscaling of the InAs diameter down to 11 nm with a flexible gate placement.", "author_names": [ "Elvedin Memisevic", "Johannes Svensson", "Markus Hellenbrand", "Erik Lind", "Lars-Erik Wernersson" ], "corpus_id": 32398230, "doc_id": "32398230", "n_citations": 44, "n_key_citations": 1, "score": 0, "title": "Scaling of Vertical InAs GaSb Nanowire Tunneling Field Effect Transistors on Si", "venue": "IEEE Electron Device Letters", "year": 2016 }, { "abstract": "Subthreshold characteristics of vertical tunneling field effect transistors (VTFETs) with an n+ pocket in the p+ source are studied by simulating the transfer characteristics with a commercial device simulator. Three types of subthreshold characteristics are demonstrated for the device with different pocket thicknesses and doping concentrations. Band diagram analysis shows that such a VTFET can be treated as a gate controlled tunnel diode connected in series with a conventional n channel metal oxide semiconductor FET. This VTFET can work either as a TFET or an n MOSFET in the subthreshold region, depending on the turn on sequence of these two components. To our knowledge, this is the first time such a device model has been used to explain the subthreshold characteristics of this kind of VTFET and the simulation results demonstrate that such a device model is convictive and valid. Our results indicate that the design of the n+ pocket is crucial for such a VTFET in order to achieve ultra steep turn on characteristics.", "author_names": [ "Han Zhongfang", "Ru Guo-Ping", "Ruan Gang" ], "corpus_id": 111013813, "doc_id": "111013813", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Analysis of the subthreshold characteristics of vertical tunneling field effect transistors", "venue": "", "year": 2013 }, { "abstract": "The effect of interface traps on InGaAs based vertical gate all around (GAA) tunneling field effect transistors (TFETs) has been investigated using technology computer aided design (TCAD) simulation. The interface traps distributed within different energy levels (Et) in the energy bandgap of a semiconductor material exhibit various influences on the device performances. In this work, InGaAs based TFETs are simulated to analyze the effects on the on state current (Ion) off state current (Ioff) threshold voltage (Vth) subthreshold swing (SS) and the ambipolar characteristics according to Et and type of the interface traps. We have confirmed that Ioff and SS are degraded by the interface traps. Further, it can be shown that Ion is mainly affected by the acceptor like traps and ambipolar behavior is affected by the donor like traps. All the effects increase as Et becomes closer to the midgap. The effects of the interface traps with gate underlap and overlap at the source channel region also have been investigated, considering the device fabrication. Additionally, the analysis of the effect of junction trap created at the source channel junction has been performed.", "author_names": [ "Won Douk Jang", "Young Jun Yoon", "Min Su Cho", "Bo Gyeong Kim", "D In Man Kang" ], "corpus_id": 135381569, "doc_id": "135381569", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Effect of Interface Traps on the Device Performance of InGaAs Based Gate All Around Tunneling Field Effect Transistors.", "venue": "Journal of nanoscience and nanotechnology", "year": 2019 }, { "abstract": "Doping organic semiconductors has become a key technology to increase the performance of organic light emitting diodes, solar cells, or field effect transistors (OFETs) However, doping can be used.", "author_names": [ "Shiyi Liu", "Max Lutz Tietze", "Akram Al-Shadeedi", "Vikash Kaphle", "Changmin Keum", "Bjorn Lussem" ], "corpus_id": 200019910, "doc_id": "200019910", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Vertical Organic Tunnel Field Effect Transistors", "venue": "ACS Applied Electronic Materials", "year": 2019 }, { "abstract": "A structure of a tunneling field effect transistor (TFET) featuring an extremely thin body, a double gated vertical channel, and a source design to maximize the drive current is proposed and optimized on the basis of technology computer aided design (TCAD) simulation. The field coupling effect at the double gated thin body channel and an engineered tunneling barrier are implemented to maximize the operation current of the device. Weak current drivability under a small drain bias and the directionality of current flow are the expected challenges in building logic circuits with TFETs. A co integration scheme to build vertical channel TFETs and metal oxide semiconductor field effect transistors (MOSFETs) is proposed as the solution. A new low power design using the co integration scheme is suggested.", "author_names": [ "Min-Chul Sun", "Sang Wan Kim", "Hyun Woo Kim", "Garam Kim", "Hyungjin Kim", "Jongho Lee", "Hyungcheol Shin", "Byung-Gook Park" ], "corpus_id": 111068345, "doc_id": "111068345", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Design of Thin Body Double Gated Vertical Channel Tunneling Field Effect Transistors for Ultralow Power Logic Circuits", "venue": "", "year": 2012 }, { "abstract": "In this work, design optimization of vertical double gate (VDG) tunneling field effect transistors (TFETs) with hetero gate dielectric (HG) materials has been performed. High k materials such as Si3N4, HfO2, and ZrO2 were used for the HG structure. The optimized parameters for maximizing the device performances were the length of the high k material (Lhigh k) and the thickness of silicon channel (tSi) For HfO2, the subthreshold swing (SS) and on current were optimized at a Lhigh k of 11 nm and a tSi of 5 nm. The optimized device had an on current (Ion) of 151 uA/um and a SS of 46.6 mV/dec. In addition, to improve the on current level of the optimized device, we inserted a thin n doped layer into the channel near the source side, and we analyzed the performance. The on current level of the device with an n doped layer was nearly double that of the device without an n doped layer.", "author_names": [ "Young Jun Yoon", "Sung Yun Woo", "Jae Hwa Seo", "Jae-Sung Lee", "Yun Soo Park", "Jung-Hee Lee", "In Man Kang" ], "corpus_id": 120807570, "doc_id": "120807570", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Design optimization of vertical double gate tunneling field effect transistors", "venue": "", "year": 2012 } ]

[ { "abstract": "Abstract Paper based laser induced fluorescence immunodevice for alpha fetoprotein (AFP) detection was developed in this work by using CdTe quantum dots (QDs) embedded silica nanoparticles as the signal enhancement label. A homemade laser induced fluorescence device with two optical fibres was used here for the fluorescence detection. Laser issued by a semiconductor laser light source (405 nm, 1 mW) was exposed to the paper based chip with very lower background through an optical fiber and the fluorescence (542 nm) induced by laser was collected to a photomultiplier tube (PMT) through a glass fiber. The paper based chip was fabricated by the wax printing method and the antibody can be directly immobilized on the plasma treated paper surface. Then CdTe QDs embedded silica nanoparticles with the signal enhancement function was labeled on the signal antibody. After a sandwich type immunoreaction, AFP was linearly detected in the range from 0.001 ng/mL to 20.0 ng/mL with a detection limit of 0.4 pg/mL. Laser induced fluorescence with the homemade device was for the first time applied on the paper based chip with very higher sensitivity. What's more, the proposed strategy opened a promising platform for sensitive monitoring of cancer biomarkers in biological analysis and medical diagnostics.", "author_names": [ "Mei Zhao", "Huifang Li", "Wei Chun Liu", "Weiru Chu", "Ying Chen" ], "corpus_id": 100052988, "doc_id": "100052988", "n_citations": 31, "n_key_citations": 0, "score": 1, "title": "Paper based laser induced fluorescence immunodevice combining with CdTe embedded silica nanoparticles signal enhancement strategy", "venue": "", "year": 2017 }, { "abstract": "Cobalt element plays an important role for the properties of magnetism and thermology in steels. In this work, laser induced breakdown spectroscopy combined with laser induced fluorescence (LIBS LIF) was studied to selectively enhance the intensities of Co lines. Two states of Co atoms were resonantly excited by a wavelength tunable laser. LIBS LIF with ground state atom excitation (LIBS LIFG) and LIBS LIF with excited state atom excitation (LIBS LIFE) were compared. The results show that LIBS LIFG has analytical performance with LoD of 0.82mg/g, R(2) of 0.982, RMSECV of 86mg/g, and RE of 9.27% which are much better than conventional LIBS and LIBS LIFE. This work provided LIBS LIFG as a capable approach for determining trace Co element in the steel industry.", "author_names": [ "Jiaming Li", "Lianbo Guo", "Nan Zhao", "Xinyan Yang", "Rongxing Yi", "Kuohu Li", "Qingdong Zeng", "Xiangyou Li", "Xiaoyan Zeng", "Yongfeng Lu" ], "corpus_id": 5045308, "doc_id": "5045308", "n_citations": 37, "n_key_citations": 0, "score": 1, "title": "Determination of cobalt in low alloy steels using laser induced breakdown spectroscopy combined with laser induced fluorescence.", "venue": "Talanta", "year": 2016 }, { "abstract": "Boron (B) is widely applied in microalloying of metals. As a typical light element, however, determination of boron in alloys with complex matrix spectra is still a challenge for laser induced breakdown spectroscopy (LIBS) due to its weak line intensities in the UV visible NIR range and strong spectral interference from the matrix spectra. In this study, a wavelength tunable laser was used to enhance the intensities of boron lines selectively. The intensities of B I 208.96 nm from boron plasmas were enhanced approximately 3 and 5.8 times while the wavelength tunable laser was tuned to 249.68 and 249.77 nm, respectively. Utilizing the selective enhancement effect, accurate determinations of trace boron in nickel based superalloys and steels were achieved by laser induced breakdown spectroscopy assisted by laser induced fluorescence (LIBS LIF) with limits of detection (LoDs) of 0.9 and 0.5 ppm, respectively. The results demonstrated that LIBS LIF can hopefully be used in boron determinations and has great potential for improving the ability of LIBS to determine light elements in alloys with a complex matrix.", "author_names": [ "Changmao Li", "Zhong-qi Hao", "Zhi Min Zou", "Ran Zhou", "Jiaming Li", "Lianbo Guo", "Xiangyou Li", "Yongfeng Lu", "Xiaoyan Zeng" ], "corpus_id": 108494, "doc_id": "108494", "n_citations": 38, "n_key_citations": 0, "score": 1, "title": "Determinations of trace boron in superalloys and steels using laser induced breakdown spectroscopy assisted with laser induced fluorescence.", "venue": "Optics express", "year": 2016 }, { "abstract": "In this paper, we present a compact handheld laser induced fluorescence (LIF) detector based on a 450 nm laser diode and quasi confocal optical configuration with a total size of 9.1 x 6.2 x 4.1 cm(3) Since there are few reports on the use of 450 nm laser diode in LIF detection, especially in miniaturized LIF detector, we systematically investigated various optical arrangements suitable for the requirements of 450 nm laser diode and system miniaturization, including focusing lens, filter combination, and pinhole, as well as Raman effect of water at 450 nm excitation wavelength. As the result, the handheld LIF detector integrates the light source (450 nm laser diode) optical circuit module (including a 450 nm band pass filter, a dichroic mirror, a collimating lens, a 525 nm band pass filter, and a 1.0mm aperture) optical detector (miniaturized photomultiplier tube) as well as electronic module (including signal recording, processing and displaying units) This detector is capable of working independently with a cost of ca. $2000 for the whole instrument. The detection limit of the instrument for sodium fluorescein solution is 0.42 nM (S/N=3) The broad applicability of the present system was demonstrated in capillary electrophoresis separation of fluorescein isothiocyanate (FITC) labeled amino acids and in flow cytometry of tumor cells as an on line LIF detector, as well as in droplet array chip analysis as a LIF scanner. We expect such a compact LIF detector could be applied in flow analysis systems as an on line detector, and in field analysis and biosensor analysis as a portable universal LIF detector.", "author_names": [ "Xiao-Xia Fang", "Han-Yang Li", "Pan Fang", "Jianzhang Pan", "Qun Fang" ], "corpus_id": 24846638, "doc_id": "24846638", "n_citations": 36, "n_key_citations": 0, "score": 1, "title": "A handheld laser induced fluorescence detector for multiple applications.", "venue": "Talanta", "year": 2016 }, { "abstract": "This chapter discusses the theory and practical application of laser induced fluorescence (LIF) Fluorescence, generally, is just another name for spontaneous emission. LIF is a two step process: (1) absorption of the laser photon, followed by (2) emission.", "author_names": [ "Ronald K Hanson", "R Mitchell Spearrin", "Christopher S Goldenstein" ], "corpus_id": 100376956, "doc_id": "100376956", "n_citations": 18, "n_key_citations": 1, "score": 1, "title": "Laser Induced Fluorescence", "venue": "", "year": 2016 }, { "abstract": "The temperature dependence of the fluorescence emission of certain organic dyes such as rhodamine B has been widely utilized for measuring the temperature in liquid flows. Measurements are generally based on two assumptions: The fluorescence signal is proportional to the intensity of the laser excitation, and the temperature sensitivity of the dye is not affected by the laser irradiance. In the ratiometric methods, these assumptions allow justifying that the influence of the laser intensity can be totally eliminated in the intensity ratio of two spectral bands of the fluorescence emission and thus that measurements can be taken with no biases under experimental conditions, where the laser propagation is disturbed by the flow. However, when pulsed lasers are used (mainly in planar LIF measurements) the peak irradiance usually compares or exceeds the saturation intensity of the dyes. The present study assesses the consequences of a saturation of the dye emission on temperature measurements. Tests among fluoresceins and rhodamines reveal that the saturation can be accompanied by a significant loss of temperature sensitivity. The dyes, for which this loss of sensitivity is observed, mainly owe their temperature dependence to the fluorescence quantum yield and have a fluorescence signal decreasing with the temperature. The couple fluorescein/sulforhodamine 640 is finally proposed for an implementation of the ratiometric method, since its relatively high temperature dependence +3 \\circ \\mathrm{C}$C) is not altered at high laser irradiances. The possibility of measuring instantaneous temperature fields with this pair of dyes using a single laser shot is finally demonstrated on a turbulent heated jet injected into quiescent water.", "author_names": [ "William Chaze", "Ophelie Caballina", "G Castanet", "Fabrice Lemoine" ], "corpus_id": 54814431, "doc_id": "54814431", "n_citations": 49, "n_key_citations": 3, "score": 0, "title": "The saturation of the fluorescence and its consequences for laser induced fluorescence thermometry in liquid flows", "venue": "", "year": 2016 }, { "abstract": "Abstract Downwards co current gas liquid annular flows were studied experimentally and characterized. An advanced optical laser based measurement technique, namely Planar Laser Induced Fluorescence (PLIF) was used for the visualization of the annular flow over a range of liquid Reynolds numbers Re L 306 1 532 and gas Reynolds numbers Re G 0 84 600 Four distinct flow regimes, namely the 'dual wave' 'thick ripple' 'disturbance wave' and 'regular wave' regimes, have been identified based on qualitative information and a consequent quantitative analysis that provided information on the film thickness, interface and wave statistics, and gas entrainment into the liquid film. The mean film thickness data are generally in good agreement with previous studies. Evidence suggests that the turbulent gas phase affects strongly the shape of the interface, and that the mechanism for gas entrainment into the liquid film is strongly reliant on the existence of large amplitude waves.", "author_names": [ "Ivan Zadrazil", "Omar K Matar", "Christos N Markides" ], "corpus_id": 120374997, "doc_id": "120374997", "n_citations": 98, "n_key_citations": 2, "score": 0, "title": "An experimental characterization of downwards gas liquid annular flow by laser induced fluorescence: Flow regimes and film statistics", "venue": "", "year": 2014 }, { "abstract": "Abstract In this work, laser induced fluorescence (LIF) has been applied to probe PAHs in two atmospheric sooting flames: a premixed flat flame of methane and a Diesel turbulent spray one. Different laser excitation wavelengths have been used. UV excitations at 266 and 355 nm have been operated from the fourth and the third harmonic frequencies of an Nd: YAG laser while visible excitations were emitted by an OPO pumped by the third harmonic of the YAG laser. Because of the different nature of the flames, the recorded fluorescence spectra highlight different spectral properties. The diffusion flame appears to provide a better selectivity to the LIF measurements because of the stratification of the PAHs size classes along the flame height. In the premixed flame, all PAHs size classes spatially coexist making the analysis of LIF measurements more complex. Upon visible excitations, it is highlighted in this paper that PAHs can absorb and fluoresce up to 680 nm. Fluorescence emission spectra are shown to present Stokes and anti Stokes components. Discussion of these non conventional absorption and fluorescence features are provided on the basis of the knowledge of PAH spectroscopy and flame kinetics. Hence, different families of PAHs are successively envisaged and discussed to elucidate the experimental spectra recorded in both flames. It is shown that only a limited number of PAHs are able to lead to such spectral features. From this discussion, it appears that large pericondensed PAHs are unlikely to give rise to such signals. Some other possibilities are therefore discussed which could potentially correspond to the latest fluorescent gaseous species at the origin of the soot formation.", "author_names": [ "Salma Bejaoui", "X Mercier", "Pascale Desgroux", "Eric Therssen" ], "corpus_id": 93949691, "doc_id": "93949691", "n_citations": 85, "n_key_citations": 4, "score": 0, "title": "Laser induced fluorescence spectroscopy of aromatic species produced in atmospheric sooting flames using UV and visible excitation wavelengths", "venue": "", "year": 2014 }, { "abstract": "Abstract. The NASA In Situ Airborne Formaldehyde (ISAF) instrument is a high performance laser based detector for gas phase formaldehyde (HCHO) ISAF uses rotational state specific laser excitation at 353 nm for laser induced fluorescence (LIF) detection of HCHO. A number of features make ISAF ideal for airborne deployment, including (1) a compact, low maintenance fiber laser, (2) a single pass design for stable signal response, (3) a straightforward inlet design, and (4) a stand alone data acquisition system. A full description of the instrument design is given, along with detailed performance characteristics. The accuracy of reported mixing ratios is 10% based on calibration against IR and UV absorption of a primary HCHO standard. Precision at 1 Hz is typically better than 20% above 100 pptv, with uncertainty in the signal background contributing most to variability at low mixing ratios. The 1 Hz detection limit for a signal noise ratio of 2 is 36 pptv for 10 mW of laser power, and the e fold time response at typical sample flow rates is 0.19 s. ISAF has already flown on several field missions and platforms with excellent results.", "author_names": [ "Maria Cazorla", "Glenn M Wolfe", "Steven A Bailey", "Andrew K Swanson", "H L Arkinson", "Thomas F Hanisco" ], "corpus_id": 650393, "doc_id": "650393", "n_citations": 71, "n_key_citations": 10, "score": 0, "title": "A new airborne laser induced fluorescence instrument for in situ detection of formaldehyde throughout the troposphere and lower stratosphere", "venue": "", "year": 2014 }, { "abstract": "This article presents a review of work performed over the past ten years in France, centered on the utilization of laser induced fluorescence (LIF) spectroscopy to diagnose the low pressure magnetized dc discharge of a Hall thruster (HT) The latter is a gridless electric propulsion device in a crossed electric and magnetic field configuration, which is used onboard satellites and space probes for various types of maneuvers. Although the design of a HT is relatively simple, the physical mechanisms that govern thrust generation and efficiency are not yet fully understood. Characterization of the ion and atom velocity distribution function (VDF) appears to be a powerful way to obtain insights into the underlying physics. The VDF of xenon and krypton the most common propellants is therefore locally interrogated by means of LIF on excited levels. In this review emphasis is placed on time averaged and time resolved continuous wave LIF measurements, associated quantities and recent outcomes. Results will be presented concerning a variety of phenomena: velocity vector field structuring, ion population interaction, electric field generation, ion magnetic drift, apparent atom acceleration, interaction of the plasma plume with background gas and low frequency electric field oscillations, to name only a few.", "author_names": [ "Stephane Mazouffre" ], "corpus_id": 95706879, "doc_id": "95706879", "n_citations": 71, "n_key_citations": 1, "score": 0, "title": "Laser induced fluorescence diagnostics of the cross field discharge of Hall thrusters", "venue": "", "year": 2012 } ]

[ { "abstract": "An innovative method for utilizing synthetic calcium fluoride (CaF2) recovered from fluoride containing semiconductor wastewater, and waste sulfuric acid (H2SO4) to produce hydrofluoric acid (HF) was investigated. The research was set to study the low temperature production of HF via reaction of synthetic CaF2 and waste H2SO4. The impact of four factors, including H2SO4 concentration, total volume (H2SO4 H2O)/CaF2 ratio, drying temperature of synthetic CaF2, and reaction carried out under different temperature, on HF productivity was investigated in this study. HF yield increased with increasing H2SO4 concentration and total volume/CaF2 ratio under room temperature. Generally, reactions carried out under low temperature 100 degC) had a positive impact on HF yield. The higher temperature led to an increase in absorbed HF but a decrease in total HF. The reaction of commercial CaF2 and 70% H2SO4 had a higher absorbed HF yield of 61.7% than synthetic CaF2 and 70% waste H2SO4, which had a yield of 36% This was due to the higher purity of the commercial CaF2 and fewer interference ions in H2SO4. HF productivity was lowered by CaSO4, which hindered the reaction of reactants and also the generation of fluorosulfuric acid.", "author_names": [ "Min-Fa Lin", "Jhong Lin Wu", "Ken-Lin Chang", "Wen-Jhy Lee", "Chih-Ping Chang", "Yung-Chang Lin", "Po-Han Chen" ], "corpus_id": 220854233, "doc_id": "220854233", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Recycle of synthetic calcium fluoride and waste sulfuric acid to produce electronic grade hydrofluoric acid", "venue": "Environmental Science and Pollution Research", "year": 2020 }, { "abstract": "", "author_names": [ "Min-Fa Lin", "Chih-Ping Chang", "Ken-Lin Chang", "Wen-Jhy Lee", "Jhong Lin Wu", "Po-Han Chen" ], "corpus_id": 216288046, "doc_id": "216288046", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "A study on the low temperature wet synthesis of hydrofluoric acid from synthetic calcium fluoride and waste sulfuric acid", "venue": "", "year": 2020 }, { "abstract": "The fluoride ions of the industrially largely irreplaceable, locally corrosive hydrofluoric acid (HF) can scavenge cations in biological tissues, which explains their high toxic potential, and also leads to local acidification through proton release. The influence of three complexing agents, calcium (Ca2+ gluconate (as 2.5% Ca2+gel and individually (2.84% or commercially (10% formulated Ca2+solution) magnesium (Mg2+ gluconate (2.84% solution and aluminium (Al3+ solution (Hexafluorine(r) pure and diluted) on the absorption of fluoride following HF exposure (1 3 min, 100 ml, 30%/0.64 cm2) through human skin was investigated in an ex vivo diffusion cell model. Fluoride absorption was assessed over 6 24 h and analysed with a fluoride electrode. Decreasing the contamination time reduced the fluoride absorption distinctly which was further reduced by the application of fluoride binding decontamination agents (Ca2+ Mg2+ Al3+ or water alone without being significantly different. Ca2+ appeared slightly more effective than Mg2+ in reducing fluoride absorption. Moreover, the addition of pH adjusting buffer promoted the decontamination efficacy. Fluoride binding agents can facilitate the decontamination of dermal HF exposure. However, prompt decontamination appeared to be the key to successful limitation of fluoride absorption and pushes the choice of decontamination agent almost into the background.", "author_names": [ "Suvarna Mini Vijayan", "Thomas Goen", "Kathrin Dennerlein", "Raymund E Horch", "Ingo Ludolph", "Hans Drexler", "Sonja Kilo" ], "corpus_id": 227158987, "doc_id": "227158987", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "Calcium, magnesium and aluminium ions as decontaminating agents against dermal fluoride absorption following hydrofluoric acid exposure.", "venue": "Toxicology in vitro an international journal published in association with BIBRA", "year": 2020 }, { "abstract": "Introduction After dermal contact to occupational hazardous substances the cleaning of exposed skin areas is an important first aid measure to reduce adverse health effects. Due to possible severe systemic intoxication following dermal exposure to hydrofluoric acid (HF) the decontamination of skin should focus on the inactivation of free fluoride ions. The present ex vivo study investigated the effects of exposure duration and different antidotes on the potential systemic uptake of fluoride. Methods The transdermal penetration of HF (c=30% through excised human skin was investigated by using static diffusion cells. After dermal application of the acid (100 ul/0.64 cm2) for 1 min the excess was removed using one dry cotton swab. Subsequently, the skin was cleaned with water, calcium gluconate (CaGl) polyethylene glycol (PEG) 400 or hexafluorine(c) using a standardised protocol. In a further study, the application time was extended to 3 min to assess the effect of exposure duration. Chemical analyses of fluoride were carried out by GC MS or via a fluoride sensitive electrode. Result Extension of the exposure time from 1 to 3 min led to an enhancement in the transdermal penetration of fluoride, however with similar penetration kinetics. At the end of experiments (6 hour) a 7 fold higher fluoride amount was detected in the receptor fluid (16 vs 114 ug) In all test series maximum flux was achieved within the first hour past exposure. Decontamination of the skin reduced the cumulative penetrated amount of fluoride by 28% (PEG 400) 49% (water) and 64% (CaGl/hexafluorine(c) compared to control. Discussion The results indicate that the systemic uptake of fluoride ions and therefore possible systemic intoxication after exposure to hydrofluoric acid can be diminished by shortening the exposure duration. Reduction was further increased by decontamination of skin most by substances which are known to supply the complexation of fluoride ions.", "author_names": [ "Kathrin Dennerlein", "T Hahn", "Thomas Goen", "Hans Drexler", "Sonja Kilo" ], "corpus_id": 80224719, "doc_id": "80224719", "n_citations": 2, "n_key_citations": 1, "score": 1, "title": "914 Hydrofluoric acid effects of skin decontamination on the bioavailability of fluoride", "venue": "", "year": 2018 }, { "abstract": "ABSTRACT The production of phosphoric acid generates an enormous amount of phosphogypsum with emission of toxic fluorine acid gas. To remedy these environmental problems, a novel and a simple procedure permits converting phosphogypsum waste by recycled fluorine acid into valuable products. The obtained results confirm the efficiency of this procedure, which synthesises at room temperature the calcium fluoride in the form of nano crystalline powder and the ammonium bisulphate salt from the exact stoichiometric proportions of phosphogypsum, hydrofluoric acid and ammonia. The total conversion of phosphogypsum is achieved after reaction time equal to one hour and a half. Generally, this novel procedure offers not only a solution for reducing phosphogypsum waste and fluorine gas emission, but also gives rise to valuable products, useful to industry and agriculture.", "author_names": [ "Yassine Ennaciri", "Mohammed Bettach", "Hanan El Alaoui-Belghiti" ], "corpus_id": 216387200, "doc_id": "216387200", "n_citations": 3, "n_key_citations": 1, "score": 1, "title": "Recovery of nano calcium fluoride and ammonium bisulphate from phosphogypsum waste", "venue": "", "year": 2020 }, { "abstract": "The phosphoric acid production in the world generates a large amount of phosphogypsum with the emission of toxic acid fluorine gas into the atmosphere, which forms a significant source of environmental contamination. In this work, a novel and a simple procedure allows converting phosphogypsum waste by using hydrofluoric acid and sodium fluoride into valuable products. The obtained results confirm well the efficiency of this procedure, which permits to synthesize at room temperature, the sodium hydrogen sulfate monohydrate and a relatively pure nano calcium fluoride from the exact stoichiometric proportions of the phosphogypsum, hydrofluoric acid, and sodium fluoride. The total phosphogypsum conversion is achieved after reaction time equal to 1.5 h. Generally, this procedure offers not only a solution for reducing phosphogypsum waste but also permits to obtain valuable products, which interest several sectors of industry.", "author_names": [ "Yassine Ennaciri", "Mohammed Bettach", "Hanan El Alaoui-Belghiti" ], "corpus_id": 225396520, "doc_id": "225396520", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Conversion of Moroccan phosphogypsum waste into nano calcium fluoride and sodium hydrogen sulfate monohydrate", "venue": "", "year": 2020 }, { "abstract": "Waste has been identified as one of the main sources of greenhouse gas (GHG) emissions resulting from global population growth. Climate change and resource scarcity have emerged as pressing environmental issues in recent years. Resource recycling and recovery have been proven effective ways of implementing circular economy and GHG reduction to maintain sustainable resource use. Calcium fluoride sludge and hydrofluoric acid are the primary wastes generated from the electronics industry, such as from semiconductors, liquid crystal displays, light emitting diodes, solar cells and other optoelectronic sectors. The accumulation of such waste has become a major problem of Taiwan's electronics industry. If not properly treated or managed, electronic waste would cause serious health and environmental problems; however, if recycled, they can be recovered and transformed into artificial fluorite (CaF2) and sodium fluorosilicate (NaSiF6) which have economic and environmental benefits. For example, CaF2 can be applied as fluxing agent to replace raw fluorite in the steel industry. Moreover, both materials can be used as substitutes for cement in construction. The main objective of this study is to evaluate carbon footprint of renewable material from calcium fluoride sludge to understand the carbon emission of waste reuse method from a life cycle perspective. The scope and system boundary of the assessment will be determined on the basis of literature review and expert consultation. Data for calculating carbon footprints will be collected by in situ inventory and from the literature. The commercial software SimaPro 8.2.0 will be used for calculations. The results of carbon footprint may be used to develop strategies for life cycle management of waste reuse to realize sustainable usage.", "author_names": [ "Allen H Hu", "Chien-Hung Kuo", "Ciao-Sin Hong", "Lance Hongwei Huang" ], "corpus_id": 135000616, "doc_id": "135000616", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Carbon Footprint Assessment of Recycling Fluorspar from Waste Calcium Fluoride (CaF 2 Sludge", "venue": "", "year": 2019 }, { "abstract": "Hydrofluoric acid was discovered in 1771 by Swedish pharmaceutical chemist Carl Wilhelm Scheele when he was investigating the mineral called fluorite (Calcium fluoride) Hydrogen fluoride (HF) has several synonyms: Hydrofluoric acid, Fluoric acid, Hydrofluoride, Fluorine monohydride, Fluorane. Hydrofluoric (HF) acid is an extremely powerful inorganic acid and a vigorous dehydrating agent that is used in many industrial branches including production of aluminum, stainless steel and hydrofluorocarbons, glass etching, stevedoring and transportation industries, inorganic and organic chemical manufacturing, mineral processing, petroleum oil refineries, fire extinguishers manufacturing, steel mills, cleaning HVAC systems, and as the precursor to all fluorine compands in the pharmaceutical industry. [1][2][3][4] Consumer products containing hydrofluoric acid include rust removers, detergents, marble, brick and stone cleaning, toilet bowl clearners, insecticides, automobile wheel cleaners and air conditioner cleaners. [4][5] Hydrofluoric acid is comprised of a diatomic compound of hydrogen and fluoride atoms as a gas, while in the liquid state it has strong hydrogen bonds between the chains forming a polymeric compound. [6] Anhydrous hydrofluoric acid and hydrofluoric acid in aqueous solutions range in appearance from colorless to slightly tinted based upon the concentration and impurities. It has a boiling point of 20 degrees celcius (68 degrees fahrenheit) at 760 mmHg, vapour density greater than air and readily dissolves in water that when diluted (exothermal reaction) is visibly indistinguishable from water. Hydrofluoric acid has a disagreeable, pungent odor at concentrations of 0.04 ppm which is way below the OSHA PEL (Permissible Exposure Limit) of 3 ppm and is extremely corrosive and has the ability to dissovle a number of materials especially oxides. [4] The Major source of production of hydrofluoric acid is by treating fluorite with concentrated sulfuric acid at temperatues of 265 degrees fahrenheit to produce hydrofluic acid and calcium sulfate. Alternate production is a by product in the production of phosphoric acid from the mineral apatite. Hydrofluoric acid is also produced by the release from industrial and welding processes and environmental activities such as volcanoes. HF production exceeds one million tons world wide by a number of manufactors and is transported and stored under high pressure as a highly concentrated liquid. [7] In the United States of America, the Department of Transportation Hazard Label and National Fire Protection Assocation (NFPA) 704 lists the health value of 4 (can be lethal) flammability value of 0 (will not burn under typical fire conditions) instability value of 2 (readily undergoes violent chamical changes at elevated temperatures and pressures) and special value of W with line through (reacts violently or exposevely with water) Domestic concentrations of hydrofluoric acid is typically around 0.5% with industrial concentrations approaching 100% Primary health consequences including dermal burns, eye injury, acute respiratory symptoms, gastrointestinal symptoms and cardiac abnormalities can occur from direct skin eye contact, ingestion of solutions or inhalation of fumes and vapors with unintentional and intentional exposures. Unintentional exposure of hydrofluoric acid in and out of the workplace include inappropriate operations, mechanical failure of equipment, explosions of containers and tanks containing HF, during traffic incidents with leakage of HF, inadequate protective equipment and children accidentally exposed through ingestion of domestic cleaners. [4][8][9][10] Intentional cases of ingestion, with suicidal and homicidal intent, of hydrofluoric acid have been documented.[4][11] Hydrofluoric acid is highly toxic and damaging to humans due to the \"double danger\" properties of the corrisive nature of the hydrogen ions and toxic effect due to the ability of fluoride ions to penetrate into deep tissue causing liquefactive necrosis and release of cellular products. Hydrofluoric acid burns present with a unique concern for systemic fluoride toxicity including cardiovascular, pulmonary, renal and neuromuscular symptoms, electrolyte imbalance and enzyme inhibition which can lead to cardiac arrhythmias and death. [12] Chronic symptoms may occur or persist for months after HF ingestion or respiratory exposure. [3][9]", "author_names": [ "Daniel L Schwerin", "J Hatcher" ], "corpus_id": 208381592, "doc_id": "208381592", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Hydrofluoric Acid Burns", "venue": "", "year": 2019 }, { "abstract": "Occupational injuries to digits due to hydrofluoric acid (HFA) are frequently encountered. They have distinctive features, including intense pain, progressive tissue necrosis, and possible bone erosion. To minimize tissue damage, it is of great importance to execute prudent preoperative assessment and determine the correct surgical modality to reconstruct and maintain the function of the hand. However, proper protocols for fingers have not been presented in previous studies. Eight cases with HFA burn to digits were presented to the emergency room. Wounds were immediately irrigated with saline, calcium gluconate was applied topically to block destructive effects of fluoride ions. Blisters that could lead to progressive tissue destruction were debrided. A fish mouth fasciotomy was performed and prostaglandin was administered intravenously to maintain maximal distal circulation. Wounds were evaluated daily for apparent demarcation for 6 or 7 days. Digits were reconstructed with free sensate second toe pulp free flap to provide sufficient padding for the fingertip. All patients showed excellent recovery with stable flaps with acceptable external contour, durable soft tissue padding, and full range of motion of affected joints. In conclusion, when a patient is admitted due to HFA exposure to the finger, early treatment including irrigation, topical neutralizers, and fasciotomy are of great importance to minimize tissue damage. In addition, a physician should wait at least 7days until the degree of damage to the tissue can be classified so that the physician can decide whether aggressive debridement should be proceeded. In case of deep layer injuries of weight bearing portions such as finger pulp, reconstruction techniques utilizing durable tissues such as partial second toe pulp free flap should be employed.", "author_names": [ "Hyun Ho Han", "Byung Yeun Kwon", "Sung-No Jung", "Suk-Ho Moon" ], "corpus_id": 26675067, "doc_id": "26675067", "n_citations": 10, "n_key_citations": 0, "score": 1, "title": "Importance of initial management and surgical treatment after hydrofluoric acid burn of the finger.", "venue": "Burns journal of the International Society for Burn Injuries", "year": 2017 }, { "abstract": "Recent experimental in vivo studies have shown that aqueous solutions of stannous fluoride (SnF2) and hydrofluoric acid (HF) can reduce enamel solubility after 5 min. The aim of this study was to evaluate the longer term protective effect of SnF2 (0.78% pH 2.9) and HF (0.2% pH 2.0) (both ~0.1 mol/l F) using the same experimental model. Labial surfaces of healthy anterior teeth (all four surfaces when possible, otherwise a pair of surfaces) in 103 subjects (n 399 teeth) were exposed to citric acid (0.01 mol/l, pH 2.7) The acid was applied using a peristaltic pump (5 ml, 6 ml/min) and was collected in coded test tubes (etch I) The test solutions were then applied to the same surfaces of the teeth (1 min, 6 ml/min) After either 1, 7, 14 or 28 days, citric acid was again applied to the same surfaces and subsequently collected (etch II) Enamel solubility was examined by assessment of calcium concentration in etch I and etch II solutions using atom absorption spectroscopy. Median values were calculated for all time periods and statistical analysis was carried out using the Wilcoxon signed ranks test. Results showed that HF reduced enamel solubility by 54 and 36% after 1 and 7 days, respectively. After 14 and 28 days, there was no longer any effect. SnF2 showed no protective effect after the first day. Given these results, repeated application of HF and especially SnF2 may be necessary to improve the protective effect of these fluorides, and this requires further testing.", "author_names": [ "Carl Hjortsjo", "Grazyna Jonski", "Per Stanley Thrane", "Erik Saxegaard", "Alix Young" ], "corpus_id": 25859965, "doc_id": "25859965", "n_citations": 17, "n_key_citations": 2, "score": 1, "title": "Effect of Stannous Fluoride and Dilute Hydrofluoric Acid on Early Enamel Erosion over Time in vivo", "venue": "Caries Research", "year": 2009 } ]

[ { "abstract": "Theoretical Analysis of Swarm Intelligence Algorithms. Stability Problem for a Predator Prey System. Study on the Local Search Ability of Particle Swarm Optimization. The Performance Measurement of a Canonical Particle Swarm Optimizer with Diversive Curiosity. Mechanism and Convergence of Bee Swarm Genetic Algorithm. On the Farther Analysis of Performance of the Artificial Searching Swarm Algorithm. Orthogonality and Optimality in Non Pheromone Mediated Foraging. An Adaptive Staged PSO Based on Particles' Search Capabilities. PSO Algorithms. A New Particle Swarm Optimization Algorithm and Its Numerical Analysis. A New PSO Model Mimicking Bio parasitic Behavior. KNOB Particle Swarm Optimizer. Grouping Shuffling Particle Swarm Optimization: An Improved PSO for Continuous Optimization. Gender Hierarchy Particle Swarm Optimizer Based on Punishment. An Improved Probability Particle Swarm Optimization Algorithm. An Automatic Niching Particle Swarm for Multimodal Function Optimization. An Availability Aware Task Scheduling for Heterogeneous Systems Using Quantum behaved Particle Swarm Optimization. A Novel Encoding Scheme of PSO for Two Machine Group Scheduling. Improved Quantum Particle Swarm Optimization by Bloch Sphere. An Improved Particle Swarm Optimization for Permutation Flowshop Scheduling Problem with Total Flowtime Criterion. Applications of PSO Algorithms. Broadband MVDR Beamformer Applying PSO. Medical Image Registration Algorithm with Generalized Mutual Information and PSO Powell Hybrid Algorithm. Particle Swarm Optimization for Automatic Selection of Relevance Feedback Heuristics. Performance of Optimized Fuzzy Edge Detectors using Particle Swarm Algorithm. PSO Heuristics Algorithm for Portfolio Optimization. A New Particle Swarm Optimization Solution to Nonconvex Economic Dispatch Problem. Optimal Micro siting of Wind Farms by Particle Swarm Optimization. PSO Applied to Table Allocation Problems. Finding the Maximum Module of the Roots of a Polynomial by Particle Swarm Optimization. ACO Algorithms. Research on the Ant Colony Optimization Algorithm with Multi population Hierarchy Evolution. Graph Partitioning Using Improved Ant Clustering. A Knowledge Based Ant Colony Optimization for a Grid Workflow Scheduling Problem. An Improved Parallel Ant Colony Optimization Based on Message Passing Interface. Applications of ACO Algorithms. Research on Fault Diagnosis Based on BP Neural Network Optimized by Chaos Ant Colony Algorithm. Edge Detection of Laser Range Image Based on a Fast Adaptive Ant Colony Algorithm. A Real Time Moving Ant Estimator for Bearings Only Tracking. Two Stage Inter Cell Layout Design for Cellular Manufacturing by Using Ant Colony Optimization Algorithms. Images Boundary Extraction Based on Curve Evolution and Ant Colony Algorithm. ACO Based Energy Balance Routing Algorithm for WSNs. Swarm Intelligence Algorithms for Portfolio Optimization. Artificial Immune System. Document Classification with Multi layered Immune Principle. A Quantum Immune Algorithm for Multiobjective Parallel Machine Scheduling. A Resource Limited Immune Approach for Evolving Architecture and Weights of Multilayer Neural Network. Cryptanalysis of Four Rounded DES Using Binary Artificial Immune System. An Immune Concentration Based Virus Detection Approach Using Particle Swarm Optimization. Novel Swarm Based Optimization Algorithms. Fireworks Algorithm for Optimization. Bacterial Foraging Optimization Algorithm with Particle Swarm Optimization Strategy for Distribution Network Reconfiguration. Optimization Design of Flash Structure for Forging Die Based on Kriging PSO Strategy. A Scatter Search Algorithm for the Slab Stack Shuffling Problem. Collaboration Algorithm of FSMAS. GPU Based Parallelization Algorithm for 2D Line Integral Convolution. Biogeography Migration Algorithm for Traveling Salesman Problem. An Approach of Redistricting Based on Simple and Compactness. Genetic Algorithms. A Rapid Chaos Genetic Algorithm. Fitness Function of Genetic Algorithm in Structural Constraint Optimization. Using Genetic Algorithm for Classification in Face Recognition. Dynamic Path Optimization of Emergency Transport Based on Hierarchical Genetic Algorithm. Fault Diagnosis of Analog Circuits Using Extension Genetic Algorithm. A Collision Detection Algorithm Based on Self adaptive Genetic Method in Virtual Environment. A Non dominated Sorting Bit Matrix Genetic Algorithm for P2P Relay Optimization. Fast Parallel Memetic Algorithm for Vector Quantization Based for Reconfigurable Hardware and Softcore Processor. Evolutionary Computation. Optimization of Minimum Completion Time MTSP Based on the Improved DE. Differential Evolution for Optimization of Land Use. Hybrid Differential Evolution for Knapsack Problem. Bottom Up Tree Evaluation in Tree Based Genetic Programming. Solving Vehicle Assignment Problem Using Evolutionary Computation. A Computerized Approach of the Knowledge Representation of Digital Evolution Machines in an Artificial World. An Improved Thermodynamics Evolutionary Algorithm Based on the Minimal Free Energy. Hybrid Algorithms. A Hybrid Evolutionary Algorithm Based on Alopex and Estimation of Distribution Algorithm and Its Application for Optimization. A Hybrid Swarm Intelligent Method Based on Genetic Algorithm and Artificial Bee Colony. A Hybrid PSO/GA Algorithm for Job Shop Scheduling Problem. A Hybrid Particle Swarm Optimization Algorithm for Order Planning Problems of Steel Factory. Hybrid Particle Swarm and Conjugate Gradient Optimization Algorithm. A Hybrid of Particle Swarm Optimization and Local Search for Multimodal Functions. A Cooperative Ant Colony System and Genetic Algorithm for TSPs. Tracking Control of Uncertain DC Server Motors Using Genetic Fuzzy System. Multi objective Optimization Algorithms. Novel Multi Objective Genetic Algorithm Based on Static Bayesian Game Strategy. A Hybrid Pareto Based Tabu Search for Multi objective Flexible Job Shop Scheduling Problem with E/T Penalty. Research on Multi objective Optimization Design of the UUV Shape Based on Numerical Simulation. Multi Objective Optimization for Massive Pedestrian Evacuation Using Ant Colony Algorithm. An Improved Immune Genetic Algorithm for Multiobjective Optimization. Multi robot Systems. Enhanced Mapping of Multi robot Using Distortion Reducing Filter Based SIFT. Study on Improved GPGP Based Multi agent Semiconductor Fabrication Line Dynamic Scheduling Method. Multi robot Formation Control Using Reinforcement Learning Method. Development of Image Stabilization System Using Extended Kalman Filter for a Mobile Robot. Multi agent Based Complex Systems. Diffusing Method for Unknown Environment Exploration in Multi Robot Systems. Impulsive Consensus Seeking in Delayed Networks of Multi agents. The Application of Multi agent Technology on the Level of Repair Analysis. The Framework of an Intelligent Battlefield Damage Assessment System Based on Multi Agent System. Adaptive System of Heterogeneous Multi agent Investors in an Artificial Evolutionary Double Auction Market. Average Consensus for Directed Networks of Multi agent with Time Varying Delay. Multi Agent Cooperative Reinforcement Learning in 3D Virtual World.", "author_names": [ "Ying Tan", "Yuhui Shi", "Kay Chen Tan" ], "corpus_id": 37861569, "doc_id": "37861569", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Advances in Swarm Intelligence, First International Conference, ICSI 2010, Beijing, China, June 12 15, 2010, Proceedings, Part II", "venue": "ICSI", "year": 2010 }, { "abstract": "Keywords: Swarm Intelligence Swarm Robotics Swarmanoid Evolutionary Computation Evolutionary Robotics Reference EPFL BOOK 161827 URL: http:/iridia.ulb.ac.be/ants2010/ Record created on 2010 12 20, modified on 2017 05 10", "author_names": [ "Marco Dorigo", "M Birattari", "Gianni A Di Caro", "Rene Doursat", "Andries Petrus Engelbrecht", "Dario Floreano", "Luca Maria Gambardella", "R Gross", "Erol Sahin", "Hiroki Sayama", "Thomas Stutzle" ], "corpus_id": 60093231, "doc_id": "60093231", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Swarm Intelligence. Proceedings of the 7th International Conference, ANTS 2010", "venue": "", "year": 2010 }, { "abstract": "A Graph Based Developmental Swarm Representation and Algorithm. A Graph Based Developmental Swarm Representation and Algorithm. A Modified Particle Swarm Optimization Algorithm for the Best Low Multilinear Rank Approximation of Higher Order Tensors. A Robotic Validation of the Attractive Field Model: An Inter disciplinary Model of Self regulatory Social Systems. A Thermodynamic Approach to the Analysis of Multi robot Cooperative Localization under Independent Errors. An Alternative ACO Algorithm for Continuous Optimization Problems. An Efficient Optimization Method for Revealing Local Optima of Projection Pursuit Indices. Ant Colony Optimisation for Ligand Docking. Antbots: A Feasible Visual Emulation of Pheromone Trails for Swarm Robots. Automatic Configuration of Multi Objective ACO Algorithms. Autonomous Morphogenesis in Self assembling Robots Using IR Based Sensing and Local Communications. Autonomous Multi agent Cycle Based Patrolling. Biologically Realistic Primitives for Engineered Morphogenesis. Evaluating the Robustness of Activator Inhibitor Models for Cluster Head Computation. Evolution of Self organised Path Formation in a Swarm of Robots. Extensions to the Ant Miner Classification Rule Discovery Algorithm. Functional Blueprints: An Approach to Modularity in Grown Systems. Heterogeneous Particle Swarm Optimization. Modern Continuous Optimization Algorithms for Tuning Real and Integer Algorithm Parameters. Multi agent Deployment on a Ring Graph. Multi Swarm Optimization for Dynamic Combinatorial Problems: A Case Study on Dynamic Vehicle Routing Problem. Off line vs. On line Tuning: A Study on Ant System for the TSP. Opinion Dynamics for Decentralized Decision Making in a Robot Swarm. Positional Communication and Private Information in Honeybee Foraging Models. Rank Based Particle Swarm Optimization. Self organized Task Partitioning in a Swarm of Robots. Slime Mold Inspired Path Formation Protocol for Wireless Sensor Networks. Solving the Multi dimensional Multi choice Knapsack Problem with the Help of Ants. Theoretical Properties of Two ACO Approaches for the Traveling Salesman Problem. Short Papers. A Cooperative Network Game Efficiently Solved via an Ant Colony Optimization Approach. A Deterministic Metaheuristic Approach Using \"Logistic Ants\" for Combinatorial Optimization. A Model Based Ant Colony Design for the Protein Engineering Problem. ACOPHY: A Simple and General Ant Colony Optimization Approach for Phylogenetic Tree Reconstruction. ACS Searching for D 4t Hadamard Matrices. Ant Based Semi supervised Classification. Automatic Generation of Optimised Working Time Models in Personnel Planning. Bee Sensor: A Step Towards Meta Routing Strategies in Hybrid Ad Hoc Networks. Cooperation in a Heterogeneous Robot Swarm through Spatially Targeted Communication. Early Stage Diagnosis of Endogenous Diseases by Swarms of Nanobots: An Applicative Scenario. EDA PSO: A Hybrid Paradigm Combining Estimation of Distribution Algorithms and Particle Swarm Optimization. Emergent Flocking with Low End Swarm Robots. Exploiting Loose Horizontal Coupling in Evolutionary Swarm Robotics. Formal Verification of Probabilistic Swarm Behaviours. Inverse Modeling in Geoenvironmental Engineering Using a Novel Particle Swarm Optimization Algorithm. Mobile Stigmergic Markers for Navigation in a Heterogeneous Robotic Swarm. Motif Finding Using Ant Colony Optimization. Multiple Ant Colony System for Substructure Discovery. Opportunistic Ant Based Path Management for Wireless Mesh Networks. Parallel Ant Colony Optimization Algorithm on a Multi core Processor. Particle Swarm Optimization in High Dimensional Spaces. Particle Swarm Optimization of Bollinger Bands. Protein Structure Prediction in Lattice Models with Particle Swarm Optimization. Short and Robust Communication Paths in Dynamic Wireless Networks. The ACO Encoding. The Complexity of Grid Coverage by Swarm Robotics. The Design of an Active Structural Vibration Reduction System Using a Modified Particle Swarm Optimization. Extended Abstracts. Ant Colony Extended: Search in Solution Spaces with a Countably Infinite Number of Solutions. Automatic Parameter Configuration of Particle Swarm Optimization by Classification of Function Features. Constructing Low Cost Swarm Robots That March in Column Formation. Coordinating Heterogeneous Swarms through Minimal Communication among Homogeneous Sub swarms. Effect of Particle Initialization on the Performance of Particle Swarm Niching Algorithms. Energy Efficient Swarm Deployment for Search in Unknown Environments. Genetic Encoding of Robot Metamorphosis: How to Evolve a Glider with a Genetic Regulatory Network. How Ant Systems Can Help in Management of pH for Industrial Wastewater Discharges. Hybrid Metaheuristic Combining Ant Colony Optimization and H Method. Increasing Individual Density Reduces Extra Variance in Swarm Intelligence. \"Look out!\" Socially Mediated Obstacle Avoidance in Collective Transport. On Possible Connections between Ant Algorithms and Random Matrix Theory. Soft Variable Fixing in Path Relinking: An Application to ACO Codes. Training Randomly Connected, Recurrent Artificial Neural Networks Using PSO.", "author_names": [ "Marco Dorigo" ], "corpus_id": 723544, "doc_id": "723544", "n_citations": 0, "n_key_citations": 0, "score": 2, "title": "Swarm Intelligence 7th International Conference, ANTS 2010, Brussels, Belgium, September 8 10, 2010. Proceedings", "venue": "ANTS Conference", "year": 2010 }, { "abstract": "", "author_names": [ "Ying Tan", "Yuhui Shi", "Kay Chen Tan" ], "corpus_id": 25292737, "doc_id": "25292737", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Advances in Swarm Intelligence, First International Conference, ICSI 2010, Beijing, China, June 12 15, 2010, Proceedings, Part I", "venue": "ICSI", "year": 2010 }, { "abstract": "", "author_names": [ "Marco Dorigo", "M Birattari", "Gianni A Di Caro", "Rene Doursat", "Andries Petrus Engelbrecht", "Dario Floreano", "Luca Maria Gambardella", "R Gross", "Erol Sahin", "Hiroki Sayama", "Thomas Stutzle" ], "corpus_id": 60297429, "doc_id": "60297429", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Swarm Intelligence: 7th International Conference, ANTS 2010. Proceedings", "venue": "", "year": 2010 }, { "abstract": "Electronic media have unlocked a hitherto largely untapped potential for swarm intelligence (SI; generally, the realisation that group living can facilitate solving cognitive problems that go beyond the capacity of single animals) in humans with relevance for areas such as company management, prediction of elections, product development and the entertainment industry. SI is a rapidly developing topic that has become a hotbed for both innovative research and wild speculation. Here, we tie together approaches from seemingly disparate areas by means of a general definition of SI to unite SI work on both animal and human groups. Furthermore, we identify criteria that are important for SI to operate and propose areas in which further progress with SI research can be made.", "author_names": [ "Jens Krause", "Graeme D Ruxton", "Stefan Krause" ], "corpus_id": 15172882, "doc_id": "15172882", "n_citations": 280, "n_key_citations": 12, "score": 0, "title": "Swarm intelligence in animals and humans.", "venue": "Trends in ecology evolution", "year": 2010 }, { "abstract": "This paper surveys the intersection of two fascinating and increasingly popular domains: swarm intelligence and data mining. Whereas data mining has been a popular academic topic for decades, swarm intelligence is a relatively new subfield of artificial intelligence which studies the emergent collective intelligence of groups of simple agents. It is based on social behavior that can be observed in nature, such as ant colonies, flocks of birds, fish schools and bee hives, where a number of individuals with limited capabilities are able to come to intelligent solutions for complex problems. In recent years the swarm intelligence paradigm has received widespread attention in research, mainly as Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO) These are also the most popular swarm intelligence metaheuristics for data mining. In addition to an overview of these nature inspired computing methodologies, we discuss popular data mining techniques based on these principles and schematically list the main differences in our literature tables. Further, we provide a unifying framework that categorizes the swarm intelligence based data mining algorithms into two approaches: effective search and data organizing. Finally, we list interesting issues for future research, hereby identifying methodological gaps in current research as well as mapping opportunities provided by swarm intelligence to current challenges within data mining research.", "author_names": [ "David Martens", "Bart Baesens", "Tom Fawcett" ], "corpus_id": 13215551, "doc_id": "13215551", "n_citations": 225, "n_key_citations": 5, "score": 0, "title": "Editorial survey: swarm intelligence for data mining", "venue": "Machine Learning", "year": 2010 }, { "abstract": "The quadratic minimum spanning tree problem (Q MST) is an extension of the minimum spanning tree problem (MST) In Q MST, in addition to edge costs, costs are also associated with ordered pairs of distinct edges and one has to find a spanning tree that minimizes the sumtotal of the costs of individual edges present in the spanning tree and the costs of the ordered pairs containing only edges present in the spanning tree. Though MST can be solved in polynomial time, Q MST is NP Hard. In this paper we present an artificial bee colony (ABC) algorithm to solve Q MST. The ABC algorithm is a new swarm intelligence approach inspired by intelligent foraging behavior of honey bees. Computational results show the effectiveness of our approach.", "author_names": [ "Shyam Sundar", "Alok Singh" ], "corpus_id": 42541623, "doc_id": "42541623", "n_citations": 111, "n_key_citations": 6, "score": 0, "title": "A swarm intelligence approach to the quadratic minimum spanning tree problem", "venue": "Inf. Sci.", "year": 2010 }, { "abstract": "This paper gives a broad overview of swarm intelligence in three parts: biological basis, artificial literature and swarm engineering. In biological basis part, the paper gives some operational principles from biological systems by naturalists and biologists. In artificial literature part, two fundamental approaches are provided to analyze swarm topology. The prevalent swarm models and techniques such as Reynolds's rules, discrete and continuum theory of flocking, coordination stability of the swarm motion, etc, are also summarized in this part. In swarm engineering part, the paper discusses Kazadi's \"two step\" process. Many engineering applications come from Kazadi's researches. Also, the main application of swarm intelligence on robot systems and other applications are introduced in this part. We say this paper provides concepts for a better understanding of swarm intelligence both in principles and in applications.", "author_names": [ "Yan-fei Zhu", "Xiong Tang" ], "corpus_id": 18973865, "doc_id": "18973865", "n_citations": 48, "n_key_citations": 2, "score": 0, "title": "Overview of swarm intelligence", "venue": "2010 International Conference on Computer Application and System Modeling (ICCASM 2010)", "year": 2010 }, { "abstract": "In the last decade, wireless sensor networks have attracted many researchers. One of the main topics adopted by researchers studying on wireless sensor networks is developing routing protocols for wireless systems. Routing protocol development deals with problems such as complexity, scalability, adaptability, survivability and battery life in wireless systems. Routing protocols grounded for wireless systems are developed in order to solve these problems. In this paper, we briefly discussed especially, swarm intelligence based routing protocols for wireless sensor networks. Key words:", "author_names": [ "Fatih Celik", "Ahmet Zengin", "Sinan Tuncel", "Bulent Cobanoglu" ], "corpus_id": 15373375, "doc_id": "15373375", "n_citations": 70, "n_key_citations": 4, "score": 0, "title": "A survey on swarm intelligence based routing protocols in wireless sensor networks", "venue": "", "year": 2010 } ]

[ { "abstract": "A model to explore the scaling limits of electrostatically actuated nanorelays is presented, which shows that adhesion in a nanorelay's contact interface limits its performance with respect to operating voltage, contact resistance, and switching energy. For logic applications, we show that an ultimately scaled relay can be more efficient than conventional metal oxide semiconductor devices if (1) it is designed with very high contact resistances, leading to 1 MHz operation due to large RC delays, or (2) its actuation area is extremely large compared with its contacting area, leading to very low voltage operation, which reduces overall CV2 losses. We propose new relay scaling relations that account for the scaling of contact interfaces.", "author_names": [ "Chytra Pawashe", "Kevin L Lin", "Kelin J Kuhn" ], "corpus_id": 7877937, "doc_id": "7877937", "n_citations": 48, "n_key_citations": 2, "score": 1, "title": "Scaling Limits of Electrostatic Nanorelays", "venue": "IEEE Transactions on Electron Devices", "year": 2013 }, { "abstract": "Static and dynamic mechanical deflections were electrically induced in cantilevered, multiwalled carbon nanotubes in a transmission electron microscope. The nanotubes were resonantly excited at the fundamental frequency and higher harmonics as revealed by their deflected contours, which correspond closely to those determined for cantilevered elastic beams. The elastic bending modulus as a function of diameter was found to decrease sharply (from about 1 to 0.1 terapascals) with increasing diameter (from 8 to 40 nanometers) which indicates a crossover from a uniform elastic mode to an elastic mode that involves wavelike distortions in the nanotube. The quality factors of the resonances are on the order of 500. The methods developed here have been applied to a nanobalance for nanoscopic particles and also to a Kelvin probe based on nanotubes.", "author_names": [ "" ], "corpus_id": 29251749, "doc_id": "29251749", "n_citations": 1678, "n_key_citations": 42, "score": 0, "title": "Electrostatic deflections and electromechanical resonances of carbon nanotubes", "venue": "Science", "year": 1999 }, { "abstract": "Microelectromechanical switches are of interest for low power circuit applications due to their minimal OFF state leakage current. This paper uses 22 nm CMOS fabrication technology and the clamped cantilever geometry as the basis for establishing design rules for electrostatic nanorelays and estimates the design parameters needed for nanorelay actuation. The adhesive pull off force of various substrate/cantilever combinations is simulated using molecular dynamics with a force field that parameterizes van der Waals interactions, and measured using atomic force microscopy. Both methods show that for the substrates studied, H passivated Si produces the least adhesive surface with adhesive pressure close to the critical pressure required for pull out. Experimental results quantifying adhesion and electrical current conduction show that it is impossible to simultaneously meet the adhesion and current conduction requirements of a nanorelay. We show that contact adhesion is the key parameter limiting the scalability of electromechanical relays at the nanoscale.", "author_names": [ "Kevin L Lin", "Graham L W Cross", "Peter Gleeson", "Johann P de Silva", "Alejandro Levander", "Jorge A Munoz", "Chytra Pawashe", "Alexis Potie", "Patrick Lauren Theofanis", "John J Boland", "Kelin J Kuhn" ], "corpus_id": 36934199, "doc_id": "36934199", "n_citations": 3, "n_key_citations": 1, "score": 0, "title": "Adhesion Limits and Design Criteria for Nanorelays", "venue": "IEEE Transactions on Electron Devices", "year": 2016 }, { "abstract": "The exploding market of portable electronic appliances has fuelled the demand for complex integrated systems that can be run by light weight batteries with long shelf life. But as technology continued to scale, leakage power has proven to be a dominant source of power dissipation. Looking beyond the Complementary Metal Oxide Semiconductor (CMOS) transistor, this paper presents an unexplored alternative the Nanorelay that can potentially eradicate the foreseen crisis in the IC era. By using modern CMOS processes the relay can get a microscopic makeover which can lead to further advances in power reduction as these devices posses \"green switch\" properties like zero leakage current, infinite sub threshold slope and temperature resilient behavior and are hence ideal candidates for ultra low power (ULP) chips that can run of scavenged energy from light, acoustic vibrations or ambient RF signals and primarily for realizing programmable switches in FPGAs. Power consumption is a key issue in the design of portable systems such as smart cards, pacemakers and defibrillators that posses critical functionality. These systems rely on embedded batteries as their source of power which has limited life. Increased power consumption leads to increased battery size and an increase in product size and weight. Henceforth, methods of reducing power is explored and incorporated.", "author_names": [ "S Shetty", "Syed Shafiuddin" ], "corpus_id": 209443696, "doc_id": "209443696", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Nanorelays Power Driver of the Next Decade", "venue": "", "year": null }, { "abstract": "We report on the electromechanical actuation and switching performance of nanoconstructs involving doubly clamped, individual multiwalled carbon nanotubes. Batch fabricated, three state switches with low ON state voltages (6.7 V average) are demonstrated. A nanoassembly architecture that permits individual probing of one device at a time without crosstalk from other nanotubes, which are originally assembled in parallel, is presented. Experimental investigations into device performance metrics such as hysteresis, repeatability and failure modes are presented. Furthermore, current driven shell etching is demonstrated as a tool to tune the nanomechanical clamping configuration, stiffness, and actuation voltage of fabricated devices. Computational models, which take into account the nonlinearities induced by stress stiffening of 1 D nanowires at large deformations, are presented. Apart from providing accurate estimates of device performance, these models provide new insights into the extension of stable travel range in electrostatically actuated nanowire based constructs as compared to their microscale counterparts.", "author_names": [ "Arunkumar Subramanian", "Andreas R Alt", "Lixin Dong", "Bradley Kratochvil", "Colombo R Bolognesi", "Bradley J Nelson" ], "corpus_id": 207732494, "doc_id": "207732494", "n_citations": 18, "n_key_citations": 0, "score": 0, "title": "Electrostatic actuation and electromechanical switching behavior of one dimensional nanostructures.", "venue": "ACS nano", "year": 2009 }, { "abstract": "We demonstrate the use of torsion in nanorelays to achieve low voltages, high speeds, single lithography step construction, and a form useful for configurability and electronic design enhancements in 3 D integrated implementations. The combined bending and torsion of self aligned nanopillars facilitates the first top down fabricated vertical three terminal nanoscale relay. Experimental devices, even at 500 nm features, operate at ~10 V and 1 3 ms. Scaling to 45 nm suggests operation at approximately 1 V.", "author_names": [ "Joshua Rubin", "Ravishankar Sundararaman", "Moonkyung Mark Kim", "Sandip Tiwari" ], "corpus_id": 38225317, "doc_id": "38225317", "n_citations": 14, "n_key_citations": 1, "score": 0, "title": "A Low Voltage Torsion Nanorelay", "venue": "IEEE Electron Device Letters", "year": 2011 }, { "abstract": "We proposed and demonstrated a mechanically operated random access memory (MORAM) based on an electrostatically actuated metallic microswitch for nonvolatile memory applications. The metallic microswitch based MORAM successfully showed program and erase operations, wherein the microswitch had an essentially zero off current, an abrupt switching with less than 1 mV/dec, and an on/off current ratio over 107, and its stored charge was investigated with the metal oxide semiconductor (MOS) capacitor. Moreover, first reported were an endurance of up to 105 cycles in air ambient and a retention time of more than 104 s in vacuum ambient.", "author_names": [ "Weon Wi Jang", "Jeong Oen Lee", "Hyun-Ho Yang", "Jun-Bo Yoon" ], "corpus_id": 30732796, "doc_id": "30732796", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "Mechanically Operated Random Access Memory (MORAM) Based on an Electrostatic Microswitch for Nonvolatile Memory Applications", "venue": "IEEE Transactions on Electron Devices", "year": 2008 }, { "abstract": "The charge distribution on the surface of a biased conductive, finite length, cylindrical nanotube, free standing above an infinite grounded plane, is investigated. The diameter range of the cylinder tube under study is 20 60 nm, which is much larger than the screening length, meaning the quantum and statistical effects on the charge distribution are negligible. The relationship between the charge distribution and the geometry of the nanotube is examined in detail by classical electrostatics using full three dimensional numerical simulations based on the boundary element method. A model of the concentrated charge at the end of nanotubes is proposed. The charge distribution for a clamped cantilever nanotube is also computed and discussed. The findings here reported are of particular usefulness in the design and modeling of electrostatic actuated nanotube/ nanowire based nano electromechanical systems.", "author_names": [ "Changhong Ke", "Horacio Dante Espinosa" ], "corpus_id": 1952510, "doc_id": "1952510", "n_citations": 75, "n_key_citations": 1, "score": 0, "title": "Numerical Analysis of Nanotube Based NEMS Devices Part I: Electrostatic Charge Distribution on Multiwalled Nanotubes", "venue": "", "year": 2005 }, { "abstract": "In this Letter, we demonstrate a strong dependence of the electrostatic deformation of doubly clamped single walled carbon nanotubes on both the field strength and the tube length, using molecular simulations. Metallic nanotubes are found to be more sensitive to an electric field than semiconducting ones of the same size. For a given electric field, the induced deformation increases with tube length but decreases with tube radius. Furthermore, it is found that nanotubes can be more efficiently bent in a center oriented transverse electric field.", "author_names": [ "Zhao Wang", "Laetitia Philippe" ], "corpus_id": 17347949, "doc_id": "17347949", "n_citations": 22, "n_key_citations": 1, "score": 0, "title": "Deformation of doubly clamped single walled carbon nanotubes in an electrostatic field.", "venue": "Physical review letters", "year": 2009 }, { "abstract": "This paper qualitatively explores the performance limits, i.e. energy vs. frequency, of adiabatic logic circuits based on nanoelectromechanical (NEM) switches. It is shown that the contact resistance and the electro mechanical switching behavior of the NEM switches dictate the performance of such circuits. Simplified analytical expressions are derived based on a 1 dimensional reduced order model (ROM) of the switch; the results given by this simplified model are compared to classical CMOS based, and sub threshold CMOS based adiabatic logic circuits. NEMS based circuits and CMOS based circuits show different optimum operating conditions, depending on the device parameters and circuit operating frequency.", "author_names": [ "Samer Houri", "Christophe Poulain", "Alexandre Valentian", "Herve Fanet" ], "corpus_id": 17671020, "doc_id": "17671020", "n_citations": 6, "n_key_citations": 1, "score": 0, "title": "Performance Limits of Nanoelectromechanical Switches (NEMS) Based Adiabatic Logic Circuits", "venue": "", "year": 2013 } ]

[ { "abstract": "Abstract In this work, TiO2:Co thin films were prepared by the DC Magnetron Co Sputtering system on glass substrates, varying the substrate temperature. The magnetron power for each target (TiO2, Co) work pressure and deposition time in the samples were kept constant. From XRD, XPS and EDXS measurements, it was possible to establish the formation of a TiO2 semiconductor matrix without binary phases of cobalt oxides. AFM and MFM micrographs evidenced the formation of smaller grains without domains in the surface. The magnetic curves show the dependence of the substrate temperature in the magnetic behaviour of thin films. The presences of hysteresis loops at high temperature in the thin films were observed.", "author_names": [ "Heiddy P Quiroz", "A Dussan" ], "corpus_id": 108464283, "doc_id": "108464283", "n_citations": 14, "n_key_citations": 0, "score": 1, "title": "Synthesis temperature dependence on magnetic properties of cobalt doped TiO2 thin films for spintronic applications", "venue": "Applied Surface Science", "year": 2019 }, { "abstract": "Cobalt oxide films are of technological interest as magnetic substrates that may support the direct growth of graphene, for use in various spintronic applications. In this work, we demonstrate the controlled growth of both Co_3O_4(111) and CoO(111) on Ru(0001) substrates. The growth is performed by Co molecular beam epitaxy, at a temperature of 500 K and in an O_2 partial pressure of 10^ 4) Torr for Co_3O_4(111) and 7.5 x 10^ 7) Torr for CoO(111) The films are distinguished by their dissimilar Co 2p x ray photoemission (XPS) spectra, while XPS derived O/Co stoichiometric ratios are 1.33 for Co3O4(111) and 1.1 for CoO(111) Electron energy loss (EELS) spectra for Co_3O_4(111) indicate interband transitions at ~2.1 and 3.0 eV, while only a single interband transition near 2.0 eV is observed for CoO(111) Low energy electron diffraction (LEED) data for Co_3O_4(111) indicate twinning during growth, in contrast to the LEED data for CoO(111) For Co_3O_4(111) films of less than 20 A average thickness, however, XPS, LEED and EELS data are similar to those of CoO(111) XPS data indicate that both Co oxide phases are hydroxylated at all thicknesses. The two phases are moreover found to be thermally stable to at least 900 K in UHV, while ex situ atomic force microscopy measurements of Co_3O_4(111)/Ru(0001) indicate an average surface roughness below 1 nm. Electrical measurements indicate that Co_3O_4(111)/Ru(0001) films exhibit dielectric breakdown at threshold voltages of ~1 MV cm^ 1) Collectively, these data show that the growth procedures yield Co_3O_4(111) films with topographical and electrical characteristics that are suitable for a variety of advanced device applications.", "author_names": [ "Opeyemi Olanipekun", "Chad Ladewig", "Jeffry A Kelber", "M D Randle", "J Nathawat", "C -P Kwan", "Jonathan P Bird", "Priyanka Chakraborti", "Peter A Dowben", "Tao Cheng", "William A Goddard" ], "corpus_id": 102882506, "doc_id": "102882506", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Epitaxial growth of cobalt oxide phases on Ru(0001) for spintronic device applications", "venue": "", "year": 2017 }, { "abstract": "In this current work, we report the synthesis of transition metal (TM) Cobalt(Co) doped ZnO (Zn1 x Cox O where x 0.01, 0.05, 0.1) powders by solution combustion process using urea (NH2CONH2) as fuel. The synthesized powders were characterized by XRD for phase anlalysis and SEM for microstructure. The powder XRD patterns of the samples confirms the formation of polycrystalline ZnO of hexagonal wurtzite structure by comparing with the standard peaks of JCPDS card no 36 1451. The crystallite size of the powder ranges from 18 30nm when calculated by Scherrer formula. SEM images shows the leaf like ZnO particales of thikness 60nm with 400 600nm length. Keywords Combustion, Zinc Nitrate, Cobalt Nitrate, Urea.", "author_names": [ "J Venkatesh B", "Baburao N Sherikar" ], "corpus_id": 99012957, "doc_id": "99012957", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Synthesis of Cobalt (Co) doped ZnO Spintronic Nano Powders by Solution Combustion Method and Their Characterization", "venue": "", "year": 2017 }, { "abstract": "", "author_names": [ "Biju Mani Rajbongshi" ], "corpus_id": 56376166, "doc_id": "56376166", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Investigation on mixed phase cobalt doped ZnO as novel spintronic photocatalyst and the engineering scheme for enhancing its performance", "venue": "", "year": 2016 }, { "abstract": "Abstract DFT based structural optimizations and cohesive energies of novel Co based Heusler compounds confirm the stability of these alloys in L21 phase (Cu2MnAl prototype) Later, the equilibrium lattice constants are predicted. While defining the electronic structure, the modified Beckhe Johnson scheme for exchange correlations predicted more efficient results than the generalized gradient approximation and onsite Hubbard approximation. Calculated band structure and densities of states together with spin magnetic moments designate the half metallic character of these alloys. The elastic constants are calculated to define the mechanical stability and ductile nature of these alloys. The ferromagnetic spin moments amount to an integral value of 3mB for each system with a maximum contribution from transition metal cobalt atom. Present study opens a way out for the potential application of these alloys as spintronic materials.", "author_names": [ "Shakeel Ahmad Khandy", "Ishtihadah Islam", "Dinesh Chandra Gupta", "Amel Laref" ], "corpus_id": 105388792, "doc_id": "105388792", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "Full Heusler alloys (Co2TaSi and Co2TaGe) as potential spintronic materials with tunable band profiles", "venue": "Journal of Solid State Chemistry", "year": 2019 }, { "abstract": "Abstract The inexorable trend of next generation spintronics is to develop smaller, lighter, faster, and more energy efficient devices. Ultimately, spintronics driven by free energy, for example, solar power, is imperative. Here, a prototype photovoltaic spintronic device with an optical magneto electric tricoupled photovoltaic/magnetic thin film heterojunction, where magnetism can be manipulated directly by sunlight via interfacial effect, is proposed. The magnetic anisotropy is reduced evidenced by the out of plane ferromagnetic resonance (FMR) field change of 640.26 Oe under 150 mW cm 2 illumination via in situ electron spin resonance (ESR) method. The transient absorption analysis and the first principles calculation reveal that the photovoltaic electrons doping in the cobalt film alter the band filling of this ferromagnetic film. The findings provide a new path of electron doping control magnetism and demonstrate an optical magnetic dual controllable logical switch with limited energy supply, which may further transform the landscape of spintronics research.", "author_names": [ "Yifan Zhao", "Shishun Zhao", "Lijun Wang", "Ziyao Zhou", "Junxue Liu", "Tai Min", "Bin Peng", "Zhongqiang Hu", "Shengye Jin", "Ming Liu" ], "corpus_id": 209445679, "doc_id": "209445679", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Sunlight Control of Interfacial Magnetism for Solar Driven Spintronic Applications", "venue": "Advanced science", "year": 2019 }, { "abstract": "", "author_names": [ "Luis Serrano-Ramon" ], "corpus_id": 135682952, "doc_id": "135682952", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Cobalt nanostructures grown by focused electron beam induced deposition for future spintronic applications", "venue": "", "year": 2014 }, { "abstract": "El objetivo de esta tesis consiste en la creacion de nuevas nanoestructuras magneticas basadas en cobalto crecido por deposicion inducida por haz focalizado de electrones (FEBID) para su implementacion en futuros dispositivos de espintronica basados en la conduccion de paredes de dominio. Estos depositos han demostrado en el pasado poseer alta pureza (mas de un 90% at. de cobalto) poco comun en estructuras crecidas mediante esta tecnica. Ademas, los nanohilos crecidos mediante FEBID presentan una buena conduccion de paredes de dominio, caracteristica necesaria en este tipo de dispositivo. Estas cualidades, junto con la enorme versatilidad de los procesos de FEBID, permiten la creacion de estructurabi y tridimensionales en un unico paso,imposibles de conseguir mediante metodos tradicionales de litografia. Con objeto de crear estructuras competitivas con la tecnologia actual es necesario mejorar nuestro conocimiento sobre las estructuras magneticas creadas por este metodo asi como reducir sus dimensiones.En esta trabajo la investigacion se ha centrado en cuatro campos bien diferenciados: la mejora en la resolucion lateral de los depositos (previo a este trabajo 150 nm) mediante el estudio de los diferentes parametros involucrados en el crecimiento y el desarrollo de un nuevo protocolo para la creacion de estructuras tridimensionales funcionales, el estudio mediante imagen de la estructura magnetica de nanohilos crecidos por este metodo y de las paredes de dominio que albergan, estudiar la dinamica del movimiento de paredes de dominio en estas nanoestructuras y modificar de manera controlada las propiedades magneticas de los depositos mediante irradiacion global o local de galio.", "author_names": [ "Luis Enrique Serrano Ramon" ], "corpus_id": 155290443, "doc_id": "155290443", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Cobalt nanostructures grown by focused electron beam induced deposition for future spintronic applications", "venue": "", "year": 2014 }, { "abstract": "This article reports the fabrication and characterization of thin films of pure and cobalt doped ZnO (Co at 4% and 7% a transparent diluted magnetic semiconductor (DMS) grown on 'Si' and glass substrates by RF magnetron sputtering technique. The crystalline structure and phase of the grown thin films were analyzed by using X ray diffraction (XRD) method which confirmed the hexagonal wurtzite structure of the ZnO with slight lattice strain and change in orientation of the planes. The XRD also confirmed that, the films exhibit prominent peaks of (1 0 1) and (1 0 3) with polycrystalline nature. The morphology of the grown thin films was investigated by scanning electron microscopy (SEM) which confirmed the variation of micro structure and size of the polycrystalline film's surface. The energy dispersive X ray spectra (EDS) from SEM have confirmed the presence of constituent elements in the films and concentration (in of each element. The crystalline properties and morphology of the film's cross section were studied by high resolution transmission electron microscopy (HR TEM) The average thickness of the films was found to be about 600 nm from the cross section electron microscopic images. The selected area electron diffraction (SAED) pattern from TEM was recorded for the Co (7% doped ZnO film which has good polycrystalline quality. The optical transmittance of the films coated on corning glass substrates was investigated by UV Visible spectrophotometer for pure, 4% and 7% Co doped ZnO films, which revealed the optical transparency of 85% 75% and 65% respectively. The room temperature ferromagnetism of the doped films was analysed by vibrating sample magnetometry and magneto optic Kerr effect. It was found that the ferromagnetic behaviour of films increases with 'Co' content and the results were discussed in detail.", "author_names": [ "R Siddheswaran", "Rostislav Medlin", "C Esther Jeyanthi", "Srinivasan Gokul Raj", "Ramalinga Viswanathan Mangalaraja" ], "corpus_id": 201221047, "doc_id": "201221047", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Structural, morphological, optical and magnetic properties of RF sputtered Co doped ZnO diluted magnetic semiconductor for spintronic applications", "venue": "Applied Physics A", "year": 2019 }, { "abstract": "Cobalt doped Mn2O3 nanoparticles have been synthesized by chemical route. The structural properties were analyzed by X ray diffraction (XRD) and scanning electron microscope (SEM) analysis. The SEM image shows that the nanoclusters having spherical geometry. The optical properties were analyzed by ultraviolet visible (UV Vis) and Fourier transform infrared (FTIR) spectroscopy. UV Vis spectra illustrates that Co doped Mn2O3 nanosystem acquire blue shift from bulk value (2.5 eV) The chemical composition and purity of the samples were examined using energy dispersive analysis of X ray spectroscopy (EDAX) Magnetic properties were studied using electron of 3.5mB shows the enhancement in magnetic transition temperature (Tc) of Mn2O3 nanosystem due to the incorporation of cobalt ions. (c) 2013 Published by Elsevier Ltd. Selection and/or peer review under responsibility of SMND.", "author_names": [ "K S Pugazhvadivua", "K Ramachandranb", "K Tamilarasana" ], "corpus_id": 165161262, "doc_id": "165161262", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "ScienceDirect Spintronic Materials Nanostructures and Devices SMND 2011 Synthesis and Characterization of Cobalt doped Manganese Oxide Nanoparticles by Chemical Route", "venue": "", "year": 2013 } ]

[ { "abstract": "Renewable energy sources and technologies are increasingly gaining popularity in developing countries as their increasing energy demand can be met by the unexplored potential of renewable energy. With help of decentralized system the power can be directly used at local load centers which will ease centralized grid. The Impedance Source Inverter (ZSI) has many unique advantages as compared to normal Voltage Source Inverter (VSI) and is suitable for both centralized and decentralized applications. This paper elaborates the distinguishing feature of ZSI which makes it suitable for isolated and grid integrated applications for a source whose nature is highly intermittent. Operating principle, steady state analysis, different carrier modulation techniques to control shoot through (ST) states are described. ZSI is able to maintain the constant load bus voltage when connected to a highly intermittent PV panel with help of suitable control technique. Its superiority in decentralized photovoltaic (PV) application is verified with help of MATLAB/Simulink environment. An insight of inter dependency of semiconductor device voltage stress, boosting factor (B) and modulation index (M) for sinusoidal pulsewidh modulation (SVPWM) control techniques is also presented.", "author_names": [ "Arvind Yadav", "Subhash Chandra", "Vinay Kumar Deolia", "Sanjay Agrawal" ], "corpus_id": 46796591, "doc_id": "46796591", "n_citations": 7, "n_key_citations": 0, "score": 1, "title": "Z source inverter application and control for decentralized photovoltaic system", "venue": "2017 3rd International Conference on Condition Assessment Techniques in Electrical Systems (CATCON)", "year": 2017 }, { "abstract": "This paper discusses the performance of Maximum Boost Control Z Source Inverter (MBC ZSI) on the application of Induction Motor Drives with varying loads. The proposed system is able to achieve a steady speed of 1198 Rpm in an average time of 0.5 s with a variable motor load. To validate the performance of the proposed system, a comparison is made with the SPWM VSI inverter system. The results of the comparison found that MBC ZSI requires a faster time to reach a steady speed with an average of 0.26 s even though the load on the motor changes.", "author_names": [ "Indra Ferdiansyah", "", "Diah Septi Yanaratri", "Lucky Pradigta Setiya Raharja" ], "corpus_id": 169037952, "doc_id": "169037952", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Comparative Study of Maximum Boost Control Z Source Inverter with SPWM VSI for Induction Motor Drive", "venue": "2018 3rd International Conference on Information Technology, Information System and Electrical Engineering (ICITISEE)", "year": 2018 }, { "abstract": "The paper focuses on the implementation of selective harmonic eliminated (SHE) PWM applied to the three phase voltage source inverter (VSI) to supply synchronous machine with permanent magnets. Theoretical basis of the obtaining of the three phase VSI switching angles, that provide given spectrum of the output voltage is expounded. Values of the switching angles are derived by the Newton Raphson iterative method. Mathematical model of permanent magnet synchronous motor drive system with VSI is designed. Simulation and comparison of the sinusoidal pulse width modulation (SPWM) and SHE PWM algorithms of power VSI is present.", "author_names": [ "Aleksei Yu Kuzin", "I S Grigorev", "Dmitry V Lukichev", "Galina L Demidova" ], "corpus_id": 201811450, "doc_id": "201811450", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Application of the Selective Harmonic Eliminated PWM Algorithm in High Speed Electric Drive Based on Three Phase Voltage Source Inverter", "venue": "2019 Electric Power Quality and Supply Reliability Conference (PQ) 2019 Symposium on Electrical Engineering and Mechatronics (SEEM)", "year": 2019 }, { "abstract": "Abstract In this paper we address the problem of consensus in hardware interconnected networks. As an example of such, we focus on three phase AC microgrids with Voltage Source Inverters (VSI) as generation units and the consensus control objectives of active power sharing and frequency synchronization. By distinguishing between the interconnected control plant, the control objectives, and the feedback controller, we analytically study a non linear model of the power flow within the microgrid through a robust linear approximation. From here we suggest a Linear Matrix Inequality (LMI) based methodology to verify that the proposed control strategy makes the network reach the consensus objectives. The theoretical analysis is complemented with a simulation study of an arbitrary microgrid.", "author_names": [ "Miguel Parada Contzen" ], "corpus_id": 71715351, "doc_id": "71715351", "n_citations": 2, "n_key_citations": 1, "score": 0, "title": "Analysis of consensus in hardware interconnected networks: An application to inverter based AC microgrids", "venue": "Eur. J. Control", "year": 2019 }, { "abstract": "This paper investigates the power losses for two different IGBT technologies (nonpunch through and punch through) for use in PWM VSI inverters in order to choose the right device technology for a given application. A loss model of the inverter is developed based on experimental determination of the power losses. The loss model is used on two different modulation strategies which are a sine wave with a third harmonic added and a 60/spl deg/ PWM modulation where only two inverter legs are active at the same time. The two IGBT technologies are characterized on an advanced measurement system which is described. The total power losses in the inverter are estimated by simulation at different conditions and it is concluded that the nonpunch through (NPT) technology is most useful for higher switching frequencies, while the punch through (PT) technology is especially useful at lower switching frequencies and high load currents. It is also concluded that the 60/spl deg/ PWM modulation has the lowest power losses and the power losses are almost independent of phase angle cos(/spl phi/ for normal motor operation.", "author_names": [ "Frede Blaabjerg", "Ulrich Jaeger", "Stig Munk-Nielsen", "John Kim Pedersen" ], "corpus_id": 110573548, "doc_id": "110573548", "n_citations": 288, "n_key_citations": 4, "score": 0, "title": "Power losses in PWM VSI inverter using NPT or PT IGBT devices", "venue": "", "year": 1994 }, { "abstract": "A method for minimisation of current harmonics spectrum for asynchronous traction motor fed from three level neutral point clamped voltage source inverter is described in this study. A selective harmonic elimination and mitigation based algorithm using particle swarm optimisation has been utilised. Since the load is an induction motor suitable for traction application, a modified objective function with constraint of individual current harmonics has been proposed in this study to obtain improved harmonic elimination and control with low switching frequency. The proposed method has been compared with conventional technique considering only torque spectrum as objective function. Moreover, a suitable formulation for loss calculation has been proposed to optimise both the motor losses and torque harmonics. Suitable simulations along with experiments are performed with a practical induction motor of cage type to justify the proposed method.", "author_names": [ "Marcin Steczek", "Arunava Chatterjee", "Debashis Chatterjee" ], "corpus_id": 117160138, "doc_id": "117160138", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Optimisation of current harmonics for three level VSI based induction motor drive suitable for traction application", "venue": "", "year": 2018 }, { "abstract": "The current source inverter (CSI) is a power electronics topology that allows for the realization of variable speed drives (VSD) Compared to the most common voltage source inverter (VSI) which can be directly connected to a voltage source, the CSI needs a prestage to generate a constant current bus. This article therefore seeks to challenge this \"accepted\" consideration that a CSI always needs this precircuit and seeks to remove this circuit by proposing an innovative $i_{dc} current control scheme. The proposed scheme is applied to a single stage motor drive driven by a CSI converter. It is shown how implementing this control scheme removes the need for the front end stage, thus removing an unnecessary converter and optimizing the efficiency at the same time. The CSI state space equations are presented and the developed models are verified using simulations. Stability analysis of small signal model is considered through Nyquist criterion with the robustness in presence of variations of the most important system parameters. Experimental results driving a permanent magnet synchronous machine (PMSM) are shown confirming the validity of the proposed control, potentially paving the way to a larger adoption of the CSI topologies for motor drive applications.", "author_names": [ "Giovanni Migliazza", "Giampaolo Buticchi", "Emilio Carfagna", "Emilio Lorenzani", "Vincenzo Madonna", "Paolo Giangrande", "Michael Galea" ], "corpus_id": 226230408, "doc_id": "226230408", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "DC Current Control for a Single Stage Current Source Inverter in Motor Drive Application", "venue": "IEEE Transactions on Power Electronics", "year": 2021 }, { "abstract": "In this paper a three phase voltage source inverter (VSI) has been simulated with controller circuit that can be used in future for hardware implementation using dSPACE 1104 controller in photovoltaic application. The dSPACE controller can be used, as it can link the MATLAB Simulink model directly into a real time operating prototype. The switching of IGBTs will be controlled by generating sinusoidal pulse width modulation (SPWM) signals with proportional integral (PI) controller circuit and parks transformation. The three phase inverter ac output voltage will be stabilized with the help of controller circuit attached to it in simulation model. Here DC voltage source is taken as the photovoltaic generator that supplying power to the three phase inverter. With this model the simulation output is showing a result of 2.83% of total harmonic distortion and supports that the controller circuit used is improving inverter ac voltage output to a great extent. This control system can be transformed into a prototype model with the dSPACE controller board as suggested in this paper.", "author_names": [ "Tanushree Bhattacharjee", "Majid Jamil", "Anup Jana" ], "corpus_id": 211244809, "doc_id": "211244809", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Designing a Controller Circuit for Three Phase Inverter in PV application", "venue": "2018 International Conference on Electrical, Electronics, Communication, Computer, and Optimization Techniques (ICEECCOT)", "year": 2018 }, { "abstract": "This paper proposes a standalone PV fed PMSM drive for water pumping. The proposed system aims at reducing the switching losses and overall cost by using reduced switch inverter. The proposed system comprises of a PMSM drive, fed by PV source through an inverter employing reduced number of switches. The inverter uses only four switches whereas the conventional VSI utilizes six switches. Field oriented control scheme is employed to control the PMSM drive. Perturb and Observe (P&O) MPPT technique is used to generate a speed reference to PMSM drive. Simulation studies for the proposed PV fed 400 W PMSM driven water pumping system are performed using MATLAB platform and respective results are presented to show the efficacy of the system.", "author_names": [ "Anbalagan Karthikeyan", "K K Prabhakaran", "S Varsha", "B Venkatesa Perumal", "S Mishra" ], "corpus_id": 148573195, "doc_id": "148573195", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Single stage PV fed reduced inverter based PMSM for standalone water pumping application", "venue": "2018 IEEE International Conference on Power Electronics, Drives and Energy Systems (PEDES)", "year": 2018 }, { "abstract": "In this paper, an optimal voltage control structure for Voltage Source Inverter (VSI) in series with LC filter for Medium Voltage DC Shipboard Power System (MVDC SPS) applications is proposed. The objective of the proposed method is to design a closed loop controller that makes the output of the system optimally track a given desired signal and reject a given disturbance. Therefore, it is called Linear Quadratic Tracking (LQT) which is considered as a modified form of the Linear Quadratic Regulation (LQR) Computer simulation is used to validate the performance of the proposed control scheme under different scenarios.", "author_names": [ "Maziar Babaei", "Thaer Qunais", "Sherif Abdelwahed" ], "corpus_id": 742154, "doc_id": "742154", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "A linear quadratic tracking based voltage controller for VSI; MVDC shipboard power system application", "venue": "2017 IEEE Power Energy Society General Meeting", "year": 2017 } ]

[ { "abstract": "It is well known that combining the benefits of bipolar and CMOS (Complementary Metal Oxide Semiconductor) devices in BiCMOS technology, one can achieve better speed and power density in microelectronic circuitry. In this work, we present the device design, process development and optimization of diffusion bipolar junction transistor (BJT) for the first time in India, for analog and RF applications. The baseline 180nm CMOS process of Semi Conductor Lab (SCL) at Chandigarh is used to develop the BiCMOS process. All the TCAD simulations are calibrated with the measured data of baseline BJT from 180nm CMOS process with two different process splits. Calibrated simulations of our proposed silicon BJT show current gain 90 and current driving capacity 10 mA. The breakdown voltage of the transistor is above 25 V (BVCB0) with cut off frequency (fT) and maximum oscillation frequency (fmax) more than 5 GHz and 3 GHz, respectively.", "author_names": [ "Suresh Balanethiram", "S Pande", "Ashutosh Kumar Singh", "B Umapathi", "H S Jatana", "Nihar Ranjan Mohapatra", "Anjan Chakravorty" ], "corpus_id": 208212148, "doc_id": "208212148", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Development of Low Cost Silicon BiCMOS Technology for RF Applications", "venue": "2019 IEEE Conference on Modeling of Systems Circuits and Devices (MOS AK India)", "year": 2019 }, { "abstract": "SiGe BiCMOS is reviewed with focus on today's production 0.18 /spl mu/m technology at f/sub T//f/sub MAX/ of 150/200 GHz and future technology where device scaling is bringing about higher f/sub T//f/sub MAX/ as well as lower power consumption, noise figure, and improved large signal performance at higher levels of integration. High levels of radio frequency (RF) integration are enabled by the availability of a number of active and passive modules described in this paper including high voltage and high power devices, complementary PNPs, high quality MIM capacitors, and inductors. Key RF circuit results highlighting the advantages of SiGe BiCMOS in addressing today's RF IC market are also discussed both for applications at modest frequencies (1 to 10 GHz) as well as for emerging applications at higher frequencies (20 to >100 GHz)", "author_names": [ "Marco Racanelli", "Paul Kempf" ], "corpus_id": 23922372, "doc_id": "23922372", "n_citations": 65, "n_key_citations": 1, "score": 0, "title": "SiGe BiCMOS technology for RF circuit applications", "venue": "IEEE Transactions on Electron Devices", "year": 2005 }, { "abstract": "The generation of RF/microwave power is required not only in wireless communications, but also in applications such as jamming, imaging, RF heating, and miniature dc/dc converters. Each application has its own unique requirements for frequency, bandwidth, load, power, efficiency, linearity, and cost. RF power is generated by a wide variety of techniques, implementations, and active devices. Power amplifiers are incorporated into transmitters in a similarly wide variety of architectures, including linear, Kalm, envelope tracking, outphasing, and Doherty. Linearity can be improved through techniques such as feedback, feedforward, and predistortion.", "author_names": [ "Frederick H Raab", "Peter M Asbeck", "Steve C Cripps", "Peter B Kenington", "Zoya Popovic", "Nick Pothecary", "John F Sevic", "Nathan O Sokal" ], "corpus_id": 16321248, "doc_id": "16321248", "n_citations": 1223, "n_key_citations": 57, "score": 0, "title": "Power amplifiers and transmitters for RF and microwave", "venue": "", "year": 2002 }, { "abstract": "The construction and electrical characteristics of two port transformers (1:1 and 1:n turns ratio) and multi port transformer baluns fabricated in a production silicon technology are presented. A high linearity 5 GHz mixer design illustrates the advantages of the trifilar transformer in an RF IC application.", "author_names": [ "D T S Cheung", "John R Long", "Robert A Hadaway", "David L Harame" ], "corpus_id": 111058822, "doc_id": "111058822", "n_citations": 285, "n_key_citations": 20, "score": 0, "title": "Monolithic transformers for silicon RF IC design", "venue": "Proceedings of the 1998 Bipolar/BiCMOS Circuits and Technology Meeting (Cat. No.98CH36198)", "year": 1998 }, { "abstract": "Today more than ever, low cost, high performance RF devices are in high demand due to explosive growth in the wireless communications business. As the RF performance of silicon based technologies improve, silicon solutions are an obvious choice due to its low cost, high reliability and the ability to integrate other analog and logic functions on chip. This paper will highlight some of the development efforts that are taking place to improve silicon device technologies for RF and microwave applications. Performance of current state of the art silicon bipolar, MOSFET, TFSOI and SiGe HBTs will be discussed.<ETX>", "author_names": [ "Natalino Camilleri", "David K Lovelace", "J Costa", "David Ngo" ], "corpus_id": 111352186, "doc_id": "111352186", "n_citations": 21, "n_key_citations": 3, "score": 0, "title": "New development trends for silicon RF device technologies", "venue": "Proceedings of 1994 IEEE Microwave and Millimeter Wave Monolithic Circuits Symposium", "year": 1994 }, { "abstract": "A subharmonic transceiver for sensing and imaging applications in the 122 GHz ISM band has been proposed. The receiver consists of a single ended LNA, a push push VCO with 1/32 divider, a polyphase filter, and a subharmonic mixer. The receiver is fabricated in SiGe:C BiCMOS technology with fT/fmax of 255GHz/315GHz. Its differential down conversion gain is 31 dB at 122 GHz, and the corresponding noise figure is 11 dB. The 3 dB bandwidth reaches from 121 GHz to 124 GHz. The input 1 dB compression point is at 44 dBm. The receiver consumes 113 mA at a supply voltage of 3.2 V.", "author_names": [ "Klaus Schmalz", "Wolfgang Winkler", "Johannes Borngraber", "Wojciech Debski", "Bernd Heinemann", "J Christoph Scheytt" ], "corpus_id": 24330726, "doc_id": "24330726", "n_citations": 27, "n_key_citations": 2, "score": 0, "title": "122 GHz ISM band transceiver concept and silicon ICs for low cost receiver in SiGe BiCMOS", "venue": "2010 IEEE MTT S International Microwave Symposium", "year": 2010 }, { "abstract": "1 Introduction. 2 SOI Materials. 2.1 Introduction. 2.2 Heteroepitaxial techniques. 2.2.1 Silicon on Sapphire (SOS) 2.2.2 Other heteroepitaxial SOI materials. 2.2.2.1 Silicon on Zirconia (SOZ) 2.2.2.2 Silicon on Spinel. 2.2.2.3 Silicon on Calcium Fluoride. 2.3 Dielectric Isolation (DI) 2.4 Polysilicon melting and recrystallization. 2.4.1 Laser recrystallization. 2.4.2 E beam recrystallization. 2.4.3 Zone melting recrystallization. 2.5 Homoepitaxial techniques. 2.5.1 Epitaxial lateral overgrowth. 2.5.2 Lateral solid phase epitaxy. 2.6 FIPOS. 2.7 Ion beam synthesis of a buried insulator. 2.7.1 Separation by implanted oxygen (SIMOX) 2.7.1.1 \"Standard\"SIMOX. 2.7.1.2 Low dose SIMOX. 2.7.1.3 ITOX. 2.7.1.4 SMOXMLD. 2.7.1.5 Related techniques. 2.7.1.6 Material quality. 2.7.2 Separation by implanted nitrogen (SIMNI) 2.7.3 Separation by implanted oxygen and nitrogen (SIMON) 2.7.4 Separation by implanted Carbon. 2.8 Wafer Bonding and Etch Back (BESOI) 2.8.1 Hydrophilic wafer bonding. 2.8.2 Etch back. 2.9 Layer transfer techniques. 2.9.1 Smart Cut(R) 2.9.1.1 Hydrogen rare gas implantation. 2.9.1.2 Bonding to a stiffener. 2.9.1.3 Annealing. 2.9.1.4 Splitting. 2.9.1.5 Further developments. 2.9.2 Eltran(R) 2.9.2.1 Porous silicon formation. 2.9.2.2 The original Eltran(R) process. 2.9.2.3 Second generation Eltran(R) process. 2.9.3 Transferred layer material quality. 2.10 Strained silicon on insulator (SSOI) 2.11 Silicon on diamond. 2.12 Silicon on nothing (SON) 3 SOI Materials Characterization. 3.1 Introduction. 3.2 Film thickness measurement. 3.2.1 Spectroscopic reflectometry. 3.2.2 Spectroscopic ellipsometry. 3.2.3 Electrical thickness measurement. 3.3 Crystal quality. 3.3.1 Crystal orientation. 3.3.2 Degree of crystallinity. 3.3.3 Defects in the silicon film. 3.3.3.1 Most common defects. 3.3.3.2 Chemical decoration of defects. 3.3.3.3 Detection of defects by light scattering. 3.3.3.4 Other defect assessment techniques. 3.3.3.5 Stress in the silicon film. 3.3.4 Defects in the buried oxide. 3.3.5 Bond quality and bonding energy. 3.4 Carrier lifetime. 3.4.1 Surface Photovoltage. 3.4.2 Photoluminescence. 3.4.3 Measurements on MOS transistors. 3.4.3.1 Accumulation mode transistor. 3.4.3.2 Inversion mode transistor. 3.4.3.3 Bipolar effect. 3.5 Silicon/Insulator interfaces. 3.5.1 Capacitance measurements. 3.5.2 Charge pumping. 3.5.3 MOSFET. 4 SOI CMOS Technology. 4.1 SOI CMOS processing. 4.1.1 Fabrication yield and fabrication cost. 4.2 Field isolation. 4.2.1 LOCOS. 4.2.2 Mesa isolation. 4.2.3 Shallow trench isolation. 4.2.4 Narrow channel effects. 4.3 Channel doping profile. 4.4 Source and drain engineering. 4.4.1 Silicide source and drain. 4.4.2 Elevated source and drain. 4.4.3 Tungsten clad. 4.4.4 Schottky source and drain. 4.5 Gate stack. 4.5.1 Gate material. 4.5.2 Gate dielectric. 4.5.3 Gate etch. 4.6 SOI MOSFET layout. 4.6.1 Body contact. 4.7 SOI bulk CMOS design comparison. 4.8 ESD protection. 5 The SOI MOSFET. 5.1 Capacitances. 5.1.1 Source and drain capacitance. 5.1.2 Gate capacitance. 5.2 Fully and partially depleted devices. 5.3 Threshold voltage. 5.3.1 Body effect. 5.3.2 Short channel effects. 5.4 Current voltage characteristics. 5.4.1 Lim Fossum model. 5.4.2 C? continuous model. 5.5 Transconductance. 5.5.1 gm/ID ratio. 5.5.2 Mobility. 5.6 Basic parameter extraction. 5.6.1 Threshold voltage and mobility. 5.6.2 Source and drain resistance. 5.7 Subthreshold slope. 5.8 Ultra thin SOI MOSFETs. 5.8.1 Threshold voltage. 5.8.2 Mobility. 5.9 Impact ionization and high field effects. 5.9.1 Kink effect. 5.9.2 Hot carrier degradation. 5.10 Floating body and parasitic BJT effects. 5.10.1 Anomalous subthreshold slope. 5.10.2 Reduced drain breakdown voltage. 5.10.3 Other floating body effects. 5.11 Self heating. 5.12 Accumulation mode MOSFET. 5.12.1 I V characteristics. 5.12.2 Subthreshold slope. 5.13 Unified body effect representation. 5.14 RF MOSFETs. 5.15 CAD models for SOI MOSFETs. 6 Other SOI Devices. 6.1 Multiple gate SOI MOSFETs. 6.1.1 Multiple gate SOI MOSFET structures. 6.1.1.1 Double gate SOI MOSFETs. 6.1.1.2 Triple gate SOI MOSFETs. 6.1.1.3 Surrounding gate SOI MOSFETs. 6.1.1.4 Triple plus gate SOI MOSFETs. 6.1.2 Device characteristics. 6.1.2.1 Current drive. 6.1.2.2 Short channel effects. 6.1.2.3 Threshold voltage. 6.1.2.4 Volume inversion. 6.1.2.5 Mobility. 6.2 MTCMOS/DTMOS. 6.3 High voltage devices. 6.3.1 VDMOS and LDMOS. 6.3.2 Other high voltage devices. 6.4 Junction Field Effect Transistor. 6.5 Lubistor. 6.6 Bipolar junction transistors. 6.7 Photodiodes. 6.8 G4 FET. 6.9 Quantum effect devices. 7 The SOI MOSFET in a Harsh Environment. 7.1 Ionizing radiations. 7.1.1 Single event phenomena. 7.1.2 Total dose effects. 7.1.3 Dose rate effects. 7.2 High temperature operation. 7.2.1 Leakage current. 7.2.2 Threshold voltage. 7.2.3 Output conductance. 7.2.4 Subthreshold slope. 8 SOI Circuits. 8.1 Introduction. 8.2 Mainstream CMOS applications. 8.2.1 Digital circuits. 8.2.2 Low voltage, low power digital circuits. 8.2.3 Memory circuits. 8.2.3.1 Non volatile memory devices. 8.2.3.2 Capacitorless DRAM. 8.2.4 Analog circuits. 8.2.5 Mixed mode circuits. 8.3 Niche applications. 8.3.1 High temperature circuits. 8.3.2 Radiation hardened circuits. 8.3.3 Smart power circuits. 8.4 Three dimensional integration.", "author_names": [ "J P Colinge" ], "corpus_id": 108908203, "doc_id": "108908203", "n_citations": 1539, "n_key_citations": 97, "score": 0, "title": "Silicon on Insulator Technology: Materials to VLSI", "venue": "", "year": 1991 }, { "abstract": "Electrostatic discharge (ESD) continues to be a semiconductor quality and reliability area of interest as semiconductor components are reduced to smaller dimensions. The combination of scaling, design integration, circuit performance objectives, new applications, and the evolving system environments, ESD robustness will continue to be a technology concern. With the transition from silicon bipolar junction transistor to modern BiCMOS silicon germanium (SiGe) semiconductor technologies, new semiconductor process and integration issues have evolved which influence both device performance and ESD protection. Additionally, the issues of low cost, low power and radio frequency (RF) GHz performance objectives has lead to both revolutionary as well as derivative technologies; these have opened new doors for discovery, development and research in the area of on chip ESD protection and design. With the growth of interest of ESD in RF technology, new innovations and inventions are occurring at a rapid pace. In this paper, we will provide an introductory review of silicon germanium technology and ESD.", "author_names": [ "Steven H Voldman" ], "corpus_id": 990323, "doc_id": "990323", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "A review of latchup and electrostatic discharge (ESD) in BiCMOS RF silicon germanium technologies: Part I ESD", "venue": "Microelectron. Reliab.", "year": 2005 }, { "abstract": "The low resistivity substrate that is used in bulk silicon processes (CMOS and BiCMOS) limits the integration of high quality passives components and gives rise to severe substrate coupling issues. This paper shows how to take advantage of HR SOI to improve RF circuit performances as well as the effectiveness of HR SOI to reduce substrate coupling. Potentiality of mm wave passive integration is also shown.", "author_names": [ "Carlo Tinella", "Frederic Gianesello", "Daniel Gloria", "Christine Raynaud", "P Delatte", "A Engelstein", "J M Fournier", "Philippe Benech", "Jalal Jomaah" ], "corpus_id": 40233934, "doc_id": "40233934", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Partially depleted CMOS SOI technology for low power RF applications", "venue": "European Gallium Arsenide and Other Semiconductor Application Symposium, GAAS 2005", "year": 2005 }, { "abstract": "A detail fabricating process and characterization of thin film microstrip line (TFML) on low K polyimide, used for interconnects in radio frequency integrated circuits (RFICs) technology, is reported in this study. By incorporating a spin on dielectric polyimide and sputtering of aluminum, the TFML is fabricated on low cost low resistivity silicon (LRS) substrate @r=[email protected] The TFML with a thickness of [email protected] polyimide dielectric layer presents attenuation losses of 0.385dB/mm at 25GHz and 0.438dB/mm at 50GHz. Effective dielectric constant and attenuation of TFML on polyimide are carefully investigated and discussed.", "author_names": [ "Hung-Wei Wu", "Yan Kuin Su", "Ru-Yuan Yang", "Min-Hang Weng", "Yu-Der Lin" ], "corpus_id": 26897217, "doc_id": "26897217", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Fabrication of low loss thin film microstrip line on low resistivity silicon for RF applications", "venue": "Microelectron. J.", "year": 2007 } ]

[ { "abstract": "Memristive devices, which exhibit a dynamical conductance state that depends on the excitation history, can be used as nonvolatile memory elements by storing information as different conductance states. We describe the implementation of a nonvolatile synchronous flip flop circuit that uses a nanoscale memristive device as the nonvolatile memory element. Controlled testing of the circuit demonstrated successful state storage and restoration, with an error rate of 0.1% during 1000 power loss events. These results indicate that integration of digital logic devices and memristors could open the way for nonvolatile computation with applications in small platforms that rely on intermittent power sources. This demonstrated feasibility of tight integration of memristors with CMOS (complementary metal oxide semiconductor) circuitry challenges the traditional memory hierarchy, in which nonvolatile memory is only available as a large, slow, monolithic block at the bottom of the hierarchy. In contrast, the nonvolatile, memristor based memory cell can be fast, fine grained and small, and is compatible with conventional CMOS electronics. This threatens to upset the traditional memory hierarchy, and may open up new architectural possibilities beyond it.", "author_names": [ "Warren Robinett", "Matthew D Pickett", "Julien Borghetti", "Qiangfei Xia", "Greg Snider", "Gilberto Medeiros-Ribeiro", "R Stanley Williams" ], "corpus_id": 9905639, "doc_id": "9905639", "n_citations": 79, "n_key_citations": 3, "score": 1, "title": "A memristor based nonvolatile latch circuit.", "venue": "Nanotechnology", "year": 2010 }, { "abstract": "In this paper, a modified design of memristor based logic circuits integrated with CMOS components is introduced. Design of a compact and nonvolatile S R Latch is examined using a general memristor model as the nonvolatile element to store data. The proposed design operates efficiently in both \"Set\" and \"Reset\" modes. The simulation results demonstrate that this novel S R latch design offers better performance in terms of power, non volatility, and size of the topology compared with other memristor based designs proposed in the literature. We proved that this design has non volatile characteristics and is able to store data. This nonvolatile memristor based S R latch is a real alternative for future low power applications adding non volatility.", "author_names": [ "Khaoula Mbarek", "Sami Ghedira", "Faten Ouaja Rziga", "Kamel Besbes" ], "corpus_id": 221847410, "doc_id": "221847410", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Design and Analysis of Nonvolatile Memristor based S R Latch", "venue": "2020 IEEE International Conference on Design Test of Integrated Micro Nano Systems (DTS)", "year": 2020 }, { "abstract": "Sequential devices are the fundamental building blocks for almost all digital electronic systems with memory. Due to the importance of instant data recovery after unexpected data loss such as unplanned power down, sequential devices need to have the nonvolatile property, which motivates the recent research and practice in integrating the nonvolatile memristor into CMOS devices. In this paper, we study how to apply this approach to improve the quality of nonvolatile D latch. Unlike the structure of conventional design, the proposed D latch consists of only one memristor, several transmission gates, and CMOS inverters. Our design overcomes the negative effect due to the threshold loss of the transistors. As simulation shows, compared with the current designs, our proposed memristor based D latch can support the memristor to switch between different resistance states 2.3X 3.6X faster, and thus achieving a clock of higher frequency. In addition, our design allows the threshold value of the memristor to be selected from a much wider range. As an application, we use the proposed memristor based D latch to implement a nonvolatile master slave D flip flop, which has smaller delay than all the state of the art designs and smaller area than all but one of them. Our designs improve the quality of memristor based D latch and D flip flop in terms of latency, area, and flexibility of threshold voltage selection, making them a promising option for data backup in real life systems.", "author_names": [ "Zhenxing Chang", "Aijiao Cui", "Ziming Wang", "Gang Qu" ], "corpus_id": 234477404, "doc_id": "234477404", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Novel Memristor based Nonvolatile D Latch and Flip flop Designs", "venue": "2021 22nd International Symposium on Quality Electronic Design (ISQED)", "year": 2021 }, { "abstract": "Flip flops are basic units for all kinds of sequential logic circuits and complex digital electronics systems, which can be used to store binary data owing to their two stable logic states 0 and 1. SR flip flop and D flip flop are widely employed in digital circuits as representative types of basic flip flops. In this paper, logic circuits of nonvolatile synchronous SR flip flop and D flip flop are proposed, which utilize nanoscale memristors as the nonvolatile memory elements to store the information with different conductance states. The resistive switching property of memristors is well suited for implementing trigger function in flip flop circuits. Compared with traditional flip flop ones, the proposed memristor based SR flip flop and D flip flop have nonvolatile characteristic, which is suitable for occasions with unstable power supply. Meanwhile, the designed circuits provide experimental references for the development of digital circuit structures based on the feasibility of tight integration of memristors with CMOS circuitry.", "author_names": [ "Jian Zheng", "Zhigang Zeng", "Yidong Zhu" ], "corpus_id": 12002484, "doc_id": "12002484", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Memristor based nonvolatile synchronous flip flop circuits", "venue": "2017 Seventh International Conference on Information Science and Technology (ICIST)", "year": 2017 }, { "abstract": "This paper presents a chaotic circuit based on a nonvolatile locally active memristor model, with non volatility and local activity verified by the power off plot and the DC V I plot, respectively. It is shown that the memristor based circuit has no equilibrium with appropriate parameter values and can exhibit three hidden coexisting heterogeneous attractors including point attractors, periodic attractors, and chaotic attractors. As is well known, for a hidden attractor, its attraction basin does not intersect with any small neighborhood of any unstable equilibrium. However, it is found that some attractors of this circuit can be excited from an unstable equilibrium in the locally active region of the memristor, meaning that its basin of attraction intersects with neighborhoods of an unstable equilibrium of the locally active memristor. Furthermore, with another set of parameter values, the circuit possesses three equilibria and can generate self excited chaotic attractors. Theoretical and simulated analyses both demonstrate that the local activity and an unstable equilibrium of the memristor are two reasons for generating hidden attractors by the circuit. This chaotic circuit is implemented in a digital signal processing circuit experiment to verify the theoretical analysis and numerical simulations.", "author_names": [ "Yujiao Dong", "Guangyi Wang", "Herbert Ho-Ching Iu", "Guanrong Chen", "Long Chen" ], "corpus_id": 226242982, "doc_id": "226242982", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Coexisting hidden and self excited attractors in a locally active memristor based circuit.", "venue": "Chaos", "year": 2020 }, { "abstract": "Memristor, one of the fundamental circuit elements, has promising applications in non volatile memory and storage technology as it can theoretically achieve infinite states. Information can be stored independently in these states and retrieved whenever required. In this paper, we have proposed a non volatile memory cell based on memristor emulator. The circuit is able to perform read and write operations. In this memristor based memroy cell, unipolar pulse is used for writing and bipolar pulse is used for reading. Unlike other earlier designs, the circuit does not need external read/write enable switches to switch between read and write operations; the switching is achieved by the zero average bipolar read pulse given after the completion of write cycle. In our proposed memristor based memory cell, single bit can be read and any voltages from 0 to 5 volts can be written. Mathematical analysis and the simulation results of memristor emulator based read write circuit have been presented to confirm its operation.", "author_names": [ "S Parajuli", "Ram Kaji Budhathoki", "Hyongsuk Kim" ], "corpus_id": 212697122, "doc_id": "212697122", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Nonvolatile Memory Cell Based on Memristor", "venue": "", "year": 2020 }, { "abstract": "For ultra low power Internet of Things (IoT) devices powered by batteries or energy harvesting, a nonvolatile flip flop (NV FF) operating in the near threshold voltage (NTV) region has been widely studied to save both standby and active power. However, in the NTV region, the NV FF suffers from restore yield and performance degradation due to the increase in process variation combined with the decrease in supply voltage. This paper presents a comparative analysis of the previous NV FFs according to supply voltage scaling and suggests the design directions for implementing the NV FF that can operate with compact area and high performance even in the NTV region. Through the comparative analysis, a novel offset cancellation sensing circuit (OCSC) based NV FF, which adopts a separate latch and sensing circuit structure and an offset cancellation technique, is proposed. The Monte Carlo HSPICE simulation results using industry compatible 65 nm model parameters show that the proposed NV FF satisfies a target restore yield with 32% area, 88% speed, and 82% energy savings in comparison with a representative NV FF of the merged latch and sensing circuit structure.", "author_names": [ "Byungkyu Song", "Sara Choi", "Seung H Kang", "Seong-ook Jung" ], "corpus_id": 182385014, "doc_id": "182385014", "n_citations": 3, "n_key_citations": 2, "score": 0, "title": "Offset Cancellation Sensing Circuit Based Nonvolatile Flip Flop Operating in Near Threshold Voltage Region", "venue": "IEEE Transactions on Circuits and Systems I: Regular Papers", "year": 2019 }, { "abstract": "Reduction of leakage power and vulnerability to radiation are of critical challenges in modern nanometer CMOS technologies because of scaling down requirement. Spintronic logic has been progressed to realize these demands based on magnetic based elements properties especially magnetic tunnel junction (MTJ) such as radiation hardened, non volatility, and CMOS process compatibility. A novel soft error tolerant and highly reliable latch circuit is proposed in this paper which is a promising choice for reliable and low power architectures. Furthermore, employing the proposed shadow latch based on MTJ cells as a backup structure along with the rad hard main latch is aimed to the realization of a nonvolatile and SEU immune flip flop which is applicable in next generation CMOS circuits. Simulations of proposed circuits have been performed by SPICE tool and a 45 nm CMOS technology model to evaluate the effectiveness of topologies.", "author_names": [ "Abdolah Amirany", "Fahimeh Marvi", "Kian Jafari", "Ramin Rajaei" ], "corpus_id": 207833169, "doc_id": "207833169", "n_citations": 12, "n_key_citations": 2, "score": 0, "title": "Nonvolatile Spin Based Radiation Hardened Retention Latch and Flip Flop", "venue": "IEEE Transactions on Nanotechnology", "year": 2019 }, { "abstract": "Latches and flip flops are the basic unit in digital systems and for almost all sequential circuits. They preserve their state in the absence of the clock signal and hence store information as 0s (low voltage level) and 1s (high voltage level) This paper presents a novel design of a non volatile D Latch having minimum components using memristors. The circuits are designed and simulated in Cadence Virtuoso Analog Design Environment Product Suite and Spectre(r) Circuit simulation platform and the simulation results are also presented. The simplicity and the highly efficiency area utilization of the proposed D Latch makes it an ideal candidate to be used in various aspects of digital domain.", "author_names": [ "", "R Arundeepakvel", "Parth Khatter", "Neeta Pandey" ], "corpus_id": 209496452, "doc_id": "209496452", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Realization of Memristor based D Latch", "venue": "2019 International Conference on Computing, Power and Communication Technologies (GUCON)", "year": 2019 }, { "abstract": "Memristor, one of the fundamental circuit elements, has promising applications in non volatile memory and storage technology as it can theoretically achieve infinite states. Information can be stored independently in these states and retrieved whenever required. In this paper, we have proposed a non volatile memory cell based on memristor emulator. The circuit is able to perform read and write operations. In this memristor based memroy cell, unipolar pulse is used for writing and bipolar pulse is used for reading. Unlike other earlier designs, the circuit does not need external read/write enable switches to switch between read and write operations; the switching is achieved by the zero average bipolar read pulse given after the completion of write cycle. In our proposed memristor based memory cell, single bit can be read and any voltages from 0 to 5 volts can be written. Mathematical analysis and the simulation results of memristor emulator based read write circuit have been presented to confirm its operation.", "author_names": [ "S Parajuli", "Ram Kaji Budhathoki", "Hyongsuk Kim" ], "corpus_id": 152282736, "doc_id": "152282736", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Nonvolatile Memory Cell Based on Memristor Emulator", "venue": "ArXiv", "year": 2019 } ]

[ { "abstract": "Many applications require laser pump sources with high output power (tens to hundreds of Watts) in the smallest spot, with the smallest divergence. Such high brightness pump sources typically use edge emitting semiconductor lasers. However, it is also possible to use high power two dimensional vertical cavity surfaceemitting laser (VCSEL) arrays for this purpose. Using a single 976nm 2D VCSEL array chip in an external cavity configuration, combined with a matching micro lens array, we have demonstrated more than 30W output power from a 50mm/0.22NA fiber, corresponding to a brightness of 10MW/cm2.sr. This represents a substantial reduction in module complexity compared to edge emitter based modules with similar brightness. These novel high brightness pump sources exhibit some well known intrinsic VCSEL performance features such as wavelength stability and narrow spectrum. Power and brightness can be scaled up using polarization and spectral combining.", "author_names": [ "Jean-Francois P Seurin", "Guoyang Xu", "Qing Wang", "Baiming Guo", "Robert van Leeuwen", "Alexander Miglo", "Prachi Pradhan", "James D Wynn", "Viktor Khalfin", "Chuni L Ghosh" ], "corpus_id": 111046230, "doc_id": "111046230", "n_citations": 29, "n_key_citations": 1, "score": 1, "title": "High brightness pump sources using 2D VCSEL arrays", "venue": "OPTO", "year": 2010 }, { "abstract": "We review recent results on high power, high efficiency two dimensional vertical cavity surface emitting laser (VCSEL) arrays emitting around 980nm. Selectively oxidized, bottom emitting single VCSEL emitters with 51% power conversion efficiency were developed as the basic building block of these arrays. More than 230W of continuous wave (CW) power is demonstrated from a ~5mm x 5mm array chip. In quasi CW mode, smaller array chips exhibit 100W output power, corresponding to more than 3.5kW/cm2 of power density. High brightness arrays have also been developed for pumping fiber lasers, delivering a fiber output power of 40W. We show that many of the advantages of low power single VCSEL devices such as reliability, wavelength stability, low divergence circular beam, and low cost manufacturing are preserved for these high power arrays. VCSELs thus offer an attractive alternative to the dominant edge emitter technology for many applications requiring compact high power laser sources.", "author_names": [ "Jean-Francois P Seurin", "Chuni L Ghosh", "Viktor Khalfin", "Aleksandr Miglo", "Guoyang Xu", "James D Wynn", "Prachi Pradhan", "L A D'asaro" ], "corpus_id": 111002668, "doc_id": "111002668", "n_citations": 93, "n_key_citations": 1, "score": 0, "title": "High power high efficiency 2D VCSEL arrays", "venue": "SPIE OPTO", "year": 2008 }, { "abstract": "A face pumped Nd:YAG slab laser with high power output and temperature fluctuation adaptability is proposed and demonstrated for the first time. A two dimensional (2D) vertical cavity surface emitting laser (VCSEL) array at 808 nm with a low wavelength shift coefficient is used as the pump source with a total pump power of 1.38 kW. The array is cooled by a double layer vascularized macro channel heat sink for effective heat management. A 1064 nm maximum power of 437 W from the slab laser is obtained by optimizing the output coupling, and the power variation is only 4.9% over the temperature range from 16 degC to 34 degC. The results show that the high power slab laser pumped by VCSEL has an excellent performance in temperature tolerance and lower requirements for coolant, which is only water cooled by the macro channel heat sink and no need for deionized water; it also provides a solution for high power lasers used in the complicated environment. Furthermore, it is possible to scale the output power to ~kW level by further increasing the VCSEL pump power.", "author_names": [ "Peng-Cheng Di", "Xue-peng Li", "Rujia Wang", "Xiao-Jun Wang", "Da-Fu Cui", "Qin-Jun Peng" ], "corpus_id": 232372886, "doc_id": "232372886", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "High Power VCSEL Pumped Slab Laser With Temperature Fluctuation Adaptability", "venue": "IEEE Photonics Technology Letters", "year": 2021 }, { "abstract": "Vertical cavity surface emitting lasers (VCSELs) are attractive for many pumping and direct diode applications due to combined advantages in low cost, high reliability, narrow and thermally stable spectrum, high power scalability, and easy system integration, etc. We report our progress on electrically pumped, GaAs based, high power high brightness VCSELs and 2D arrays in the infrared wavelength range. At 976nm, over 5.5W peak CW output and 60% peak power conversion efficiency (PCE) were demonstrated with 225um oxide confined device. For 5x5mm arrays, peak PCE of 54% and peak power of >450W at 976nm, peak PCE of 46% and peak power of >110W at 808nm were achieved respectively under QCW conditions. External cavity configuration was used to improve the VCSEL brightness. Single mode output of 280mW and 37% PCE were realized from 80um device. For large 325um device, we obtained single mode (M2=1.1) CW output of 2.1W, corresponding to a brightness of 160MW/cm2*sr. Three major areas of applications using such VCSELs are discussed: 1. High brightness fiber output; 2. High power, high efficiency green lasers from 2nd harmonic generation. 3.34W green output with 21.2% PCE were achieved; 3. Pumping solid state lasers for high energy pulse generation. We have demonstrated Q switched pulses with 16.1mJ at 1064nm and 4.9mJ with 1W average power at 473nm.", "author_names": [ "Delai Zhou", "Jean-Francois P Seurin", "Guoyang Xu", "Pu Zhao", "Bing Xu", "Tong Chen", "Robert van Leeuwen", "Joseph Matheussen", "Qing Wang", "Chuni L Ghosh" ], "corpus_id": 31684410, "doc_id": "31684410", "n_citations": 9, "n_key_citations": 1, "score": 0, "title": "Progress on high power high brightness VCSELs and applications", "venue": "Photonics West Optoelectronic Materials and Devices", "year": 2015 }, { "abstract": "Summary form only given. We present the first reported results for linear arrays of /spl alpha/DFB lasers in the 915 nm and 1064 nm wavelength regimes with record high brightness values. We also present results for a 2D array of /spl alpha/DFB lasers at 915 nm with a record high brightness using a novel stacking architecture. To our knowledge, this is the highest reported brightness from a multi Watt semiconductor laser source and is over a factor of 5X higher than the accessible brightness of the highest power broad area bars reported to date. High brightness laser diode arrays are attractive sources for applications such as soldering, heat treatment, marking and pumping of solid state lasers.", "author_names": [ "Vince Wong", "A Schoenfelder", "S O'brien", "Scott Demars", "Robert J Lang" ], "corpus_id": 108557039, "doc_id": "108557039", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "High brightness /spl alpha/DFB arrays at 915 nm and 1.06 /spl mu/m", "venue": "", "year": 1999 }, { "abstract": "Direct laser diodes can typically provide only a limited single mode power, while ultrahigh brightness is required for many of the market relevant applications. Thus, multistage power conversion schemes are applied, when the laser diodes are used just as a pumping source. In this paper we review the recent advances in ultra large output aperture edge emitting lasers based on the photonic band crystal (PBC) concept. The concept allows near and far field engineering robust to temperature and strain gradients and growth nonuniformities. High order modes are selectively filtered and the effective optical confinement of the fundamental mode can be dramatically enhanced. At first, we show that robust ultra narrow vertical beam divergence <5 deg. FWHM) can be achieved simultaneously with ultrahigh differential efficiency (80 85% and significant single mode power for several wavelengths of the key regions. A maximum single mode power of 1.4 W is achieved for 980 nm lasers. At second we extend the PBC concept towards the 2D photonic crystal. A significant field extension in the vertical direction allows a robust fabrication of the field coupled lateral multistripe PBC arrays with a total multistripe width of 0.2 mm. We also demonstrate that the concept of high order modes filtering works well also in the lateral direction. Finally, we address possible options for 3D managing of light towards wavelength stabilized laser operation by processing of the multistripe arrays along their lengths. The concept opens a way for 3D photonic crystal edge emitting lasers potentially allowing scalable single mode power increase to arbitrary high levels.", "author_names": [ "Nikita Yu Gordeev", "Mikhail Maximov", "Y M Shernyakov", "Innokenty Novikov", "Leonid Karachinsky", "Vitaly A Shchukin", "Th Kettler", "Kristijan Posilovic", "Nikolai N Ledentsov", "Dieter Bimberg", "R Duboc", "Andre Sharon", "D B Arbiv", "Udi Ben-Ami" ], "corpus_id": 109277643, "doc_id": "109277643", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "High power one two and three dimensional photonic crystal edge emitting laser diodes for ultra high brightness applications", "venue": "SPIE OPTO", "year": 2008 }, { "abstract": "High power laser diode arrays, which are made of stacks of individual or multistripe laser diodes, or in some cases vertical cavity surfaceemitting lasers (VCSELs) can put out watts to kilowatts of optical power for uses such as laser pumping, industrial heating, illumination, or as the input for fiber optic direct diode laser devices for materials processing or for medicine. Laser diodes typically have much higher electrical to optical (wall plug) efficiencies than other types of lasers; in fact, they are some of the most efficient light emitters known. The d i sadvantage of laser diode arrays is their rela t i v e l y low beam quality there are no sing le mode kilowatts level laser diode sources in our near future. However, there are many applications that do not require a single mode beam; in addition, laser manufacturers are constantly refining beamcombining techniques to produce ever brighter high power laser diode sources.", "author_names": [ "John Wallace" ], "corpus_id": 33218971, "doc_id": "33218971", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Diode arrays are compact high power light dynamos", "venue": "", "year": 2015 }, { "abstract": "High power 808nm semiconductor lasers are widely used for pumping neodymium doped yttrium aluminum garnet (Nd:YAG) crystal to produce high brightness lasing at 1064nm. In addition, there are growing interest to use such high power 808nm lasers in the field of automotive infra red (IR) illumination and medical aesthetic treatment. Vertical cavity surface emitting lasers (VCSELs) have emerged as a promising candidate and attracted increased interests for those applications, due to their combined advantages of high efficiency, low diverging circular beam, narrow emission spectrum with reduced temperature sensitivity, low cost manufacturability, simpler coupling optics, and increased reliability, especially at high temperatures. They can emit very high power with very high power density as they can be conveniently configured into large two dimensional arrays and modules of arrays. We report recent development on such high power, high efficiency 808nm VCSELs with industrial leading ~55% power conversion efficiency (PCE) Top emitting VCSELs were grown by MOCVD and processed into single devices and 2D arrays using selective wet oxidation process and substrate removal technique for efficient current confinement and heat removal. Peak PCE of 51% and peak power of 800W were achieved from 5x5mm array, corresponding to peak power density of ~4kW/cm2. Pumped with new generation of 2.3kW VCSEL module, Q switched laser pulse energy at 1064nm reached 46.9mJ, more than doubled from previously reported results.", "author_names": [ "Delai Zhou", "Jean-Francois P Seurin", "Guoyang Xu", "Robert van Leeuwen", "Alexander Miglo", "Qing Wang", "A R Kovsh", "Chuni L Ghosh" ], "corpus_id": 125799754, "doc_id": "125799754", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Progress on high power 808nm VCSELs and applications", "venue": "OPTO", "year": 2017 }, { "abstract": "The context of this thesis falls in the wide applications of UV light sources such as sterilization and purification. Compared to the conventional UV sources (excimer lasers, Nd: YAG lasers or mercury lamps) the semiconductor devices have advantages in reliability, compactness, high efficiency and minimum environmental effects. On the material aspect, III nitrides (BAlGaInN) are promising candidates since they are chemically and physically stable with direct bandgaps covering from visible to DUV spectrum. On the structure aspect, vertical cavity surface emitting laser (VCSEL) is one of the most attractive configurations considering its low threshold, high efficiency, and the possibility for the integration of 2D arrays and the wafer level tests. It constitutes a multiple quantum well (MQW) active region sandwiched by a top and a bottom distributed Bragg reflector (DBR) However, no VCSELs can operate below 300 nm until now. The major challenges lie in the two main blocks: the emission efficiency of MQWs and the reflectivity of DBRs, which are limited by the quality of the substrates and epitaxial layers, optical polarization properties of the MQW emission, small refractive index contrast of the layers used for DBRs at short wavelengths, etc. The objective of this thesis is to address this need by studying metal organic vapor phase epitaxy (MOVPE) growth of BAlGaN materials, developing AlGaN MQWs with enhanced surface emission and exploring BAlN/AlGaN DBRs, for the future development of optically pumped VCSELs operating below 300 nm", "author_names": [ "Xianbo Li" ], "corpus_id": 137874265, "doc_id": "137874265", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "BAlGaN based vertical cavity surface emitting lasers operating in deep UV region", "venue": "PHOTOPTICS 2016", "year": 2016 }, { "abstract": "The context of this thesis falls in the wide applications of UV light sources such as sterilization and purification. Compared to the conventional UV sources (excimer lasers, Nd: YAG lasers or mercury lamps) the semiconductor devices have advantages in reliability, compactness, high efficiency and minimum environmental effects. On the material aspect, III nitrides (BAlGaInN) are promising candidates since they are chemically and physically stable with direct bandgaps covering from visible to DUV spectrum. On the structure aspect, vertical cavity surface emitting laser (VCSEL) is one of the most attractive configurations considering its low threshold, high efficiency, and the possibility for the integration of 2D arrays and the wafer level tests. It constitutes a multiple quantum well (MQW) active region sandwiched by a top and a bottom distributed Bragg reflector (DBR) However, no VCSELs can operate below 300 nm until now. The major challenges lie in the two main blocks: the emission efficiency of MQWs and the reflectivity of DBRs, which are limited by the quality of the substrates and epitaxial layers, optical polarization properties of the MQW emission, small refractive index contrast of the layers used for DBRs at short wavelengths, etc. The objective of this thesis is to address this need by studying metal organic vapor phase epitaxy (MOVPE) growth of BAlGaN materials, developing AlGaN MQWs with enhanced surface emission and exploring BAlN/AlGaN DBRs, for the future development of optically pumped VCSELs operating below 300 nm", "author_names": [ "Xin Li" ], "corpus_id": 138150029, "doc_id": "138150029", "n_citations": 1, "n_key_citations": 1, "score": 0, "title": "Lasers a cavite vertical emettant par la surface dans l'ultraviolet profond a base des materiaux BAlGaN", "venue": "", "year": 2015 } ]

[ { "abstract": "With the intention to tune the charge transport nature of preliminary 4,6 di(thiophen 2 yl)pyrimidine (DTP) structure, six novel V shaped organic semiconductor compounds were designed by nitrogen doping and acene moieties elongation. Initially, the nitrogen atoms were doped in DTP to design 4,6 bis thiazol 2 yl pyrimidine (1) Moreover, by bridge elongation strategy, 4,6 bis benzo[b]thiazol 2 yl pyrimidine (2) 4,6 bis(naphthothiazol 2 yl)pyrimidine (3) 4,6 bis(anthracenothiazol 2 yl)pyrimidine (4) 4,6 bis(tetracenothiazol 2 yl)pyrimidine (5) and 4,6 bis(pentacenothiazol 2 yl)pyrimidine (6) were designed by substituting various oligocenes at both ends. The ground as well as excited state structures were optimized using density functional theory (DFT) and time dependent DFT at B3LYP/6 31G* and TD B3LYP/6 31G* levels, correspondingly. We explored their frontier molecular orbitals, electron injection aptitude, photo stability, ionization energies (IE) electron affinity (EA) and reorganization energies. The bridge elongation significantly elevate the EA while reduce the IE which would results to decrease the injection barrier for electron and hole transport. Furthermore, acene cores elongation expressively decrease the hole and electron reorganization energies as compared to frequently used materials pentacene and tris(8 hydroxyquinolinato)aluminum (mer Alq3) which revealed that newly designed materials would be proficient to be used in p and/or n type semiconductor devices.", "author_names": [ "Ahmad Irfan" ], "corpus_id": 234504170, "doc_id": "234504170", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Effect of nitrogen doping and acene cores elongation on charge transport and electronic nature of organic semiconductor materials: A DFT study", "venue": "", "year": 2020 }, { "abstract": "Abstract The effects of doping of Ba atom(s) on structural, electronic and optical properties of binary strontium chalcogenide semiconductor compounds have been investigated theoretically using DFT based FP LAPW approach by modeling the rock salt (B1) ternary alloys BaxSr1 xS, BaxSr1 xSe and BaxSr1 xTe at some specific concentrations x 0.0, 0.25, 0.50, 0.75 and 1.0 and studying their aforesaid properties. The exchange correlation potentials for their structural properties have been computed using the Wu Cohen generalized gradient approximation (WC GGA) scheme, while those for the electronic and optical properties have been computed using the WC GGA and Tran Blaha modified Becke Johnson (TB mBJ) scheme. The thermodynamic stability of all the modeled ternary alloys have been investigated by calculating their respective enthalpy of formation. The atomic and orbital origin of different electronic states in the band structure of each of the compounds have been identified from the respective density of states (DOS) Using the approach of Zunger and co workers, the microscopic origin of band gap bowing has been discussed in term of volume deformation, charge exchange and structural relaxation. Bonding characteristics among the constituent atoms of each of the specimens have been discussed from their charge density contour plots. Optical properties of the binary compounds and ternary alloys have been investigated theoretically in terms of their respective dielectric function, refractive index, normal incidence reflectivity and optical conductivity. Several calculated results have been compared with available experimental and other theoretical data.", "author_names": [ "Rahul Bhattacharjee", "Surya Chattopadhyaya" ], "corpus_id": 136232276, "doc_id": "136232276", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Effects of barium (Ba) doping on structural, electronic and optical properties of binary strontium chalcogenide semiconductor compounds A theoretical investigation using DFT based FP LAPW approach", "venue": "", "year": 2017 }, { "abstract": "In this work, the electronic band structures, total density of state, partial density of state, and optical properties were investigated using the first principle method for SnWO4 via generalized gradient approximation (GGA) based on the Perdew Burke Ernzerhof (PBE0) The estimated band gap was found to be 0.557 eV which is supported for good semiconductor. The density of states and partial density of the states were simulated for evaluating the nature of 5s, 4d 5p for Sn, 6s, 4f, 5d for W and 2s, 2p for O atom for SnWO4. The optical properties for instance, conductivity, dielectric function, and the loss function were calculated. The main goal of this research study was to determine the Fe doping activity on the electronics structure and optical properties by 8% and the band gap was recorded in 0.0 eV, showing as a superconductor. Regarding the optical properties, the loss function was decreased after doping.", "author_names": [ "Md Mahmud Hasan", "Ajoy Kumer", "Unesco Chakma" ], "corpus_id": 234739269, "doc_id": "234739269", "n_citations": 8, "n_key_citations": 0, "score": 1, "title": "Theoretical Investigation of Doping Effect of Fe for SnWO4 in Electronic Structure and Optical Properties: DFT Based First Principle Study", "venue": "", "year": 2020 }, { "abstract": "Abstract Cadmium sulfide has been the subject of wide studies due to its vast applications in solar cells. Bilayer system of Fe doped CdS, is used for synthesis of metal coated semiconductor nanocrystals to fabricate variety of electroluminescent and optical devices. The electronic and optical properties of Fe doped CdS nanostructures were investigated by first principles computations. The electronic properties (band structures and densities of states) have been estimated to evaluate the effect of the Fe doping on the electronic and optical properties of CdS nanostructure. Results show that the properties of CdS are changed when Fe is doped in the parent material. Calculations reveal a semiconducting nature with different behavior for both spin up and down band structures. Fe induced change in the studied properties nanostructured CdS is discussed. Absorption characteristics of Fe doped CdS may be related to the change among valence band and vacant d orbitals of Fe.", "author_names": [ "Sikander Azam", "Zeesham Abbas", "Qasim Bilal", "Muhammad Irfan", "Muhammad Adil Khan", "S H Naqib", "Rabah Khenata", "Shabbir Muhammad", "H Algarni", "Abdullah G Al-Sehemi", "Xiaotian Wang" ], "corpus_id": 214065545, "doc_id": "214065545", "n_citations": 4, "n_key_citations": 0, "score": 1, "title": "Effect of Fe doping on optoelectronic properties of CdS nanostructure: Insights from DFT calculations", "venue": "", "year": 2020 }, { "abstract": "The structural, magnetic, and optical properties of the pristine and Gd doped ZnO nanorods (NRs) prepared by facile thermal decomposition, have been studied using a combination of experimental and density functional theory (DFT) with Hubbard U correction approaches. The XRD patterns demonstrate the single phase wurtzite structure of the pristine and doped ZnO. The rod like shape of the nanoparticles has been examined by FESEM and TEM techniques. Elemental compositions of the pure and doped samples were identified by EDX measurement. Due to the Burstein Moss shift, the optical band gaps of the doped samples have been widened compared to pristine ZnO. The PL spectra show the presence of complex defects. Room temperature magnetic properties have been measured using VSM and revealed the coexistence of paramagnetic and weak ferromagnetic ordering in Gd3+ doped ZnO NRs. The magnetic moment was increased upon addition of more Gd ions into the ZnO host lattice. The DFT+U calculations confirm that the presence of vacancy complexes has a significant effect on the structural, electronic, and magnetic properties of a pristine ZnO system.", "author_names": [ "Mohammed M Obeid", "Hamad Rahman Jappor", "Kutaiba Al-Marzoki", "I A D Al-Hydary", "Shaker J Edrees", "Majid Muhi Shukur" ], "corpus_id": 208691849, "doc_id": "208691849", "n_citations": 54, "n_key_citations": 1, "score": 0, "title": "Unraveling the effect of Gd doping on the structural, optical, and magnetic properties of ZnO based diluted magnetic semiconductor nanorods", "venue": "", "year": 2019 }, { "abstract": "Abstract Energy bandgap engineering is used to produce semiconductor heterostructure systems that perform processes such as the resonant tunneling in nanoelectronics and the solar energy conversion in solar cell applications. However, the performance of such systems degrades as their size is reduced. Graphene based nanoelectronics has appeared as a candidate to enable high performance down to the single molecule scale. Here, graphene nanoribbons (GNRs) can have bandgaps that are tunable by using chemical doping method. We have been predicted that bandgap engineering within a GNR may be achieved by varying the number and geometrical pattern of phosphorus (P) impurities in the GNS, so that we have carried out first principles calculations of the energetic and electronic properties of P doped GNR based on density functional theory (DFT) with Gaussian 09W packages. The geometric and electronic properties of the GNR with and without various dopants of phosphorus impurities were performed and discussed. Our results show that the electronic properties of GNR do not only depend on the phosphorus impurity concentrations, but also depend on the geometrical pattern of phosphorus impurities in the GNR. As a result, we can bandgap engineering of GNR by doping phosphorous impurities to create semiconductor heterostructure, which can be used in many important applications.", "author_names": [ "Fouad Nimr Ajeel", "Mohammed H Mohammed", "Alaa M Khudhair" ], "corpus_id": 125741136, "doc_id": "125741136", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "Energy bandgap engineering of graphene nanoribbon by doping phosphorous impurities to create nano heterostructures: A DFT study", "venue": "", "year": 2019 }, { "abstract": "Borophene nanosheet has been doped with lithium, beryllium, carbon, and hydrogen atom(s) Modification of electronic properties through the splitting and shifting of the Dirac point has been explored within the framework of ab initio density functional theory (DFT) Doping the Pmmn borophene structure with lithium, beryllium, carbon, and hydrogen atoms leads to semiconductor metallic transitions as well as absorption of light within the different parts of the electromagnetic spectrum. Indirect band gap opening is noticed when the system is doped with one hydrogen atom. But when the doping is made double, the system becomes metallic. For lithium and beryllium doping, the split Dirac point has been observed to be situated at the conduction band (CB) However, for single site carbon atom doping, it is seen to be situated at the valence band (VB) while, for double doping, the system becomes semiconducting with an indirect bandgap of 528 meV. Optical properties calculations show that, for parallel and perpendicular polarization, the excitations have mainly occurred within the low and high energy regions, respectively. The effective number of valence electrons does not show any saturation effect for all the doped systems in parallel as well as for perpendicular polarizations.", "author_names": [ "Suman Chowdhury", "Arnab Majumdar", "Debnarayan Jana" ], "corpus_id": 150264074, "doc_id": "150264074", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Electronic and optical properties of the supercell of 8 Pmmn borophene modified on doping by H, Li, Be, and C: a DFT approach", "venue": "Applied Physics A", "year": 2019 }, { "abstract": "The experimental results of Metal graphene (M G) contact resistance RC have been investigated in depth by means of Density Functional Theory (DFT) The simulations allowed us to build a consistent picture explaining the RC dependence on the metal contact materials employed in this work and on the applied back gate voltage. In this respect, the M G distance is paramount in determining the RC behavior.", "author_names": [ "Pedram Khakbaz", "Francesco Driussi", "Alberto Gambi", "Paolo Giannozzi", "Stefano Venica", "David Esseni", "A Gaho", "Satender Kataria", "Max Christian Lemme" ], "corpus_id": 204817495, "doc_id": "204817495", "n_citations": 2, "n_key_citations": 1, "score": 0, "title": "DFT study of graphene doping due to metal contacts", "venue": "2019 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD)", "year": 2019 }, { "abstract": "In this work, we present a theoretical study of the electronic band structure and the Young's modulus of hydrogen passivated silicon nanowires (H SiNWs) grown along the [110] crystallographic direction, as a function of the concentration of interstitial sodium (Na) and lithium (Li) atoms. The study is performed using the supercell scheme and the density functional theory (DFT) within the local density approximation (LDA) The results show that the presence of Na or Li atoms closes the former semiconducting band gap of the H SiNWs and shifts the Fermi energy into the conduction band. The transition from semiconductor to metal occurs as soon as a single Na or Li atom is added to the nanowire and the number of occupied states near the Fermi level is larger for the H SiNWs with Li atoms in comparison with those nanowires with the same concentration of Na atoms. The calculated formation energies reveal that the system becomes less stable when the concentration of Na and Li atoms augments. Moreover, the obtained binding energies indicate that Si Li and Si Na bonds are formed. It is worth mentioning that the binding energies of H SiNWs with interstitial Li atoms are larger than those corresponding to the H SiNWs with interstitial Na atoms. On the other hand, the Young's moduli of H SiNWs with Na atoms are lower than those of pure H SiNWs and their values diminish when the concentration of Na atoms increases. In contrast, Young's moduli of H SiNWs present a non monotonic behavior as a function of the concentration of interstitial Li atoms and for the largest studied concentration the nanowire fractures. These results give insight into the changes that electronic and mechanical properties of H SiNWs suffer during the charge discharge process, which should be taken into account in the design of electrodes of Na or Li ion batteries.", "author_names": [ "Fernando Salazar", "A Trejo-Banos", "Alvaro Miranda", "Luis Antonio Perez", "Miguel Cruz-Irisson" ], "corpus_id": 207941824, "doc_id": "207941824", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Interstitial sodium and lithium doping effects on the electronic and mechanical properties of silicon nanowires: a DFT study", "venue": "Journal of Molecular Modeling", "year": 2019 }, { "abstract": "Abstract Via the FP APW+lo method, we have performed a systematic theoretical study of the structural, electronic and thermoelectric properties of b AgBiS2 compound. The estimated structural properties such as cell parameters a and c, c/a ratio and internal parameters are in reasonable agreement with the earlier measured one. From band structure calculations we have found that b AgBiS2 is semiconductor with a band gap of 1.23 eV using the TB mBJ approximation. In addition, the analysis of the total and partial DOS shows a considerable hybridization between Ag 'd' states and S 'p' Bi 's' states indicating that both Ag S and Bi S have covalent character. The main thermoelectric properties such as electrical conductivity, thermo power, electronic thermal conductivity, power factor and figure of merit are calculated and discussed. We observed that ZT increases when temperature is augmented and reached its maximum of 0.95 and 0.85 at 2 x 1019 cm 3 for p and n type doping, respectively. Thus, b AgBiS2 compound has interesting thermoelectric properties in both p and n type doping.", "author_names": [ "A Tabeti", "Mohammed Batouche", "Kada Bidai", "A Djied", "T Seddik", "Rabah Khenata", "Hadj Baltach", "Xiaotian Wang" ], "corpus_id": 149658733, "doc_id": "149658733", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "DFT investigation on the electronic and thermoelectric properties of ternary semiconductor AgBiS2 for energy conversion application", "venue": "Chinese Journal of Physics", "year": 2019 } ]

[ { "abstract": "Inhomogeneous superconductors can host electronic excitations, known as Andreev bound states (ABSs) below the superconducting energy gap. With the advent of topological superconductivity, a new kind of zero energy ABS with exotic qualities, known as a Majorana bound state (MBS) has been discovered. A special property of MBS wavefunctions is their non locality, which, together with non Abelian braiding, is the key to their promise in topological quantum computation. We focus on hybrid superconductor semiconductor nanowires as a flexible and promising experimental platform to realize one dimensional topological superconductivity and MBSs. We review the main properties of ABSs and MBSs, state of the art techniques for their detection and theoretical progress beyond minimal models, including different types of robust zero modes that may emerge without a band topological transition. Topological Majorana bound states have potential for encoding, manipulating and protecting quantum information in condensed matter systems. This Review discusses emergence and characterization of Majorana bound states in realistic devices based on hybrid semiconducting nanowires and their connection to more conventional Andreev bound states. Non uniform superconductors and hybrid normal metal superconducting systems can develop discrete bound states inside the superconducting gap, known as Andreev bound states (ABSs) through Andreev reflection processes. Andreev bound states are a superposition of electrons and holes, and can also develop a non trivial spin structure if the system exhibits spin orbit coupling and low densities, as is the case in proximitized semiconducting nanowires. Precise experimental characterization of ABSs in proximitized nanowires is now possible through a range of spectroscopic techniques, including tunnelling transport, quantum dot spectroscopy and microwave cavity spectroscopy. The interplay of spin orbit coupling, Zeeman fields and low densities in proximitized semiconducting nanowires can induce a quantum phase transition into a topological superconducting phase, whereupon ABSs transform into zero energy, topologically protected Majorana bound states (MBSs) with exotic properties, promising for quantum computation purposes. The experimental search for MBSs in proximitized nanowires has encountered a rich and complex phenomenology that has required standard theoretical models to be extended substantially, revealing in the process a host of mechanisms for the emergence of zero energy bound states beyond the original band topological framework. These states are known in the field as quasi MBSs, partially separated MBSs or non topological MBSs.", "author_names": [ "Elsa Prada", "Pablo San-Jose", "Michiel W A de Moor", "Attila Geresdi", "Eduardo J H Lee", "Jelena Klinovaja", "Daniel Loss", "Jesper Nygard", "Ramon Aguado", "L P Kouwenhoven" ], "corpus_id": 207863791, "doc_id": "207863791", "n_citations": 63, "n_key_citations": 1, "score": 1, "title": "From Andreev to Majorana bound states in hybrid superconductor semiconductor nanowires", "venue": "", "year": 2019 }, { "abstract": "Zero energy Andreev levels in hybrid semiconductor superconductor nanowires mimic all expected Majorana phenomenology, including $2{e}{2}/h$$2e2/h conductance quantisation, even where band topology predicts trivial phases. This surprising fact has been used to challenge the interpretation of various transport experiments in terms of Majorana zero modes. Here we show that the Andreev versus Majorana controversy is clarified when framed in the language of non Hermitian topology, the natural description for quantum systems open to the environment. This change of paradigm allows one to understand topological transitions and the emergence of zero modes in more general systems than can be described by band topology. This is achieved by studying exceptional point bifurcations in the complex spectrum of the system's non Hermitian Hamiltonian. Within this broader topological classification, Majoranas from both conventional band topology and a large subset of Andreev levels at zero energy are in fact topologically equivalent, which explains why they cannot be distinguished.The existence of Majorana zero modes have been potentially confirmed in superconductor semiconductor nanowires but recent studies suggest the data can also be interpreted using Andreev bound states, throwing into doubt the conclusions regarding Majorana modes. To resolve this controversy the authors use non Hermitian topology to determine the boundaries between the Majorana and Andreev states.", "author_names": [ "Julio Avila", "Fernando Penaranda", "Elsa Prada", "Pablo San-Jose", "Ramon Aguado" ], "corpus_id": 119394080, "doc_id": "119394080", "n_citations": 47, "n_key_citations": 0, "score": 0, "title": "Non hermitian topology as a unifying framework for the Andreev versus Majorana states controversy", "venue": "Communications Physics", "year": 2019 }, { "abstract": "The aim of the present work is to gather the data already acquired about the use of Origanum majorana (manjerona) botanical characteristics, main constituents and scientific studies about the species as a phytotherapeutic agent in dentistry, focusing on potential use as anxiolytic. A literature review was conducted from 2009 to 2019 on the Academic Google and Scientific Electronic Library Online search platforms. The main constituents identified in O. majorana essential oil were terpinen 4 ol, g terpinene and a terpinene. Another important compound of this species would be cis terpineol, which would have anesthetic activity and the potential to modulate GABA A capacity. Studies conducted with O. majorana essential oils promoted muscle relaxation in the gastropod Pomacea canaliculata at concentrations above 100mL L 1, as well as sedation in the fish species Rhamdia quelen at a concentration of 100 mL L 1, and anesthesia at concentrations of 200, 300, 400 and 500 mL L 1 Marjoram is also attributed to antimicrobial, antioxidant, anesthetic, relaxing and cytotoxic effects. Origanum majorana is a species widely used in the treatment of Central Nervous System disorders due to its antiepileptic and sedative effects. Recent research has shown that the antimicrobial effect is also present, but further studies focusing only on isolated microbial strains are needed. Although their results are proving to be effective, it must be emphasized that natural products can also have adverse effects.", "author_names": [ "Gabrielli Bezerra Sales", "Janaina Barbosa de Alencar", "Rafaela Oliveira Santos", "Servulo da Costa Rodrigues Neto", "Aleson Sousa", "Abrahao Alves de Oliveira Filho" ], "corpus_id": 216493190, "doc_id": "216493190", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Origanum majorana as ansiolitic agent in dentistry: a literary review", "venue": "", "year": 2020 }, { "abstract": "Focusing specifically on the recently retracted Nature 2018 Zhang et al. work [Zhang et al. Nature (2021) and the related recently available correctly analyzed data from this Delft experiment [Zhang et al. arXiv:2101.11456 (2021) we discuss the general problem of confirmation bias in experiments verifying various theoretical topological quantization predictions. We show that the Delft Majorana experiment is most likely dominated by disorder, which produces trivial (but quite sharp and large) zero bias Andreev tunneling peaks with large conductance 2e/h in the theory, closely mimicking the data. Thus, although the corrected Delft data are by far the best tunnel spectroscopy results available in the literature, manifesting large and sharp zero bias peaks rising above the background with an impressive hard superconducting gap, our theory shows that the most natural explanation for these zero bias peaks is that they are disorder induced and not topological Majorana modes. It is possible to misinterpret such disorder induced zero bias trivial peaks as the apparent Majorana quantization, as was originally done in 2018 arising from confirmation bias. One characteristic of the disorder induced trivial peaks is that they manifest little stability as a function of Zeeman field, chemical potential, and tunnel barrier, distinguishing their trivial behavior from the expected topological robustness of non Abelian Majorana zero modes. We also analyze a more recent nanowire experiment [Yu et al. Nature Physics (2021) which is known to have a huge amount of disorder, showing that such highly disordered nanowires may produce very small above background trivial peaks with conductance values 2e/h in a dirty system manifesting very soft superconducting gap with substantial in gap conduction, as were already reported by several groups almost 10 years ago. Removing disorder and producing cleaner samples through materials quality improvement and better fabrication is the only way for future progress in this field.", "author_names": [ "Sankar Das Sarma", "Haining Pan" ], "corpus_id": 232168727, "doc_id": "232168727", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Disorder induced zero bias peaks in Majorana nanowires", "venue": "", "year": 2021 }, { "abstract": "The search for new states that exhibit topological order is currently a very active and exciting area of research. Like a topological insulator, superconducting order can also exhibit topological order, which is different from that of a conventional superconductor. This superconductor is so called \" topological superconductor\" which has a full pairing gap in the bulk and gapless surface state. Majorana Fermions obey non Abelian fractional statistics, and have been proposed to construct topological qubits, so there is a great prospect of scientific research and application in topological quantum computing. It is very interesting that Majorana Fermions are predicted to exist in topological superconductors. However, natural topological superconductor is very rare. Inspired by the realization of topological insulators, theoretical physicists have proposed that via the fabrication of the s wave superconductor/topological insulator heterostructure, Majorana Fermions may exist in the superconducting topological insulator induced by proximate effect. Due to various kinds of topological insulators and conventional s wave superconductors, heterostructures constructed by this method can greatly increase the variety of artificial topological superconductors. In this paper we review the experimental progress in the heterostructure composed of the Bi2Te3 type topological insulator and the conventional s wave superconductor NbSe2. Using molecular beam epitaxy, atomically flat topological insulator film can be fabricated at the top of superconductor substrate. The spatial distribution of Majorana Fermions on the surface of topological insulator can be directly observed by in situ scanning tunneling microscopy/spectroscopy. In the center of a magnetic vortex, Majorana Fermions will appear as the Majorana zero mode, a zero energy peak inside the superconducting gap. Although the energy gap between low energy quasiparticle excitation and the Majorana zero mode is very small, the evidences such as zero bias conductance anomaly, Y shape splitting of zero bias conductance, spin selective Andreev reflection are self consistent and reveal that the Majorana zero mode exists in the center of a magnetic vortex. These experiments have led to a new insight into superconductivity. It may open a door to probing the novel physics of Majorana fermions.", "author_names": [ "Li Yaoyi", "Jia Jin-Feng" ], "corpus_id": 229833405, "doc_id": "229833405", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Search for Majorana zero mode in the magnetic vortex of artificial topological superconductor", "venue": "", "year": 2019 }, { "abstract": "The epidemic associated with the new Sars CoV 2 coronavirus has affected almost all countries of the world and no reliable treatment for this infection exists yet Many laboratories in the world are currently conducting intensive experimental and theoretical/in silico studies to find effective drugs specific for this disease (COVID 19) but unfortunately, it may take a long time before new drugs appear in the clinical practice One of the currently widely accepted approaches for finding active compounds is based on the possibility of using existing drugs approved by government medical organizations (as the FDA) Their choice is based on screening, based on the use of computer models that evaluate the specific binding (energy minimization) of such drugs to target molecules that are important for the life cycle Thus, a few well known antiviral drugs against HIV, hepatitis C and others selected on this basis exerted an antiviral effect in vitro, but their real effectiveness was far from expected It should be emphasized that the severe clinical manifestation of the disease is an acute respiratory distress syndrome, mediated by oxidative stress and an aggressive immune attack on its own cells In this regard, the use of compounds with high antioxidant activity could have advantages both prophylactically and medically There is a huge range of natural compounds, including official and traditional medicine, which represent valuable unlimited potential for COVID 19 therapy, the advantage of such compounds in their low toxicity In this review, we tried to focus on the clinical and pharmacological properties of natural substances, mainly flavonoids, which can become promising drugs for the treatment and prevention of COVID 19 The review includes information on possible virus targets and antiviral drugs Much attention is paid to the question of inhibition of viral activity Based on published data, including structural features of various compounds, a prediction is made about the prospects of using these compounds as inhibitors of viral activity, as well as anti inflammatory drugs for the treatment of COVID 19 An important step in the analysis of compounds was the study of the possibility of their interaction with cellular targets of the virus, as well as the ability to bind to the proteins of the Sars CoV 2 virus itself Epidemiia, sviazannaia s novym koronavirusom Sars CoV 2, porazila prakticheski vse strany zemnogo shara, i nadezhnykh lechebnykh sredstv ot etoi infektsii poka ne sushchestvuet Mnogie laboratorii v mire v nastoiashchee vremia vedut intensivnye eksperimental'nye i teoreticheskie issledovaniia s tsel'iu poiska effektivnykh preparatov, spetsifichnykh dlia etogo zabolevaniia (COVID 19) no, k sozhaleniiu, mozhet potrebovat'sia mnogo vremeni, prezhde chem novye lekarstva poiaviatsia v klinicheskoi praktike Odin iz samykh populiarnykh podkhodov osnovan na vozmozhnosti ispol'zovaniia dlia lecheniia sushchestvuiushchikh preparatov, odobrennykh pravitel'stvennymi meditsinskimi organizatsiiami Ikh vybor osnovan na skrininge, v osnove kotorogo lezhit ispol'zovanie komp'iuternykh modelei, otsenivaiushchikh spetsificheskoe sviazyvanie (minimizatsiia energii sviazyvaniia) takikh preparatov s molekulami misheniami, vazhnykh dlia zhiznennogo tsikla Tak, riad izvestnykh antivirusnykh preparatov protiv VICh, gepatita S, vybrannykh podobnym obrazom, okazyvali protivovirusnyi effekt in vitro, no ikh klinicheskaia effektivnost' byla nevysokoi Sleduet podcherknut' chto tiazhelaia forma klinicheskogo proiavleniia zabolevaniia predstavliaet soboi ostryi respiratornyi distress sindrom, oposredovannyi okislitel'nym stressom i agressivnoi immunnoi atakoi na sobstvennye kletki V etoi sviazi primenenie soedinenii s vysokoi antioksidantnoi aktivnost'iu mozhet imet' preimushchestva kak v profilakticheskom, tak i v lechebnom plane Sushchestvuet ogromnyi spektr prirodnykh soedinenii, vkliuchaia preparaty ofitsial'noi i traditsionnoi meditsiny, kotorye predstavliaiut neogranichennyi potentsial, v tom chisle dlia terapii virusnykh zabolevanii Osnovnym preimushchestvom podobnykh soedinenii iavliaetsia ikh nizkaia toksichnost' V dannom obzore my postaralis' sdelat' aktsent na klinicheskie i farmakologicheskie svoistva prirodnykh veshchestv, preimushchestvenno flavonoidov, kotorye mogut stat' perspektivnymi preparatami dlia lecheniia i profilaktiki COVID 19 V obzor vkliuchena informatsiia o vozmozhnykh misheniakh virusa i protivovirusnykh preparatakh Bol'shoe vnimanie udeleno voprosu ingibirovaniia virusnoi aktivnosti Na osnove literaturnykh dannykh, v tom chisle o strukturnykh osobennostiakh razlichnykh soedinenii, sdelan prognoz o perspektivnosti ispol'zovaniia dannykh soedinenii v kachestve ingibitorov virusnoi aktivnosti, a takzhe v kachestve protivovospalitel'nykh sredstv dlia terapii COVID 19 Vazhnym etapom pri analize soedinenii bylo izuchenie vozmozhnosti ikh vzaimodeistviia s kletochnymi misheniami virusa, a takzhe sposobnosti sviazyvaniia s belkami samogo virusa Sars CoV 2", "author_names": [ "Sergey M Andreev", "Nadezhda Shershakova", "Ksenia V Kozhikhova", "Artyom A Shatilov", "Anastasiia V Timofeeva", "Evgeny A Turetskiy", "Dmitry A Kudlay", "Musa R Khaitov" ], "corpus_id": 225459827, "doc_id": "225459827", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Promising compounds from natural sources against COVID 19", "venue": "", "year": 2020 }, { "abstract": "This review paper presents a framework to evaluate the artificial intelligence (AI) readiness for the healthcare sector in developing countries: a combination of adequate technical or technological expertise, financial sustainability, and socio political commitment embedded in a healthy psycho cultural context could bring about the smooth transitioning toward an AI powered healthcare sector. Taking the Vietnamese healthcare sector as a case study, this paper attempts to clarify the negative and positive influencers. With only about 1500 publications about AI from 1998 to 2017 according to the latest Elsevier AI report, Vietnamese physicians are still capable of applying the state of the art AI techniques in their research. However, a deeper look at the funding sources suggests a lack of socio political commitment, hence the financial sustainability, to advance the field. The AI readiness in Vietnam's healthcare also suffers from the unprepared information infrastructure using text mining for the official annual reports from 2012 to 2016 of the Ministry of Health, the paper found that the frequency of the word \"database\" actually decreases from 2012 to 2016, and the word has a high probability to accompany words such as \"lacking\" \"standardizing\" \"inefficient\" and \"inaccurate.\" Finally, manifestations of psycho cultural elements such as the public's mistaken views on AI or the non transparent, inflexible and redundant of Vietnamese organizational structures can impede the transition to an AI powered healthcare sector.", "author_names": [ "Quan-Hoang Vuong", "Thu-Trang Vuong", "Viet-Phuong La", "Kien-Cuong P Nghiem", "Hai-Ha Giang", "Thu-Vu Giang", "Carl A Latkin", "Roger C M Ho" ], "corpus_id": 73416770, "doc_id": "73416770", "n_citations": 25, "n_key_citations": 3, "score": 0, "title": "Artificial Intelligence vs. Natural Stupidity: Evaluating AI Readiness for the Vietnamese Medical Information System", "venue": "Journal of clinical medicine", "year": 2019 }, { "abstract": "In these notes, we review the main results of our approach to fermion masses. The marge mass ratios between fermions, confronted with a unique breaking mechanism leading to vector bosons masses, led us to consider the possibility that they result from the overlap of fermion wave functions. Such overlaps vary indeed very strongly if the observed fermion families in 4 dimensions originate in a single family in 6 dimensions, through localized wave functions. This framework leads in a natural way to large mass ratios and small mixing angles between quarks. What came as a surprise is that if we impose that neutrinos behave as 2 component \"Majorana\" particles in 4D, a completely different situation is obtained for them. Instead of diagonal mass matrices, anti diagonal ones emerge and lead to a generic prediction of combined inverted hierarchy, large mixing angles in the leptonicsector, and a suppression of neutrinoless double beta decay placing it at the lower limit of the inverted hierarchy branch, a challenging situation for on going and planned experiments. Our approach predicted the size of the th13 mixing angle before its actual measurement. Possible signals at colliders are only briefly evoked.", "author_names": [ "Jean Marie Frere", "Maxim Libanov", "Simon Mollet", "S V Troitsky" ], "corpus_id": 119104490, "doc_id": "119104490", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Fermion masses from six dimensions and implications for Majorana neutrinos", "venue": "", "year": 2014 }, { "abstract": "We suggest a way to overcome the obstacles that disorder and high density of states pose to the creation of unpaired Majorana fermions in onedimensional systems. This is achieved by splitting the system into a chain of quantum dots, which are then tuned to the conditions under which the chain can be viewed as an effective Kitaev model, so that it is in a robust topological phase with well localized Majorana states in the outermost dots. The tuning algorithm that we develop involves controlling the gate voltages and the superconducting phases. Resonant Andreev spectroscopy allows us to make the tuning adaptive, so that each pair of dots may be tuned independently of the other. The calculated quantized zero bias conductance serves then as a natural proof of the topological nature of the tuned phase. 4 Author to whom any correspondence should be addressed. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. New Journal of Physics 15 (2013) 04502", "author_names": [ "Hoi-Yin Hui", "J P Dahlhaus", "Bjorn Zocher", "Mats Horsdal", "Bernd Rosenow", "Patrik Recher" ], "corpus_id": 221807872, "doc_id": "221807872", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Adaptive tuning of Majorana fermions in a quantum dot chain", "venue": "", "year": 2013 }, { "abstract": "We review recent progress in the exploration of topological quantum states of matter in iron based superconductors. In particular, we focus on the non trivial topology existing in the band structures and superconducting states of iron's 3d orbitals. The basic concepts, models, materials and experimental results are reviewed. The natural integration between topology and high temperature superconductivity in iron based superconductors provides great opportunities to study topological superconductivity and Majorana modes at high temperature.", "author_names": [ "Ningning Hao", "Jiangping Hu" ], "corpus_id": 53702982, "doc_id": "53702982", "n_citations": 33, "n_key_citations": 1, "score": 0, "title": "Topological quantum states of matter in iron based superconductors: from concept to material realization", "venue": "", "year": 2019 } ]

[ { "abstract": "We report the first demonstration of direct modulation of InAs/GaAs quantum dot (QD) lasers grown on on axis (001) Si substrate. A low threading dislocation density GaAs buffer layer enables us to grow a high quality 5 layered QD active region on on axis Si substrate. The active layer has p modulation doped GaAs barrier layers with a hole concentration of 5 x 10 cm to suppress gain saturation. Small signal measurement on a 3 x 580 mm Fabry Perot laser showed a 3dB bandwidth of 6.5 GHz at a bias current of 116 mA. A 12.5 Gbit/s non return to zero signal modulation was achieved by directly probing the chip. Open eyes with an extinction ration of 3.3dB was observed at room temperature. The biterror rate (BER) curve showed no error floor up to BER of 1 x 10. 12 km single mode fiber transmission experiments using the QD laser on Si showed a low power penalty of 1 dB at 5 Gbit/s. These results demonstrate the potential for QD lasers epitaxially grown on Si to be used as a low cost light source for optical communication systems. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement OCIS codes: (250.5960) Semiconductor lasers; (230.5590) Quantum well, wire and dot devices; (060.4080) Modulation. References and links 1. A. Vahdat, H. Liu, X. Zhao, and C. Johnson, \"The emerging optical data center,\" in Optical Fiber Communication Conference (OFC) 2011 OSA Technical Digest Series (Optical Society of America, 2011),paper OTuH2. 2. J. A. Tatum, D. Gazula, L. A. Graham, J. K. Guenter, R. H. Johnson, J. King, C. Kocot, G. D. Landry, I. Lyubomirsky, A. N. MacInnes, E. M. Shaw, K. Balemarthy, R. Shubochkin, D. Vaidya, M. Yan, and F. Tang, \"VCSEL based interconnects for current and future data centers,\" J. Lightwave Technol. 33(4) 727 732 (2015) 3. T. Tadokoro, W. Kobayashi, T. Fujisawa, T. Yamanaka, and F. 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Sci. 213(4) 958 964 (2016) Vol. 26, No. 6 19 Mar 2018 OPTICS EXPRESS 7023", "author_names": [ "", "G C", "Besana E" ], "corpus_id": 44136387, "doc_id": "44136387", "n_citations": 13, "n_key_citations": 1, "score": 1, "title": "Directly modulated 1 3 m m quantum dot lasers epitaxially grown on silicon", "venue": "", "year": 2018 }, { "abstract": "P3 10 04: A open label, randomized, parallel, phase III trial to evaluate the efficacy and safety of Genexol (r) PM compared to Genexol (r) (conventional paclitaxel with cremorphor EL) in recurrent or metastatic breast cancer patients. Cancer Research 2015; 75 (9 Supplement) P3 10 04 P3 10 04. Varela Moreira A, Shi Y, Fens MH, Lammers T, Hennink WE, [17] Schiffelers RM. Clinical application of polymeric micelles for the Radiolabeling Methods and Nuclear Imaging Techniques Current Applied Polymer Science, 2018, Vol. 2, No. 1 15 treatment of cancer. Materials Chemistry Frontiers 2017; 1(8) 1485 501. 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Radiolabeling polymeric micelles for in viv", "author_names": [ "R M de Kruijff", "Alexandra G Arranja", "Antonia G Denkova" ], "corpus_id": 60374208, "doc_id": "60374208", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Radiolabeling Methods and Nuclear Imaging Techniques in the Design of New Polymeric Carriers for Cancer Therapy", "venue": "", "year": 2018 }, { "abstract": "Tissue mimicking phantoms are widely used for the calibration, evaluation and standardisation of medical imaging systems, and for clinical training. For photoacoustic imaging, tissue mimicking materials (TMMs) that have tuneable optical and acoustic properties, high stability, and mechanical robustness are highly desired. In this study, gel wax is introduced as a TMM that satisfies these criteria for developing photoacoustic imaging phantoms. The reduced scattering and optical absorption coefficients were independently tuned with the addition of TiO2 and oil based inks. The frequency dependent acoustic attenuation obeyed a power law; for native gel wax, it varied from 0.71 dB/cm at 3 MHz to 9.93 dB/cm at 12 MHz. The chosen oil based inks, which have different optical absorption spectra in the range of 400 to 900 nm, were found to have good photostability under pulsed illumination with photoacoustic excitation light. Optically heterogeneous phantoms that comprised of inclusions with different concentrations of carbon black and coloured inks were fabricated, and multispectral photoacoustic imaging was performed with an optical parametric oscillator and a planar Fabry Perot sensor. We conclude that gel wax is well suited as a TMM for multispectral photoacoustic imaging. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. OCIS codes: (170.3880) Medical and biological imaging; (110.5120) Photoacoustic imaging; (170.7170) Ultrasound; (110.3000) Image quality assessment; (160.4760) Optical properties; (120.5820) Scattering measurements. References and links 1. P. Beard, \"Biomedical Photoacoustic Imaging,\" Interface Focus 1(4) 602 631 (2011) 2. L. V. Wang and S. Hu, \"Photoacoustic tomography: in vivo imaging from organelles to organs,\" Science 335(6075) 1458 1462 (2012) 3. V. Ntziachristos and D. Razansky, \"Molecular imaging by means of multispectral optoacoustic tomography (MSOT)\" Chem. Rev. 110(5) 2783 2794 (2010) 4. Y. Cao, A. Kole, L. Lan, P. Wang, J. Hui, M. Sturek, and J. X. Cheng, \"Spectral analysis assisted photoacoustic imaging for lipid composition differentiation,\" Photoacoustics 7, 12 19 (2017) 5. M.A.L. Bell, A.K. Ostrowski, K. Li, P. Kazanzides, and E.M. 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Am. 93(3) 1609 1612 (1993) Vol. 9, No. 3 1 Mar 2018 BIOMEDICAL OPTICS EXPRESS 1152", "author_names": [ "", "D L", "W J", "H C", "D E" ], "corpus_id": 3468522, "doc_id": "3468522", "n_citations": 16, "n_key_citations": 0, "score": 0, "title": "Gel wax based tissue mimicking phantoms for multispectral photoacoustic imaging", "venue": "", "year": 2018 }, { "abstract": "Ultrafast laser inscription has been used to produce channel waveguides in Ge22As20Se58 glass (GASIR 1, Umicore N.V) The mode field diameter and waveguide losses at 2.94 mm were measured along with the waveguide dispersion in the 1 to 4.5 mm range, which is used to estimate the zero dispersion wavelength. Z scan measurements of bulk samples have also been performed to determine the nonlinear refractive index. Finally, midIR supercontinuum generation has been shown when pumping the waveguides with femtosecond pulses centered at 4.6 mm. Supercontinuum spanning approximately 4 mm from 2.5 to 6.5 mm was measured which, to the best of the authors' knowledge, represents the broadest and the deepest IR supercontinuum from an ultrafast laser inscribed waveguide to date. This work, combined with the long wavelength transmission of GASIR 1 up to 15 mm, paves the way for realizing further ultrafast laser inscribed waveguide devices in GASIR 1 for mid IR integrated optics applications. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. OCIS codes: (130.2755) Glass waveguides; (130.3060) Infrared; (160.4330) Nonlinear optical materials. References and links 1. D. W. Hewak, \"Chalcogenide glasses for photonics device applications,\" in Photonic Glasses and GlassCeramics, G. S. Murugan, ed. (Research Signpost, 2010) 2. B. J. Eggleton, B. 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Dupont, J. Ramsay, T. Benson, S. Sujecki, N. Abdel Moneim, Z. Tang, D. Furniss, A. Seddon, and O. Bang, \"Mid infrared supercontinuum covering the 1.4 13.3 mm molecular fingerprint region using ultra high NA chalcogenide step index fibre,\" Nat. Photonics 8(11) 830 834 (2014)", "author_names": [ "", "Giorgos Demetriou", "Ole Bang" ], "corpus_id": 53684919, "doc_id": "53684919", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Ge 22 As 20 Se 58 glass ultrafast laser inscribed waveguides for midIR integrated optics", "venue": "", "year": 2018 }, { "abstract": "We present the possibility of steering the direction of correlations between the offresonant Raman scattered photons from the angularly multimode atomic memory based on warm rubidium vapors. Using acousto optic deflectors (AOD) driven by different modulation frequencies we experimentally change the angle of incidence of the laser beams on the atomic ensemble. Performing correlations measurements for various deflection angles we verify that we can choose the anti Stokes light propagation direction independently of the correlated Stokes scattered light in the continuous way. As a result we can select the spatial mode of photons retrieved from the memory, which may be important for future development of quantum information processing. c (c) 2018 Optical Society of America OCIS codes: (270.5585) Quantum information and processing; (020.0020) Quantum optics; (230.1040) Atomic and molecular physics; (290.5910) Scattering, stimulated Raman; (270.0270) Acousto optical devices. References and links 1. C. H. Bennett, \"Quantum cryptography using any two nonorthogonal states,\" Phys. Rev. Lett. 68(21) 3121 3124 (1992) 2. N. Gisin, G. Ribordy, W. Tittel, and H. Zbinden, \"Quantum cryptography,\" Rev. Mod. Phys. 74(1) 145 195 (2002) 3. E. Knill, R. Laflamme, and G. J. 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Commun. 317, 1 6 (2014)", "author_names": [ "" ], "corpus_id": 221641891, "doc_id": "221641891", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Correlation steering in the angularly multimode Raman atomic memory", "venue": "", "year": 2018 }, { "abstract": "We present and demonstrate an experimental scheme that enables overlap free reconstruction of attosecond beating by the interference of two photon transition (RABBITT) measurements at high extreme ultraviolet (XUV) photon energies. A compact passively stabilized attosecond beamline employing a multilayer (ML) mirror allows us to obtain XUV pulses consisting of only two odd high harmonic orders from an attosecond pulse train (APT) We compare our new technique to existing schemes that are used to perform RABBITTmeasurements and discuss how our scheme resolves the limitations imposed by spectral complexity of the harmonic comb at high photon energies. We further demonstrate first applications of our scheme for rare gases and gas mixtures, and show that this scheme can be extended to gas molecule mixtures. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement OCIS codes: (020.0020) Atomic and molecular physics; (320.7100) Ultrafast measurements; (260.5210) Photoionization; (140.7240) UV, EUV, and X ray lasers. References and links 1. P. B. Corkum and F. Krausz, \"Attosecond science,\" Nat. Phys. 3, 381 387 (2007) 2. E. Goulielmakis, Z. H. Loh, A. Wirth, R. Santra, N. Rohringer, V. S. Yakovlev, S. Zherebtsov, T. Pfeifer, A. M. Azzeer, M. F. Kling, S. R. Leone, and F. Krausz, \"Real time observation of valence electron motion,\" Nature. 466, 739 743 (2010) 3. V. Gruson, L. Barreau, A. Jimenez Galan, F. Risoud, J. Caillat, A. Maquet, B. Carre, F. Lepetit, J. F. Hergott, T. Ruchon, L. Argenti, R. Taieb, F. Martin, and P. 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Lett. 92, 163002 (2004) 38. T. Popmintchev, M. C. Chen, D. Popmintchev, P. Arpin, S. Brown, S. Alisauskas, G. Andriukaitis, T. Balciunas, O. D. Mucke, A. Pugzlys, A. Baltuska, B. Shim, S. E. Schrauth, A. Gaeta, C. Hernandez Garcia, L. Plaja, A. Becker, Vol. 26, No. 22 29 Oct 2018 OPTICS EXPRESS 28605", "author_names": [ "" ], "corpus_id": 221837945, "doc_id": "221837945", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Using a passively stable attosecond beamline for relative phjavascript:void(0);otoemission time delays at high XUV photon energies", "venue": "", "year": 2018 }, { "abstract": "L. Adamczyk,1 J. R. Adams,29 J. K. Adkins,19 G. Agakishiev,17 M. M. Aggarwal,31 Z. Ahammed,54 N. N. Ajitanand,42 I. Alekseev,15,26 D. M. Anderson,44 R. Aoyama,48 A. Aparin,17 D. Arkhipkin,3 E. C. Aschenauer,3 M. U. Ashraf,47 A. Attri,31 G. S. Averichev,17 X. Bai,7 V. Bairathi,27 K. Barish,50 A. Behera,42 R. Bellwied,46 A. Bhasin,16 A. K. Bhati,31 P. Bhattarai,45 J. Bielcik,10 J. 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"Tatiana Grigoryevna Dedovich", "Jun Deng", "I M Deppner", "A A Derevschikov", "Larysa Didenko", "Christopher Dilks", "X Dong", "James Drachenberg", "James E Draper", "John Charles Dunlop", "L G Efimov", "Nicholas Elsey", "J M Engelage", "Geary W Eppley", "R T Esha", "Shin-ichi Esumi", "O Evdokimov", "Justin Ewigleben", "Oleg Eyser", "Renee Fatemi", "Salvatore Fazio", "Pavol Federic", "P Federicova", "Jan Fedorisin", "Z Feng", "Peter Filip", "Evan Finch", "Yuri V Fisyak", "C E Flores", "Jiro Fujita", "Lukasz Fulek", "Carl A Gagliardi", "Frank J M Geurts", "Adam Gibson", "Martin Robert Girard", "David Grosnick", "Devika Gunarathne", "Y Guo", "Anoop Gupta", "Wlodek Guryn", "Ayman Hamad", "Ahmed M Hamed", "Alena Harlenderova", "J W Harris", "L He", "Samuel Heppelmann", "Norbert Herrmann", "Andrew S Hirsch", "Stephen Horvat", "X Y Huang", "H Z Huang", "T C Huang", "B Huang", "Thomas J Humanic", "Peng Huo", "George J Igo", "William W Jacobs", "Alexander M Jentsch", "J Jia", "K J Jiang", 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Trentalange", "Robert E Tribble", "Prithwish Tribedy", "Srikanta Kumar Tripathy", "Barbara Antonina Trzeciak", "O D Tsai", "Biao Tu", "Thomas Ullrich", "David G Underwood", "Isaac Upsal", "Gene van Buren", "Gerrit Jan van Nieuwenhuizen", "Andrey Vasiliev", "F Videbaek", "S Vokal", "Sergey Voloshin", "A Vossen", "G Wang", "F Wang", "Grant Webb", "Jason C Webb", "Liwen Wen", "Gary D Westfall", "Howard Henry Wieman", "Scott W Wissink", "Richard Witt", "Yuanfang Wu", "Z G Xiao", "G Xie", "Wei Xie", "Q Xu", "Y Xu", "J Xu", "Nu Xu", "Z Z Xu", "C G Yang", "S Yang", "Q Yang", "Ying Yang", "Zhenyu Ye", "Liang Yi", "Kin Yip", "I -K Yoo", "Ning Yu", "Hanna Paulina Zbroszczyk", "Wangmei Zha", "Ji Zhang", "S H Zhang", "Liang Zhang", "Xiang Zhang", "Zhong-Chao Zhang", "Yao Xuan Zhang", "J Zhao", "Chao Zhong", "C Zhou", "L P Zhou", "X L Zhu", "Z Zhu", "Maksym Zyzak" ], "corpus_id": 195181462, "doc_id": "195181462", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "C 98 014915 2018 Azimuthal anisotropy in Cu Au collisions at", "venue": "", "year": 2018 }, { "abstract": "A subwavelength water metamaterial is proposed and analyzed for ultra broadband perfect absorption at microwave frequencies. 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Capolino, Theory and Phenomena of Metamaterials (CRC, 2009) 3. Y. Cui, L. Kang, S. Lan, S. Rodrigues, and W. Cai, \"Giant chiral optical response from a twisted arc metamaterial,\" Nano Lett. 14, 1021 1025 (2014) 4. A. S. Baimuratov, T. P. Pereziabova,W. Zhu,M.Yu. Leonov, A.V. Baranov, A.V. Fedorov, and I. D. Rukhlenko,\"Optical anisotropy of topologically distorted semiconductor nanocrystals,\" Nano Lett. 14, 1021 1025 (2014) 5. N. Yu and F. Capasso, \"Flat optics with designer metasurfaces,\" Nature Mater. 13, 139 150 (2014) 6. Y. Zhang, R. Zhang, X. Li, L. Ma, C. Liu, C. He, and C. Cheng, \"Radially polarized plasmonic vector vortex generated by a metasurface spiral in gold film,\" Opt. Express 25, 32150 32160 (2017) 7. D. Schurig, J. J. Mock, B. J. Justice, S. A. Cummer, J. B. Pendry, A. F. Starr, D. R. Smith, \"Metamaterial electromagnetic cloak at microwave frequencies,\" Science 314, 977 980 (2006) 8. Z. H. Jiang, S. Yun, L. Lin, J. A. Bossard, D. H. Werner, and T. S. Mayer, \"Tailoring Dispersion for Broadband Low loss Optical Metamaterials Using Deep subwavelength Inclusions,\" Sci. Rep. 3, 1571 (2013) 9. P. Tassin, Lei Zhang, Th. Koschny, E. N. Economou, and C. M. Soukoulis, \"Low loss metamaterials based on classical electromagnetically induced transparency,\" Phys. Rev. Lett. 102, 053901 (2009) 10. M. Premaratne and G. P. Agrawal, Light Propagation in Gain Media: Optical Amplifiers (Cambridge University, 2011) 11. Z. Dong, H. Liu, T. Li, Z. Zhu, S. Wang, J. Cao, S. Zhu, and X. Zhang, \"Optical loss compensation in a bulk left handed metamaterial by the gain in quantum dots,\" Appl. Phys. Lett. 96, 044104 (2010) 12. N. I. Landy, S. Sajuyigbe, J. J. Mock, D. R. Smith, and W. J. Padilla, \"Perfect metamaterial absorber,\" Phys. Rev. Lett. 100, 207402 (2008) 13. W. Zhu, F. Xiao, M. Kang, and M. Premaratne, \"Coherent perfect absorption in an all dielectric metasurface,\" Appl. Phys. Lett. 108, 121901 (2016) 14. C. M. Watts, X. Liu, and W. J. Padilla, \"Metamaterial electromagnetic wave absorbers,\" Adv. Mater. 24, OP98 OP120 (2012) Vol. 26, No. 4 19 Feb 2018 OPTICS EXPRESS 5052 #318885 https:/doi.org/10.1364/OE.26.005052 Journal (c) 2018 Received 3 Jan 2018; revised 11 Feb 2018; accepted 11 Feb 2018; published 16 Feb 2018 15. H. Wang, P. V. Sivan, A. Mitchell, G. Rosengarten, P. Phelan, and L. Wang, \" Highly efficient selective metamaterial absorber for high temperature solar thermal energy harvesting,\" Sol. Energy Mater. Sol. Cells 137, 235 242 (2015) 16. S. Gu, B. Su, and X. Zhao, \"Planar isotropic broadband metamaterial absorber,\" J. Appl. Phys. 104, 163702 (2013) 17. Y. Cui, K. H. Fung, J. Xu, H. Ma, Y. Jin, S. He, and N. X. Fang, \"Ultrabroadband light absorption by a sawtooth anisotropic metamaterial slab,\" Nano Lett. 12, 1443 (2012) 18. Y. Shen, Y. Pang, J. Wang, H. Ma, and Z. Pei, \"Ultra broadband terahertz absorption by uniaxial anisotropic nanowire metamaterials,\" IEEE Photon. Technol. Lett. 27, 2284 (2015) 19. M. Pu, M. Wang, C. Hu, C. Huang, Z. Zhao, Y. Wang, and X. Luo, \"Engineering heavily doped silicon for broadband absorber in the terahertz regime,\" Opt. Express 20, 25513 25519 (2012) 20. W. Ellison, \"Permittivity of pure water, at standard atmospheric pressure, over the frequency range 0 25 THz and the temperature range 0 100*C,\" J. Phys. Chem. Ref. Data 36, 1 18 (2007) 21. A. Andryieuski, S. M. Kuznetsova, S. V. Zhukovsky, Y. S. Kivshar, and A. V. Lavrinenko, \"Water: Promising opportunities for tunable all dielectric electromagnetic metamaterials,\" Sci. Rep. 5, 13535 (2015) 22. Y. J. Yoo, S. Ju, S. Y. Park, Y. J. Kim, J. Bong, T. Lim, K. W. Kim, J. Y. Rhee, and Y. Lee, \"Metamaterial absorber for electromagnetic waves in periodic water droplets,\" Sci. Rep. 5, 14018 (2015) 23. W. Zhu, I. D. Rukihlenko, F. Xiao, C. He, J. Geng, X. Liang, M. Premaratne, and R. Jin, \"Multiband coherent perfect absorption in a water based metasurface,\" Optics Express 25, 15737 15745 (2017) 24. Y. Pang, J. Wang, Q. Cheng, S. Xia, X. Zhou, Z. Xu, T. Cui, and S. Qu, \"Thermally tunable water substrate broadband metamaterial absorbers,\" Appl. Phys. Lett. 110, 104103 (2017) 25. M. Odit, P. Kapitanova, A. Andryieuski, P. Belov, and A. V. Lavrinenko, \"Thermally tunable water substrate broadband metamaterial absorbers,\" Appl. Phys. Lett. 109, 011901 (2016) 26. H. Tao, C. M. Bingham, A. C. Strikwerda, D. Pilon, D. Shrekenhamer, N. I. Landy, K. Fan, X. Zhang, W. J. Padilla, and R. D. Averitt, \"Highly flexible wide angle of incidence terahertz metamaterial absorber: Design, fabrication, and characterization,\" Phys. Rev. B 78, 241103(R) (2008)", "author_names": [ "", "R D" ], "corpus_id": 189920775, "doc_id": "189920775", "n_citations": 5, "n_key_citations": 1, "score": 0, "title": "Water metamaterial for ultra broadband and wide angle absorption", "venue": "", "year": 2018 }, { "abstract": "Time resolved multispectral imaging has many applications in different fields, which range from characterization of biological tissues to environmental monitoring. In particular, optical techniques, such as lidar and fluorescence lifetime imaging, require imaging at the subnanosecond scales over an extended area. In this paper, we demonstrate experimentally a time resolved multispectral acquisition scheme based on single pixel imaging. Single pixel imaging is an emerging paradigm that provides low cost high quality images. Here, we use an adaptive strategy that allows acquisition and image reconstruction times to be reduced drastically with respect to conventional single pixel approaches that are based on compressed sensing or full basis scans. Adaptive time resolved multispectral imaging scheme can have significant applications in biological imaging, at scales from macroscopic to microscopic. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement OCIS codes: (100.7410) Wavelets; (100.3020) Image reconstruction restoration; (110.1085) Adaptive imaging; (300.6280) Spectroscopy, fluorescence and luminescence; (110.4234)Multispectral and hyperspectral imaging; (170.6920) Time resolved imaging. References and links 1. J. Shan and C. K. Toth, Topographic laser ranging and scanning: principles and processing (CRC press, 2008) 2. W. Becker, \"Fluorescence lifetime imaging techniques and applications,\" J. Microsc. 247, 119 136 (2012) 3. L. Marcu, \"Fluorescence lifetime techniques in medical applications,\" Annals Biomed. Eng. 40, 304 331 (2012) 4. K. Amarnath, J. Zaks, S. Park, K. Niyogi, and G. Fleming, \"Fluorescence lifetime snapshots reveal two rapidly reversible mechanisms of photoprotection in live cells of chlamydomonas reinhardtii,\" Proc. Natl. Acad. Sci. United States Am. 109, 8405 8410 (2012) 5. T. Laviv, B. Kim, J. Chu, A. Lam, M. Lin, and R. Yasuda, \"Simultaneous dual color fluorescence lifetime imaging with novel red shifted fluorescent proteins,\" Nat. Methods 13, 989 992 (2016) 6. R. Lussana, F. Villa, A. Dalla Mora, D. Contini, A. Farina, L. D. Sieno, and F. Zappa, \"Non contact inclusion detection in food through a single photon time of flight imager,\" IEEE Sensors J. 17, 78 83 (2017) 7. G. Satat, M. Tancik, and R. Raskar, \"Lensless Imaging with Compressive Ultrafast Sensing,\" IEEE Transactions on Comput. Imaging 3, 398 407 (2016) 8. A. Kirmani, A. Colaco, F. N. C. Wong, and V. K. Goyal, \"Exploiting sparsity in time of flight range acquisition using a single time resolved sensor,\" Opt. Express 19, 21485 21507 (2011) 9. M. Duarte, M. Davenport, D. Takhar, J. Laska, T. Sun, K. Kelly, and R. Baraniuk, \"Single pixel imaging via compressive sampling,\" Signal Process. Mag. IEEE 25, 83 91 (2008) 10. S. S. Welsh, M. P. Edgar, R. Bowman, B. Sun, and M. J. Padgett, \"Near video rate linear stokes imaging with single pixel detectors,\" J. Opt. 17, 025705 (2015) 11. Z. Zhang and J. Zhong, \"Three dimensional single pixel imaging with far fewer measurements than effective image pixels,\" Opt. Lett. 41, 2497 2500 (2016) 12. B. L. Liu, Z. H. Yang, X. Liu, and L. A. Wu, \"Coloured computational imaging with single pixel detectors based on a 2d discrete cosine transform,\" J. Mod. Opt. 64, 259 264 (2017) 13. H. Dai, G. Gu, W. He, F. Liao, J. Zhuang, X. Liu, and Q. Chen, \"Adaptive compressed sampling based on extended wavelet trees,\" Appl. Opt. 53, 6619 6628 (2014) 14. Y. R. Huo, H. J. He, F. Chen, and H. M. Tai, \"Adaptive single pixel imaging based on guided coefficients,\" J. Opt. Soc. Am. A 34, 39 51 (2017) 15. F. Rousset, N. Ducros, A. Farina, G. Valentini, C. D'Andrea, and F. Peyrin, \"Adaptive basis scan by wavelet prediction for single pixel imaging,\" IEEE Transactions on Comput. Imaging 3, 36 46 (2017) 16. J. Ma, \"Single pixel remote sensing,\" IEEE Geosci. Remote. Sens. Lett. 6, 199 203 (2009) 17. S. S. Welsh, M. P. Edgar, R. Bowman, P. Jonathan, B. Sun, and M. J. Padgett, \"Fast full color computational imaging with single pixel detectors,\" Opt. Express 21, 23068 23074 (2013) 18. C. M. Watts, D. Shrekenhamer, J. Montoya, G. Lipworth, J. Hunt, T. Sleasman, S. Krishna, D. R. Smith, and W. J. Padilla, \"Terahertz compressive imaging with metamaterial spatial light modulators,\" Nat. Photonics 8, 605 609 (2014) 19. E. Tajahuerce, V. Duran, P. Clemente, E. Irles, F. Soldevila, P. Andres, and J. Lancis, \"Image transmission through dynamic scattering media by single pixel photodetection,\" Opt. Express 22, 16945 16955 (2014) 20. Y. Zhang, M. P. Edgar, B. Sun, N. Radwell, G. M. Gibson, and M. J. Padgett, \"3d single pixel video,\" J. Opt. 18, 035203 (2016) 21. Q. Pian, R. Yao, N. Sinsuebphon, and X. Intes, \"Compressive hyperspectral time resolved wide field fluorescence lifetime imaging,\" Nat. Photonics 11, 411 414 (2017) 22. Q. Pian, R. Yao, L. Zhao, and X. Intes, \"Hyperspectral time resolved wide field fluorescence molecular tomography based on structured light and single pixel detection,\" Opt. Lett. 40, 431 434 (2015) 23. A. Farina, M. Betcke, L. di Sieno, A. Bassi, N. Ducros, A. Pifferi, G. Valentini, S. Arridge, and C. D'Andrea, \"Multiple view diffuse optical tomography system based on time domain compressive measurements,\" Opt. Lett. 42, 2822 2825 (2017) 24. C. D'Andrea, D. Comelli, A. Pifferi, A. Torricelli, G. Valentini, and R. Cubeddu, \"Time resolved optical imaging through turbid media using a fast data acquisition system based on a gated ccd camera,\" J. Phys. D: Appl. Phys. 36, 1675 1681 (2003) 25. S. Mallat, A Wavelet Tour of Signal Processing, Third Edition: The Sparse Way (Academic Press, 2008) 3rd ed. 26. F. Rousset and N. Ducros, SPIRIT (https:/www.creatis.insa lyon.fr/~ducros/WebPage/ spirit.html, 2017) 27. I. Van Stokkum, D. Larsen, and R. Van Grondelle, \"Global and target analysis of time resolved spectra,\" Biochimica et Biophys. Acta Bioenerg. 1657, 82 104 (2004) 28. P. Peronio, I. Labanca, G. Acconcia, A. Ruggeri, A. A. Lavdas, A. A. Hicks, P. P. Pramstaller, M. Ghioni, and I. Rech, \"32 Channel Time Correlated Single Photon Counting System for High Throughput Lifetime Imaging,\" Rev. Sci. Instruments 88, 083704 (2017)", "author_names": [ "" ], "corpus_id": 201857997, "doc_id": "201857997", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Time resolved multispectral imaging based on an adaptive single pixel camera", "venue": "", "year": 2018 }, { "abstract": "Compressive sensing (CS) combines data acquisition with compression coding to reduce the number of measurements required to reconstruct a sparse signal. In optics, this usually takes the form of projecting the field onto sequences of random spatial patterns that are selected from an appropriate random ensemble. We show here that CS can be exploited in 'native' optics hardware without introducing added components. Specifically, we show that random sub Nyquist sampling of an interferogram suffices to reconstruct the field modal structure despite the structural constraints of the measurement system set by its limited degrees of freedom. The distribution of the reduced (and structurally constrained) sensing matrices corresponding to random measurements is provably incoherent and isotropic, which helps us carry out CS successfully. We implement compressive interferometry using a generalized Mach Zehnder interferometer in which the traditional temporal delay is replaced with a linear transformation corresponding to a fractional transform. By randomly sampling the order of the fractional transform, we efficiently reconstruct the modal content of the input beam in the Hermite Gaussian and Laguerre Gaussian bases. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement OCIS codes: (260.3160) Interference; (120.3180) Interferometry; (030.4070) Modes. References and links 1. B. E. A. Saleh and M. C. Teich, Fundamentals of Photonics (Wiley, 2007) 2. A. F. Abouraddy, T. M. Yarnall, and B. E. A. Saleh, \"Generalized optical interferometry for modal analysis in arbitrary degrees of freedom,\" Opt. Lett. 37, 2889 2891 (2012) 3. A. F. Abouraddy, T. M. Yarnall, and B. E. A. Saleh, \"Angular and radial mode analyzer for optical beams,\" Opt. Lett. 36, 4683 4685 (2011) 4. J. Wang, J. Yang, I. M. Fazal, N. Ahmed, Y. Yan, H. Huang, Y. Ren, Y. Yue, S. Dolinar, M. Tur, and A. E. Willner, \"Terabit free space data transmission employing orbital angular momentum multiplexing,\" Nat. Photon. 6, 488 496 (2012) 5. N. Bozinovic, Y. Yue, Y. Ren, M. Tur, P. Kristensen, H. Huang, A. E. Willner, and S. Ramachandran, \"Terabit scale orbital angular momentum mode division multiplexing in fibers,\" Science 340, 1545 1548 (2013) 6. D. J. Richardson, J. M. Fini and L. E. Nelson, \"Space division multiplexing in optical fibres,\" Nat. Photon. 7, 354 362 (2013) 7. Lluis Torner, Juan P. Torres, and Silvia Carrasco, \"Digital spiral imaging,\" Opt. Express 13, 873 881 (2005) 8. L. Martin, D. Mardani, H. E. Kondakci, W. D. Larson, S. Shabahang, A. K. Jahromi, T. Malhotra, A. N. Vamivakas, G. K. Atia, and A. F. Abouraddy, \"Basis neutral Hilbert space analyzers,\" Sci. Rep. 7, 44995 (2017) 9. D. L. Donoho, \"Compressed sensing,\" IEEE Trans. Inf. Theory 52, 1289 1306 (2006) 10. E. J. Candes, \"The restricted isometry property and its implications for compressed sensing,\" C. R. Acad. Sci. 346, 589 592 (2008) 11. E. J. Candes, \"Compressed sensing,\" Proc. Int. Congress of Mathematicians (2006) 12. M. F. Duarte, M. A. Davenport, D. Takhar, J. N. Laska, T. Sun, K. F. Kelly and R. G. Baraniuk, \"Single pixel imaging via compressive sampling,\" IEEE Signal Process. Mag. 25, 83 91 (2008) 13. F. Magalhaes, F. M. Araujo, M. V. Correia, M. Abolbashari, and F. Farahi, \"Active illumination single pixel camera based on compressive sensing,\" Appl. Opt. 50, 405 414 (2011) 14. L. Martinez Leon, P. Clemente, Y. Mori, V. Climent, J. Lancis, and E. Tajahuerce, \"Single pixel digital holography with phase encoded illumination,\" Opt. Express 25, 4975 4984 (2017) 15. P. Clemente, V. Duran, E. Tajahuerce, P. Andres, V. Climent, and J. Lancis, \"Compressive holography with a single pixel detector,\" Opt. Lett. 38, 2524 2527 (2013) Vol. 26, No. 5 5 Mar 2018 OPTICS EXPRESS 5225 #312604 https:/doi.org/10.1364/OE.26.005225 Journal (c) 2018 Received 2 Nov 2017; revised 10 Jan 2018; accepted 7 Feb 2018; published 21 Feb 2018 16. B. Deepan, C. Quan, and C. J. Tay, \"Compressive sensing for digital holographic interferometry,\" Proc. SPIE 9234, 923419 (2014) 17. Y. Rivenson, A. Stern, and J. Rosen, \"Reconstruction guarantees for compressive tomographic holography,\" Opt. Lett. 38, 2509 2511 (2013) 18. A. Liutkus, D. Martina, S. Popoff, G. Chardon, O. Katz, G. Lerosey, S. Gigan, L. Daudet, and I. Carron, \"Imaging with nature: Compressive imaging using a multiply scattering medium,\" Sci. Rep. 4, 5552 (2014) 19. C. G. Graff and E. Y. Sidky, \"Compressive sensing in medical imaging,\" Appl. Opt. 54, C23 C44 (2015) 20. L. Zhu, Y. Chen, J. Liang, Q. Xu, L. Gao, C. Ma, and L. Wang, \"Space and intensity constrained reconstruction for compressed ultrafast photography,\" Optica, 3, 694 697 (2016) 21. M. Suzen, A. Giannoula, and T. Durduran, \"Compressed sensing in diffuse optical tomography,\" Opt. Express 18, 23676 23690 (2010) 22. R. Yao, Q. Pian, and X. Intes, \"Wide field fluorescence molecular tomography with compressive sensing based preconditioning,\" Biomed. Opt. Express 6, 4887 4898 (2015) 23. E. Thiebaut, \"Principles of image reconstruction in interferometry,\" New Concepts in Imaging: Optical and Statistical Models, EAS Publications Series 59, 157 187 (2013) 24. J. Li, J. S. Li, Y. Y. Pan, and R. Li, \"Compressive optical image encryption,\" Sci. Rep. 5, 10374 (2015) 25. N. Rawat, B. Kim, I. Muniraj, G. Situ, and B. G. Lee, \"Compressive sensing based robust multispectral double image encryption,\" Appl. Opt. 54, 1782 1793 (2015) 26. Z. Wang and Z. Yu, \"Spectral analysis based on compressive sensing in nanophotonic structures,\" Opt. Express 22, 25608 25614 (2014) 27. G. A. Howland, J. Schneeloch, D. J. Lum, and J. C. Howell, \"Simultaneous measurement of complementary observables with compressive sensing,\" Phys. Rev. Lett. 112, 253602 (2014) 28. M. Mirhosseini, O. S. Magana Loaiza, S. M. H. Rafsanjani, and R. W. Boyd, \"Compressive Direct Measurement of the Quantum Wave Function,\" Phys. Rev. Lett. 113, 090402 (2014) 29. A. Kalev, R. L. Kosut and I. H. Deutsch, \"Quantum tomography protocols with positivity are compressed sensing protocols,\" npj Quantum Inf. 1, 15018 (2015) 30. G. A. Howland, S. H. Knarr, J. Schneeloch, D. J. Lum, and J. C. Howell, \"Compressively characterizing highdimensional entangled states with complementary, random filtering,\" Phys. Rev. X 6, 021018 (2016) 31. N. Mohan, I. Stojanovic, W. C. Karl, B. E. A. Saleh, and M. C. Teich, \"Compressed sensing in optical coherence tomography,\" Proc. SPIE 7570, 75700L (2010) 32. D. Mardani, A. F. Abouraddy, and G. K. Atia, \"Efficient modal analysis using compressive optical interferometry,\" Opt. Express 23, 28449 28458 (2015) 33. E. Tajahuerce, V. Duran, P. Clemente, E. Irles, F. Soldevila, P. Andres, and J. Lancis, \"Image transmission through dynamic scattering media by single pixel photodetection,\" Opt. Express 22, 16945 16955 (2014) 34. V. Duran, F. Soldevila, E. Irles, P. Clemente, E. Tajahuerce, P. Andres, and J. Lancis, \"Compressive imaging in scattering media,\" Opt. Express 23, 14424 14433 (2015) 35. G. Gibson, B. Sun, M. Edgar, D. Phillips, N. Hempler, G. Maker, G. Malcolm, and M. Padgett, \"Real time imaging of methane gas leaks using a single pixel camera,\" Opt. Express 25, 2998 3005 (2017) 36. B. Lawrie and R. Pooser, \"Toward real time quantum imaging with a single pixel camera,\" Opt. Express 21, 7549 7559 (2013) 37. D. Starling, I. Storer, and G. Howland, \"Compressive sensing spectroscopy with a single pixel camera,\" Appl. Opt. 55, 5198 5202 (2016) 38. W. Yu, X. Yao, X. Liu, L. Li, and G. Zhai, \"Three dimensional single pixel compressive reflectivity imaging based on complementary modulation,\" Appl. Opt. 54, 363 367 (2015) 39. G. Howland, P. Dixon, and J. Howell, \"Photon counting compressive sensing laser radar for 3D imaging,\" Appl. Opt. 50, 5917 5920 (2011) 40. M. Sun, M. Edgar, D. Phillips, G. Gibson, and M. Padgett, \"Improving the signal to noise ratio of single pixel imaging using digital microscanning,\" Opt. Express 24, 10476 10485 (2016) 41. Y. Wu, P. Ye, I. Mirza, G. Arce, and D. Prather, \"Experimental demonstration of an Optical Sectioning Compressive Sensing Microscope (CSM)\" Opt. Express 18, 24565 24578 (2010) 42. G. Satat, M. Tancik, and R. Raskar, \"Lensless imaging with compressive ultrafast sensing,\" arXiv, http:/arxiv.org/abs/1610.05834 (2016) 43. M. Akhlaghi and A. Dogariu, \"Compressive correlation imaging with random illumination,\" Opt. Lett. 40, 4464 4467 (2015) 44. D. Xu, N. Vaswani, Y. Huang, and J. Kang, \"Modified compressive sensing optical coherence tomography with noise reduction,\" Opt. Lett. 37, 4209 4211 (2012) 45. C. Liu, A. Wong, K. Bizheva, P. Fieguth, and H. Bie, \"Homotopic, non local sparse reconstruction of optical coherence tomography imagery,\" Opt. Express 20, 10200 10211 (2012) 46. D. Xu, Y. Huang, and J. Kang, \"Real time compressive sensing spectral domain optical coherence tomography,\" Opt. Lett. 39, 76 79 (2014) 47. Y. Rivenson, A. Stern, and B. Javidi, \"Compressive Fresnel holography,\" J. Display Technol. 6, 506 509 (2010) 48. Y. Rivenson, A. Stern, and J. Rosen, \"Compressive multiple view projection incoherent holography,\" Opt. Express 19, 6109 6118 (2011) Vol. 26, No. 5 5 Mar 2018 OPTICS EXPRESS 5226", "author_names": [ "Deepan Balakrishnan", "Chenggen Quan", "C J Tay", "Antoine Liutkus", "David Martina", "Sebastien M Popoff", "Gilles Chardon" ], "corpus_id": 4498687, "doc_id": "4498687", "n_citations": 2, "n_key_citations": 1, "score": 0, "title": "Compressive optical interferometry under structural constraints", "venue": "", "year": 2018 } ]

[ { "abstract": "Digital integrated circuits require thorough testing in order to guarantee product quality. This is usually achieved with the use of scan chains and automatically generated test patterns. However, functional approaches are often used to complement test suites. Software Based Self Test (SBST) can be used to increase defect coverage in microcontrollers, to replace part of the scan pattern set to reduce tester requirements, or to complement the defect coverage achieved by structural techniques when advanced semiconductor technologies introduce new defect types. Delay testing has become common practice with VLSI integration, and with the latest technologies, targeting small delay defects (SDDs) has become necessary. This chapter deals with SBST for delay faults and describes a case of study based on a peripheral module integrated in a System on Chip (SoC) A method to develop an effective functional test is first described. A comparative analysis of the delay faults detected by scan and SBST is then presented, with some discussion about the obtained results.", "author_names": [ "Kai Rannenberg" ], "corpus_id": 220680148, "doc_id": "220680148", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "VLSI SoC: New Technology Enabler: 27th IFIP WG 10.5/IEEE International Conference on Very Large Scale Integration, VLSI SoC 2019, Cusco, Peru, October 6 9, 2019, Revised and Extended Selected Papers", "venue": "VLSI SoC", "year": 2020 }, { "abstract": "The gut microbiota coexists in partnership with the human host through adaptations to environmental and physiological changes that help maintain dynamic homeostatic healthy states. Break down of this delicate balance under sustained exposure to stressors (e.g. unhealthy diets) can, however, contribute to the onset of disease. Diet is a key modifiable environmental factor that modulates the gut microbiota and its metabolic capacities that, in turn, could impact human physiology. On this basis, the diet and the gut microbiota could act as synergistic forces that provide resilience against disease or that speed the progress from health to disease states. Associations between unhealthy dietary patterns, non communicable diseases and intestinal dysbiosis can be explained by this hypothesis. Translational studies showing that dietary induced alterations in microbial communities recapitulate some of the pathological features of the original host further support this notion. In this introductory paper by the European project MyNewGut, we briefly summarize the investigations conducted to better understand the role of dietary patterns and food components in metabolic and mental health and the specificities of the microbiome mediating mechanisms. We also discuss how advances in the understanding of the microbiome's role in dietary health effects can help to provide acceptable scientific grounds on which to base dietary advice for promoting healthy living.", "author_names": [ "Yolanda Sanz", "Marina Romani-Perez", "Alfonso Benitez-Paez", "Kevin J Portune", "Patrizia Brigidi", "Simone Rampelli", "Ted G Dinan", "Catherine Stanton", "Nathalie M Delzenne", "Francois Blachier", "Audrey M Neyrinck", "Martin Beaumont", "Marta Olivares", "Peter Holzer", "Kathrin Gunther", "Maike Wolters", "Wolfgang Ahrens", "Sandrine P Claus", "Cristina Campoy", "Rinki Murphy", "Christina Sadler", "L Rey Fernandez", "J W van der Kamp" ], "corpus_id": 51709157, "doc_id": "51709157", "n_citations": 20, "n_key_citations": 1, "score": 0, "title": "Towards microbiome informed dietary recommendations for promoting metabolic and mental health: Opinion papers of the MyNewGut project.", "venue": "Clinical nutrition", "year": 2018 }, { "abstract": "Project based and problem based learning are widespread and proven pedagogical techniques to achieve a variety of learning outcomes. In this paper, several projects in the circuits, systems, VLSI and signal processing areas are described. The projects can be implemented using both project based and problem based learning and as part of an Electrical and Computer Engineering curriculum without the need for additional expensive resources. Learning outcomes in Science, Technology, Engineering and Mathematics (STEM) are emphasized such that students achieve analytical, design, software and communication skills. The VLSI design project also has an entrepreneurship component. Assessment results are provided.", "author_names": [ "Ravi P Ramachandran", "Kevin D Dahm", "Linda M Head", "John L Schmalzel" ], "corpus_id": 115969367, "doc_id": "115969367", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Project and Problem Based Learning for Circuits, Systems, VLSI and Digital Signal Processing Courses", "venue": "", "year": 2015 }, { "abstract": "We have used an image sensor as a multi year project chip for undergraduates. With this project, students experience VLSI through an entire design cycle from start to finish. Students are involved in the design, simulation, testing i.e. all aspects of the project. The curriculum at Alfred is such that Juniors and Seniors can both take courses in VLSI emphasizing such topics as systems level design, analog design as well as other advanced topics. Students who take VLSI courses in their junior year are then allowed to work on the project chip during their senior year. Sensors constructed are based on the silicon retina, using transistors in subthreshold to produce signal compression at the pixel level.", "author_names": [ "Wallace B Leigh" ], "corpus_id": 46461848, "doc_id": "46461848", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "An image sensor as an undergraduate VLSI project chip", "venue": "Proceedings 2001 International Conference on Microelectronic Systems Education", "year": 2001 }, { "abstract": "", "author_names": [ "Patrick Dewilde" ], "corpus_id": 60599669, "doc_id": "60599669", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "The Integrated Circuit Design Book Papers on VLSI Design Methodology from the ICD NELSIS Project", "venue": "", "year": 1986 }, { "abstract": "VLSI design and verification is the kernel course of both the computer science and technology major and the electronic engineering major.The practice methods of this course in recent years are summarized.Consulting the experiences from corresponding courses in other leading universities,the course projects and laboratories have been evolved and optimized with the updated contents.We explore the all in one integrated EDA experiment platform based on virtual machine technology.The statistical data shows that this platform improves the capability and possibility for students to complete the project in self teaching or practice after class.", "author_names": [ "Chen Hai-ya" ], "corpus_id": 64324030, "doc_id": "64324030", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Exploration of VLSI design and verification course project and laboratory", "venue": "", "year": 2014 }, { "abstract": "Using small spacecrafts for a wide range of research and applied purposes is one of the major trends in the aerospace field. Modular network architectures implemented on the \"system on chip\" hardware platform provide required characteristics of onboard control systems. Selecting this system architecture significantly increases demands on very large scale integration (VLSI) design efficiency and project solution quality. In this paper, we propose a new approach to VLSI high level synthesis based on a functional flow parallel computing model. The modified VLSI design flow uses a functional flow parallel programming language Pythagoras, which allows describing a VLSI operation algorithm with the maximal degree of parallelism. An offered intermediate representation of VLSI architecture in the form of a control flow graph and a data flow graph provides an opportunity for synthesizing circuits and verifying projects on the stage of a formal description, without returning to previous hierarchical levels of the project. A set of software tools supporting new design process is developed. The proposed technology is successfully tested on the example of a digital signal processing function. Further, this technology is suggested for use in the synthesis of onboard control system components for small spacecrafts.", "author_names": [ "Oleg V Nepomnyashchiy", "Irina Ryjenko", "Vladimir V Shaydurov", "N Y Sirotinina", "Aleksey Postnikov" ], "corpus_id": 64949820, "doc_id": "64949820", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "The VLSI High Level Synthesis for Building Onboard Spacecraft Control Systems", "venue": "", "year": 2018 }, { "abstract": "This article describes test ship design and parameter extraction of parasitic capacitance of MOSFET in VLSI. The test structure for separating area and side wall capacitance components of N+Psub junction and P+Nwell junction are used as testing devices. The BSIM3v3 models are proposed also. The results suggest that the correlation was found in 2% level. The manual calculation should be used for the benefit of extraction methodology. Finally, the overall data should be a data base of the design tool kit which hand out to the circuit designer in Multi Project Chip.", "author_names": [ "Anucha Ruangphanit", "Rujipad Pedlub", "Rangson Muanghlua" ], "corpus_id": 44043389, "doc_id": "44043389", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Test chip design and parameter extraction of parasitic capacitance of MOSFET in VLSI", "venue": "2017 International Electrical Engineering Congress (iEECON)", "year": 2017 }, { "abstract": "", "author_names": [ "Miia Martinsuo", "Ole Jonny Klakegg", "Alfons van Marrewijk" ], "corpus_id": 117498603, "doc_id": "117498603", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Call for papers: Delivering value in projects and project based business", "venue": "", "year": 2017 }, { "abstract": "The literature base regarding the development of sporting talent is extensive, and includes empirical articles, reviews, position papers, academic books, governing body documents, popular books, unpublished theses and anecdotal evidence, and contains numerous models of talent development. With such a varied body of work, the task for researchers, practitioners and policy makers of generating a clear understanding of what is known and what is thought to be true regarding the development of sporting talent is particularly challenging. Drawing on a wide array of expertise, we address this challenge by avoiding adherence to any specific model or area and by providing a reasoned review across three key overarching topics: (a) the performer; (b) the environment; and (c) practice and training. Within each topic sub section, we review and calibrate evidence by performance level of the samples. We then conclude each sub section with a brief summary, a rating of the quality of evidence, a recommendation for practice and suggestions for future research. These serve to highlight both our current level of understanding and our level of confidence in providing practice recommendations, but also point to a need for future studies that could offer evidence regarding the complex interactions that almost certainly exist across domains.", "author_names": [ "Tim Rees", "Lew Hardy", "Arne Gullich", "Bruce Abernethy", "Jean Cote", "Tim Woodman", "Hugh Montgomery", "Stewart Laing", "Chelsea Warr" ], "corpus_id": 246193, "doc_id": "246193", "n_citations": 168, "n_key_citations": 12, "score": 0, "title": "The Great British Medalists Project: A Review of Current Knowledge on the Development of the World's Best Sporting Talent", "venue": "Sports Medicine", "year": 2016 } ]

[ { "abstract": "The rapid development of nanotechnology, such as microelectromechanical systems (MEMS) microelectronics and nanophotonics, has led to the emerging attentions in achieving functional optoelectronic structures and/or metamaterials at micro and nanoscale resolution. Multiphoton absorption nanofabrication has demonstrated its great potential for applications in preparation of complex three dimensional (3D) nanostructures at micro and nanoscales. Here, we report new laser nano manufacturing approaches, multiphoton polymerization (MPP) and multiphoton photoreduction (MPR) to fabricate optical functional nanostructures. The luminescent nanostructures have been created by the in situ synthesis of semiconductor nanoparticles in a polymer matrix with fine size control and the MPP process. This represents the first successful fabrication of multicolor 3D microstructures of semiconductor polymer nanocomposites using a laser microstereolithography technique. Ultra thin chiral metasurfaces with giant broadband optical activity in the infrared wavelength have been realized. The chiral metasurfaces consisting of periodic hole arrays of complementary asymmetric split ring resonators (SRRs) are fabricated by MPP. Enhanced transmission with strong polarization conversion up to 97% is observed owing to the chiral surface plasmons from mirror symmetry broken. Furthermore, a planar electromagnetic metamaterial made of U shaped SRRs has been fabricated by the MPR in the aqueous solution of gold ions with the assistance of ionic liquid (IL) The measured spectra are consistent with theoretical predictions for the metamaterial fabricated by laser direct writing technique. The proposed laser nano manufacturing technique would open up new avenues for the fabrication and application of micro and nanoscale devices in photonics, electronics, and biotechnology.", "author_names": [ "Mei-Ling Zheng", "Xuanming Duan" ], "corpus_id": 9082204, "doc_id": "9082204", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Laser nano manufacturing technology and applications towards optical functional nanostructures and devices", "venue": "2015 Opto Electronics and Communications Conference (OECC)", "year": 2015 }, { "abstract": "Nanoconstruction of metals is a significant challenge for the future manufacturing of plasmonic devices. Such a technology requires the development of ultra fast, high throughput and low cost fabrication schemes. Laser processing can be considered as such and can potentially represent an unrivalled tool towards the anticipated arrival of modules based in metallic nanostructures, with an extra advantage: the ease of scalability. Specifically, laser nanostructuring of either thin metal films or ceramic/metal multilayers and composites can result on surface or subsurface plasmonic patterns, respectively, with many potential applications. In this chapter, the photo thermal processes involved in surface and subsurface nanostructuring are discussed and processes to develop functional plasmonic nanostructures with pre determined morphology are demonstrated. For the subsurface plasmonic conformations, the temperature gradients that are developed spatially across the metal/dielectric structure during the laser processing can be utilized. For the surface plasmonic nanoassembling, the ability to tune the laser's wavelength to either match the absorption spectral profile of the metal or to be resonant with the plasma oscillation frequency can be utilised, i.e. different optical absorption mechanisms that are size selective can be probed. Both processes can serve as a platform for stimulating further progress towards the engineering of large scale plasmonic devices.", "author_names": [ "Nikolaos Kalfagiannis", "Demosthenes C Koutsogeorgis", "Elefterios Lidorikis", "Panos Patsalas" ], "corpus_id": 197644371, "doc_id": "197644371", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Chapter 18 Laser Annealing as a Platform for Plasmonic", "venue": "", "year": 2019 }, { "abstract": "Recently, we show a method of color printing on nanoimprinted plasmonic metasurfaces using laser post writing. Laser pulses induce transient local heat generation that leads to melting and reshaping of the imprinted nanostructures. Depending on the laser pulse energy density, different surface morphologies that support different plasmonic resonances can be created. This technology creates a laser printer capable of producing color images with a resolution up to 127,000 DPI. With tailored trains of laser pulses, multiple optical states are flatiron onto the metasurface film with a nanoscale controlling. Thus, this diffraction limited resolution optical writing process can be further used to demonstrate a variety of applications in addition to large area structural color printing. Multi focus Fresnel zone plates with subwavelength focus, and more meta surfaces different functions, such as spectroscope filters, Raman substrates and biosensors are also applicable.", "author_names": [ "X Zhu", "Marcus S Carstensen", "Christoph Vannahme", "Emil Hojlund-Nielsen", "Niels Asger Mortensen", "Anders Kristensen" ], "corpus_id": 7852242, "doc_id": "7852242", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Plasmonic laser printing for functional metasurfaces", "venue": "2016 Progress in Electromagnetic Research Symposium (PIERS)", "year": 2016 }, { "abstract": "Abstract Nanophotonics research relies heavily on state of the art and costly nano and microfabrication technologies. While such technologies are fairly mature, their implementation in large scale manufacturing of photonic devices is not straightforward. This is a major roadblock for integrating nanophotonic functionalities, such as flat optics or high definition, ink free color printing, into real life applications. In particular, optical metasurfaces nanoscale textured surfaces with engineered optical properties hold great potential for a myriad of such applications. Digital laser printing has recently been introduced as a low cost lithography solution, which allows the fabrication of high resolution features on optical substrates. By exploiting resonant opto thermal modification of individual nanoscale elements, laser printing can achieve nanometer sized resolution. In addition, the concept of digital resonant laser printing at the nanoscale supports mass customization and may therefore convert nanophotonic science into everyday consumer products.", "author_names": [ "Xiaolong Zhu", "Mehdi Keshavarz Hedayati", "Soren Raza", "Uriel Levy", "Niels Asger Mortensen", "Anders Kristensen" ], "corpus_id": 216796136, "doc_id": "216796136", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Digital resonant laser printing: Bridging nanophotonic science and consumer products", "venue": "", "year": 2017 }, { "abstract": "Fabrication of plasmonic nanostructures has been an important topic for their potential applications in photonic and optoelectronic devices. Among plasmonic materials, gold is one of the most promising materials due to its low ohmic loss at optical frequencies and high oxidation resistance. However, there are two major bottlenecks for its industrial applications: (1) the need for large scale fabrication technology for high precision plasmonic nanostructures; and (2) the need to integrate the plasmonic nanostructures on various substrates. While conventional top down approaches involve high cost and give low throughput, bottom up approaches suffer from irreproducibility and low precision. Herein, we report laser shock induced direct imprinting of large area plasmonic nanostructures from physical vapor deposited (PVD) gold thin film on a flexible commercial free standing aluminum foil. Among the important characteristics of the laser shock direct imprinting is their unique capabilities to reproducibly deliver designer plasmonic nanostructures with extreme precision and in an ultrafast manner. Excellent size tunability (from several mm down to 15 nm) has been achieved by varying mold dimensions and laser parameters. The physical mechanism of the hybrid film imprinting is elaborated by finite element modeling. A mechanical robustness test of the hybrid film validates a significantly improved interfacial contact between gold arrays and the underlying substrate. The strong optical field enhancement was realized in the large area fabricated engineered gold nanostructures. Low concentration molecular sensing was investigated employing the fabricated structures as surface enhanced Raman scattering (SERS) substrates. The ability to ultrafast direct imprint plasmonic nanoarrays on a flexible substrate at multiscale is a critical step towards roll to roll manufacturing of multi functional devices which is poised to inspire several emerging applications.", "author_names": [ "Yaowu Hu", "Prashant Kumar", "Rong Xu", "Kejie Zhao", "Gary J Cheng" ], "corpus_id": 9382267, "doc_id": "9382267", "n_citations": 30, "n_key_citations": 0, "score": 0, "title": "Ultrafast direct fabrication of flexible substrate supported designer plasmonic nanoarrays.", "venue": "Nanoscale", "year": 2016 }, { "abstract": "Semiconductor lasers are ideal sources for efficient electrical to optical power conversion and for many applications where their small size and potential for low cost are required to meet market demands. Yellow lasers find use in a variety of bio related applications, such as photocoagulation, imaging, flow cytometry, and cancer treatment. However, direct generation of yellow light from semiconductors with sufficient beam quality and power has so far eluded researchers. Meanwhile, tapered semiconductor lasers at near infrared wavelengths have recently become able to provide neardiffraction limited, single frequency operation with output powers up to 8 W near 1120 nm. We present a 1.9 W single frequency laser system at 562 nm, based on single pass cascaded frequency doubling of such a tapered laser diode. The laser diode is a monolithic device consisting of two sections: a ridge waveguide with a distributed Bragg reflector, and a tapered amplifier. Using single pass cascaded frequency doubling in two periodically poled lithium niobate crystals, 1.93 W of diffraction limited light at 562 nm is generated from 5.8 W continuous wave infrared light. When turned on from cold, the laser system reaches full power in just 60 seconds. An advantage of using a single pass configuration, rather than an external cavity configuration, is increased stability towards external perturbations. For example, stability to fluctuating case temperature over a 30 K temperature span has been demonstrated. The combination of high stability, compactness and watt level power range means this technology is of great interest for a wide range of biological and biomedical applications.", "author_names": [ "Anders Kragh Hansen", "Mathias Christensen", "Danny Noordegraaf", "Peter G Heist", "Evangelos Papastathopoulos", "Valentin Loyo-Maldonado", "Ole Bjarlin Jensen", "Michelle Lynn Stock", "Peter M W Skovgaard" ], "corpus_id": 1755342, "doc_id": "1755342", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "1.9 W yellow, CW, high brightness light from a high efficiency semiconductor laser based system", "venue": "LASE", "year": 2017 }, { "abstract": "Recent breakthroughs in solid state photonic quantum technologies enable generating and detecting single photons with near unity efficiency as required for a range of photonic quantum technologies. The lack of methods to simultaneously generate and control photons within the same chip, however, has formed a main obstacle to achieving efficient multi qubit gates and to harness the advantages of chip scale quantum photonics. Here we propose and demonstrate an integrated voltage controlled phase shifter based on the electro optic effect in suspended photonic waveguides with embedded quantum emitters. The phase control allows building a compact Mach Zehnder interferometer with two orthogonal arms, taking advantage of the anisotropic electro optic response in gallium arsenide. Photons emitted by single self assembled quantum dots can be actively routed into the two outputs of the interferometer. These results, together with the observed sub microsecond response time, constitute a significant step towards chip scale single photon source de multiplexing, fiber loop boson sampling, and linear optical quantum computing. 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Yamamoto, \"Ultrafast optical spin echo in a single quantum dot,\" Nat. Photonics 4(6) 367 370 (2010) 35. F. Pagliano, Y. Cho, T. Xia, F. v. Otten, R. Johne, and A. Fiore, \"Dynamically controlling the emission of single excitons in photonic crystal cavities,\" Nat. Commun. 5, 5786 (2014) 36. D. Parrain, C. Baker, G. Wang, B. Guha, E. Gil Santos, A. Lemaitre, P. Senellart, G. Leo, S. Ducci, and I. Favero, \"Origin of optical losses in gallium arsenide disk whispering gallery resonators,\" Opt. Express 23(15) 19656 19672 (2015) 37. C. P. Michael, K. Srinivasan, T. J. Johnson, and O. Painter, \"Wavelengthand material dependent absorption in GaAs and AlGaAs microcavities,\" Appl. Phys. Lett. 90, 051108 (2007) 38. L. M. Duan and H. J. Kimble, \"Scalable photonic quantum computation through cavity assisted interactions,\" Phys. Rev. Lett. 92, 127902 (2004) 39. L. Sapienza, M. Davanco, A. Badolato, and K. Srinivasan, \"Nanoscale optical positioning of single quantum dots for bright and pure single photon emission,\" Nat. Commun. 6, 7833 (2015)", "author_names": [ "", "H L" ], "corpus_id": 39313547, "doc_id": "39313547", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "Electro optic routing of photons from a single quantum dot in photonic integrated circuits Midolo,", "venue": "", "year": 2018 }, { "abstract": "Condition monitoring is increasingly benefitting from the application of emerging technologies, such as mobile computing and wireless sensors, including photonics sensors. The latter can be applicable to diverse application needs, due to their versatility, low costs, installation and operational flexibility, as well as unique safety and reliable operation characteristics in real industrial environments of excessive electromagnetic interference and noise. Coupling the monitoring flexibility offered by photonics technologies, with the data transmission flexibility of wireless networking provides opportunities to develop hybrid wireless sensor solutions, incorporating optical sensors into wireless condition monitoring architectures. This paper presents ongoing work within an integrated architecture for condition monitoring and maintenance management support, exploiting the added value of optical technology, inherently safe with respect to electromagnetic compatibility. The reported results are part of a collaborative project involving technology providers in wireless sensor networking, embedded systems and maintenance engineering, as well as research organizations active on photonics technologies and informatics for wireless and intelligence enabled engineering asset management. The industrial test cases are from a lifts manufacturing industry, focusing on both production facilities assets, as well as on the end product. The photonic platform of plastic optical fibers was selected due to its versatility and suitability for rapid customization and prototyping. The platform can serve diverse sensing and monitoring needs, ranging from physical parameters as strain and displacement in machinery parts, to chemical and biochemical monitoring of industrial grade coolants' aging. Use of novel nanostructured optical materials together with laser based micromachining techniques enabled the functional enhancement through rapid prototyping of optical fiber devices towards highly customizable sensors. The integration of the sensing elements within the wireless sensor network architecture offers substantial flexibility for industrial applications.", "author_names": [ "Christos Emmanouilidis", "Christos Riziotis" ], "corpus_id": 60429148, "doc_id": "60429148", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Wireless Condition Monitoring Integrating Smart Computing and Optical Sensor Technologies", "venue": "", "year": 2015 }, { "abstract": "This paper reports on chip based optical detection with threedimensional spatial resolution by integration of an optofluidic microscope (OFM) in a microfluidic pinched flow fractionation (PFF) separation device. This setup also enables on chip particle image velocimetry (PIV) The position in the plane perpendicular to the flow direction and the velocity along the flow direction of separated fluorescent labeled polystyrene microspheres with diameters of 1 mm, 2.1 mm, 3 mm and 4 mm is determined by the OFM. These results are bench marked against those obtained with a PFF device using conventional fluorescence microscope readout. The size separated microspheres are detected by OFM with an accuracy of =0.92mm. The position in the height of the channel and the velocity of the separated microspheres are detected with an accuracy of 1.4 mm and 0.08 mm/s respectively. Throughout the measurements of the height and velocity distribution, the microspheres are observed to move towards the center of the channel in regard to its height. (c) 2010 Optical Society of America OCIS codes: (110.0180) Microscopy; (110.2970) Image detection systems; (110.4235) Nanolithography; (120.1880) Detection; (130.3990) Micro optical devices; (220.4000) Microstructure fabrication; (220.4241) Nanostructure fabrication. References and links 1. S. Balslev, A. M. Jorgensen, B. Bilenberg, K. B. Mogensen, D. Snakenborg, O. Geshke, J. P. Kutter, and A. Kristensen, \"Lab on a chip with integrated optical transducers,\" Lab Chip 6, 213 217 (2006) 2. T. L. Olesen, B. B. Buus, J. G. Howalt, and M. F. Hansen, \"Magnetic micromixer: Influence og magnetic element geometry and field amplitude,\" Appl. Phys. 103, 07E902 (2008) 3. N. Pamme, \"Continous flow separation in microfluidic devices,\" Lab Chip 7, 1644 1654 (2007) 4. D. Janasek, J. Franzke, and A. Manz, \"Scaling and design of miniaturized chemical analysis systems,\" Nature 442, 374 380 (2006) 5. A. Manz, J. C. Fettinger, E. Verpoorte, H. Ldi, H. M. Widmer, and D. J. Harrison, \"Micromachining of monocrystalline silicon and glass for chemical analysis systems A look into next century's technology or just a fasionable craze,\" Trends Anal. Chem. 10, 144 149 (1991) 6. X. Heng, D. Erickson, L. R. Baugh, Z. Yaqoob, P. W. Sternberg, D. Psaltis, and C. Yang, \"Optofluidic microscopy a method for implementing a high resolution optical microscope on a chip,\" Lab Chip 6, 1274 1276 (2006) 7. X. Cui, L. M. Lee, X. Heng, W. Zhong, P. W. Sternberg, D. Psaltis, and C. Yang, \"Lensless high resolution onchip optofluidic microscopes for Caenorhabditis elegans and cell imaging,\" Proc. Natl. Acad. Sci. U.S.A. 105, 10670 10675 (2008) 8. X. Heng, E. Hsiao, D. Psaltis, and C.Yang, \"An optical tweezer actuated, nanoaperture grid based Optofluidic Microscope implementation method,\" Opt. Express 15, 16367 16375 (2007) 9. R. Lindken, M. Rossi, S. Grosse, and J. Westerweel, \"Micro particle Image Velocimetry (mPIV) Recent developments, applications, and guidelines,\" Lab Chip 15, 2551 2567 (2009) 10. M. Yamada, M. Nakashima, and M. Seki, \"Pinched Flow Fractionation: Continous Size Separation of Particles Utilizing a Laminar Flow Profile in a Pinched Microchannel,\" Anal. Chem. 76, 5465 5471 (2004) (C) 2010 OSA 1 March 2010 Vol. 18, No. 5 OPTICS EXPRESS 4158 #118773 $15.00 USD Received 22 Oct 2009; revised 8 Feb 2010; accepted 11 Feb 2010; published 17 Feb 2010 11. J. Takagi, M. Yamada, M. Yasuda, and M. Seki, \"Continous particle separation in a microchannel having asymmetrically arranged multiple branches,\" Lab Chip 5, 778 784 (2005) 12. Y. Sai, M. Yamada, M. Yasuda, and M. Seki, \"Continous separation of particles using a microfluidic device equipped with flow rate controle valves,\" J. Chromatogr. A 1127, 214 220 (2006) 13. H. Maenaka, M. Yamada, M. Yasuda, and M. Seki, \"Continous and Size Dependent Sorting of Amulsion Droplets Using Hydrodynamics in Pinched Microchannels,\" Langmuir 24, 4405 4410 (2008) 14. A. V. Larsen, L. Poulsen, H. Birgens, M. Dufva, and A. Kristensen, \"Pinched flow fractionation devices for detection of single nucleotide polymorphisms,\" Lab Chip 8, 818 821 (2008) 15. N. A. Mortensen, \"Comment on 'Pinched Flow Fractionation: Contonous Size Separation of Particles Utilizing a Laminar Flow Profile in a Pinched Microchannel'\" Anal. Chem. 79, 9240 9241 (2007) 16. A. L. Vig and A. Kristensen, \"Separation enhancement in pinched flow fractionation,\" Appl. Phys. Lett. 93, 203507 (2008) 17. B. Bilenberg, M. Hansen, D. Johansen, V. Ozkapici, C. Jeppesen, P. Szabo, I. M. Obieta, O. Arroyo, J. O. Tegenfeldt, and A. Kristensen,\"Topas based lab on a chip microsystems fabricated by thermal nanoimprint lithography,\" J. Vac. Sci. Technol. B 23, 2944 2949 (2005) 18. J. C. Giddings, Unified separation science, (Wiley and Sons, Inc, 1991) 19. K. Yapici, R. L. Powell, and R. J. Phillips,\"Particle migration and suspension structure in a steady and oscillatory plane Poiseuille flow,\" Phys. Fluids 21, 053302 (2009)", "author_names": [ "Asger Laurberg Vig", "Rodolphe Marie", "Eric Jensen", "Anders Kristensen" ], "corpus_id": 67764627, "doc_id": "67764627", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Optofluidic microscope with 3 D spatial resolution", "venue": "", "year": 2018 }, { "abstract": "The simplicity of synthesis of deterministically positioned inorganic semiconductor nanorods (NRs) and nanotubes (NTs) coupled with their chemical stability, high surface area, controllable optical properties and tunable surface functionality, have sparked worldwide research efforts towards biodiagnostic applications. Biosensors based on oriented and aligned one dimensional (1 D) inorganic semiconductor nanostructures have demonstrated remarkable detection sensitivity, high throughput and label free operability. In comparison to suspensions of nanoparticles and discrete randomly oriented nanowires, nanowire (NW) and nanotube arrays offer continuous charge transport pathways, a major advantage for all electrical detection and in exploiting electrokinetic effects. We review highly sensitive biosensors based on oriented and aligned NTs/NRs/NWs employing conventional detection methods, inclusive of fluorescence, electrochemistry and electromechanical sensing as well as detection methods unique to nanowires such as field effect transistors. Entirely new types of sensing applications such as the impaling of living cells to monitor cellular events in situ, and substrates with electrically controlled wetting for surface assisted laser desorption and ionization are emerging to take advantage of the unique properties of nanowire arrays. Concurrently, we explain the semiconductor materials and architectures employed, and the functionalization procedures used to construct the biosensors. Aligned semiconductor array based approaches are critically examined in relation to prevailing technologies to get a sense of the exclusive niches that nanotube/nanorod array biosensors inhabit. The versatility of the detection principles that nanowire/nanotube arrays are compatible with are enabling hybrid approaches where combinations of detection methods are used. Such advantages offset the complexity associated with changing the status quo with respect to the current state of the art in biodiagnostic platforms and devices.", "author_names": [ "Piyush Kar", "Karthik Shankar" ], "corpus_id": 27486908, "doc_id": "27486908", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Biodiagnostics using oriented and aligned inorganic semiconductor nanotubes and nanowires.", "venue": "Journal of nanoscience and nanotechnology", "year": 2013 } ]

[ { "abstract": "Abstract In this work passivated rear contacts are used to replace point contact passivation schemes for high efficiency n type crystalline silicon solar cells. Our structure is based on an ultra thin tunnel oxide (SiO2) and a phosphorus doped silicon layer, which significantly reduce the surface recombination at the metal semiconductor interface. The passivation and transport mechanisms of this passivated contact will be addressed within this paper. Particular consideration will be given to the tunnel oxide's impact on interface passivation and on the I V characteristics of n type Si solar cells featuring a boron diffused emitter. It will be shown that the tunnel oxide is a vital part of this passivated contact and that it is required to achieve excellent interface passivation for both open circuit and maximum power point (MPP) conditions (implied open circuit voltage iVoc>710 mV and implied fill factor iFF>84% It will also become clear that the transport barrier arising from the tunnel oxide does not constrict the majority carrier flow. Thus, a low series resistance is obtained, which in conjunction with the high iFF enables FFs well above 82% Investigations on cell levels lead to an independently confirmed conversion efficiency of 23.0% for n type cells with a boron diffused emitter and the herein developed passivated rear contact, in which the efficiency is not limited by the electrical properties of our passivated contacts.", "author_names": [ "Frank Feldmann", "Martin Bivour", "Christian Reichel", "Martin Hermle", "Stefan W Glunz" ], "corpus_id": 95309419, "doc_id": "95309419", "n_citations": 387, "n_key_citations": 8, "score": 1, "title": "Passivated rear contacts for high efficiency n type Si solar cells providing high interface passivation quality and excellent transport characteristics", "venue": "", "year": 2014 }, { "abstract": "Due to the improvements in material quality and surface passivation, high efficiency solar cells are often limited by the recombination at the metal semiconductor contacts. As a solution to this problem, Swanson proposed \"to put a heterojunction with a band gap larger than silicon between the metal and silicon\"[1] also known as passivated contact. In this work, a tunnel oxide passivated contact (TOPCon) structure allowing both an excellent surface passivation and an effective carrier transport is presented. High efficiency n type solar cells featuring this novel passivated rear contact instead of a point contact structure at the rear side yield a maximum efficiency of 23.7 a FF of 82.2 and a Voc of 703 mV.", "author_names": [ "Stefan W Glunz", "Martin Hermle", "Christian Reichel", "Martin Bivour", "Frank Feldmann" ], "corpus_id": 51745026, "doc_id": "51745026", "n_citations": 44, "n_key_citations": 2, "score": 0, "title": "A Passivated Rear Contact for High Efficiency n Type Si Solar Cells Enabling High Voc's and FF>82", "venue": "", "year": 2013 }, { "abstract": "Abstract Bifacial crystalline silicon (c Si) solar cells have currently attracted much attention due to the front high efficiency and additional gain of power generation from the back side. Here, we have presented n type passivated emitter and rear totally diffused (n PERT) bifacial c Si solar cells featuring front selective emitter (SE) and polysilicon (poly Si) based passivating contacts. The SE formation was scanned with laser doping based on front boron diffusion p+ emitter. The poly Si based passivating contacts consisting of nano layer SiOx of ~1.5 nm thickness grown with cost effective nitric acid oxidation and phosphorus doped polysilicon exhibited excellent passivation for high open circuit voltage. We have successfully achieved the large area (156 x 156 mm2) n PERT bifacial solar cells yielding top efficiency of 21.15% together with a promising short circuit current density of 40.40 mA/cm2. Theoretical calculation has further demonstrated that the optimal thickness of SiOx nano layer will increase from 1.5 nm to 1.8 nm if the density of interface defect state decreases by one magnitude from 1 x 1010 cm 2/eV, and the cell efficiency can be improved up to 24.64% with open circuit voltage over 0.720 V by optimizing the parameters of functional materials and interface layers. The present work has indicated that the commercialization of low cost and high efficiency n PERT bifacial c Si cells is possible due to the processes compatible with existing production lines.", "author_names": [ "Dongyan Ding", "Guilin Lu", "Zhengping Li", "Yue-heng Zhang", "Wen-zhong Shen" ], "corpus_id": 209989074, "doc_id": "209989074", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "High efficiency n type silicon PERT bifacial solar cells with selective emitters and poly Si based passivating contacts", "venue": "Solar Energy", "year": 2019 }, { "abstract": "Abstract In this work, we used the numerical simulation method to study the tunnel oxide passivated carrier selective contacts (TOPCon) structured solar cells, with the focus especially on the paths towards excellent surface passivation and low contact resistance. The presence of an ultra thin silicon oxide (SiO 2 with high quality (typically low interface states density, D it 1 x 10 10 cm 2 eV 1 and low pinhole density, D ph 4 suppresses the recombination of carriers at the rear surface. As a result, implied open circuit voltage (i V oc could be promoted by a value of more than 30 mV comparing with the solar cell without oxide layer, which is the primary benefit originated from TOPCon structure. Corresponding, the iV oc and recombination current density J oe could reach ~745 mV and ~9.5 fA/cm 2 (Dn 5 x 10 15 cm 3 for the 1 O cm and 200 mm n type wafer covered with high quality oxide and n Si layers. In addition to passivation, a well designed SiO 2 /n Si backside structure is also critical for carrier collection. The tunneling current is susceptible to oxide thickness, i.e. a 0.2 nm increase in SiO 2 thickness results in the decrease of the tunneling current by more than one magnitude under certain circumstance. Fortunately, raising the doping in n Si layer enhances the tunneling possibility of electron, which allows for a thicker oxide that is favorable to a stable mass production. The simulation suggests that to obtain a high fill factor FF >84% a minimum forward bias saturated tunneling current of about 0.01 A/cm 2 more favorable of 0.1 A/cm 2 is required for the Si/SiO 2 /n Si structure. Generally, our work offers an improved understanding of tunnel oxide, doping layer and their combined effects on TOPCon solar cells. Besides simulation, we also discuss the practical manufactures of how to control the above mentioned parameters, as well as the problems needed to be solved for further work.", "author_names": [ "Yuheng Zeng", "Tong Hui", "Cheng Quan", "Cai Liang", "Zhenhai Yang", "Kangmin Chen", "Zhi Zhong Yuan", "Chung-Han Wu", "Baojie Yan", "Pingqi Gao", "Jichun Ye" ], "corpus_id": 125359768, "doc_id": "125359768", "n_citations": 31, "n_key_citations": 0, "score": 0, "title": "Theoretical exploration towards high efficiency tunnel oxide passivated carrier selective contacts (TOPCon) solar cells", "venue": "", "year": 2017 }, { "abstract": "High efficiency silicon heterojunction (SHJ) solar cells have already reached more than 26% (Yoshikawa et al. 2017) efficiency when tunnel oxide passivated contacts solar cells just broke the 26% barrier at the beginning of February 2018 (ISFH, 2018) For such devices, major losses occur at both the front and rear contacts where parasitic recombination can be very high. Carrier selective contacts use a special design in order to build a barrier that would block one specific charge carrier and let the other one go through. A Hybrid solar cell is a combination between a heterojunction solar cell and a TOPCon device, featuring then carrier selective contacts at both sides. In this thesis, a p type TOPCon structure is implemented at the rear when the front contact is made of n type amorphous silicon (a Si:H) Intrinsic amorphous silicon (a Si:H) used as front passivation layer, is deposited on top of crystalline silicon and requires an interface with as few defects as possible to minimize the parasitic recombination velocity. A new pretreatment method studied in this thesis involves the growth of a silicon oxide (SiO2) on a crystalline silicon substrate, that will allow to get rid of most of the superficial defects after etching and before a Si:H deposition. Lifetimes of up to 6 ms and saturation current density (J0) as low as 14 fA/cm2 can be reached with a 200 nm thick oxide. As a Si:H presents a very low lateral conductivity, a transparent conductive oxide (TCO) is needed to transport the charge carriers towards the front metal contacts. The resistivity of such a material should be as low as possible. While increasing the deposition temperature of Indium Tin Oxide (ITO) it has been possible to decrease the resistivity up to 2.5 *10 4 O.cm at a temperature of 130degC, without reducing the optical properties of such a layer. Finally, manufacturing defects are often introduced during the fabrication process, leading to some shunt losses (low shunt resistance) As we are fabricating several solar cells per wafer, it is most of the time necessary to cut them to get rid of the shunt before doing the measurements. This sensitive step could be avoided with a better isolation of each solar cell. Patterned ITO and metal have been developed in this thesis, allowing to reduce the shunt power losses in the range of 1 2% without the need to cut the cells.", "author_names": [ "Guillaume le Boucher d'Herouville" ], "corpus_id": 102338659, "doc_id": "102338659", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "High Efficiency SHJ/Poly Si Hybrid Solar Cells", "venue": "", "year": 2018 }, { "abstract": "To improve the conversion efficiency of c Si solar cells, it is crucial to quench the recombination losses at c Si/metal interface. Such recombination losses are able to be reduced by using carrier selective passivating contacts by means of hydrogenated amorphous silicon (a Si:H) and poly crystalline silicon (poly Si)/tunneling silicon oxide (SiOx) In this thesis, a novel hybrid solar cell concept is presented. The novel structure combines the advantages of silicon heterojunction (SHJ) as front surface field (FSF) and poly Si passivating contact as rear emitter. This project aims to improve the passivation quality of FSF composed of intrinsic n type (i/n) a Si:H stacks and evaluate transparent conductive oxide (TCO) layer. Considering FSF optimization, effective cleaning pre treatment has been developed to provide ultra clean surface and prevent cross contamination. Lifetime measurements has shown that three cycles of NAOC improves effective lifetime significantly to 12.6 ms on symmetric structure. Plasma cleaning of chamber and plasma deposition on substrate holder decreases saturation current density (J0) by 10.9 fA/cm2. Comparing to post deposition annealing in air, H2 environment annealing shows more appealing passivation quality which improves effective lifetime to 4.7 ms and reduces J0 to 28.7 fA/cm2 on solar cell precursors. VOC demonstrates improvements for thicker i a Si:H films, but leading to more parasitic absorption losses. This effect results in a trade off between VOC and JSC. Furthermore, thicker i a Si:H layer degrades the carrier transport by means of FF. In terms of TCO optimization, novel hydrogen doped indium oxide (IO:H)/indium tin oxide (ITO) stacks is presented as an attractive alternative to replace conventional single ITO layer. Hall effect measurements have shown that post annealing in vacuum is an effective method to decrease carrier density and increase mobility of IO:H/ITO stacks. Accordingly, the opto electrical properties of IO:H/ITO stacks, single ITO layer and single IO:H layer are compared. 180 degC annealed sample shows optimal performance with high mobility of 117 cm2/(Vs) and low carrier density of 1.07 x 1020 cm 3. Either IO:H/ITO stacks or IO:H single layer shows nearly 4 times higher mobility and half carrier density compared to single ITO film after post deposition annealing. Spectra measurements reveal that the parasitic absorption of IO:H/ITO stacks is lower than that of ITO film over the complete spectral range. Before post deposition annealing, it was observed that TCO sputtering decreases passivation quality, but it is less pronounced for IO:H than ITO deposition. However, after post deposition annealing, passivation degradation is able to be nearly fully recovered for both sputtering: IO:H and ITO.", "author_names": [ "Haonan Ge" ], "corpus_id": 204829722, "doc_id": "204829722", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Development of High Efficiency SHJ/Poly Si Passivating Contact Hybrid Solar Cells", "venue": "", "year": 2017 }, { "abstract": "To improve the conversion efficiency of c Si solar cells, it is crucial to quench the recombination losses at c Si/metal interface. Such recombination losses are able to be reduced by using carrier selective passivating contacts by means of hydrogenated amorphous silicon (a Si:H) and poly crystalline silicon (poly Si)/tunneling silicon oxide (SiOx) In this thesis, a novel hybrid solar cell concept is presented. The novel structure combines the advantages of silicon heterojunction (SHJ) as front surface field (FSF) and poly Si passivating contact as rear emitter. This project aims to improve the passivation quality of FSF composed of intrinsic n type (i/n) a Si:H stacks and evaluate transparent conductive oxide (TCO) layer. Based on aforementioned optimization, the highest conversion efficiency of 20.5% was achieved (VOC 704 mV, JSC 39.5 mA/cm2 and FF 73.8%", "author_names": [ "Haonan Ge" ], "corpus_id": 115402187, "doc_id": "115402187", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Development of High Efficiency SHJ/Poly Si Passivating Contact Hybrid Solar Cells", "venue": "", "year": 2017 }, { "abstract": "This paper presents an analysis of physical mechanisms related to operation and optimization of interdigitated back contact (IBC) poly silicon based devices. Concepts of carrier selectivity and tunneling are used to identify the parameters that impact on the fill factor. Then, based on technology computer aided design (TCAD) numerical simulations, we describe the device performance in terms of transport and passivation. A validation of the model is performed by matching measured and simulated R, T, and external quantum efficiency spectra and electrical parameters. As result of such process, the opto electrical losses of the reference device are identified. Then, we execute a study of the impact of process parameters on the performance of the IBC device under analysis. Assuming a uniform SiO2 layer, simulation results reveal that both n type and p type poly Si contacts can be theoretically perfect (i.e. approx. lossless) if assuming no interface recombination but considering tunneling of both carrier types. In other words, there exists an optimum oxide thickness (1 nm) for which majority carriers tunneling works already very well, and minority tunneling is still low enough to not result in significant recombination. Moreover, SiO2 thickness up to maximum 1.6 nm is crucial to achieve high efficiency. Regarding rear geometry analysis, the efficiency curve as a function of emitter width peaks at 70% of pitch coverage. Further, it is shown that diffused dopants inside crystalline silicon make the device resilient to passivation quality. Finally, the calibrated model is used to perform an optimization study aiming at calculating the performance limit. The estimated performance limit is 27.3% for a 100 mm thick bulk, 20 nm thick poly silicon layers, silver as rear contact, and double ARC.", "author_names": [ "Paul Procel", "Guangtao Yang", "Olindo Isabella", "Miro Zeman" ], "corpus_id": 67871951, "doc_id": "67871951", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Numerical Simulations of IBC Solar Cells Based on Poly Si Carrier Selective Passivating Contacts", "venue": "IEEE Journal of Photovoltaics", "year": 2019 }, { "abstract": "The goal of this thesis is the fabrication of high efficiency interdigitated back contact (IBC) c Si solar cell at low temperature and low cost manufacturing technology. This thesis proposes a new concept and at the same time a simple and elegant fabrication process that has been fully developed and culminated with the fabrication of a \"cold\" IBC solar cell as a proof of concept. To carry out this proposal, we focus our research on the study and application of low temperature processes such as Atomic Layer Deposition (ALD) and Plasma enhanced Chemical Vapor Deposition (PECVD) to deposit dielectric layers. A process based on laser techniques was also developed to be applied on these dielectric layers to form p+ and n+ regions into the c Silicon sample. The laser highly doped regions are formed in a point like structure avoiding the classical high temperature diffusion process. The dielectrics used, Al2O3 and a SiCx (n) stack play the role of aluminum and phosphorous dopant sources respectively. A detailed study has been accomplished to find the best laser parameters and obtain the optimal p+ and n+ junction. At the same time, these layers work as excellent surface passivating films and improves the front and the rear reflectance. To get the film which better fulfills these tasks, an extensive investigation has been performed to optimize the deposition and post deposition processes in terms of temperature, time and layer thickness. In order to fabricate the \"cold\" IBC cell, we firstly developed a IBC cell performed on p type FZ c Si with a conventional phosphorous diffusion. The SiCx(n) stack passivated the n region interface as well as provided phosphorous atoms to create n+ regions or selective emitter structures after laser processing. The aluminium atoms supplied by the Al2O3 layer formed a p+ region or Back surface field (BSF) after the laser processing and simultaneously passivated the p region interface. A promising efficiency of 18.7% (Jsc= 39.1 mA/cm2, Voc= 638 mV, FF= 75.3% was obtained as a result of this new concept. The first \"cold\" IBC cell was obtained after elimination of conventional phosphorous diffusion and rearrangement of the fabrication steps in order to reduce the thermal budget and the complex photolithographic steps. The laser employed is a pulsed Nd YAG lamp pumped working at 1064 nm in nanosecond regime. The efficiency achieved was 18.0% (Jsc 39.2 mA/cm2, Voc= 647mV, FF= 71.1% on 280 micras thick 2.5 Ohmcm n type FZ Si with a designated area of 9 cm2. The final efficciency achieved of the final \"Cold\" IBC cell was 20% (Jsc= 40.5 mA/cm2, Voc 650 mV and FF 76.4% using a pulsed Nd:YVO4 Laser operating at 355 nm (UV) The total fabrication process was carried out at low temperatures (below 400 oC) avoiding the high temperature difussion processes.", "author_names": [ "G Rodriguez" ], "corpus_id": 115810245, "doc_id": "115810245", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Interdigitated back contacted(IBC) c Si solar cells based on laser processed dielectric layers", "venue": "", "year": 2016 }, { "abstract": "Silicon heterojunction technology (HJT) uses silicon thin film deposition techniques to fabricate photovoltaic devices from mono crystalline silicon wafers (c Si) This enables energy conversion efficiencies above 21 also at industrial production level. In this presentation we review the present status of this technology and point out recent trends. We first discuss how the properties of thin hydrogenated amorphous silicon (a Si:H) films can be exploited to fabricate passivating contacts, which is the key to high efficiency HJT solar cells. Such contacts enable very high operating voltages, approaching the theoretical limits, and yield small temperature coefficients. With this approach, an increasing number of groups are reporting devices with conversion efficiencies well over 20 on both sides contacted n type cells, Panasonic leading the field with 24.7 Exciting results have also been obtained on p type wafers. Despite these high voltages, important efficiency gains can still be made in fill factor and optical design. This requires improved understanding of carrier transport across device interfaces and reduced parasitic absorption in HJT solar cells. For the latter, several strategies can be followed: Short wavelength losses can be reduced by replacing the front a Si:H films with wider bandgap window layers, such as silicon alloys or even metal oxides. Long wavelength losses aremore mitigated by introducing new high mobility TCO's such as hydrogenated indium oxide, and also by designing new rear reflectors. Optical shadow losses caused by the front metallization grid are significantly reduced by replacing printed silver electrodes with fine line plated copper contacts, leading also to possible cost advantages. The ultimate approach to minimize optical losses is the implementation of back contacted architectures, which are completely devoid of grid shadow losses and parasitic absorption in the front layers can be minimized irrespective of electrical transport requirements. The validity of this approach was convincingly demonstrated by Panasonic, Japan in 2014, reporting on an interdigitated back contacted HJT cell with an efficiency of 25.6% setting the new single junction c Si record. Finally, given the virtually perfect surface passivation and excellent red response of HJT solar cells, we anticipate these devices will also become the preferred bottom cell in ultra high efficiency c Si based tandem devices, exploiting better the solar spectrum. Such tandem cells have the potential to overcome the fundamental single junction limit of silicon solar cells (29.4% Combining HJT cells with perovskite solar cells as top cell appears to be particularly appealing. less", "author_names": [ "Stefaan De Wolf", "Jonas Geissbuehler", "Philipp Loper", "S Martin de Nicholas", "Johannes Peter Seif", "Andrea Tomasi", "Christophe Ballif" ], "corpus_id": 114369694, "doc_id": "114369694", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "High efficiency silicon heterojunction solar cells: Status and perspectives", "venue": "", "year": 2015 } ]

[ { "abstract": "Abstract Applications of the wide band gap (WBG) semiconductors, such as GaN, AlGaN, and InGaN, range from lighting and ultraviolet (UV) technology to high power, radiation hard, high temperature, terahertz (THz) and sub THz electronics and pyroelectronics. Wurtzite (hexagonal) symmetry makes these materials to be quite different from conventional cubic semiconductors. Spontaneous and piezoelectric polarization associated with the wurtzite crystal structure induces two dimensional electron gases at AlGaN/GaN, AlInN/GaN, and AlGaN/InGaN interfaces with sheet concentrations 10 20 times higher than those in Si CMOS. A high current carrying capability and a high breakdown field make these materials perfect for high power applications. Adjusting the energy gaps of AlxGa1 xN and of InxGa1 xN by varying the molar fraction changes the wavelength of light they emit or absorb and enables light and UV emitters, solar cells, and photodetectors operating from THz and infrared to deep UV range. Blue, green, and white LEDs using InGaN revolutionized smart solid state lighting. AlGaN UV LEDs are used for water purification, fighting antibiotic resistant bacteria and viruses, and dramatically increasing produce storage time. InN, ZnO, and BN have potential to compete with the AlN/GaN family. Diamond has re emerged not only as a substrate for a record heat removal but also as a viable THz detector material. The WBG technology has many difficult problems to solve. High dislocation density in the WBG materials leads to a low efficiency of deep AlGaN UV LEDs and reliability problems of high power devices. Non uniformities of the electric field distribution cause a premature breakdown. Using ultrathin WBG quantum well layers and nanowires and exploring radically new physics based device designs might alleviate or even solve these problems.", "author_names": [ "Michael S Shur" ], "corpus_id": 107644023, "doc_id": "107644023", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "Wide band gap semiconductor technology: State of the art", "venue": "Solid State Electronics", "year": 2019 }, { "abstract": "The international technology roadmap of semiconductors (ITRS) is approaching the historical end point and we observe that the semiconductor industry is driving complementary metal oxide semiconductor (CMOS) further towards unknown zones. Today's transistors with 3D structure and integrated advanced strain engineering differ radically from the original planar 2D ones due to the scaling down of the gate and source/drain regions according to Moore's law. This article presents a review of new architectures, simulation methods, and process technology for nano scale transistors on the approach to the end of ITRS technology. The discussions cover innovative methods, challenges and difficulties in device processing, as well as new metrology techniques that may appear in the near future.", "author_names": [ "Henry H Radamson", "Huilong Zhu", "Zhenhua Wu", "Xiaobin He", "Hongxiao Lin", "Jinbiao Liu", "Jinjuan Xiang", "Zhenzhen Kong", "Wenjuan Xiong", "Junjie Li", "Hushan Cui", "Jian-feng Gao", "Hong Yang", "Yong Du", "Buqing Xu", "Ben Li", "Xuewei Zhao", "Jiahan Yu", "Yan Dong", "Guilei Wang" ], "corpus_id": 221126630, "doc_id": "221126630", "n_citations": 29, "n_key_citations": 0, "score": 1, "title": "State of the Art and Future Perspectives in Advanced CMOS Technology", "venue": "Nanomaterials", "year": 2020 }, { "abstract": "The power density limits of complementary metal oxide semiconductor (CMOS) technology could be overcome by moving from a binary to a ternary logic system. However, ternary devices are typically based on multi threshold voltage schemes, which make the development of power scalable and mass producible ternary device platforms challenging. Here we report a wafer scale and energy efficient ternary CMOS technology. Our approach is based on a single threshold voltage and relies on a third voltage state created using an off state constant current that originates from quantum mechanical band to band tunnelling. This constant current can be scaled down to a sub picoampere level under a low applied voltage of 0.5 V. Analysis of a ternary CMOS inverter illustrates the variation tolerance of the third intermediate output voltage state, and its symmetric in out voltage transfer characteristics allow integrated circuits with ternary logic and memory latch cell functions to be demonstrated. Quantum mechanical band to band tunnelling can be used to create an energy efficient ternary logic technology that can be fabricated on the wafer scale using complementary metal oxide semiconductor (CMOS) processes.", "author_names": [ "Jae Won Jeong", "Young Eun Choi", "Woo Seok Kim", "Jee-Ho Park", "Sunmean Kim", "Sunhae Shin", "Kyuho Lee", "Jiwon Chang", "Seong-Jin Kim", "Kyung Rok Kim" ], "corpus_id": 199187261, "doc_id": "199187261", "n_citations": 22, "n_key_citations": 2, "score": 0, "title": "Tunnelling based ternary metal oxide semiconductor technology", "venue": "Nature Electronics", "year": 2019 }, { "abstract": "This paper presents a systematized review of the research on the production of nanosecond high power pulses using solid state generators based on an inductive energy store and a semiconductor opening switch that have been performed in the past 25 years. This research has been underway since 1992 1993 when the nanosecond cutoff of ultrahigh density currents in semiconductor diodes was discovered and named the SOS (Semiconductor Opening Switch) effect. The discovery of the SOS effect provided a breakthrough in the development of semiconductor generators, as their most important characteristics, such as pulse power and output voltage, were increased tens and hundreds of times compared with previously known semiconductor generators. In particular, in the nanosecond semiconductor technology, megavolt voltages combined with gigawatt peak powers have been achieved. This review considers the main physical processes that determine the mechanism of operation of a SOS based on the SOS effect. The principle of operation, design, and characteristics of SOS diodes and SOS generators is described, and prospects for their further development are discussed. Examples are given of using SOS generators in various pulsed power applications such as electron accelerators, X ray pulse devices, high power microwave electronics, pumping of gas lasers, and ignition of electrical discharges.", "author_names": [ "Sergei N Rukin" ], "corpus_id": 211023605, "doc_id": "211023605", "n_citations": 17, "n_key_citations": 1, "score": 0, "title": "Pulsed power technology based on semiconductor opening switches: A review.", "venue": "The Review of scientific instruments", "year": 2020 }, { "abstract": "A new time domain wideband numerical model for simulation of quantum dot reflective semiconductor optical amplifier (QD RSOA) steady state and dynamic behavior, is described. The model is used to investigate 1 ps full width at half maximum input Gaussian pulse amplification and also modulation cancellation. A large modulation cancellation dynamic range of about 35 dB, is predicted for high input powers, which is not attainable in bulk and QW RSOAs. The model can be applied to traveling wave and reflective QD SOAs. The combination of the unique features of quantum dots and a reflective structure can be used to realize a colorless modulator for wavelength division multiplexed passive optical networks (WDM PONs)", "author_names": [ "Khalil Safari Anzabi", "Amir Habibzadeh-Sharif", "Michael J Connelly", "Ali Rostami" ], "corpus_id": 209985489, "doc_id": "209985489", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Wideband Steady State and Pulse Propagation Modeling of a Reflective Quantum Dot Semiconductor Optical Amplifier", "venue": "Journal of Lightwave Technology", "year": 2020 }, { "abstract": "The International Technology Roadmap for Semiconductors (ITRS) has roadmapped technology requirements of the semiconductor industry over the past two decades. The roadmap identifies major challenges in advanced technology and leads the investment of research in a cost effective way. Traditionally, the ITRS identifies major semiconductor IC products as drivers; these set requirements for the state of the art semiconductor technologies. High performance microprocessor unit (MPU HP) for servers and consumer portable system on chip (SOC CP) for smartphones are two examples. Throughout the history of the ITRS, Moore's Law has been the main impetus for these drivers, continuously pushing the transistor density to scale at a rate of 2x per technology generation (aka \"node\" However, as new requirements from applications such as data center, mobility, and context aware computing emerge, the existing roadmapping methodology is unable to capture the entire evolution of the current semiconductor industry. Today, comprehending how key markets and applications drive the process, design and integration technology roadmap requires new system level studies along with chip level studies. In this paper, we extend the current ITRS roadmapping process with studies of key requirements from a system level perspective, based on multiple generations of smartphones and microservers. We describe potential new system drivers and new metrics, and we refer to the new system level framing of the roadmap as ITRS 2.0.", "author_names": [ "Juan Antonio Carballo", "Wei-Ting Jonas Chan", "Paolo A Gargini", "Andrew B Kahng", "Siddhartha Nath" ], "corpus_id": 3221445, "doc_id": "3221445", "n_citations": 65, "n_key_citations": 3, "score": 0, "title": "ITRS 2.0: Toward a re framing of the Semiconductor Technology Roadmap", "venue": "2014 IEEE 32nd International Conference on Computer Design (ICCD)", "year": 2014 }, { "abstract": "The Planar Technology. Solid State Technology. Vapor Phase Growth. Thermal Oxidation. Solid State Diffusion. Semiconductors and Semiconductor Devices. Elements of Semiconductor Physics. Semiconductors under Non Equilibrium Conditions. p n Junction. Junction Transistor. Junction Field Effect Transistors. Surface Effects and Surface Controlled Devices. Theory of Semiconductor Surfaces. Surface Effects on p n Junctions. Surface Field Effect Transistors. Properties of the Silicon Silicon Dioxide System.", "author_names": [ "Andrew S Grove" ], "corpus_id": 108892408, "doc_id": "108892408", "n_citations": 2260, "n_key_citations": 51, "score": 0, "title": "Physics and Technology of Semiconductor Devices", "venue": "", "year": 1967 }, { "abstract": "This volume is a collection of papers presented at the 10th International Autumn Meeting on \"Gettering and Defect Engineering in Semiconductor Technology GADEST 2003\" which took place from the 21st to the 26th of September 2003 at the Seehotel Zeuthen, in the state of Brandenburg, Germany. It provided a forum for interactions between scientists and engineers engaged in the field of semiconductor defect physics, materials science and technology, to reflect upon aspects of the coming era of conversion from micro electronics to nano electronics. In addition, a particular ambition was to strengthen the interactions and exchanges between communities working in the fields of crystalline silicon for electronics and photovoltaics.", "author_names": [ "H W Richter", "Martin Kittler" ], "corpus_id": 106678625, "doc_id": "106678625", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Gettering and defect engineering in semiconductor technology GADEST 2003 proceedings of the 10th International Autumn Meeting, Seehotel Zeuthen (suburb of Berlin) State of Brandenburg, Germany, September 21 26, 2003", "venue": "", "year": 2004 }, { "abstract": "Abstract The electrical detection of DNA methylation based biomarkers using semiconductor technology shows great promise for early cancer screening. Presented is the very first proof of concept example of using CMOS based technology for real time DNA methylation detection using Ion Sensitive Field Effect Transistors (ISFETs) An electrochemical label free approach was applied in two gene assays, each one of which incorporated the sequences of DAPK 1 and CDKN 2 A p 16 INK 4 p 16) gene promoters at a both methylated and unmethylated state, performing isothermal methylation specific amplification and detection both in tube and on chip (real time) Good discrimination was shown between the two states, achieving a very good average pH signal change for the methylated state of 1.91 for DAPK 1 assay and of 1.58 for p 16 assay in the tube test. The real time on chip test showed similarly good real time differential signal change in favour of methylated DNA, reaching 37 mV for DAPK 1 assay and 23 mV for p 16 assay, validating the results from the proof of concept test of pH LAMP in tube while confirming the sensitivity of real time methylation specific pH LAMP on chip.", "author_names": [ "Melpomeni Kalofonou", "Christofer Toumazou" ], "corpus_id": 93830973, "doc_id": "93830973", "n_citations": 32, "n_key_citations": 1, "score": 0, "title": "Semiconductor technology for early detection of DNA methylation for cancer: From concept to practice", "venue": "", "year": 2013 }, { "abstract": "An outstanding goal in quantum optics and scalable photonic quantum technology is to develop a source that each time emits one and only one entangled photon pair with simultaneously high entanglement fidelity, extraction efficiency, and photon indistinguishability. By coherent two photon excitation of a single InGaAs quantum dot coupled to a circular Bragg grating bull's eye cavity with a broadband high Purcell factor of up to 11.3, we generate entangled photon pairs with a state fidelity of 0.90(1) pair generation rate of 0.59(1) pair extraction efficiency of 0.62(6) and photon indistinguishability of 0.90(1) simultaneously. Our work will open up many applications in high efficiency multiphoton experiments and solid state quantum repeaters.", "author_names": [ "Hui Wang", "Hai Hu", "T H Chung", "Jian Qin", "Xiaoxia Yang", "J-P Li", "R-Z Liu", "Han-Sen Zhong", "Y -M He", "Xing Ding", "Y -H Deng", "Qing Dai", "Yongheng Huo", "Sven Hofling", "Chao-Yang Lu", "Jian-Wei Pan" ], "corpus_id": 84836268, "doc_id": "84836268", "n_citations": 109, "n_key_citations": 2, "score": 0, "title": "On Demand Semiconductor Source of Entangled Photons Which Simultaneously Has High Fidelity, Efficiency, and Indistinguishability.", "venue": "Physical review letters", "year": 2019 } ]

[ { "abstract": "Phosphorene, a monolayer of black phosphorus, is promising for nanoelectronic applications not only because it is a natural p type semiconductor but also because it possesses a layer number dependent direct bandgap (in the range of 0.3 to 1.5 eV) On basis of the density functional theory calculations, we investigate electronic properties of the bilayer phosphorene with different stacking orders. We find that the direct bandgap of the bilayers can vary from 0.78 to 1.04 eV with three different stacking orders. In addition, a vertical electric field can further reduce the bandgap to 0.56 eV (at the field strength 0.5 V/A) More importantly, we find that when a monolayer of MoS2 is superimposed with the p type AA or AB stacked bilayer phosphorene, the combined trilayer can be an effective solar cell material with type II heterojunction alignment. The power conversion efficiency is predicted to be ~18 or 16% with AA or AB stacked bilayer phosphorene, higher than reported efficiencies of the state of the art trilayer graphene/transition metal dichalcogenide solar cells.", "author_names": [ "Jun Dai", "Xiao Cheng Zeng" ], "corpus_id": 18465799, "doc_id": "18465799", "n_citations": 610, "n_key_citations": 3, "score": 1, "title": "Bilayer Phosphorene: Effect of Stacking Order on Bandgap and Its Potential Applications in Thin Film Solar Cells.", "venue": "The journal of physical chemistry letters", "year": 2014 }, { "abstract": "Already, several technologies of polycrystalline thin film photovoltaic materials have achieved certified record small cell power conversion efficiencies exceeding 22% They are CdTe, Cu(In,Ga)(S,Se)2 (CIGS) and metal halide perovskite (PSC) each named after the light absorbing semiconductor material. Thin film solar cells and modules require very little active material due to their very high absorption coefficient. Efficient production methods with low materials waste, moderate temperatures, attractive cost structures, and favorable energy payback times will play a strong role in market development as thin film technologies reach full maturity, including mass production and the standardization of production machineries. In fact, the first two technologies have already been developed up to the industrial scale with a market share of several GW. In this review article, we outline similarities and differences between these high efficiency thin film technologies from both the materials and the industrial point of view. We address the materials characteristics and device concepts for each technology, including a description of recent developments that have led to very high efficiency achievements. We provide an overview of the CIGS industry players and their current status. The newcomer PSC has demonstrated its potential in the laboratory, and initial efforts in industrial production are underway. A large number of laboratories are experimenting through a wide range of options in order to optimize not only the efficiency but also stability, environmental aspects, and manufacturability of PSC. Its high efficiency and its high bandgap make PSC particularly attractive for tandem applications. An overview of all these topics is included here along with a list of materials configurations.", "author_names": [ "Michael Powalla", "Stefan Paetel", "Erik Ahlswede", "Roland Wuerz", "Cordula D Wessendorf", "Theresa Magorian Friedlmeier" ], "corpus_id": 139533600, "doc_id": "139533600", "n_citations": 76, "n_key_citations": 2, "score": 0, "title": "Thin film solar cells exceeding 22% solar cell efficiency: An overview on CdTe Cu(In,Ga)Se2 and perovskite based materials", "venue": "", "year": 2018 }, { "abstract": "Abstract Silicon nitride (SixNy) and silicon oxynitride (SiOxNy) are materials that can find multifarious application in solar cells by tuning their microstructure and optical properties. In this work we have investigated a series of SixNy and SiOxNy films deposited by rf PECVD at a low temperature of 200 degC having different compositional and optical properties by changing the gas mixture ratio during deposition resulting in varying refractive index materials. The effect of varying gas ratio on the composition of these materials has been investigated comprehensively by X ray Photoelectron Spectroscopy (XPS) and the bond analysis using Fourier Transform Infrared Spectroscopy (FTIR) thereby creating a material library to select materials of desired properties and bond composition for specific applications in solar cells. The structural and optical properties were also analysed using Micro Raman spectroscopy, X ray Diffraction (XRD) UV VIS NIR spectrophotometer and ellipsometry. The films were found to be amorphous, hydrogenated, compact, presents high deposition rates and needs lesser thermal budget. In order to demonstrate their multifaceted application potential, we have fabricated multilayer anti reflection coatings (ARC) novel Rugate ARC, dielectric Bragg mirrors using SiOxNy/SixNy multi layers as back reflectors for thin crystalline silicon (c Si) wafers as well as the passivation of c Si. The novel bilayer passivation stack over CZ p type c Si wafers using SiOxNy/SixNy presented a minority carrier lifetime of 169 ms with an implied Voc of 673 mV.", "author_names": [ "Anishkumar Soman", "Aldrin Antony" ], "corpus_id": 100079584, "doc_id": "100079584", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "Broad range refractive index engineering of SixNy and SiOxNy thin films and exploring their potential applications in crystalline silicon solar cells", "venue": "", "year": 2017 }, { "abstract": "Abstract Semi transparent solar cells have been well developed in recent years, and can potentially be applied in many areas. Sb2Se3 has also received an increasing amount of attention because of its excellent optoelectronic properties. In order to combine these advantages, we attempted to fabricate a semi transparent thin film Sb2Se3 solar cell which meanwhile maintains the high efficiency. The effect of thickness of Sb2Se3 thin film on the optical and electrical properties were investigated. The optical absorption and power conversion efficiency were improved for Sb2Se3 thin film solar cells as the increase of the thickness of Sb2Se3 thin film, however, the obtained 120 nm thick Sb2Se3 film was completely opaque. The optimized device was achieved with the thickness of 80 nm which exhibits the semi transparent property and almost the same efficiency as the 120 nm Sb2Se3 thin film solar cell. This work demonstrates that the fabricated device has potential for applications in small wearable devices and may be extended to large area glass face applications.", "author_names": [ "Zhiwen Chen", "Xiaohai Guo", "Huafei Guo", "Changhao Ma", "J H Qiu", "Ningyi Yuan", "Jianning Ding" ], "corpus_id": 139595453, "doc_id": "139595453", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Fabrication of a semi transparent thin film Sb2Se3 solar cell", "venue": "Materials Letters", "year": 2019 }, { "abstract": "Abstract Cu2ZnSn(S,Se)4 (CZTSSe) has gained significant attention as a solar cell absorber material owing to its great long time application potential. In this study, the precursors deposited by single quaternary target sputtering were annealed in different S/S Se ratios atmosphere and CZTSSe solar cells were prepared. The mechanism of the S/Se replacement process and its effect on the composition, morphology, bandgap, and performance of the CZTSSe solar cells were systematically investigated. It was found that a decrease in the Se content in the annealing atmosphere showed an effect on the growth and properties of the thin films similar to that shown by an increase in the S/(S Se) ratio. However, this effect was much milder than that of the increase in the S/(S Se) ratio. The S/(S Se) ratio of the CZTSSe thin films could be controlled by varying their S and Se contents in the annealing atmosphere and then adjusting their bandgaps. An increase in the bandgap improved the open circuit voltage and efficiency of the resulting solar cells. The cell annealed with the S:Se molar ratio of 1:3 showed an efficiency of 8.41% without anti reflection coating.", "author_names": [ "Chunhong Zeng", "Yunfeng Liang", "Longlong Zeng", "Linquan Zhang", "Jian Zhou", "Ruijiang Hong" ], "corpus_id": 203140761, "doc_id": "203140761", "n_citations": 3, "n_key_citations": 1, "score": 0, "title": "Effect of S/(S+Se) ratio during the annealing process on the performance of Cu2ZnSn(S,Se)4 solar cells prepared by sputtering from a quaternary target", "venue": "", "year": 2019 }, { "abstract": "Abstract Increasing global energy consumption together with environmental concerns has led to much interest in alternative, cleaner sources of energy such as solar photovoltaic. Researchers in the solar cell community have been looking for ways to reduce costs while maintaining or increasing already high efficiencies. A fundamental understanding of the materials under consideration is essential to rapid development of new technologies. The I III VI2 thin films offer promising systems for achieving high efficiency solar cells at lower costs. In fact, by tailoring the chemistry of the compounds it is possible to change the bandgap of the material in order to collect sunlight more efficiently. First of all, this thesis focuses on absorber layer material preparation and characterization, especially nanocrystalline thin films and consideration of both structural and electrical characteristics of such main cell absorber layer.The thesis examines how different preparation techniques and material usage could affect the properties of the synthesized thin films (absorber layer) In this study CuInSe2 and CuInS2 thin films were deposited onto ITO glass substrate using the electrodeposition technique in aqueous solution. The electrodeposited films were characterized by X ray diffraction (XRD) scanning electron microscopy (SEM) and energy dispersive X ray analysis (EDS) The annealing effects on the electrodeposited precursors were investigated. The chalcopyrite structure of CuInSe2/CuInS2 showed an enhancement of crystallinity after subsequent selenization/sulfurization treatment in Se/S atmosphere, respectively. XRD and SEM studies revealed a dramatic improvement of the crystalline quality of CIS films after annealing treatments. The optical properties of annealed CuInSe2 Se and CuInSe2 S thin films have been studied in order to determine the effect of annealing process in different selenium and sulfur atmosphere. In the second step we modified copper indium CuInxCryGa1 x ySe2 where x=0.4, y= (0.0, 0.1, 0.2, 0.3)superstrate layer by spin coating process. CuInxCryGa1 x ySe2 where x=0.4, y= (0.0, 0.1, 0.2, 0.3) nanoparticles have been synthesized firstly using a wet chemical hydrothermal method that is based on a non vacuum thermal process without any additional selenization process. Introducing different metal sources in an autoclave with ethylenediamine as solvent, CIGS nanoparticles were obtained at different temperatures range 190 230degC. The X ray diffraction (XRD) results confirmed the formation of a tetragonal CuInxCryGa1 x ySe2 chalcopyrite structure. Finally, we turned again to the study of the annealing temperature effect onKesterite materials but this time in those of very low cost materials and environmentally friendly Cu2ZnSnS4. We studied the growth of quaternary Cu2ZnSnS4 (CZTS) kesterite thin films by a single step electrochemical deposition followed by annealing at low temperature. The influence of different annealing atmospheres at constant annealing times (t 45 min) and fixed preparation controlling parameters; i.e. starting materials (precursor metal salts) solution concentration, time of deposition and electrodeposition potential. Structural, compositional, morphological, and optical properties, as well as photoelectrochemical properties were studied.", "author_names": [ "Suzan Saber" ], "corpus_id": 104341896, "doc_id": "104341896", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Synthesis and characterization of some nano selenides and their applications in solar cells.", "venue": "", "year": 2018 }, { "abstract": "Abstract Since the absorption spectrum of CuO is well matched with the spectrum of the sunlight, it is considered to have potential applications in some optoelectronic devices such as solar cells etc. In order to obtain better performance of CuO based devices, it is necessary to deeply understand the effect of structural parameters of thin films such as thickness on the physical properties of CuO thin films. In this study, the CuO thin films with different thicknesses were prepared by a facile sol gel method. The structural, morphological, compositional and optical properties of the samples were analyzed by X ray diffraction (XRD) scanning electron microscopy (SEM) X ray photoelectron spectroscopy (XPS) UV vis absorption spectra and photoluminescence, respectively. The results show that all samples have a cubic structure regardless of film thickness. However, the photoluminescence behavior that strongly depends on the film thickness is found. When the film thickness is thin, CuO films show a strong violet, green and red co emission. However, as the thickness increases, the fluorescence of the CuO films is rapidly quenched. It is proposed that the photoluminescence behavior of CuO thin films is closely related to the change of optical bandgap caused by the variation of crystallite size and we gave a tentative explanation for the luminescence changes.", "author_names": [ "Linhua Xu", "Gaige Zheng", "Shi-xin Pei", "Junfeng Wang" ], "corpus_id": 125856400, "doc_id": "125856400", "n_citations": 35, "n_key_citations": 0, "score": 0, "title": "Investigation of optical bandgap variation and photoluminescence behavior in nanocrystalline CuO thin films", "venue": "", "year": 2018 }, { "abstract": "The work presented in this thesis focuses on the investigation and improvement of the window stack of layers for thin film CdTe solar cells fabricated in the Center for Renewable Energy Systems Technology (CREST) laboratories. In particular the aim was to change the standard structure including TCO, high resistive transparent (HRT)layer and CdS which is limited by the low transparency of the CdS layer, to a better performing one. The first result chapter of the thesis describes the study of ZnO HRT layers. ZnO thin films were deposited by radio frequency (RF) magnetron sputtering with different structural, optical and electrical properties which were characterized by X ray diffraction, electron microscopy, spectrophotometry, Hall Effect method and 4 point probe. ZnO films were then incorporated in CdTe solar cells with the structure: FTO/ZnO/CdS/CdTe/Au back contact and the performance of these devices were compared with the film properties to single out trends and identify optimal film characteristics. By varying the deposition pressure of ZnO films, it was possible to increase their transparency and significantly increase their resistivity. While better transparency positively affected the solar cell current density output and efficiency, the resistivity of ZnO films did not show any clear impact on device efficiency. By increasing the deposition temperature the ZnO film grain size was increased. Increased FF was observed in devices incorporating ZnO layers with bigger grains, although this gain was partially counterbalanced by the Voc degradation, leading to a limited efficiency improvement. Finally the addition of oxygen had the main effect of increasing the resistivity of ZnO films, similarly to what happened with the increase of the sputtering pressure. In this case however, an improvement of FF, Jsc and efficiency was observed, especially at an O2/Ar ratio of 1% By simulating the solar cells behavior with SCAPS 1D, it was found that these performance change can be explained by the variation of interface properties, precisely the amount of interface defects, rather than by bulk properties. The study presented in the second result chapter focuses on magnesium doped zinc oxide (MZO) and the variation of its energy band structure. MZO was initially used as the HRT layer within a solar cell structure: FTO/MZO/CdS/CdTe/Au back contact. Sputtering MZO films with a target containing MgO 11 weight% and ZnO 89 weight% allowed for and increased band gap from 3.3 eV of intrinsic ZnO to 3.65 eV for MZO deposited at room temperature. Increasing the superstrate deposition temperature allowed for a further band gap increase up to 3.95 eV at 400 degC due mainly to an conduction band minimum upward shift. It was highlighted the importance to create a positive conduction band offset with the MZO layer conduction band slightly above the CdS conduction band, with an optimum found in this case to be 0.3 eV (efficiency 10.6 By creating a positive conduction band offset all the performance parameters (Voc, FF, Jsc, efficiency) significantly increased. One of the reasons for this improvement was found to be a diminished interface recombination due to a more ideal MZO/CdS band alignment. In the second part of this investigation the MZO was used as a replacement for the CdS in a simplified structure: FTO/MZO/CdTe/Au back contact. The concepts used to optimise the performance of these devices also involved tuning the conduction band alignment between MZO/CdTe and efficiencies of 12.5 were achieved with a at conduction band offset. The efficiency increase was achieved mainly thanks to a better transparency of the MZO layer and a higher Jsc output, compared to devices using a CdS buffer layer. The MZO buffers have been tested in combination with different TCOs. Results are presented in the third result chapter and showed that AZO is a good alternative to FTO working effectively in combination with MZO. AZO/MZO efficiency thin film CdTe solar cells (12.6% compared to 12.5% with FTO) It was found that increasing the IR transparency of the TCOs leads to a potentially higher Jsc. Achieving a better transparency was obtained by using TCOs with high mobility and lower carrier concentration (AZO and ITiO) and also by using a boro aluminosilicate glass with low iron content. ITiO yielded the best opto electrical properties among all the TCO materials. Devices incorporating ITiO however, showed lower performance then those using FTO and AZO. ITO/MZO windows also yielded poor performance. In addition, the ITO films deposited had a high carrier concentration leading to a high NIR absorption by plasma resonance and resulted not ideal for application in thin film CdTe PV.", "author_names": [ "Francesco Bittau" ], "corpus_id": 139409868, "doc_id": "139409868", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Analysis and optimisation of window layers for thin film CDTE solar cells", "venue": "", "year": 2017 }, { "abstract": "An improved technique for synthesis of Cu(In,Al)Se2 is demonstrated, associated with sequential electrodeposition of a stacked layer in the order of Cu/Al/In followed by annealing in selenium vapor. Many advantages such as adjustable constitutes composition, good polycrystalline structure, pure chalcopyrite phase, uniform and compact surface morphology are obtained compared to the film fabricated by conventional electrodeposition process. The film thickness and the concentration of each metal deposited were controlled by the flexibility parameters of deposition time. The influence of Al content on the crystal structure, surface morphology, photoelectrochemical performance, optical and electronic properties of the films were investigated. The crystal size decrease and the energy bandgap of Cu(In,Al)Se2 thin film increase gradually with the increasing Al were revealed. Impedance potential test reveals the manufactured Cu(In,Al)Se2 thin films are all p type semiconductor and the carrier concentration increases with the Cu/(Al In) and Al/(In Al) ratio. Photoelectrochemical investigation of Cu(In,Al)Se2 films verified that a higher photocurrent was obtained with a relative lower Al content due to a narrower bandgap leading to lower energy photon absorption and a lower carrier density and a larger grain size both benefitting the transfer of photogenerated carriers and decrease the recombination of charge carriers. The obtained optimum Cu(In,Al)Se2 thin film based solar cell has been theoretical modeling and simulated. A high PCE of 17.08% was gained implying its potential application in photovoltaic devices.", "author_names": [ "Jiahui Luo", "Jie Jiang", "Yaguang Shi", "Jie Yi", "Sui Yang", "Rui Shan", "Hongxing Li", "Jianxin Zhong" ], "corpus_id": 213501861, "doc_id": "213501861", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Cu(In,Al)Se2Photovoltaic Thin Film Solar Cell from Electrodeposited Stacked Metallic Layers", "venue": "", "year": 2020 }, { "abstract": "To thoroughly disclose the role of siloxane terminated side chain with different substituent positions, three difluorobenzotriazole dithienylbenzodithiophene (FTAZ BDTT) based polymers PBZ 1Si, PBZ 2Si and PBZ 3Si with the siloxane terminated side chain on the FTAZ unit (PBZ 1Si) on the BDTT unit (PBZ 2Si) and both on BDTT and FTAZ unit (PBZ 3Si) respectively, were synthesized. The different side chain substitutions have slight influences on absorption behavior, thermal stability, and frontier molecular orbitals, but showing great effect on the aggregation of the polymers. Grazing incidence wide angle X ray scattering (GIWAXS) measurements reveal that, relative to PBZ 1Si with branched alkyl on the BDTT unit, polymers PBZ 2Si and PBZ 3Si, bearing the siloxane terminated side chains on the BDTT unit, exhibit smaller p p stacking distances and larger crystal coherence lengths (CL) suggesting that adopting the siloxane terminated side chain on the BDTT unit can promote the interchain p p interaction and the ordering of molecular packing. With IT M as the non fullerene acceptor, among the three polymers, the PBZ 2Si based active layer possesses the highest ordered crystals for both polymer and IT M as well as the purest domain, which affords efficient exciton dissociation, the most balanced hole electron transport, and reduced recombination, leading to the highest short circuit current density (Jsc) and fill factor (FF) and then the highest power conversion efficiency (PCE) of 11.14% In contrast, PBZ 1Si and PBZ 3Si based devices show lower PCEs of 8.98% and 9.92% respectively. Moreover, PBZ 2Si:IT M also exhibits good thickness tolerance and its thick active layer of 240 nm shows the most limited decreasing of efficiency after a storage for 77 days, supplying good potential for mass farbication. Our work suggests that the fine pairing of a siloxane terminated side chain and an alkyl side chain is benifical for the opitmizing of a conjugated polymer donor towards high performance non fullerene polymer solar cells.", "author_names": [ "Haiying Jiang", "Feilong Pan", "Lianjie Zhang", "Xiaobo Zhou", "Zhen Wang", "Yao Nian", "Cang Liu", "Wei Tang", "Qiao Ma", "Z -H Ni", "Mingjun Chen", "Wei Ma", "Yong Cao", "Junwu Chen" ], "corpus_id": 198193154, "doc_id": "198193154", "n_citations": 16, "n_key_citations": 0, "score": 0, "title": "Impact of Siloxane Terminated Side Chain on Photovoltaic Performances of Dithienylbenzodithiophene Difluorobenzotriazole Based Wide Bandgap Polymer Donor in Non fullerene Polymer Solar Cells.", "venue": "ACS applied materials interfaces", "year": 2019 } ]

[ { "abstract": "We propose that a half semiconducting state can exist in trigonal prismatic transition metal dichalcogenide (TMDC) monolayers of d${1} configuration. In that state both electrons and holes are spin polarized and share the same spin channel. On the basis of hybrid density functional theory, we predict in particular that VS$_2$ monolayers are half semiconductors with a direct band gap. Moreover, we find that the conduction electron spin orientation of VS$_2$ switches under moderate strain. Our predictions thus open up intriguing possibilities for applications of VS$_2$ in spintronics and optoelectronics. Our analysis of trigonal prismatic group V MX$_2$ (M=V, Nb, Ta; X=S, Se, Te) monolayers reveals a broad diversity of electronic states that can be understood qualitatively in terms of localization of $d$ electrons.", "author_names": [ "Peng-Ru Huang", "Yao He", "Hridis Kumar Pal", "M Kindermann" ], "corpus_id": 119180649, "doc_id": "119180649", "n_citations": 4, "n_key_citations": 0, "score": 1, "title": "Prediction of switchable half semiconductor in d${1} transition metal dichalcogenide monolayers", "venue": "", "year": 2015 }, { "abstract": "Vasiliy D. Buchelnikov, Vladimir V. Sokolovskiy, Olga N. Miroshkina, Danil R. Baigutlin, Mikhail A. Zagrebin, Bernardo Barbiellini, and Erkki Lahderanta Faculty of Physics, Chelyabinsk State University, 454001 Chelyabinsk, Russia National University of Science and Technology \"MISiS\" 119049 Moscow, Russia Department of Physics, School of Engineering Science, LUT University, FI 53850 Lappeenranta, Finland Faculty of Physics and Center for Nanointegration Duisburg Essen (CENIDE) University of Duisburg Essen, 47048 Duisburg, Germany National Research South Ural State University, 454080 Chelyabinsk, Russia and Physics Department, Northeastern University, Boston, Massachusetts 02115, USA (Dated: February 16, 2021)", "author_names": [ "Vasiliy D Buchelnikov", "Vladimir V Sokolovskiy", "Olga N Miroshkina", "Danil R Baigutlin", "Mikhail A Zagrebin", "Bernardo Barbiellini", "Erkki Lahderanta" ], "corpus_id": 231924621, "doc_id": "231924621", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Prediction of a Heusler alloy with switchable metal to half metal behavior", "venue": "", "year": 2021 }, { "abstract": "In this paper a polarization independent wavelength switchable flat top fiber comb filter is newly proposed, which is based on a Solc type birefringence combination and polarization diversity loop configuration. The proposed filter consists of a polarization beam splitter, two concatenated polarization maintaining fibers, and two half wave plates. Our theoretical analysis shows that the proposed apparatus has a much flatter passband and sharper notch than the conventional Sagnac birefringence filter. Particularly, by interchanging the Solc type birefringence combination within the filter between the folded and fan designs, channel wavelength switching operation, more specifically channel interleaving operation, can be achieved through the proper adjustment of the half wave plates contained within the apparatus. Theoretical prediction was verified by experimental demonstration.", "author_names": [ "Yong Wook Lee", "Hyun-tak Kim", "Jaehoon Jung", "Byoungho Lee" ], "corpus_id": 19175943, "doc_id": "19175943", "n_citations": 42, "n_key_citations": 1, "score": 0, "title": "Wavelength switchable flat top fiber comb filter based on a Solc type birefringence combination.", "venue": "Optics express", "year": 2005 }, { "abstract": "INTRODUCTION Hemophilia A is a genetic bleeding disorder resulting from a lack of clotting factor VIII. Where extended half life products are available, people with hemophilia may stop their current drug regimen and switch to a EHL product providing a more convenient dosing regimen. While most factor VIII concentrate regimens are started prophylactically based on international units per weight, this \"one size fits all\" approach does not account for the large pharmacokinetic variability between individuals. AIMS We explored methods to predict individual PK of an EHL product by using population pharmacokinetic models and eta values (e) a value that quantifies how individuals deviate from a population for any PK parameter, derived from a prior product. In addition, we wanted to investigate which individuals would benefit from this method compared to using a PopPK model alone. METHODS PK data from subjects (n 39) who have taken both Adynovate and Eloctate was collected from clinical trial data and from the Web Accessible Population Pharmacokinetic Service Hemophilia (WAPPS Hemo) database. In addition, PK data from subjects (n 200) who switched from a standard half life product to Eloctate was also extracted from the WAPPS Hemo database. Two methods to estimate individual PK outcomes of the second product were compared. The PopPK method used the Eloctate PopPK model published from WAPPS Hemo, while the e method incorporated individually scaled e from the prior product's PopPK model. Both methods were assessed for its performance in predicting PK outcomes. Absolute percent differences were calculated between the predicted and observed PK outcomes. Infusions were parsed into subgroups based on number of samples and individual e percentiles for analysis. RESULTS For the three switching protocols (Adynovate to Eloctate, Eloctate to Adynovate, and SHL FVIII to Eloctate) the e method resulted in a relative difference reduction in mean absolute percent difference of 27.8% (range 1 59% 4.9% (range 0 129% and 18.0% (0 79% in half life compared to the PopPK method respectively. With some exceptions (in particular central volume) the e method produced relative difference reduction in mean absolute percent differences up to 33% lower compared to the PopPK method. When individuals were parsed based on their e values (either CL or V1) the two methods differentiate up to 64% in terms of half life and time to 0.02 IU/mL predictions for individuals with a low (0th to 20th percentile) eCL or eV1 on the first product. Individuals with higher number of observations per infusion on the first product resulted in better predictions in PK parameter estimates when using the e method. CONCLUSION The use of prior knowledge by implementing e values into PopPK models may provide clinicians with a safer and more effective method to choose a dosing regimen for patients with hemophilia A switching from one factor concentrate to another. However, the e method was unable to better predict an increase or decrease in half life of a future product compared to the PopPK method, and thus supports the conclusion that most individuals would still benefit from a trial on the EHL and subsequent estimation of their individual PK profile from sparse measurements on the EHL.", "author_names": [ "Jacky K Yu", "Alfonso Iorio", "Andrea N Edginton" ], "corpus_id": 226276234, "doc_id": "226276234", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A comparison of methods for prediction of pharmacokinetics when switching to extended half life products in hemophilia A patients.", "venue": "Thrombosis research", "year": 2020 }, { "abstract": "Based on first principles calculations, we predict a stable two dimensional semiconductor, namely tin dioxide \\mathrm{SnO}}_{2} By investigating its dynamical, thermal, and mechanical properties, we find that \\mathrm{SnO}}_{2} monolayer is an auxetic material with a large in plane negative Poisson's ratio. Furthermore, our results show that \\mathrm{SnO}}_{2} is an indirect gap semiconductor with a band gap in the region of 3.7 eV and an extremely high electron mobility, \\ensuremath{\\sim}{10}{3}\\phantom{\\rule{4pt}{0ex}\\mathrm{cm}{2}\\phantom{\\rule{0.16em}{0ex}\\mathrm{V}\\ensuremath{ }1}\\phantom{\\rule{0.16em}{0ex}\\mathrm{s}\\ensuremath{ }1} Interestingly, the band structure of \\mathrm{SnO}}_{2} presents double Mexican hat like band edges in the valence bands near the Fermi level. Due to such a unique band feature, a ferromagnetic phase transition takes place with a half metallic ground state that can be induced by hole doping within a very wide concentration range. Such a magnetic phase can be well explained by the Stoner mechanism. A peculiar feature of the magnetic state is the presence of large magnetocrystalline anisotropy that can switch from in plane to out of plane upon hole doping. Hence, \\mathrm{SnO}}_{2} monolayer can be tuned to be either an $XY$ magnet or an Ising one, with a magnetic critical temperature above room temperature at proper hole concentrations. These findings demonstrate that the predicted phase of \\mathrm{SnO}}_{2} is a rare example of $p$ type magnetism and a possible candidate for spintronic applications.", "author_names": [ "Peng Jiang", "Lili Kang", "Xiaohong Zheng", "Zhi Zeng", "Stefano Sanvito" ], "corpus_id": 228904288, "doc_id": "228904288", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Computational prediction of a two dimensional semiconductor SnO2 with negative Poisson's ratio and tunable magnetism by doping", "venue": "", "year": 2020 }, { "abstract": "In this paper, a temperature dependent SPICE model of SiC power MOSFET is used for statistical electrothermal (ET) simulations of parallel devices for multichip power module applications. The proposed approach is applied to a power module in a half bridge configuration, where parallel MOSFETs are subject to mismatched parameters. The impact of threshold voltage and current factor statistical fluctuations on energy dissipation during hard switching conditions is evaluated by means of Monte Carlo ET simulations. Thereafter, the mean time to failure (MTTF) has been estimated by using the lifetime models from literature for SiC chip. Finally, the effect of current imbalance on the acceleration factor due to changes in devices self heating is analyzed and discussed.", "author_names": [ "Alessandro Borghese", "Michele Riccio", "Alberto Castellazzi", "Luca Maresca", "Giovanni Breglio", "Andrea Irace" ], "corpus_id": 222135548, "doc_id": "222135548", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Statistical Electrothermal Simulation for Lifetime Prediction of Parallel SiC MOSFETs and Modules", "venue": "2020 2nd IEEE International Conference on Industrial Electronics for Sustainable Energy Systems (IESES)", "year": 2020 }, { "abstract": "This paper presents a semi theoretical method for predicting the turn off surge voltage (Vsurge) in double pulse test (DPT) using a power module (PM) with serially connected SiC MOSFET transistors structuring half bridge, in which module a DC link decoupling capacitor is also embedded. The circuit equations are simplified based on the fact that the MOSFETs act as their own parasitic capacitance, diode, or resistor having channel resistance (Rch) in their transient modes, but the drain source voltage (Vds) dependency of the capacitances and gate source voltage dependent Rch are taken into circuit behavior calculations. The partial element equivalent circuit (PEEC) method is used to estimate the stray inductances (Ls) of the PM. Other Ls's are empirically obtained by impedance measurement and preliminarily performed switching waveforms. Finally, multiple Kirchhoff's laws based equations are simultaneously solved. This calculation process is semi theoretical, and sufficiently predicts the Vsurge observed in DPT performed under various conditions.", "author_names": [ "Tatsuya Miyazaki", "Yuta Okawauchi", "Hirotaka Otake", "Ken Nakahara" ], "corpus_id": 220261000, "doc_id": "220261000", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Semi Theoretical Prediction of Turn off Surge Voltage in a SiC MOSFET Power Module with an Embedded DC link Decoupling Capacitor", "venue": "2020 IEEE Applied Power Electronics Conference and Exposition (APEC)", "year": 2020 }, { "abstract": "In this paper, the switching characteristics of a 1200 V/300 A SiC half bridge module in a T type converter is modeled and simulated. Firstly, all current loops of the two T type configurations for double pulse testing are investigated. The dc bus bar layout is proposed to minimize the stray inductance with four layers laminated structure. To reflect the actual switching characteristics, the parasitic inductance of the DC bus bar and major parasitic elements of the power module, such as junction capacitance, terminal to substrate capacitance, and terminal to terminal inductance are extracted with ANSYS Q3D. Finally, the experiment is carried out to verify the modeling of DC bus bar and power module, and to predict the switching characteristics to investigate the potential EMI.", "author_names": [ "Yong Liu", "Kye Yak See", "Rejeki Simanjorang", "Ziyou Lim", "Zhenyu Zhao" ], "corpus_id": 49411490, "doc_id": "49411490", "n_citations": 5, "n_key_citations": 1, "score": 0, "title": "Modeling and simulation of switching characteristics of half bridge SiC power module in single leg T type converter for EMI prediction", "venue": "2018 IEEE International Symposium on Electromagnetic Compatibility and 2018 IEEE Asia Pacific Symposium on Electromagnetic Compatibility (EMC/APEMC)", "year": 2018 }, { "abstract": "Predicting radiated emissions in large and complex power systems is difficult under a single set operational conditions, however when flexibility is introduced it becomes near impossible without using thousands of Monte Carlo type simulations. In this paper it is suggested to estimate the radiation efficiency (i.e. transfer function) of a power system based on a novel theoretical model and a limited amount of measurements under operating conditions. The switching power system is modeled as a LTI system that is excited by a known Sinusoidal Pulse Width Modulation (sPWM) source, i.e. the switching node voltage waveform. The theoretical model simplifies the estimation of the sPWM power spectrum, while its amplitude is also independent of modulation index. By measuring radiated electric fields and calculating Effective Radiated Power (ERP) one can estimate the system radiation efficiency in a novel way. The derived efficiency can eventually be used to optimize the radiated EMI, for instance by avoiding highly radiative frequencies in the signal generation.", "author_names": [ "Chris Van Diemen", "Niek Moonen", "Frank Leferink" ], "corpus_id": 52926664, "doc_id": "52926664", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Estimation of Radiation Efficiency of GaN Half Bridge Based Submodule System for Radiated EMI Prediction", "venue": "2018 International Symposium on Electromagnetic Compatibility (EMC EUROPE)", "year": 2018 }, { "abstract": "Abstract In this paper, a novel linear switched reluctance motor (LSRM) is introduced in which the total electromagnetic losses and dimensions are significantly reduced compared to the conventional LSRMs. The LSRM's stator has a segmental structure, while its rotor possesses a seven pole configuration with three rotor poles equipped with the winding sets to generate the magnetic flux. The other remaining four rotor poles, i.e. auxiliary poles, are responsible for closing the magnetic flux path loop. In the proposed LSRM auxiliary mover poles (LSRM AMP) the flux path length is effectively reduced using the optimized provided auxiliary poles. Therefore, the required magnetomotive force (MMF) is reduced compared to the conventional LSRMs. In addition, as only half of the generated flux passes the stator segments, the dimensions of the stator segments and their corresponding weights are significantly reduced without any saturation issue. In order to verify the finite element (FE) based performance prediction of the proposed structure, the electromagnetic operating principles and the design rules of the LSRM AMP are separately investigated. A sensitivity analysis and comparative study for the proposed LSRM AMP and conventional LSRM topologies are presented to show the performance and characteristics superiority of the optimized LSRM AMP structure.", "author_names": [ "Amirreza Malekpour Shahraky", "Saleh Sheikhkanloy", "Hossein Torkaman", "Mohammad Sedigh Toulabi" ], "corpus_id": 236962239, "doc_id": "236962239", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Design and Performance Prediction of a Novel Linear Switched Reluctance Motor", "venue": "", "year": 2021 } ]

[ { "abstract": "We study motives for and impacts of management discretion in inventory valuation. The semiconductor industry, with continual output price declines and rapid product obsolescence, provides an ideal setting to examine managers' inventory write down and production decisions. In this context, we develop a measure of 'excess inventory' and find that inventory write downs are strongly correlated with this measure. We also find that inventory write downs are timed strategically in periods of poor performance consistent with 'big bath' incentives. We construct a proxy for abnormal write downs, and find that it is positively associated with subsequent operating performance, and negatively associated with future write downs. Neither analysts, nor investors appear to fully appreciate the predictable implications of abnormal write downs for subsequent operating performance.", "author_names": [ "Hui Chen", "Sundaresh Ramnath", "Srinivasan Rangan", "Steven M Rock" ], "corpus_id": 168207026, "doc_id": "168207026", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "Inventory Write Downs in the Semiconductor Industry", "venue": "", "year": 2015 }, { "abstract": "I: Introductory Cases. 1. Dublin Small Animal Clinic. 2. Verona Springs Mineral Water. 3. Holton Central Chairs. 4. Chang Medical Electronics. 5. Janet O'Brien. 6. Catrike. II: Governance and Regulation. 1. Xerox. 2. Microsoft Corp: Financial Reporting Issues. 3. Beazer Homes USA. 4. Corporate Governance at IBM and Google. 5. Chrysler. 6. General Growth Properties. III: Financial Reporting, Domestic. 1. Intel Corporation: Inventory Write downs. 2. Lease Restatements in the Restaurant Industry. 3. Bethlehem Steel. 4. Revenue Recognition (A) 5. Revenue Recognition (B) 6. New Century Financial Corp. 7. Sirius XM. 8. Dell, Inc. Financial Restatements. 9. Retiree Benefits at Boeing. 10. Carton Medical Products. IV: Financial Reporting, International. 1. Impairments in the Recession of 2008 2009. 2. Depreciation in the Semiconductor Industry. 3. Thomson (A) 4. Thomson (B) 5. Mitchells Butlers. 6. Barclays' acquires Lehman. 7. SAP: Financial Reporting Methods. V: Financial Statement Analysis. 1. Harley Davidson, Inc. (A) 2. Harley Davidson, Inc. (B) 3. Arby's Acquisition of Wendy's. 4. General Motors Corp. 5. Employee Stock Options at Cisco. 6. Merrill Lynch, Inc. 7. Apple, Inc. Retrospective Adoption, Revenue Recognition Rules. VI: Valuation. 1. Knowles Electronics, Inc. 2. Anheuser Busch, Inc. 3. Inbev. 4. Sunbelt Beverage. 5. Koss. 6. Asher Associates. VII: Background Notes. 1. Note on Fair Value Reporting. 2. Note on Business Combinations. 3. Note on Discounted Cash Flows. 4. Note on Bonds. 5. Note on Retiree Benefits. 6. Note on Business Valuation. 7 Note on Ratio Analysis. VIII: Short Excel based Cases. 1. Discounted Cash Flows. 2. Revenue Recognition (A) 3. Revenue Recognition (B) 4. Impairment. 5. Bonds. 6. Leases. 7. Investment Securities. 8. Retiree Benefits. 9. Securitization. 10. Valuation.", "author_names": [ "Michael Joseph Sandretto" ], "corpus_id": 167190352, "doc_id": "167190352", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Cases in Financial Reporting", "venue": "", "year": 2011 }, { "abstract": "The International Financial Reporting Standards (IFRS) No. 2 has been the worldwide accounting principle for the reduction of inventory to market allowance since January 1, 2005. Using make to stock manufacturing strategies and inventory accounting for only approximately 14% of the total costs, integrated device manufacturers have found maintaining robust records for financial statements increasingly difficult. For example, one company in the case study conducted in this study must write down losses of 2 100% of the total inventory costs for products with inventory ages of 18months 3years. However, the average cycle time for producing flash memory is approximately 3months. In other words, when the system variation and safety stock policy are considered, the company must write down the reduction of inventory to market allowance for most of work in process inventory. However, little research has been done to addressing the practical management of operations according to inventory aging processes. This study develops a polynomial time based model to obtain significant features, including inventory ages, accounting principles, and product structures (bill of material) for the accurate prediction of inventory write downs to reduce the impact of the carrying value fluctuation of inventory. An empirical study was conducted on a Taiwanese semiconductor manufacturer. The results show that predicting 3 month inventory write downs of a complete flash memory production line comprising approximately 8500 product types can be conducted in less than 10s, with the mean absolute percentage error (MAPE) less than 3.5% Discussions regarding the sensitivity analysis and cost tornado diagrams suggest the priority of affecting factors. The results show the viability of implementing the proposed model to predict inventory write downs in the semiconductor manufacturing industry.", "author_names": [ "Jei-Zheng Wu" ], "corpus_id": 239343, "doc_id": "239343", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "Inventory write down prediction for semiconductor manufacturing considering inventory age, accounting principle, and product structure with real settings", "venue": "Comput. Ind. Eng.", "year": 2013 }, { "abstract": "Manufacturers are making a transition to intelligent production, particularly in high tech industries. Robotic arms play a crucial role in the effectiveness of transforming processes. This research searches and analyzes patents related to robotic arms utilized by intelligent manufacturing systems. For this preliminary study, global patent trends are discussed which help evaluate the technology domain to be developed. Key words from a literature review are used to search for relevant patents, and then the patent text is analyzed using text mining software and program. The core technique applied to the patent document analysis is \"Term Frequency Inverse Document Frequency\" (TF IDF) Using TF IDF, the patent documents are grouped into meaningful sub technology cluster. Thus, the economic data related to the semiconductor industry is analyzed to correlate the economic impact which may be related to the transitions in technology. The data of Taiwan firms were targeted for anticipating research directions and expand intellectual property domains to invest in and pursue. For the advanced analysis, the international patent codes for global and local companies are compared. The final results help define the strength and weakness of Taiwanese robotic technology development for the semiconductor industry. Patent cluster and patent distribution analysis via a technology function matrix are the primary research approaches used for the case study. The research prepares for the development of a theoretical foundation to predict intelligent manufacturing trends.", "author_names": [ "Paul P J Chen", "Amy J C Trappey", "Betty H L Lin", "Charles V Trappey" ], "corpus_id": 52286891, "doc_id": "52286891", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Patent Analytics of Robotics Technology for Intelligent Manufacturing in the Semiconductor Industry", "venue": "2018 IEEE 22nd International Conference on Computer Supported Cooperative Work in Design (CSCWD)", "year": 2018 }, { "abstract": "Over the last years, Infineon Dresden Technologies has continuously been working on offering innovative products and enhancing the productivity of their wafer fabrication areas by increasing fab capacities as well as increasing automation in their 200 and 300 mm wafer manufacturing plants to improve productivity. One of the most important success factors is use of powerful automated material handling systems (AMHS) combined with the digitization of core processes within the whole company. Digitization supports converting a highly automated fab into a \"smart fab\" by horizontal and vertical integration of the internal supply chains. Within this paper, the authors provide an overview of three use cases for continuous improvement of the manufacturing process through use of automation and digitization to enhance the profitability of the semiconductor manufacturing plant.", "author_names": [ "Germar Schneider", "Sophia Keil", "Gerhard Luhn" ], "corpus_id": 46960316, "doc_id": "46960316", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Opportunities, challenges and use cases of digitization within the semiconductor industry", "venue": "2018 29th Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC)", "year": 2018 }, { "abstract": "Three major business models are found in the semiconductor industry, namely, the integrated device manufacturer (IDM) fabless, and foundry models. IDMs design and manufacture integrated circuits (ICs) fabless companies focus only on IC design, and foundry companies are concerned only with IC manufacturing. The business model resulting when fabless and foundry companies form a strategic alliance is called the fabless foundry model. Recently, the revenue growth rate of the fabless foundry model has been considerably higher than that of IDM. This raises the question of whether the fabless foundry model will ultimately dominate the semiconductor industry or grow only to a certain extent. To investigate this, we adopted the Hodrick Prescott filter to remove the cyclic signal from original revenue data and then applied the Lotka Volterra model to analyze the competition and cooperation relationships between pairs of these business models. The results reveal that the fabless and foundry models have a mutualistic relationship, whereas IDM competes with both the fabless and foundry models. IDM and the fabless foundry model compete, but their revenues should ultimately arrive at an equilibrium point. In the long term, IDM and the fabless foundry model should coexist; the ultimate market share of IDM is predicted to be approximately 55% and that of the fabless foundry model approximately 45%", "author_names": [ "Hui-Chih Hung", "Yu-Chih Chiu", "Muh-Cherng Wu" ], "corpus_id": 9847215, "doc_id": "9847215", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Analysis of Competition Between IDM and Fabless Foundry Business Models in the Semiconductor Industry", "venue": "IEEE Transactions on Semiconductor Manufacturing", "year": 2017 }, { "abstract": "Abstract Automated visual inspection is an image processing technique for quality control and production line automation. This paper reviews various optical inspection approaches in the semiconductor industry and categorize the previous literatures by the inspection algorithm and inspected products. The vision based algorithms that had been adopted in the visual inspection systems include projection methods, filtering based approaches, learning based approaches, and hybrid methods. To discuss about the practical applications, the semiconductor industry covers the manufacturing and production of wafer, thin film transistor liquid crystal displays, and light emitting diodes. To improve the yield rate and reduce manufacturing costs, the inspection devices are widely installed in the design, layout, fabrication, assembly, and testing processes of production lines. To achieve a high robustness and computational efficiency of automated visual inspection, interdisciplinary knowledge between precision manufacturing and advanced image processing techniques is required in the novel system design. This paper reviews multiple defect types of various inspected products which can be referenced for further implementations and improvements.", "author_names": [ "Szu-Hao Huang", "Ying-Cheng Pan" ], "corpus_id": 32383127, "doc_id": "32383127", "n_citations": 154, "n_key_citations": 4, "score": 0, "title": "Automated visual inspection in the semiconductor industry: A survey", "venue": "Comput. Ind.", "year": 2015 }, { "abstract": "Atomic layer etching (ALE) is a technique for removing thin layers of material using sequential reaction steps that are self limiting. ALE has been studied in the laboratory for more than 25 years. Today, it is being driven by the semiconductor industry as an alternative to continuous etching and is viewed as an essential counterpart to atomic layer deposition. As we enter the era of atomic scale dimensions, there is need to unify the ALE field through increased effectiveness of collaboration between academia and industry, and to help enable the transition from lab to fab. With this in mind, this article provides defining criteria for ALE, along with clarification of some of the terminology and assumptions of this field. To increase understanding of the process, the mechanistic understanding is described for the silicon ALE case study, including the advantages of plasma assisted processing. A historical overview spanning more than 25 years is provided for silicon, as well as ALE studies on oxides, III V c.", "author_names": [ "Keren J Kanarik", "Thorsten Lill", "Eric A Hudson", "Saravanapriyan Sriraman", "Samantha Tan", "Jeffrey Marks", "Vahid Vahedi", "Richard Alan Gottscho" ], "corpus_id": 96841591, "doc_id": "96841591", "n_citations": 215, "n_key_citations": 4, "score": 0, "title": "Overview of atomic layer etching in the semiconductor industry", "venue": "", "year": 2015 }, { "abstract": "A wide variety of manufacturing operations can be characterized as co production with substitutable demand. That is, there are many situations in which the availability of two or more items are related, and because of randomness in either supply or demand, it can be advantageous to substitute one of these items for another. Our research was motivated by the semiconductor industry, where chips are produced in large batches. Because of the presence of randomness in the process, individual chips in a given batch can perform differently. Because some customers have stricter specifications than others, chips within the same batch can be classified and sold as different products according to their measurable performance. We model the production and inventory problem as a stochastic dynamic program in which the objective is to minimize the costs of meeting contractual obligations. After developing heuristic methods of solving the problem in practice, we validate them against a lower bound on the cost of an optimal solution to the dynamic program.", "author_names": [ "Gabriel R Bitran", "Stephen M Gilbert" ], "corpus_id": 207242011, "doc_id": "207242011", "n_citations": 69, "n_key_citations": 9, "score": 0, "title": "Co Production Processes with Random Yields in the Semiconductor Industry", "venue": "Oper. Res.", "year": 1994 }, { "abstract": "Currently available data suggest that most of the energy and material consumption related to the production of an integrated circuit is due to the wafer fabrication process. The complexity of wafer manufacturing, requiring hundreds of steps that vary from product to product and from facility to facility and which change every few years, has discouraged the development of material, energy, and emission inventory modules for the purpose of insertion into life cycle assessments. To address this difficulty, a flexible, process based system for estimating material requirements, energy requirements, and emissions in wafer fabrication has been developed. The method accounts for mass and energy use atthe unit operation level. Parametric unit operation modules have been developed that can be used to predict changes in inventory as the result of changes in product design, equipment selection, or process flow. A case study of the application of the modules is given for energy consumption, but a similar methodology can be used for materials, individually or aggregated.", "author_names": [ "Cynthia F Murphy", "G Kenig", "David T Allen", "J Laurent", "D E Dyer" ], "corpus_id": 21990559, "doc_id": "21990559", "n_citations": 76, "n_key_citations": 6, "score": 0, "title": "Development of parametric material, energy, and emission inventories for wafer fabrication in the semiconductor industry.", "venue": "Environmental science technology", "year": 2003 } ]

[ { "abstract": "A dual wavelength \\rm TEM}_{01}$TEM01 mode synchronous continuous wave passively mode locked (CWML) Nd:YAG laser has been demonstrated for the first time to the best of our knowledge with a semiconductor saturable absorber mirror (SESAM) at 1319 and 1338 nm. The maximum average output power of 10.84 W was obtained at a 113.8 W absorbed pump power, corresponding to an optical to optical conversion efficiency of 9.5% The dual wavelength CWML pulses had a pulse duration of 35.1 ps at a repetition rate of 76 MHz. The beam quality was measured to be \\rm M}^2} {2.51}$M2=2.51.", "author_names": [ "Ning Wen", "Long-Pu Li", "Nan Zong", "Wei Tu", "Ke Liu", "Zhimin Wang", "Yong Bo", "Qinjun Peng", "Da-Fu Cui", "Zu-Yan Xu" ], "corpus_id": 209463164, "doc_id": "209463164", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Dual wavelength TEM01 mode passively mode locked Nd:YAG laser witha semiconductor saturable absorber mirror.", "venue": "Applied optics", "year": 2019 }, { "abstract": "A dual central wavelength passively mode locked laser with full modulation in the 0.31 THz optical beating is achieved by using a diffusion bonded Nd:YVO4/Nd:GdVO4 crystal and a semiconductor saturable absorber mirror. The output power of the dual band emission is well balanced by tuning the focal position of the pump waist. At a pump power of 13 W, the total output power is up to 2.7 W with a repetition rate of 297.9 MHz. The autocorrelation traces clearly reveal the synchronization of the dual band emission. Moreover, an analytical model is developed to manifest the multi pulse structure caused by the etalon effect of the gain medium. More important, we experimentally verify that the etalon effect can be completely eliminated by using the wedge cut diffusion bonded Nd:YVO4/Nd:GdVO4 crystal.", "author_names": [ "F L Chang", "C L Sung", "T L Huang", "T W Wu", "H H Cho", "H C Liang", "Yohchia Frank Chen" ], "corpus_id": 126109334, "doc_id": "126109334", "n_citations": 4, "n_key_citations": 1, "score": 0, "title": "Dual central wavelength passively mode locked diffusion bonded Nd:YVO4/Nd:GdVO4 laser with a semiconductor saturable absorber mirror", "venue": "", "year": 2017 }, { "abstract": "A self starting simple structured dual wavelength passively mode locked (ML) erbium doped fiber (EDF) laser is proposed in this Letter. An all fiber ring cavity is adopted and a transmission type semiconductor saturable absorber is used as modelocker. In this laser, there are two gain humps located at the 1530 nm region and the 1550 nm region, respectively. Along with the length of EDF increasing, the intensity of the hump at 1530 nm region is gradually suppressed because of the re absorption of emission by the ground state. With the proper length of EDF, the gain intensities of two regions are very close. When the pump power is above the ML threshold, the self starting dual wavelength ML operation is achieved easily without manual adjustment. The two spectral peaks with close intensities are located at 1532 and 1552 nm, respectively. The effect of intracavity dispersion on the output spectrum is also experimentally demonstrated.", "author_names": [ "Shi Junkai", "Weihu Zhou" ], "corpus_id": 111373241, "doc_id": "111373241", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Self starting simple structured dual wavelength mode locked erbium doped fiber laser using a transmission type semiconductor saturable absorber", "venue": "", "year": 2018 }, { "abstract": "A diode end pumped continuous wave and passively Q switched mode locked Nd:(Gd0.3Y0.7)2SiO5 laser was designed. At a pump power of 0.8W, we achieve dual wavelength continuous wave (CW) laser generation at wavelengths around 1,073.26 and 1,076.62 nm. Using a semiconductor saturable absorber mirror (SESAM) we obtain passively Q switched mode locked (QML) operation. A maximum average output power of 171 mW is obtained under a pump power of 5 W. The optical conversion efficiency for the QML laser is 3.4% The duration of the mode locked pulse is estimated to be about 649 ps at a repetition rate of 101.34 MHz.", "author_names": [ "Zhen Tian", "Beibei Wang", "Congcong Gao", "Qiang Wu", "Xiaodong Xu", "Jun Xu", "Bingyuan Zhang" ], "corpus_id": 126968195, "doc_id": "126968195", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Passively Q Switched Mode Locking Nd:(Gd0.3Y0.7)2SiO5 Laser Based on Semiconductor Saturable Absorber Mirror+", "venue": "", "year": 2019 }, { "abstract": "A dual wavelength mode locked semiconductor vertical external cavity surface emitting laser is demonstrated. A semiconductor saturable absorber mirror allows for simultaneous mode locking of pulses centered at two center wavelengths with variable frequency spacing. The difference frequency control is achieved with an intracavity etalon. Changing the finesse of the etalon enables the adjustment of the pulse duration between 6 and 35 ps. The emitted two color pulses are modulated by a beat frequency in the terahertz range. Self starting mode locking with 0.8 W average output power is demonstrated.", "author_names": [ "Maik Scheller", "Caleb W Baker", "Stephan W Koch", "Jerome V Moloney" ], "corpus_id": 1522398, "doc_id": "1522398", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Dual Wavelength Passively Mode Locked Semiconductor Disk Laser", "venue": "IEEE Photonics Technology Letters", "year": 2016 }, { "abstract": "A new diffusion bonded Nd:YVO4/Nd:GdVO4 hetero structure crystal with oblique interface between two vanadate materials is exploited to achieve dual wavelength passively mode locked laser with a semiconductor saturable absorber mirror. Experimental results show that the power ratio of the two emission wavelengths can be flexibly adjusted by controlling the vertical position of pump beam. In the optimally balanced dual wavelength operation, the maximum total output power of 2.5 W is obtained at an incident pump power of 11 W and the pulse width is measured to be 24.7 ps with pulse repetition rate of 296.6 MHz. The mode locked output pulse is further found to exhibit an optically beating with pulse duration of 1.8 ps at a repetition rate of 0.318 THz.", "author_names": [ "Hsin-Chih Liang", "Tzu-Lin Huang", "F L Chang", "C L Sung", "Yung-Fu Chen" ], "corpus_id": 30110054, "doc_id": "30110054", "n_citations": 8, "n_key_citations": 1, "score": 0, "title": "Flexibly Controlling the Power Ratio of Dual Wavelength SESAM Based Mode Locked Lasers With Wedged Bonded Nd:YVO4/Nd:GdVO4 Crystals", "venue": "IEEE Journal of Selected Topics in Quantum Electronics", "year": 2018 }, { "abstract": "We demonstrated a dual wavelength passively mode locked Nd:YSAG laser using a semiconductor saturable absorber mirror as the modulator. The maximum average output power was about 470 mW under the absorbed pump power of 4.2 W. The laser exhibited stable double wavelength synchronous mode locked oscillation at 1060.8 nm and 1063.2 nm. The pulsed repetition rate was about 87.4 MHz, and the single pulse energy was calculated to be 5.38 nJ. The envelope of the autocorrelation interference pattern presented a Gaussian pulse shape and the pulse width was about 3.8 ps. The beat pulse had a repetition rate of 0.67 THz and the beat pulse width was about 800 fs. Additionally, numerical simulation was conducted to analyze the autocorrelation trace.", "author_names": [ "Chao Feng", "Huanian Zhang", "Qingpu Wang", "Jiaxiong Fang" ], "corpus_id": 125089222, "doc_id": "125089222", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Dual wavelength synchronously mode locked laser of a Nd:Y3ScAl4O12 disordered crystal", "venue": "", "year": 2017 }, { "abstract": "A diode pumped passively mode locked Nd:LGGG disordered crystal 1.3 mm laser has been experimentally demonstrated for the first time to our knowledge. With a semiconductor saturable absorber mirror (SESAM) stable synchronous continuous wave mode locking at two wavelengths was achieved. The mode locked pulse train has a repetition rate of 32 MHz and pulse duration of 4.55 ps, with a total average output power of 259 mW under an absorbed pump power of 5.48 W.", "author_names": [ "Ying Yang", "Zhitai Jia", "Jingliang He", "Jin-long Xu", "Baitao Zhang", "Ruihua Wang", "Xunmin Liu", "Jia Hou", "Fei Lou", "Zhao-wei Wang", "He Yang", "Xutang Tao" ], "corpus_id": 122378136, "doc_id": "122378136", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Dual wavelength synchronously passively mode locked Nd:LGGG 1.3 mm laser with SESAM", "venue": "", "year": 2013 }, { "abstract": "We experimentally demonstrated dual wavelength synchronous operation of a high power passively mode locked 2 mm Tm:CaYAlO4 (Tm:CYA) disordered crystal laser with semiconductor saturable absorber mirror (SESAM) as mode locker. The mode locked laser emitted an average output power as high as 830 mW with pulse duration of 35.3 ps and repetition rate of 145.4 MHz. The mode locking dual wavelengths were centered at 1958.9 nm and 1960.6 nm, respectively. Autocorrelation trace clearly shows beating pulses with pulse width of 3.5 ps and repetition rate of 0.13 THz.", "author_names": [ "Lingchen Kong", "Zhipeng Qin", "Guoqiang Xie", "X D Xu", "J C Xu", "Pengtao Yuan", "Liejia Qian" ], "corpus_id": 207347987, "doc_id": "207347987", "n_citations": 51, "n_key_citations": 0, "score": 0, "title": "Dual wavelength synchronous operation of a mode locked 2 mm Tm:CaYAlO4 laser.", "venue": "Optics letters", "year": 2015 }, { "abstract": "In this linear cavity passively mode locked laser based on semiconductor saturable absorber mirror, an Ybdoped fiber is shared by two branch cavities as gain medium. These two cavities can respectively output single wavelength pulse with the wavelength tuning range of 1 009.7 1 057.6 nm and 1 011.6 1 052.6 nm by adjusting volume Bragg grating. When two cavities output pulses together, the dual wavelength pulses with the maximum and minimum wavelength separation of 34.8 and 2.4 nm, respectively, are achieved by net gain equalization method to suppress mode competition at room temperature. The maximum pulse energies of dual wavelength pulses are 0.47 and 0.33 nJ separately; their repetition rates are 11.39 and 11.41 MHz.", "author_names": [ "Yangbo Bai", "Wanghua Xiang", "Peng Zu", "Guizhong Zhang" ], "corpus_id": 73550265, "doc_id": "73550265", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Tunable dual wavelength passively mode locked Yb doped fiber laser using SESAM", "venue": "", "year": 2012 } ]

[ { "abstract": "Heterogeneous integration (HI) has become a key technology development and production effort in the past few years. HI for RF has become an important task for applications such as 5G in the commercial world and for many higher frequency applications in space and defense. Several factors need to be considered to select a suitable approach, including active semiconductor technologies, performance, materials for interposers, the HI method and interface, cost, yield, and last but not least the overall reliability of the integration.", "author_names": [ "Augusto Gutierrez-Aitken" ], "corpus_id": 232266476, "doc_id": "232266476", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Heterogeneous Integration for High Frequency RF Applications", "venue": "2020 IEEE International Electron Devices Meeting (IEDM)", "year": 2020 }, { "abstract": "We have demonstrated industry's first 300mm 3D heterogeneous integration of high performance, low leakage high K dielectric metal gate enhancement mode (e mode) GaN NMOS and Si PMOS transistors on 300mm high resistivity (HR) Si(111) substrate, enabled by 300mm GaN MOCVD epitaxy and 300mm 3D layer transfer. The fabricated (bottom device layer) high K dielectric e mode GaN NMOS transistors, integrated on a 300mm HR Si(111) substrate, show excellent electrical characteristics and figure of merits (FOM) for realizing energy efficient, compact voltage regulators and RF front end components such as power amplifiers, low noise amplifiers and RF switches, with (i) IOFF as low as 100pA/mm (VD=5V, VG=0V) (ii) high ID,max=1.5mA/mm; (iii) RON as low as 610O mm, significantly better than industry standard Si transistors at equivalent drain breakdown (BVD) (iv) excellent RF performance: fT=190GHz, fMAX=300GHz, PAE=56% at mmwave frequency (f=28GHz) and PAE=70% at sub 7GHz (f=5GHz) significantly better than industry standard GaAs and Si RF transistors, (v) excellent RF switch FOM, RonCoff=110fs, and (vi) low noise figure, NFmin=1.36dB (f=28GHz) 0.4dB (f=5GHz) and 0.27dB (f=1.8GHz) all at SoC compatible voltages. The fabricated (top device layer) LG=65nm and 130nm Si PMOS transistors, which are monolithically integrated on top of the bottom GaN NMOS transistors by 300mm 3D layer transfer, show respectively, high drive current of 0.85mA/mm, and low Ioff of 150pA/mm at VD= 1.2V. Such a monolithic 3D integration of GaN NMOS and Si PMOS enables full integration of energy efficient, truly compact power delivery and RF solutions with CMOS digital signal processing, logic computation and control, memory functions and analog circuitries for next generation power delivery, RF (5G and beyond) and SoC applications.", "author_names": [ "Han Wui Then", "C Y Huang", "Brian Krist", "Kimin Jun", "Kevin L Lin", "N Nidhi", "T Michaelos", "B Mueller", "R Paul", "J Peck", "Willy Rachmady", "Sansaptak Dasgupta", "D Staines", "T Talukdar", "N Thomas", "Tristan A Tronic", "Paul Fischer", "Walid M Hafez", "Marko Radosavljevic", "P Agababov", "Ibrahim Ban", "Robert L Bristol", "Manish Chandhok", "Siddharth Chouksey", "Brandon Jay Holybee" ], "corpus_id": 211209167, "doc_id": "211209167", "n_citations": 16, "n_key_citations": 4, "score": 0, "title": "3D heterogeneous integration of high performance high K metal gate GaN NMOS and Si PMOS transistors on 300mm high resistivity Si substrate for energy efficient and compact power delivery, RF (5G and beyond) and SoC applications", "venue": "2019 IEEE International Electron Devices Meeting (IEDM)", "year": 2019 }, { "abstract": "We demonstrate and review the unique fine pitch high aspect ratio tungsten filled through silicon vias (W TSVs) technology developed by Fraunhofer EMFT in high resitivity silicon substrates. The proposed process flow is fully compatible with both CMOS and MEMS technology, allowing 3D heterogeneous integration of highperformance, low power, compact tunable RF front ends. We have assessed the figures of merit of the technology for RF functionality by fabricating and characterizing different configurations for CPWs with TSV transitions, mm wave antennas and LC resonators as well as record high performance wideband out of plane micro inductors.", "author_names": [ "Montserrat Fernandez-Bolanos", "Wolfgang A Vitale", "Mariazel Maqueda Lopez", "Adrian M Ionescu", "Armin Klumpp", "Karl-Reinhard Merkel", "Josef Weber", "Peter Ramm", "Ilja Ocket", "Walter De Raedt", "Amin Enayati" ], "corpus_id": 11518590, "doc_id": "11518590", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "3D TSV based high frequency components for RF IC and RF MEMS applications", "venue": "2016 IEEE International 3D Systems Integration Conference (3DIC)", "year": 2016 }, { "abstract": "The push to conquer the sparsely used electromagnetic spectrum between 100 and 1,000 GHz, commonly known as the millimeter wave (mmW) and sub mmW regions, is now in full force. The current rapid development of electronic circuits and subsystems beyond 100 GHz is enabled by improvements in high frequency semiconductor technology and packaging techniques. In this article, we highlight recent advances we have developed in heterogeneous semiconductor material chip integration for application toward the mmW frequency bands?in essence, a waferlevel integration approach that replaces chip to chip connections with monolithic integration.", "author_names": [ "Nils G Weimann", "Maruf Hossain", "Viktor Krozer", "Wolfgang Heinrich", "Marco Lisker", "Andreas Mai", "Bernd Tillack" ], "corpus_id": 33702420, "doc_id": "33702420", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Tight Focus Toward the Future: Tight Material Combination for Millimeter Wave RF Power Applications: InP HBT SiGe BiCMOS Heterogeneous Wafer Level Integration", "venue": "IEEE Microwave Magazine", "year": 2017 }, { "abstract": "In the last few years, radio frequency (RF) applications have driven the advanced electronics packaging market to encompass different sectors. With products such as Automotive Radar, High End Smartphones or WiGig devices, the RF packaging market is expected to grow in every sector. Wafer level packaging (WLP) 3D through silicon vias (TSVs) SiPs (Systems in Packages) and electromagnetic interference (EMI) shielding are key enablers for heterogeneous integration in segments where RF devices require small form factors, high speed operation and a high degree of isolation. Also, cost efficiency is critical. Based on images extracted from physical analyses of several RF devices, we will demonstrate the present power of RF packaging solutions for manufacturers such as Qualcomm, Broadcom, and Skyworks, from the manufacturing cost to the functional integration. We will extract some clues for future fifth generation (5G) and millimeter wave (mmWave) applications. We will also present how these companies manage to provide highly integrated SiPs featuring several advanced packaging technologies cost effectively. Finally, moving forward in 5G and mmWave applications, SiPs will get more complex to maintain high performance levels, with innovations like integrated EMI shielding and integrated passive devices. We will therefore introduce some key features, like advanced substrate technologies. These are also next generation technologies for 5G and mmWave systems.", "author_names": [ "Stephane Elisabeth" ], "corpus_id": 208629902, "doc_id": "208629902", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Advanced RF Packaging Technology Trends, from WLP and 3D Integration to 5G and Mmwave Applications", "venue": "2019 International Wafer Level Packaging Conference (IWLPC)", "year": 2019 }, { "abstract": "Three dimensional system in package (3D SiP) based on silicon carriers or interposer is a fast emerging technology that offers system design flexibility and integration of heterogeneous technologies. One of the key technologies enabler for silicon carrier is through silicon via (TSV) The development of 3D SiP will require the devices with different functionality operating at high frequency to be densely packed on the silicon substrate. However, silicon substrate is usually of low resistivity, when a high frequency signal is transmitted vertically through the substrate via, significant signal attenuation can occur that leads to poor RF performance. In this paper, a coaxial TSV structure in silicon carrier is presented for high frequency applications. The coaxial TSV is able to suppress undesirable substrate loss as well as provide good impedance matching. Electrical modeling of coaxial TSV structure was carried out to obtain the required geometries for impedance matching. Three different types of test vehicles were fabricated; Cu plug TSV in both low ~10 Omega cm) and high resistivity ~4000 Omega cm) silicon substrate, and coaxial TSV in low resistivity silicon substrate. The S parameters of the via structure of the test vehicles were measured from 100 MHz to 10 GHz. The measured results show that the coaxial TSV structure is able to suppress silicon substrate loss and provide good RF performance compared to Cu plug TSV structure.", "author_names": [ "Soon Wee Ho", "Seung Wook Yoon", "Qiaoer Zhou", "Kalpendu R Pasad", "Vaidyanathan Kripesh", "John H Lau" ], "corpus_id": 11460957, "doc_id": "11460957", "n_citations": 121, "n_key_citations": 9, "score": 0, "title": "High RF performance TSV silicon carrier for high frequency application", "venue": "2008 58th Electronic Components and Technology Conference", "year": 2008 }, { "abstract": "For radar applications, the W band frequency range (75 110 GHz) is a good candidate for high resolution distance measurement and remote detection of small or hidden objects in distances of 10 cm to 20 m. As electromagnetic waves in this frequency range can easily penetrate rough atmosphere like fog, smoke or dust, W band radars are perfectly suited for automotive, aviation, industrial and security applications. Additional benefit is that atmosphere has an absorption minimum at 94 GHz, so relative small output power is sufficient to achieve long range coverage. By combining and enhancing knowledge from the disciplines of heterogeneous integration technology and compound semiconductor technology, the Fraunhofer Institutes IAF, IPA and IZM developed a miniaturized and low cost 94 GHz radar module. Result of this approach is a highly miniaturized radar module built using a modular approach. The radar components are mounted on a dedicated RF NF hybrid PCB while the signal processing is done on a separate b.", "author_names": [ "K -F Becker", "Leopold Georgi", "Ruben Kahle", "Steve Voges", "F Brandenburger", "Jan Hofer", "Christian Ehrhardt", "Christian Zech", "Benjamin Baumann", "Axel Huelsmann", "A Grasenack", "Steffen Reinold", "Bernhard Kleiner", "Tanja Braun", "Martin Schneider-Ramelow", "Klaus-D Lang" ], "corpus_id": 112680547, "doc_id": "112680547", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Heterogeneous integration of a miniaturized W band radar module", "venue": "", "year": 2015 }, { "abstract": "Applications using rf radios operating at frequencies above 1 GHz are proliferating. The highest operating frequencies continue to increase and applications above 10 GHz and up to 77 GHz are already emerging. Systems become more complex and devices need to operate at several different frequency bands using different wireless standards. The rf front end sections of these devices are characterized by a high diversity of components, in particular high precision passive components. In order to be produced cost effectively, these elements need to be integrated along with the semiconductor devices. This paper describes the requirements for successful integration of rf passive devices and proposes multilayer thin film technology as an effective rf integration technology.", "author_names": [ "Eric Beyne", "Walter De Raedt", "Geert Carchon", "Philippe Soussan" ], "corpus_id": 59676871, "doc_id": "59676871", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Heterogeneous Integration of Passive Components for the Realization of RF System in Packages", "venue": "", "year": 2008 }, { "abstract": "System in package (SiP) based on silicon carriers is a fast emerging technology that offers system design flexibility and integration of heterogeneous technologies. One of the key technologies enabler for silicon carrier is through wafer interconnects. The development of SiP will require the devices with different functionality operating at high frequency to be densely packed on the silicon substrate. However, silicon substrate is usually of low resistivity, when a high frequency signal is transmitted vertically through the substrate via, significant signal attenuation can occur that leads to substrate crosstalk and poor RF performance. In this paper, a novel coaxial shielded via in silicon carrier is presented for high frequency applications. Electrical modeling was carried out to obtain the required geometries for optimum performance. The coaxial shield via is able to suppress undesirable substrate crosstalk between vertical interconnects as well as provide excellent RF performance. The detailed fabrication process is also presented. A negative tone SU 8 photoresist is used as the dielectric for the coaxial shield via structure. A test vehicle is fabricated on 8 inch, 10 Omegamiddotcm resistivity silicon wafer with a target of achieving a transmission coefficient, S21 of greater than 0.5 dB at 40 GHz. SU 8 dielectric of approximately 112 mum thickness was deposited on the via sidewall of a 300 mum diameter through wafer via holes, and the via holes filled with copper using bottom up electroplating approach to achieve a radius ratio, n of 4", "author_names": [ "Soon Wee Ho", "Vempati Srinivasa Rao", "Qratti Kalandar Navas Khan", "Seung Uk Yoon", "Vaidyanathan Kripesh" ], "corpus_id": 43451307, "doc_id": "43451307", "n_citations": 21, "n_key_citations": 0, "score": 0, "title": "Development of coaxial shield via in silicon carrier for high frequency application", "venue": "2006 8th Electronics Packaging Technology Conference", "year": 2006 }, { "abstract": "Integrated fan out wafer level packaging (InFO WLP) technology with state of the art inductors (quality factor of 42 and self resonance frequency of 16 GHz) has been demonstrated for heterogeneous integration of digital and radio frequency (RF) systems. InFO WLP promises superior form factor, pin count, and thermal performance to existing flip chip ball grid array (FC BGA) packages. In addition, InFO WLP's high Q inductors can enhance electrical performance and lower power consumption in RF circuit applications.", "author_names": [ "C C Liu", "Shuo-Mao Chen", "Feng-Wei Kuo", "Huan-Neng Ron Chen", "En-Hsiang Yeh", "Cheng-chieh Hsieh", "Li-Hsien Huang", "M Y Chiu", "John Yeh", "Tsung-shu Lin", "Tzu-Jin Yeh", "S Y Hou", "J P Hung", "Jing-Cheng Lin", "Chewnpu Jou", "Chuei-Tang Wang", "Shin-puu Jeng", "D C H Yu" ], "corpus_id": 43514662, "doc_id": "43514662", "n_citations": 80, "n_key_citations": 8, "score": 0, "title": "High performance integrated fan out wafer level packaging (InFO WLP) Technology and system integration", "venue": "2012 International Electron Devices Meeting", "year": 2012 } ]

[ { "abstract": "As the semiconductor technology node scales into the deep submicrometer regime, it has become very difficult to obtain high IC yields because the process voltage temperature variations induce large spreads in delay and power. In this paper, we propose a new framework, called GenFin, which is, as far as we know, the first to target the multiobjective yield optimization of logic circuits. Since FinFETs are a promising substitute for CMOS at 22 nm technology node and beyond, we evaluate the framework with a 22 nm FinFET logic library. By combining the power of genetic algorithm (GA) and adaptive multiobjective optimization, GenFin produces a set of nondominated logic circuits whose timing, leakage power, and dynamic power yields are simultaneously optimized. This can help designers make tradeoff decisions wisely and avoid suboptimal solutions. We also propose an incremental statistical circuit analyzer, called incremental FinPrin, that speeds up the statistical static timing analysis by up to 9.6x and the statistical power analysis by up to 2235.7x, while incurring errors of only up to 0.031% in mean and 0.74% in standard deviation relative to nonincremental analysis. We use heuristics based on the deterministic timing analysis and gate criticality to reduce the GA search space and also improve the quality of its solutions. We present extensive experimental results to demonstrate the efficacy of GenFin.", "author_names": [ "Aoxiang Tang", "Niraj Kumar Jha" ], "corpus_id": 9400872, "doc_id": "9400872", "n_citations": 11, "n_key_citations": 0, "score": 1, "title": "GenFin: Genetic Algorithm Based Multiobjective Statistical Logic Circuit Optimization Using Incremental Statistical Analysis", "venue": "IEEE Transactions on Very Large Scale Integration (VLSI) Systems", "year": 2016 }, { "abstract": "Abstract To assess the economic benefits of battery reuse, the consistency and aging characteristics of a retired LiFePO4 battery pack are studied in this paper. The consistency of battery modules is analyzed from the perspective of the capacity and the internal resistance. Test results indicate that battery module parameter dispersion increases along with battery aging. However, battery modules with better capacity consistency doesn't ensure better resistance consistency. Then the aging characteristics of the battery pack are analyzed and the main results are as follow: (1) Weibull and normal distribution are feasible to fit the capacity and resistance distribution of battery modules respectively; (2) SOC imbalance is the dominating factor in the capacity fading process of the battery pack; (3) By employing the incremental capacity (IC) and IC peak area analysis, a consistency evaluation method representing the aging mechanism variations of the battery modules is proposed and then an accurate battery screening strategy is put forward. This study not only provides data support for evaluating economic benefits of retired batteries but also presents a method to recognize the battery aging variations, which is helpful for rapid evaluation and screening of retired batteries for 2nd use.", "author_names": [ "Yan Jiang", "Jiuchun Jiang", "Caiping Zhang", "Weige Zhang", "Yang Jun Gao", "Guo Qipei" ], "corpus_id": 114656343, "doc_id": "114656343", "n_citations": 74, "n_key_citations": 2, "score": 0, "title": "Recognition of battery aging variations for LiFePO 4 batteries in 2nd use applications combining incremental capacity analysis and statistical approaches", "venue": "", "year": 2017 }, { "abstract": "Traditionally, software development processes have relied on the use of the \"Waterfall\" and \"Vee\" models. Later, Agile methodologies were used to handle the challenges of managing complex projects during the development phase. Agile methodologies are a group of incremental and iterative methods that are more effective, and have been used in project management. Kanban and Scrum are two powerful Agile project management approaches in software development. The objective of Scrum and Kanban is achieved by optimizing the development process by identifying the tasks, managing time more effectively, and setting up teams. A review of the literature reveals that there is a lack of statistical evidence to conclude which methodology is more effective in dealing with the traditional project management factors of budget handling, risk control, quality of the project, available resources, having clear project scope, and schedule handling. This research statistically compares the effectiveness of the Scrum and Kanban methods in terms of their effects on the project management factors for software development projects. Numerical analysis is performed based on survey responses from those with experience in the Scrum and Kanban methods. Results suggest that both Scrum and Kanban lead to the development of successful projects, and that the Kanban method can be better than the Scrum method in terms of managing project schedule. Statistical analysis of Scrum vs. Kanban according to project management factors.Data obtained from surveys of people involved in software development.Analysis suggests that Kanban is slightly better than Scrum for the Schedule factor.", "author_names": [ "Howard Lei", "Farnaz Ganjeizadeh", "P Jayachandran", "Pinar Ozcan" ], "corpus_id": 111346146, "doc_id": "111346146", "n_citations": 104, "n_key_citations": 10, "score": 0, "title": "A statistical analysis of the effects of Scrum and Kanban on software development projects", "venue": "", "year": 2017 }, { "abstract": "Statistical measures provide essential and valuable information about data and are needed for any kind of data analysis. Statistical measures can be used in a purely exploratory context to describe properties of the data, but also as estimators for model parameters or in the context of hypothesis testing. For example, the mean value is a measure for location, but also an estimator for the expected value of a probability distribution from which the data are sampled. Statistical moments of higher order than the mean provide information about the variance, the skewness, and the kurtosis of a probability distribution. The Pearson correlation coefficient is a measure for linear dependency between two variables. In robust statistics, quantiles play an important role, since they are less sensitive to outliers. The median is an alternative measure of location, the interquartile range an alternative measure of dispersion. The application of statistical measures to data streams requires online calculation. Since data come in step by step, incremental calculations are needed to avoid to start the computation process each time new data arrive and to save memory so that not the whole data set needs to be kept in the memory. Statistical measures like the mean, the variance, moments in general, and the Pearson correlation coefficient render themselves easily to incremental computations, whereas recursive or incremental algorithms for quantiles are not as simple or obvious. Nonstationarity is another important aspect of data streams that needs to be taken into account. This means that the parameters of the underlying sampling distribution might change over time. Change detection and online adaptation of statistical estimators is required for nonstationary data streams. Hypothesis tests like the kh2 or the t test can be a basis for change detection, since they can also be calculated in an incremental fashion. Based on change detection strategies, one can derive information on the sampling strategy, for instance the optimal size of a time window for parameter estimations of nonstationary data streams.", "author_names": [ "Katharina Tschumitschew", "Frank Klawonn" ], "corpus_id": 124767872, "doc_id": "124767872", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Incremental Statistical Measures", "venue": "", "year": 2012 }, { "abstract": "Modeling and accuracy difficulties exist with traditional SSTA analysis and optimization methods. In this paper we describe methods to improve the efficiency of Monte Carlo based statistical static timing analysis. We propose a Stratification Hybrid Quasi Monte Carlo (SH QMC) approach to reduce the number of samples required for Monte Carlo based SSTA. Our simulations on benchmark circuits up to 90 K gates show that the proposed method requires 23.8X fewer samples on average to achieve comparable accuracy in timing estimation as a random sampling approach. Results on benchmark circuits also show that when SH QMC is performed with multiple parallel threads on a quad core processor, the approach is faster than traditional SSTA with comparable accuracy. SH QMC scales better than traditional SSTA with circuit size. We also propose an incremental approach to recompute a percentile delay metric after ECO. The results show that on average only 1.4% and 0.7% of original samples need to be evaluated for exact recomputation of the 95 percentile and 99 percentile delays, after sample size reduction using SH QMC.", "author_names": [ "Vineeth Veetil", "Dennis Sylvester", "David Blaauw" ], "corpus_id": 11344393, "doc_id": "11344393", "n_citations": 57, "n_key_citations": 5, "score": 0, "title": "Efficient Monte Carlo based incremental statistical timing analysis", "venue": "2008 45th ACM/IEEE Design Automation Conference", "year": 2008 }, { "abstract": "Incremental analysis is indispensible for efficient circuit optimization, as it analyzes the effect by the modified circuit part only instead of analyzing a whole circuit again from beginning. This paper presents a new incremental statistical static timing analysis (SSTA) method, called timing yield based incremental analysis (TYIA) TYIA uses the probability that the gate timing slack is non negative to prune the timing change propagation after a gate replacement. In the experimental results using ISCAS 85 benchmarks, TYIA showed 2~5 times better accuracy in timing yield analysis at comparable efficiency, when compared to the existing incremental SSTA methods.", "author_names": [ "Jin Wook Kim", "Wook Kim", "Hyoun Soo Park", "Young Hwan Kim" ], "corpus_id": 2911706, "doc_id": "2911706", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Incremental statistical static timing analysis with gate timing yield emphasis", "venue": "APCCAS 2008 2008 IEEE Asia Pacific Conference on Circuits and Systems", "year": 2008 }, { "abstract": "Abstract This work analyzes a database of 31 existing CO2 enhanced oil recovery (EOR) projects that was compiled for the estimation of oil reserves to better understand the CO2 retention, incremental oil recovery, and net CO2 utilization for these oil fields. The measured data begin at the start date of the CO2 flood and extend through the year 2007. Cumulative CO2 retention (in the formation) incremental oil recovery factors, and net CO2 utilization factors were calculated for each of the sites. To express all site data on a common dimensionless scale, the data were extrapolated to 300% cumulative hydrocarbon pore volume (HCPV) by fitting nonlinear functions. Summary statistics were then calculated from 0% to 300% HCPV. Across all 31 sites, the 10th, 50th (median) and 90th percentile values for the three factors at 300% HCPV were: CO2 retention: 23.1% 48.3% and 61.8% retained; incremental oil recovery: 5.3% 12.2% and 21.5% of OOIP (original oil in place) and net CO2 utilization: 4.8, 8.7, and 10.5 Mscf/STB (stock tank barrel) This work employs a novel approach that incorporates nonlinear functions to quantify uncertainty in the estimated values as a function of HCPV and to describe the shape of the CO2 retention or incremental oil recovery response with a handful of parameters, providing insight into the behavior of the reservoir across the entire timeline of the CO2 flood. These nonlinear curve fits are focused on statistical inference i.e. what is the likely outcome and uncertainty ranges for CO2 retention, incremental oil recovery, and net CO2 utilization given the historical data from the 31 CO2 EOR sites? However, the approach described in this work also provides useful information for prediction i.e. given a set of inputs from another site with similar geology, what are plausible ranges in outcomes for each of these factors? Consequently, the results of this work can be used to estimate the potential range of expected performance for similar candidate oil fields that are not currently undergoing CO2 injection, including estimates of the associated CO2 storage potential of these candidate fields. The results of this work allow estimation of CO2 storage capacity in CO2 EOR operations with various degrees of confidence. The sites in the dataset reflect water alternating gas CO2 floods all within the continental United States and heavily dominated by the West Texas carbonate floods. Other floods outside of this region, where the data were available, are also included in this study (i.e. the Rocky Mountain region and the State of Oklahoma)", "author_names": [ "Nicholas A Azzolina", "David V Nakles", "Charles D Gorecki", "Wesley D Peck", "Scott C Ayash", "L Stephen Melzer", "Sumon Chatterjee" ], "corpus_id": 129726433, "doc_id": "129726433", "n_citations": 74, "n_key_citations": 3, "score": 0, "title": "CO 2 storage associated with CO 2 enhanced oil recovery: A statistical analysis of historical operations", "venue": "", "year": 2015 }, { "abstract": "", "author_names": [ "Rafael Geraldeli Rossi", "Ricardo Marcondes Marcacini", "Solange Oliveira Rezende" ], "corpus_id": 63989025, "doc_id": "63989025", "n_citations": 18, "n_key_citations": 1, "score": 0, "title": "Analysis of Domain Independent Statistical Keyword Extraction Methods for Incremental Clustering", "venue": "", "year": 2014 }, { "abstract": "We propose the superiorization of incremental algorithms for tomographic image reconstruction. The resulting methods follow a better path in its way to finding the optimal solution for the maximum likelihood problem in the sense that they are closer to the Pareto optimal curve than the non superiorized techniques. A new scaled gradient iteration is proposed and three superiorization schemes are evaluated. Theoretical analysis of the methods as well as computational experiments with both synthetic and real data are provided.", "author_names": [ "Elias Salomao Helou", "Marcelo Victor Wust Zibetti", "Eduardo X Miqueles" ], "corpus_id": 91184528, "doc_id": "91184528", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Superiorization of incremental optimization algorithms for statistical tomographic image reconstruction", "venue": "", "year": 2016 }, { "abstract": "Article history: Ultrasonic vibration assisted single point incremental forming (UVaSPIF) is based on localized plastic deformation in a sheet metal blank. It consists of deforming gradually and locally the sheet metal using vibrating hemispherical head tool controlled by a CNC milling machine. The ultrasonic excitation of the forming tool reduces the vertical component of the forming force. In addition, application of ultrasonic vibration reduces the surface roughness of the specimen. Surface roughness is one of the quantitative and qualitative parameters, which is used to assess the quality of the final product. In the present paper, a statistical analysis and optimization of the effective factors on this parameter are performed in the UVaSPIF process. For this purpose, response surface methodology (RSM) is selected as the experiment design technique. The controllable factors such as vertical step size, sheet thickness, tool diameter, wall inclination angle, and feed rate are specified as input variables of the process. The obtained results from the analysis of variance (ANOVA) and regression analysis of the experimental data confirm the accuracy of the mathematical model. Furthermore, it is shown that the linear, quadratic, and interactional terms of the variables are effective on the surface roughness parameter. To optimize the surface roughness parameter, the most appropriate conditions of the experiment are determined using desirability method, and statistical optimization is subsequently verified by conducting the confirmation test.", "author_names": [ "Mehdi Vahdati", "Ramezanali Mahdavinejad", "Saeid Amini", "Mahmoud Moradi" ], "corpus_id": 55307434, "doc_id": "55307434", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Statistical Analysis and Optimization of Factors Affecting the Surface Roughness in the UVaSPIF Process Using Response Surface Methodology", "venue": "", "year": 2015 } ]

[ { "abstract": "This article describes an experimental comparative study of the matching between the Octo conventional (octagonal gate geometry) and Conventional (rectangular gate shape) n channel Metal Oxide Semiconductor (MOS) Field Effect Transistors (MOSFETs) which were manufactured in an 130 nm Silicon Germanium Bulk Complementary MOS (CMOS) Integrated Circuits (ICs) technology and exposed to different X rays Total Ionizing Doses (TIDs) under the on state bias conditions. The results indicate that the Octo layout style with alpha \\alpha angle equal to 90deg and a cut factor of 50% for MOSFETs is capable of boosting the device matching by at least 56.1% on average, regarding the electrical parameters studied (Threshold Voltage and Subthreshold Swing) as compared to those found in the Conventional MOSFET counterparts, considering that they present the same bias conditions and regarding different TIDs. This happens due to the Longitudinal Corner Effect (LCE) Parallel MOSFETs with Different Channel Length Effect (PAMDLE) and Deactivation of Parasitic MOSFETs in the Bird's Beak Regions Effect (DEPAMBBRE) which are present in the Octo MOSFETs. Therefore, the Octagonal layout style can be considered as an alternative hardness by design (HBD) layout strategy to boost the electrical performance and TID tolerance of MOSFETs enabling analog or radio frequency CMOS ICs applications.", "author_names": [ "Vinicius Vono Peruzzi", "William Souza da Cruz", "Gabriel Augusto da Silva", "Eddy Simoen", "Cor Claeys", "Salvador Pinillos Gimenez" ], "corpus_id": 228090829, "doc_id": "228090829", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Using the Octagonal Layout Style for MOSFETs to Boost the Device Matching in Ionizing Radiation Environments", "venue": "IEEE Transactions on Device and Materials Reliability", "year": 2020 }, { "abstract": "Digital Object Identifier 10.29292/jics.v15i2.185 Abstract This paper describes an experimental comparative study of the mismatching between the Diamond (hexagonal gate geometry) and Conventional (rectangular gate shape) n channel Metal Oxide Semiconductor (MOS) Field Effect Transistors (MOSFETs) which were manufactured in an 130 nm Silicon Germanium Bulk Complementary MOS (CMOS) technology and exposed to different X rays Total Ionizing Doses (TIDs) The results indicate that the Diamond layout style with an alpha angle equal to 90 for MOSFETs is capable of reducing the device mismatching by at least 17% regarding the electrical parameters studied as compared to the Conventional MOSFET (CnM) counterparts. Therefore, the Diamond layout style can be considered an alternative hardness by design (HBD) layout strategy to boost the electrical performance and TID tolerance of MOSFETs.", "author_names": [ "Vinicius Vono Peruzzi", "William Souza da Cruz", "Gabriel Augusto da Silva", "Eddy Simoen", "Cor Claeys", "Salvador Pinillos Gimenez" ], "corpus_id": 225463741, "doc_id": "225463741", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Using the Hexagonal Layout Style for MOSFETs to Boost the Device Matching in Ionizing Radiation Environments", "venue": "", "year": 2020 }, { "abstract": "This paper introduces a novel layout style with a reasonable generation algorithm for MOS analog modules in order to guarantee complete routing and perfect matching of devices. The introduced layout style is applicable to a variety of essential MOS analog circuits. To the transistor layout, we introduce a symmetrical row based structure where all transistors are transformed to matched pairs by duplicating sub netlists or decomposing into sub transistors. Further to these transistors, a generation algorithm is proposed to maximize the diffusion sharing along the current paths. Several design examples are used to demonstrate the effectiveness of the algorithm.", "author_names": [ "Bo Liu", "Shigetoshi Nakatake", "Bo Yang", "Gong Chen" ], "corpus_id": 40107519, "doc_id": "40107519", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Twin row style for MOS analog layout", "venue": "2016 IEEE International Conference on Electronics, Circuits and Systems (ICECS)", "year": 2016 }, { "abstract": "The accuracy and performance of analog integrated circuits often depends on the accuracy of component matching.Matching accuracy is guaranteed by the manufacturing process and layout design,which directly affect the performance of the final circuit.Based on analysis of CMOS analog layout design matching mechanism and study of common matching methods in paper,design methods is deeply discussed on the MOS transistor's common centroid layout of interdigitated structure.a basic amplifier layout is designed,and the detailed matching of input differential transistors and the current mirror are designed.", "author_names": [ "Li Liang" ], "corpus_id": 112195582, "doc_id": "112195582", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A CMOS Amplifier Layout Design Based on Matching Technology", "venue": "", "year": 2012 }, { "abstract": "A test chip with NMOS transistor pairs with different layout styles to study its influence on matching is presented. Common centroid structures are found to have much better matching performance than finger style structures. They show no systematic mismatch, and have a matching dependence on the channel area which is in agreement with measurement results on simple rectangle structures. Under die stress induced by packaging, finger style transistor pairs show a spread on transistor matching up to 5 times higher than the value predicted by only considering random fluctuation of the channel area.", "author_names": [ "J Bastos", "Michel S J Steyaert", "B Graindourze", "Willy M C Sansen" ], "corpus_id": 110590551, "doc_id": "110590551", "n_citations": 64, "n_key_citations": 3, "score": 1, "title": "Matching of MOS transistors with different layout styles", "venue": "Proceedings of International Conference on Microelectronic Test Structures", "year": 1996 }, { "abstract": "A new methodology for statistical mismatch analysis of MOS transistor pairs is presented. Size and shape, as well as placement and partitioning of devices are taken into account by using a statistical approach based on stochastic process theory. The method depends on device geometry and mutual distances between devices and has been developed by first defining a transformation which maps the statistical behavior of the technological parameters considered as sources of errors into the behavior of device parameters. A useful expression for the parameter mismatch variance depending on the layout has been derived by assuming a particular form for the autocorrelation function of process parameters. Finally, the method has been used to analyze and compare the mismatch effect on several interdigitated and common centroid structures.", "author_names": [ "Massimo Conti", "Paolo Crippa", "Simone Orcioni", "Claudio Turchetti" ], "corpus_id": 14189650, "doc_id": "14189650", "n_citations": 21, "n_key_citations": 1, "score": 0, "title": "Layout based statistical modeling for the prediction of the matching properties of MOS transistors", "venue": "", "year": 2002 }, { "abstract": "Two1 novel automatic generation methods for analog layout a symmetrical twin row method for MOS transistors and a twisted common centroid method for capacitor arrays are introduced. Based on the proposed layout styles and the corresponding algorithms, the symmetry and common centroid placement patterns for analog devices are realized to guarantee matching properties. On this basis, as the most prominent contribution of this article, channel routing based algorithms for the proposed layout styles are presented and could achieve 100% routability due to well arranged devices and corresponding low routing complexity. The algorithms benefits include a small layout area that maximizes the diffusion sharing of MOS transistors and less routing layer usage for common centroid device arrays. Moreover, we successfully applied our algorithms to the layout designs of two typical analog modules including a two stage operating amplifier and a Successive Approximation Register Analog to Digital Converter (SAR ADC) The generated layouts and the circuit simulation results demonstrate the effectiveness of our algorithms in terms of their routability and matching properties. Our algorithms can also be extended to apply to a variety of essential MOS analog circuits.", "author_names": [ "Bo Liu", "Gong Chen", "Bo Yang", "Shigetoshi Nakatake" ], "corpus_id": 49862504, "doc_id": "49862504", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Routable and Matched Layout Styles for Analog Module Generation", "venue": "ACM Trans. Design Autom. Electr. Syst.", "year": 2018 }, { "abstract": "Analysis of two layout designs used in the realization of MOS continuous time integrated filters is presented. The effect of MOS parasitic capacitances is thoroughly studied and compared in the two layout design techniques. It is found that one layout method performs well at high frequencies or high Q, at the expense of increased harmonic distortion in comparison with the other method. A tradeoff between transistor matching and sensitivity to MOS intrinsic parasitic capacitances is revealed. A set of performance graphs are developed with the ratio of parasitic to integrating capacitance, C/sub P//C, as a parameter. These graphs are useful in the design of high performance MOS continuous time integrated filters.", "author_names": [ "S V Smith", "Chung-Chih Hung", "Shu-Chuan Huang" ], "corpus_id": 62146653, "doc_id": "62146653", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Layout design considerations in MOS continuous time integrated filters", "venue": "Proceedings of APCCAS'94 1994 Asia Pacific Conference on Circuits and Systems", "year": 1994 }, { "abstract": "A sensefet monitoring is used for overload, open load detection and load current analog feedback. The sensefet matching properties to the main power mos represent the main quality factor of the device. Its current should be proportional to the main power one, maintaining the same coefficient over the entire temperature and biasing working range. In this work the effects of the edge cells layout and process are analyzed by the help of 3D device simulations. The causes for the real to theoretical ratio mismatch and the drift behavior versus the temperature are put into evidence. The corrective actions allow to reach 1/2% of drift in the range 40degC to 150degC. Only technological considerations are here faced, concerning the construction and optimization of the structure.", "author_names": [ "Rosalia Germana" ], "corpus_id": 37749901, "doc_id": "37749901", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Power mos current sensefet temperature drift study and improvement by the help of 3D simulations", "venue": "2012 24th International Symposium on Power Semiconductor Devices and ICs", "year": 2012 }, { "abstract": "Based on existing low voltage BCD technology,a 1mm 600VBCD process was developed in co operation with CSMC.In this process,600VLDMOS and high voltage isolation islands were integrated.A high voltage MOS gate drive circuit was designed and fabricated based on the process.With two independent inputs,the driver circuit had 1ms deadtime.Over current and under voltage protection circuit were integrated into the circuit.A double pulse level shifter was used to shift level from 15Vto 615V,and the layout of high side was reduced by 12%.Tape out results showed that the circuit had a floating bias voltage up to 750V,a rise time of 50ns at both high and low output,a delay matching time of 150ns,and maximum output current above 2A.The chip had rapid response and high reliability.", "author_names": [ "Fang Jian" ], "corpus_id": 111872915, "doc_id": "111872915", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "High Voltage MOS Gate Drive Circuit Based on 1mm 600 V BCD Process", "venue": "", "year": 2013 } ]

[ { "abstract": "The USB Revolution Robotic vision is the most fascinating and feasible application for neuromorphic engineering, since processing images in real time with low power consumption is the field's most critical requirement. Conventional machine vision systems have been implemented using CMOS (complimentary metal oxide semiconductor) imagers or CCD (charge coupled device) cameras that are interfaced to digital processing systems operating with serial algorithms. These systems often consume too much power, are too large, and compute with too high a cost.1 Though neuromorphic technology has advantages in these areas, there are some disadvantages too: current implementations have less programmable architectures, for example, than digital processing technologies. In addition, digital image processing has a long history and highly developed hardware and software for pattern recognition are readily available. We therefore think it is practical at least at the current stage of progress in neuromorphic engineering to combine neuromorphic sensors with conventional digital technology to implement, for robot vision, the computational essence of what the brain does. On this basis, we designed a neuromorphic vision system consisting of analog VLSI (very large silicon integration) neuromorphic chips and field programmable gate array (FPGA) circuits. Figure 1 shows a block diagram of the system, which consists of silicon retinas, 'simple cell' chips (named after the simple cell in the V1 area of the brain) and FPGA circuits. The silicon retina is implemented with active pixel sensors (conventionallysampled photo sensors)2 and has a concentric center surround Laplacian Gaussian like receptive field.2 Its output image is transferred to the simple cell chips serially. These chips then aggregate analog pixel outputs from the silicon retina to generate an orientation selective response similar to the simple cell response in the primary visual cortex.3 The architecture mimics the feed forward model proposed by Hubel and Wiesel,4 and efficiently computes the two dimensional Gabor like receptive field using the concentric center surround receptive field. The signal transfer from the silicon retina to the simple cell chip is performed using analog voltage, aided by analog memories embedded in each pixel of the simple cell chip. The output image of the simple cell chip is then converted into a digital signal and fed into the FPGA circuits, where the image is further processed with programReceptive field Silicon retina", "author_names": [ "Misha A Mahowald", "Carver Mead" ], "corpus_id": 5126325, "doc_id": "5126325", "n_citations": 189, "n_key_citations": 4, "score": 1, "title": "The silicon retina.", "venue": "Scientific American", "year": 1991 }, { "abstract": "A new rotation invariant pattern recognition system is proposed and analyzed. In this system, silicon retina cells capable of image sensing and edge extraction are used so that the system can directly process images from the real world without an extra edge detector. The rotation invariant discrete correlation function is modified and implemented in the silicon retina structure by using the current summation. Simulation results have verified the correct function of the proposed system. Moreover, an experimental chip to implement the proposed system with a 32/spl times/32 cell array has been designed and fabricated in 0.8 /spl mu/m n well CMOS process. Experimental results have successfully shown that the system works well for the arbitrary orientation pattern recognition.", "author_names": [ "Chin-Fong Chiu", "Chung-Yu Wu" ], "corpus_id": 54606077, "doc_id": "54606077", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "The design of rotation invariant pattern recognition using the silicon retina", "venue": "", "year": 1997 }, { "abstract": "In this paper a new stereo matching concept for event driven silicon retinae is presented. The main contribution of the proposed approach is the correlation of incoming events. As a novelty, not only the spatial information is used, but also the time of occurrence of the events as a part of the similarity measure. Stereo matching is used in depth generating camera systems for solving the correspondence problem and for 3D reconstruction of the sensed environment. In fact, using conventionally frame based cameras, this is a time consuming and computationally expensive task, especially for high frame rates and spatial resolutions. An event based silicon retina delivers events only on illumination changes and completely asynchronous in time. The sensor provides no frames, but a time continuous data stream of intensity differences and thus inherently reduces the visual information to a minimum. This paper focuses on an event based stereo matching algorithm implemented in hardware on a field programmable gate array (FPGA) that allows a reliable matching of the sparse input event data. Furthermore, the approach is compared to other standard frame based and event driven stereo methods. The results show that the achieved depth map outperforms other algorithms in terms of accuracy and the calculation performance of the hardware architecture is in the range or still higher than state of the art computing platforms.", "author_names": [ "Florian Eibensteiner", "Hans Georg Brachtendorf", "Josef Scharinger" ], "corpus_id": 37664826, "doc_id": "37664826", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Event driven stereo vision algorithm based on silicon retina sensors", "venue": "2017 27th International Conference Radioelektronika (RADIOELEKTRONIKA)", "year": 2017 }, { "abstract": "In this paper, we present: (i) a novel analog silicon retina featuring auto adaptive pixels that obey the Michaelis Menten law, i.e. V=V(m) I(n)/I(n)+s(n) (ii) a method of characterizing silicon retinas, which makes it possible to accurately assess the pixels' response to transient luminous changes in a 3 decade range, as well as changes in the initial steady state intensity in a 7 decade range. The novel pixel, called M(2)APix, which stands for Michaelis Menten Auto Adaptive Pixel, can auto adapt in a 7 decade range and responds appropriately to step changes up to 3 decades in size without causing any saturation of the Very Large Scale Integration (VLSI) transistors. Thanks to the intrinsic properties of the Michaelis Menten equation, the pixel output always remains within a constant limited voltage range. The range of the Analog to Digital Converter (ADC) was therefore adjusted so as to obtain a Least Significant Bit (LSB) voltage of 2.35mV and an effective resolution of about 9 bits. The results presented here show that the M(2)APix produced a quasi linear contrast response once it had adapted to the average luminosity. Differently to what occurs in its biological counterparts, neither the sensitivity to changes in light nor the contrast response of the M(2)APix depend on the mean luminosity (i.e. the ambient lighting conditions) Lastly, a full comparison between the M(2)APix and the Delbruck auto adaptive pixel is provided.", "author_names": [ "Stefano Mafrica", "Stephanie Godiot", "Mohsine Menouni", "Marc Boyron", "Fabien Expert", "Raphael Juston", "Nicolas Marchand", "Franck Ruffier", "Stephane Viollet" ], "corpus_id": 19608231, "doc_id": "19608231", "n_citations": 17, "n_key_citations": 4, "score": 0, "title": "A bio inspired analog silicon retina with Michaelis Menten auto adaptive pixels sensitive to small and large changes in light.", "venue": "Optics express", "year": 2015 }, { "abstract": "A new silicon retina structure in CMOS is proposed and analyzed, which incorporates a parasitic phototransistor as an isolated photoreceptor with many phototransistors in a common well region. The smooth function is achieved by the diffusion of photogenerated carriers in the common well. Experimental results have verified the correct functions of the new structure as a silicon retina. Small chip area and compact wiring make the new structure quite realizable with the associated neural networks in VLSI.<ETX>", "author_names": [ "Chung-Yu Wu", "Chin-Fong Chiu" ], "corpus_id": 114546204, "doc_id": "114546204", "n_citations": 9, "n_key_citations": 2, "score": 0, "title": "A new structure for the silicon retina", "venue": "1992 International Technical Digest on Electron Devices Meeting", "year": 1992 }, { "abstract": "Optical flow sensors have been a long running theme in neuromorphic vision sensors which include circuits that implement the local background intensity adaptation mechanism seen in biological retinas. This paper reports a bio inspired optical motion sensor aimed towards miniature robotic and aerial platforms. It combines a 20 x 20 continuous time CMOS silicon retina vision sensor with a DSP microcontroller. The retina sensor has pixels that have local gain control and adapt to background lighting. The system allows the user to validate various motion algorithms without building dedicated custom solutions. Measurements are presented to show that the system can compute global 2D translational motion from complex natural scenes using one particular algorithm: the image interpolation algorithm (I2A) With this algorithm, the system can compute global translational motion vectors at a sample rate of 1 kHz, for speeds up to 1000 pixels/s, using less than 5 k instruction cycles (12 instructions per pixel) per frame. At 1 kHz sample rate the DSP is 12% occupied with motion computation. The sensor is implemented as a 6 g PCB consuming 170 mW of power.", "author_names": [ "Shih-Chii Liu", "Minhao Yang", "Andreas Steiner", "Rico Moeckel", "Tobi Delbruck" ], "corpus_id": 30023786, "doc_id": "30023786", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "1 kHz 2D Visual Motion Sensor Using 20$\\times\\$20 Silicon Retina Optical Sensor and DSP Microcontroller", "venue": "IEEE Transactions on Biomedical Circuits and Systems", "year": 2015 }, { "abstract": "Abstract In the Background section of the proposal I described the basic conceptual elements which underlie the Silicon Retina (SR) and those which underlie passive mammalian hearing. My original intention was to utilize the frequency discrimination capability manifested in mammalian hearing as the mechanism on which to base an acoustic analogue to the SR concept. Specifically, mammals have sophisticated frequency dependent sensors which transmit responses to discrete and well resolved frequencies upward to higher processing levels. Each intermediate processor transmits the precise frequency information upstream. Thus one may think of acoustic frequencies as being analogous to visual positional information, since in the ray limit of optics there is a one to one correspondence between the relative locations of external objects and the retinal sensors which are stimulated at any given time. The SR mechanism was to be implemented by comparing individual frequencies with running averages over groups of nearby frequencies, eliciting a response when the intensities of these differed by a prescribed amount. The next step in the program was to remain open minded regarding the implementation of directional acoustic arrays, with the idea pf steering an array making use of the 'alert' response created by the introduction of a non background signal. In this way it was envisioned that the 'cocktail party effect' would be achieved.", "author_names": [ "Jorge F Willemsen" ], "corpus_id": 109386826, "doc_id": "109386826", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Feasibility Assessment of a Transient Sound Sensor Based on the Silicon Retina Architecture", "venue": "", "year": 1992 }, { "abstract": "This paper provides a personal perspective on human vision and event based vision sensors, algorithms, and applications over the period of last decade. The comparison between the standards of biology and technology has been the major focus throughout. Some recent advancements in the field are also briefly described.When Mahowald and Mead built the first silicon retina with asynchronous digital output around 1992 1 conventional CMOS active pixel sensors (APS) were still research chips. It required the investment by industry of about a billion dollars to bring CMOS APS to high volume production. So it is no surprise that while the imager community has been consumed by the megapixel race to make nice photos, cameras that mimic more closely how the eye works have taken a long time to come to a useful form. These \"silicon retinas\" are much more complex at the pixel level than APS cameras and they pay the price in terms of fill factor and pixel size; machine vision cameras with capability of synchronous global electronic shutter are about 5um. Silicon retina pixels are roughly 10 times the area of a machine vision camera pixel. So why are silicon retinas still interesting? What was the nessesity to mimic the biological eye? Mostly because of the high cost at the system level of processing the highly redundant data from conventional cameras, and the fixed latencies imposed by the frame intervals. High performance activitydriven event based sensors could greatly benefit applications in real time robotics, where just as in nature, latency and power are very important 2 3 Still is this the closest that technology brought the field towards biology? What important ascpect are missing to make a bionic eye? These are the few aspects that are througly discussed throughout this paper. 1 Mahowald, M.A. An Analog VLSI System for Stereoscopic Vision. Kluwer, Boston (1994) 2 Lichtsteiner, P. Posch, C. Delbruck, T. A 128x128 120 dB 15 ms latency asynchronous temporal contrast vision sensor. IEEE Journal of Solid State Circuits 43(2) 566 576 (2008) 3 Liu, S.C. van Schaik, A. Minch, B.A. Delbruck, T. Event based 64 channel binaural silicon cochlea with Q enhancement mechanisms. In: IEEE ISCAS 2009, pp. 2426 2429 (2010) Comparison between Human and Silicon Retina 5", "author_names": [ "Hauptseminar Neuroengineering", "Marcello Mulas" ], "corpus_id": 33981163, "doc_id": "33981163", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Comparison between Human and Silicon Retina 2", "venue": "", "year": 2015 }, { "abstract": "In this paper we present a new approach for the evaluation of event based Silicon Retina stereo matching results. The evaluation of stereo matching algorithm results is a necessary task for the development, comparison, and improvement of depth generating camera systems. In contrast to conventional frame based cameras, the silicon retina sensors delivers asynchronous events instead of synchronous intensity or color images. The polarity of the events represents either an increase (on event) or a decrease (off event) of the brightness of the projected scene point. This is the reason why existing ground truth data and evaluation platforms are not suitable for testing silicon retina stereo camera systems. For the analysis of the introduced novel evaluation method, we use an area based (sum of absolute difference) algorithm for the event driven sensor system. A conventional video camera stereo vision system is used to produce reference data. The results show that the presented method offers new opportunities for the evaluation of stereo matching results computed from silicon retina stereo data.", "author_names": [ "Jurgen Kogler", "Florian Eibensteiner", "M Humenberger", "Margrit Gelautz", "Josef Scharinger" ], "corpus_id": 6258804, "doc_id": "6258804", "n_citations": 9, "n_key_citations": 2, "score": 0, "title": "Ground Truth Evaluation for Event Based Silicon Retina Stereo Data", "venue": "2013 IEEE Conference on Computer Vision and Pattern Recognition Workshops", "year": 2013 }, { "abstract": "ii Zusammenfassung iv", "author_names": [ "Minhao Yang" ], "corpus_id": 87112629, "doc_id": "87112629", "n_citations": 4, "n_key_citations": 2, "score": 0, "title": "Silicon Retina and Cochlea with Asynchronous Delta Modulator for Spike Encoding", "venue": "", "year": 2015 } ]

[ { "abstract": "ABSTRACT In this research, pure SnO2 was deposited on 316 stainless steel plates using air plasma spraying. Micrograph and phase composition of the deposited films were studied using SEM and X ray diffraction, respectively; and methylene blue solution was used to evaluate the activity of the deposited photocatalytic coatings. It was shown that air plasma spraying could be used as an efficient method to deposit pure SnO2 photocatalytic coatings. UV vis diffuse reflectance spectra analysis showed higher photo absorption ability of the deposited films as compared to the initial powder. Although all the tin oxide coatings had lower band gap energy than the initial powder, further studies are needed to deposit SnO2 films, which can act as photocatalytic coatings under visible light irradiation. Comparison of the photocatalytic activity of tin oxide coatings with that of ZnO film showed the adequate activity of tin oxide coatings deposited by air plasma spraying.", "author_names": [ "Amir Hossein Navidpour", "Mohammad Bagher Fakhrzad", "Mostafa Tahari", "Sedigheh Abbasi" ], "corpus_id": 139755927, "doc_id": "139755927", "n_citations": 16, "n_key_citations": 1, "score": 1, "title": "Novel photocatalytic coatings based on tin oxide semiconductor", "venue": "", "year": 2019 }, { "abstract": "Titanium dioxide based photocatalysts have some major drawbacks that cannot be overcome at present. Firstly, the photocatalytic reaction rates are typically very low, which makes this technology not appropriate for high throughput processes, such as detoxification of highly polluted industrial waste or disinfection of heavily soiled surfaces. Secondly, only UV light can be utilized for activation of titania based materials, which is less than 5% of solar spectrum. Therefore, there is an obvious need for development of novel efficient low band gap semiconductors that can be activated using visible light and thus provide an effective, environmentally friendly solution for water treatment. Magnetron sputtering is a simple and versatile method used for the deposition of thin films, readily scalable and widely used in both laboratories and industrial production facilities, including production of photocatalytic coatings. In the present work several narrow band gap semiconductor coatings have been produced by pulsed DC magnetron sputtering and studied as potential alternatives to TiO 2 based photocatalysts. Thin films of bismuth complex oxides (molybdate and tungstate) tantalum oxynitride and nitride and cerium dioxide have been deposited onto variety of substrates and analysed by a range of methods, including SEM/EDX, XRD, TEM, XPS and Raman spectroscopy. The photocatalytic properties of the coatings were studied both under UV and visible light sources using dye degradation tests. The results of the photocatalytic tests were compared to a commercially available photocatalytic material. The results of the study revealed that, with optimised deposition conditions, the narrow band gap semiconductors studied have potential as alternatives to traditional TiO 2 based photocatalysts, demonstrating visible light activity superior to a sample of commercial photocatayst. The influence of deposition conditions and post deposition processing on photocatalytic properties are also discussed.", "author_names": [ "Marina Ratova", "Peter J Kelly", "G T West" ], "corpus_id": 222105299, "doc_id": "222105299", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Deposition of narrow band semiconductor coatings by pulsed DC magnetron sputtering for visible light photocatalysis applications", "venue": "", "year": 2016 }, { "abstract": "Thin film technology for device applications are based on material structures created by thin film deposition and characterization [1] In recent time, there are growing demands for more efficient solar cell technology and also electronic devices that could operate at high power levels. Suitable thin films for these applications require wide band gap, high optical conductivity, high transparency and stability at higher temperature [2] The numerous varieties of electronic, optical and solid state properties of metal oxides make them suitable materials for basic research that results in invention of novel systems and improvement on the exiting. Oxides have a wide range of properties from wide band gap insulators, metallic to superconducting. Tin oxide belongs to a class of materials called Transparent Conducting Oxides (TCO) constituting an important component for optoelectronic applications [3] Tin oxide thin films have some useful applications in visible light and infrared light. It has low electrical sheet resistance, rendering it suitable for a wide variety of applications as gas sensors, electrodes in solar cells, infrared reflectors for glass windows, transparent electrodes in electroluminescent lamps and displays [4, 5] Other useful properties are high mechanical hardness and good environmental stability. Tin Oxide (SnO2) is a n type semiconductor with wide energy band gap (3.7 eV) [6] The methodology employed for thin film deposition ranges from very simple and cheap to complex and very expensive depending on the substrate type, material to be deposited and the required performance of the films [7] In this work, the spin coating deposition which is a simple, quick and relatively cost effective technique was adopted. UVVis spectrophotometer and scanning electron microscopy are used to characterize the spin coated SnO2 film grown on glass substrates at room temperature. Abstract: This work consists of the preparation of thin film of tin oxide using automated spin coating technique. Investigations of the surface morphology and optical characteristics of the deposited films were examined. Thin film of tin oxide (SnO2) is a special class of transparent metal oxides that combine high optical conductivity with high transparency. Such Transparent Conducting Oxide (TCO) provides an important component for optoelectronic applications. The transmittance and reflectance spectra were obtained with a UVVis spectrophotometer while the microphotograph was obtained using a scanning electron microscope. The thin film produced has high transparency, wide band gap and low dielectric constant. Optical characterization was done over a range of wavelength of 250 nm to 1000 nm which corresponds to photon energy between 1.2 eV to 5.0 eV. The average transmittance is 85 average optical conductivity is 0.032 x 10 16 S 1 average extinction coefficient is 1.25, average real dielectric constant is 7.5 and the band gap energy is estimated to be 3.78 eV. The SEM micrograph of the SnO2 film shows the existence of some agglomerates of small rounded particles. Tin oxide thin films have a number of applications such as in optical coatings, high temperature superconductivity and communication, solar cell fabrication especially as an absorption layer and a transparent contact.", "author_names": [ "Sunday Samuel Oluyamo" ], "corpus_id": 167215226, "doc_id": "167215226", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Spin Coated Tin Oxide Thin Film For Optical And Optoelectronic Material Applications", "venue": "", "year": 2016 }, { "abstract": "Photocatalysis is a potential technology for removing pollutants from water. As the recombination of the photogenerated electron hole pairs can hinder the photocatalytic efficiency in the treatment of wastewater, the surface of the carrier is usually coated with a semiconductor. In this study, carbon microtube electrode prepared from corncob was coated with either titanium oxide (TiO2) or bismuth phosphate (BiPO4) and then used as a photocatalyst (C TiO2 or C BiPO4) to investigate the photodegradation of methylene blue (MB) The two photocatalysts, C TiO2 and C BiPO4, were characterized by phase determination, microstructure observation, water contact angle measurement, and base site analysis. The influences of reaction time, stability, MB concentration, initial pH, and OH radicals quenching on the degradation of MB were also evaluated. The degradation of MB by C TiO2 and C BiPO4 was mainly dominated by OH radical oxidation. The carbon microtube increased both the mass transfer rate and the photogenerated electron hole pairs separation rate, thereby increasing the photocatalysis of both C TiO2 and C BiPO4 as revealed by an increase in the rate of MB degradation. The rate constants obtained for the degradation of MB by C TiO2 and C BiPO4 at 20 degC were 9.739 x 10 7 mM min 1 and 1.111 x 10 7 mM min 1, respectively. The coating of TiO2 and BiPO4 on the surface of the carbon microtube electrode enhanced their photocatalytic performance, and therefore, C TiO2 and C BiPO4 could be developed into a novel material to be used in the photodegradation of dye pollutants.", "author_names": [ "Tian Xia", "Zengling Ma", "Manqing Ai", "Kairong Qian", "Shunan Zhu", "Mengwei Rong", "Pingping Zhang", "Ying Ye", "Wenli Qin" ], "corpus_id": 227182169, "doc_id": "227182169", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Photocatalyst coated carbon microtube electrodes: Preparation and characterization of their properties and photocatalytic degradation of methylene blue.", "venue": "Chemosphere", "year": 2020 }, { "abstract": "Surface temperature measurements of ceramic matrix composite (CMC) based engine components within the hot section of a gas turbine engines are needed to verify engine designs and cooling requirements. Traditional temperature sensors cannot be applied to silicon carbide (SiC) based CMC's for this purpose, since they cannot be welded or embedded in the material. For these reasons, a novel thermocouple was developed for surface temperature measurement of p type SiC SiC CMC's. This novel thermocouple uses the p type SiC SiC CMC itself as one of the thermoelements and indium tin oxide (ITO) as the other thermoelement. Since both thermoelements are wide bandgap semiconductors, this thermocouple has exceptional thermoelectric output. A thermoelectric output of 272 mV/degK was observed for this ITO:SiC CMC thermocouple, which is an order of magnitude larger than that of type K thermocouples. A drift rate of 3.28 degC/h was measured for this ITO:SiC CMC thermocouple. In addition, indium tin oxynitride (ITON) protective coatings deposited via reactive sputtering enabled these thermocouples to operate at 1000 degC. The ITON coating served as an oxygen diffusion barrier to prevent oxidation at the ITO:SiC CMC junction. Nitrogen and air anneals at 550 and 1000 degC, respectively, were used to improve the high temperature stability of the ITO and ITON coatings. Performance, fabrication details, and challenges using these ITO:SiC CMC thermocouple are discussed within.", "author_names": [ "Kevin Rivera", "Otto J Gregory" ], "corpus_id": 218833425, "doc_id": "218833425", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "ITO:SiC Ceramic Matrix Composite Thermocouples for Engine Components", "venue": "IEEE Sensors Letters", "year": 2020 }, { "abstract": "Abstract Cupric oxide (CuO) is a semiconductor of choice for photocathode in photoelectrochemical (PEC) applications due to its great sunlight absorption capability. However, photocorrosion is the main drawback of CuO. Herein, CuO/graphitic carbon nitride (g C3N4) with a unique microstructure, enhanced PEC performance, and considerable photostability is synthesized under microwave irradiation. A facile, one pot method is utilized to directly deposit the nanocomposite onto fluorine doped tin oxide from a solution containing copper precursor and urea. Possible mechanism of CuO/g C3N4 formation through this novel method is investigated. It is elucidated that controlled amounts of urea critically determine the morphological evolution of CuO, while its excess quantities convert to g C3N4 in the presence of CuO as the catalyst. Through an appropriate heat treatment, carbon is doped into CuO lattice. The obtained C doped CuO/g C3N4 demonstrates 227% enhancement over CuO in photocurrent density and ~80% photocurrent retention. The enhanced photoelectrocatalytic activity is mainly attributed to unique morphology of CuO, effective separation of charge carriers, and formation of heterojunction. These characteristics manifest the superiority of this approach over many other chemical based methods. The nanocomposite synergistically integrates the advantages of both the constituents, offering a low cost, efficient photocathode for PEC water splitting, photocatalytic hydrogen evolution, and degradation of pollutants.", "author_names": [ "Seyed Morteza Hosseini H", "Roozbeh Siavash Moakhar", "Foad Soleimani", "Sayed Khatiboleslam Sadrnezhaad", "Saeid Masudy-Panah", "Reza Katal", "Ashkan Seza", "Navid Ghane", "Seeram Ramakrishna" ], "corpus_id": 224884635, "doc_id": "224884635", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "One pot microwave synthesis of hierarchical C doped CuO dandelions/g C3N4 nanocomposite with enhanced photostability for photoelectrochemical water splitting", "venue": "", "year": 2020 }, { "abstract": "Abstract The microstructure, optical and electrical properties of CrAlN and (Cr, Al) films synthesized by DC reactive magnetron sputtering method have been comparatively investigated. The results show that CrAlN film crystallizes in B1 NaCl typed CrN structure with the preferred growth orientations of (1 1 1) and (2 2 0) and CrAlN grains show perfectly crystalline pyramid like shape. The CrAlN film is determined as Al doped CrN phase with the chemical formula of Cr 0.9136 Al 0.0864 N 0.8999 It shows similar reflectance and absorptance characteristics to those of TiN based films in the solar spectrum region (300 2600 nm) and exhibits semiconductor nature with a sheet resistance of 38 kO/sq. Hence CrAlN can be used as a novel candidate material for high temperature solar selective absorber coatings with good thermal stability and oxidation resistance.", "author_names": [ "Jianlin Chen", "Chen Guo", "Jian Chen", "Jian-jun He", "Yanjie Ren", "Hu Linlin" ], "corpus_id": 136792203, "doc_id": "136792203", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "Microstructure, optical and electrical properties of CrAlN film as a novel material for high temperature solar selective absorber applications", "venue": "", "year": 2014 }, { "abstract": "The ability to control the position and orientation of nanorods in a device is interesting both from a scientific and a technological point of view. Because semiconductor nanorods exhibit anisotropic absorption, and spontaneous and stimulated emission, aligning individual NRs to a preferred axis is attractive for many applications in photonics such as solar cells, light emitting devices, optical sensors, switches, etc. Electric field driven deposition from colloidal suspensions has proven to be an efficient method for the controlled positioning and alignment of anisotropic particles. In this work, we present a novel technique for the homogeneous deposition and alignment of CdSe/CdS NRs on a glass substrate patterned with transparent indium tin oxide interdigitated electrodes, with a spacing of a few micrometers. This method is based on applying a strong AC electric field over the electrodes during a dip coating procedure and subsequent evaporation of the solvent. The reproducible and homogeneous deposition on large substrates is required for large size applications such as solar cells or OLEDs. The accumulation, alignment, and polarized fluorescence of the nanorods as a function of the electrical field during deposition are investigated. A preferential alignment with an order parameter of 0.92 has been achieved.", "author_names": [ "Mohammad Mohammadimasoudi", "Lieven Penninck", "Tangi Aubert", "Raquel Gomes", "Zeger Hens", "Filip Strubbe", "Kristiaan Neyts" ], "corpus_id": 55549563, "doc_id": "55549563", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Polarized light emission by deposition of aligned semiconductor nanorods", "venue": "Optics Photonics NanoScience Engineering", "year": 2014 }, { "abstract": "In this paper, we present a highly efficient SnS nanoparticle sensitized zinc oxide (ZnO) nanorod based photocatalyst, which can degrade strong organic dyes under direct exposure to sunlight. The thermal decomposition technique was adopted to prepare crystalline ZnO nanorods, which were subsequently sensitized with a narrow bandgap semiconductor, namely tin sulfide (SnS) via in situ and ex situ sensitization processes. Here, SnS acts as a photosensitizer to expand the light absorption range from the UV VIS NIR spectral region. In addition, the formation of the SnS/ZnO heterostructure suppresses the electron hole pair recombination via the formation of a p n heterojunction and enhances the separation of photoexcited charge carriers. Thereafter, the photocatalytic activity of the pristine ZnO nanorods and sensitized SnS/ZnO nanorods was investigated in the degradation of three different strong dyes under sunlight illumination. It was observed that the in situ sensitization process helps in achieving a uniform coating of SnS over the surface of the ZnO nanorods, which resulted in an enhanced photocatalytic performance in dye degradation in comparison to the ex situ sensitized SnS/ZnO nanorods and pristine ZnO nanorods. The rate constants for the in situ sensitized SnS/ZnO nanorods determined from experimental data were found to be 0.0245 min 1, 0.0212 min 1 and 0.0139 min 1 in the photodegradation of Rhodamine 6G, Rhodamine B, and Methyl Orange dyes, respectively. Thus, we can infer from our experimental results that the in situ sensitized SnS/ZnO nanorods could be an economical and promising inorganic photocatalytic material, in addition to the TiO2 photocatalyst for photodegradation of toxic organic dyes present in water.", "author_names": [ "Shefali Jayswal", "Rakesh S Moirangthem" ], "corpus_id": 103071837, "doc_id": "103071837", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Construction of a solar spectrum active SnS/ZnO p n heterojunction as a highly efficient photocatalyst: the effect of the sensitization process on its performance", "venue": "", "year": 2018 }, { "abstract": "TiO2 nanotube semiconductors contain free spaces in their interior that can be filled with active materials such as chemical compounds, enzymes, and noble metals, giving them a fundamental advantage over colloids. Although the unique shape of semiconductor nanotubes makes them promising for a range of potential applications, significant developmental research is required. In this research, a novel TiO2 nanotube photocatalyst was prepared that has a p n junction. The photocatalyst particle surface is physically divided into reduction and oxidation surfaces, which poses a potential driving force for the transport of photogenerated charge carriers. The structure of this nanotube catalyst was characterized using a scanning electron microscope (SEM) and X ray diffraction (XRD) The catalyst activity was evaluated by coating the catalyst on HEPA filters and determining the destruction rate of toluene in air. The p n junction nanotube catalyst was shown to have a much higher photocatalytic destruction rate than that of commercially available, nonnanotube structured material, and a higher destruction rate for nanotube catalysts that did not contain a p n junction.", "author_names": [ "Yongsheng Chen", "John C Crittenden", "Stephen A Hackney", "Lawrence L Sutter", "David W Hand" ], "corpus_id": 19175999, "doc_id": "19175999", "n_citations": 259, "n_key_citations": 3, "score": 0, "title": "Preparation of a novel TiO2 based p n junction nanotube photocatalyst.", "venue": "Environmental science technology", "year": 2005 } ]

[ { "abstract": "Single walled carbon nanotubes (SWNTs) are a family of molecules that have the same cylindrical shape but different chiralities. Many fundamental studies and technological applications of SWNTs require a population of tubes with identical chirality that current syntheses cannot provide. The SWNT sorting problem that is, separation of a synthetic mixture of tubes into individual single chirality components has attracted considerable attention in recent years. Intense efforts so far have focused largely on, and resulted in solutions for, a weaker version of the sorting problem: metal/semiconductor separation. A systematic and general method to purify each and every single chirality species of the same electronic type from the synthetic mixture of SWNTs is highly desirable, but the task has proven to be insurmountable to date. Here we report such a method, which allows purification of all 12 major single chirality semiconducting species from a synthetic mixture, with sufficient yield for both fundamental studies and application development. We have designed an effective search of a DNA library of ~1060 in size, and have identified more than 20 short DNA sequences, each of which recognizes and enables chromatographic purification of a particular nanotube species from the synthetic mixture. Recognition sequences exhibit a periodic purine pyrimidines pattern, which can undergo hydrogen bonding to form a two dimensional sheet, and fold selectively on nanotubes into a well ordered three dimensional barrel. We propose that the ordered two dimensional sheet and three dimensional barrel provide the structural basis for the observed DNA recognition of SWNTs.", "author_names": [ "Xiaomin X Tu", "Suresh Manohar", "Anand Jagota", "Ming Zheng" ], "corpus_id": 4417004, "doc_id": "4417004", "n_citations": 882, "n_key_citations": 16, "score": 1, "title": "DNA sequence motifs for structure specific recognition and separation of carbon nanotubes", "venue": "Nature", "year": 2009 }, { "abstract": "Carbon nanotubes are man made one dimensional carbon crystals with different diameters and chiralities. Owing to their superb mechanical and electrical properties, many potential applications have been proposed for them. However, polydispersity and poor solubility in both aqueous and non aqueous solution impose a considerable challenge for their separation and assembly, which is required for many applications. Here we report our finding of DNA assisted dispersion and separation of carbon nanotubes. Bundled single walled carbon nanotubes are effectively dispersed in water by their sonication in the presence of single stranded DNA (ssDNA) Optical absorption and fluorescence spectroscopy and atomic force microscopy measurements provide evidence for individually dispersed carbon nanotubes. Molecular modelling suggests that ssDNA can bind to carbon nanotubes through p stacking, resulting in helical wrapping to the surface. The binding free energy of ssDNA to carbon nanotubes rivals that of two nanotubes for each other. We also demonstrate that DNA coated carbon nanotubes can be separated into fractions with different electronic structures by ion exchange chromatography. This finding links one of the central molecules in biology to a technologically very important nanomaterial, and opens the door to carbon nanotube based applications in biotechnology.", "author_names": [ "Ming Zheng", "Anand Jagota", "Ellen D Semke", "Bruce A Diner", "Robert S McLean", "Steven R Lustig", "Raymond E Richardson", "Nancy G Tassi" ], "corpus_id": 37635705, "doc_id": "37635705", "n_citations": 2153, "n_key_citations": 51, "score": 0, "title": "DNA assisted dispersion and separation of carbon nanotubes", "venue": "Nature materials", "year": 2003 }, { "abstract": "For a successful analysis of the relation between amino acid sequence and protein structure, an unambiguous and physically meaningful definition of secondary structure is essential. We have developed a set of simple and physically motivated criteria for secondary structure, programmed as a pattern recognition process of hydrogen bonded and geometrical features extracted from x ray coordinates. Cooperative secondary structure is recognized as repeats of the elementary hydrogen bonding patterns \"turn\" and \"bridge.\" Repeating turns are \"helices,\" repeating bridges are \"ladders,\" connected ladders are \"sheets.\" Geometric structure is defined in terms of the concepts torsion and curvature of differential geometry. Local chain \"chirality\" is the torsional handedness of four consecutive Ca positions and is positive for right handed helices and negative for ideal twisted b sheets. Curved pieces are defined as \"bends.\" Solvent \"exposure\" is given as the number of water molecules in possible contact with a residue. The end result is a compilation of the primary structure, including SS bonds, secondary structure, and solvent exposure of 62 different globular proteins. The presentation is in linear form: strip graphs for an overall view and strip tables for the details of each of 10.925 residues. The dictionary is also available in computer readable form for protein structure prediction work.", "author_names": [ "Wolfgang Kabsch", "Christian A Sander" ], "corpus_id": 29185760, "doc_id": "29185760", "n_citations": 12686, "n_key_citations": 697, "score": 0, "title": "Dictionary of protein secondary structure: Pattern recognition of hydrogen bonded and geometrical features", "venue": "Biopolymers", "year": 1983 }, { "abstract": "Publisher Summary This chapter discusses the specific synthesis of deoxyribonucleic acid (DNA) in vitro through the medium of a polymerase catalyzed chain reaction. A method whereby a nucleic acid sequence can be exponentially amplified in vitro is described in the chapter. The same method can be used to alter the amplified sequence or to append new sequence information to it. It is necessary that the ends of the sequence be known in sufficient detail that oligonucleotides can be synthesized, which will hybridize to them and that a small amount of the sequence be available to initiate the reaction. The oligonucleotides are complementary to different strands of the desired sequence and at relative positions along the sequence such that the DNA polymerase extension product of the one, when denatured, can serve as a template for the other and vice versa. Oligonucleotides were synthesized using an automated DNA synthesis machine (Biosearch, Inc. San Rafael, California) using phosphoramidite chemistry. \"Mispriming\" can be usefully employed to make intentional in vitro mutations or to add sequence information to one or both ends of a given sequence. The chapter explores the possibility of utilizing a heat stable DNA polymerase so as to avoid the need for addition of new enzyme after each cycle of thermal denaturation", "author_names": [ "Kary Banks Mullis", "Fred Faloona" ], "corpus_id": 13351081, "doc_id": "13351081", "n_citations": 5588, "n_key_citations": 250, "score": 0, "title": "Specific synthesis of DNA in vitro via a polymerase catalyzed chain reaction.", "venue": "Methods in enzymology", "year": 1987 }, { "abstract": "The specific bonding of DNA base pairs provides the chemical foundation for genetics. This powerful molecular recognition system can be used in nanotechnology to direct the assembly of highly structured materials with specific nanoscale features, as well as in DNA computation to process complex information. The exploitation of DNA for material purposes presents a new chapter in the history of the molecule.", "author_names": [ "Nadrian C Seeman" ], "corpus_id": 4335806, "doc_id": "4335806", "n_citations": 2094, "n_key_citations": 24, "score": 0, "title": "DNA in a material world", "venue": "Nature", "year": 2003 }, { "abstract": "The discovery of specific restriction endonucleases (Smith and Wilcox 1970) made possible the isolation of discrete molecular fragments of naturally occurring DNA for the first time. This capability was crucial to the development of molecular cloning (Cohen et al. 1973) and the combination of molecular cloning and endonuclease restriction allowed the synthesis and isolation of any naturally occurring DNA sequence that could be cloned into a useful vector and, on the basis of flanking restriction sites, excised from it. The availability of a large variety of restriction enzymes (Roberts 1985) has significantly extended the utility of these methods. The de novo organic synthesis of oligonucleotides and the development of methods for their assembly into long double stranded DNA molecules (Davies and Gassen 1983) have removed, at least theoretically, the minor limitations imposed by the availability of natural sequences with fortuitously unique flanking restriction sites. However, de novo synthesis, even with automated equipment, is not easy; it is often fraught with peril due to the inevitable indelicacy of chemical reagents (Urdea et al. 1985; Watt et al. 1985; Mullenbach et al. 1986) and it is not capable of producing, intentionally, a sequence that is not yet fully known. We have been exploring an alternative method for the synthesis of specific DNA sequences (Fig. 1) It involves the reciprocal interaction of two oligonucleotides and the DNA polymerase extension products whose synthesis they prime, when they are hybridized to different strands of a DNA template in a relative orientation such that their extension products overlap. The method consists of repetitive cycles of denaturation, hybridization, and polymerase extension and seems not a little boring until the realization occurs that this procedure is catalyzing a doubling with each cycle in the amount of the fragment defined by the positions of the 5' ends of the two primers on the template DNA, that this fragment is therefore increasing in concentration exponentially, and that the process can be continued for many cycles and is inherently very specific. The original template DNA molecule could have been a relatively small amount of the sequence to be synthesized (in a pure form and as a discrete molecule) or it could have been the same sequence embedded in a much larger molecule in a complex mixture as in the case of a fragment of a single copy gene in whole human DNA. It could also have been a single stranded DNA molecule or, with a minor modification in the technique, it could have been an RNA molecule. In any case, the product of the reaction will be a discrete double stranded DNA molecule with termini corresponding to the 5' ends of the oligonucleotides employed. We have called this process polymerase chain reaction or (inevitably) PCR. Several embodiments have been devised that enable one not only to extract a specific sequence from a complex template and amplify it, but also to increase the inherent specificity of this process by using nested primer sets, or to append sequence information to one or both ends of the sequence as it is being amplified, or to construct a sequence entirely from synthetic fragments.", "author_names": [ "Kary Banks Mullis", "Fred Faloona", "Stephen Joel Scharf", "Randall Keichi Saiki", "G Horn", "Henry A Erlich" ], "corpus_id": 26180176, "doc_id": "26180176", "n_citations": 3274, "n_key_citations": 177, "score": 0, "title": "Specific enzymatic amplification of DNA in vitro: the polymerase chain reaction.", "venue": "Cold Spring Harbor symposia on quantitative biology", "year": 1986 }, { "abstract": "The DNA single walled carbon nanotube (SWCNT) hybrid molecule has attracted significant attention recently for its ability to disperse and sort SWCNTs according to their chirality. Key for utilizing their unique properties is an understanding of the structure of DNA adsorbed on the SWCNT surface, which we study here using molecular simulations. Using replica exchange molecular dynamics (REMD) we explore equilibrium structures formed by single strands of 12 mer oligonucleotides, of varying sequence, adsorbed on a (6,5) SWCNT. We find a consistent motif in which the DNA strand forms a right handed helical wrap around the SWCNT, stabilized by \"stitches\" (hydrogen bonding between distant bases) to itself. Variability among equilibrium populations of DNA self stitched structures was observed and shown to be directly influenced by DNA sequence and composition. Competition between conformational entropy and hydrogen bonding between bases is predicted to be responsible for the formation of random versus stitched configurations.", "author_names": [ "Daniel Roxbury", "Anand Jagota", "Jeetain Mittal" ], "corpus_id": 1113695, "doc_id": "1113695", "n_citations": 68, "n_key_citations": 1, "score": 0, "title": "Sequence specific self stitching motif of short single stranded DNA on a single walled carbon nanotube.", "venue": "Journal of the American Chemical Society", "year": 2011 }, { "abstract": "ABSTRACT Cultured isolates of the marine cyanobacteria Prochlorococcus and Synechococcus vary widely in their pigment compositions and growth responses to light and nutrients, yet show greater than 96% identity in their 16S ribosomal DNA (rDNA) sequences. In order to better define the genetic variation that accompanies their physiological diversity, sequences for the 16S 23S rDNA internal transcribed spacer (ITS) region were determined in 32 Prochlorococcus isolates and 25 Synechococcus isolates from around the globe. Each strain examined yielded one ITS sequence that contained two tRNA genes. Dramatic variations in the length and G+C content of the spacer were observed among the strains, particularly among Prochlorococcus strains. Secondary structure models of the ITS were predicted in order to facilitate alignment of the sequences for phylogenetic analyses. The previously observed division of Prochlorococcus into two ecotypes (called high and low B/A after their differences in chlorophyll content) were supported, as was the subdivision of the high B/A ecotype into four genetically distinct clades. ITS based phylogenies partitioned marine cluster A Synechococcus into six clades, three of which can be associated with a particular phenotype (motility, chromatic adaptation, and lack of phycourobilin) The pattern of sequence divergence within and between clades is suggestive of a mode of evolution driven by adaptive sweeps and implies that each clade represents an ecologically distinct population. Furthermore, many of the clades consist of strains isolated from disparate regions of the world's oceans, implying that they are geographically widely distributed. These results provide further evidence that natural populations of Prochlorococcus and Synechococcus consist of multiple coexisting ecotypes, genetically closely related but physiologically distinct, which may vary in relative abundance with changing environmental conditions.", "author_names": [ "Gabrielle Rocap", "Daniel L Distel", "John B Waterbury", "Sallie W Chisholm" ], "corpus_id": 8327146, "doc_id": "8327146", "n_citations": 495, "n_key_citations": 65, "score": 0, "title": "Resolution of Prochlorococcus and Synechococcus Ecotypes by Using 16S 23S Ribosomal DNA Internal Transcribed Spacer Sequences", "venue": "Applied and Environmental Microbiology", "year": 2002 }, { "abstract": "Molecular self assembly presents a 'bottom up' approach to the fabrication of objects specified with nanometre precision. DNA molecular structures and intermolecular interactions are particularly amenable to the design and synthesis of complex molecular objects. We report the design and observation of two dimensional crystalline forms of DNA that self assemble from synthetic DNA double crossover molecules. Intermolecular interactions between the structural units are programmed by the design of 'sticky ends' that associate according to Watson Crick complementarity, enabling us to create specific periodic patterns on the nanometre scale. The patterned crystals have been visualized by atomic force microscopy.", "author_names": [ "Erik Winfree", "Furong Liu", "Lisa A Wenzler", "Nadrian C Seeman" ], "corpus_id": 4385579, "doc_id": "4385579", "n_citations": 2315, "n_key_citations": 52, "score": 0, "title": "Design and self assembly of two dimensional DNA crystals", "venue": "Nature", "year": 1998 }, { "abstract": "The armchair carbon nanotube is an ideal system to study fundamental physics in one dimensional metals and potentially a superb material for applications such as electrical power transmission. Synthesis and purification efforts to date have failed to produce a homogeneous population of such a material. Here we report evolutionary strategies to find DNA sequences for the recognition and subsequent purification of (6,6) and (7,7) armchair species from synthetic mixtures. The new sequences were derived by single point scanning mutation and sequence motif variation of previously identified ones for semiconducting tubes. Optical absorption spectroscopy of the purified armchair tubes revealed well resolved first and second order electronic transitions accompanied by prominent sideband features that have neither been predicted nor observed previously. Resonance Raman spectroscopy showed a single Lorentzian peak for the in plane carbon carbon stretching mode (G band) of the armchair tubes, repudiating the common practice of using such a line shape to infer the absence of metallic species. Our work demonstrates the exquisite sensitivity of DNA to nanotube metallicity and makes the long anticipated pure armchair tubes available as seeds for their mass amplification.", "author_names": [ "Xiaomin X Tu", "Angela R Hight Walker", "Constantine Y Khripin", "Ming Zheng" ], "corpus_id": 847256, "doc_id": "847256", "n_citations": 67, "n_key_citations": 3, "score": 0, "title": "Evolution of DNA sequences toward recognition of metallic armchair carbon nanotubes.", "venue": "Journal of the American Chemical Society", "year": 2011 } ]

[ { "abstract": "Semiconductor quantum dots/ graphene oxide (QDs/GO) hybrid composites, as emerging materials, have recently attracted intensive attentions in materials science and technology due to their potential applications in electronic and photonic devices. Here, a simple and universal strategy to produce DNA programmed semiconductor quantum dots/ graphene oxide (QDs/GO) hybrid composites with controllable sizes, shapes, compositions, and surface properties is reported. This proof of concept work successfully demonstrates sulfhydryl modified single stranded DNA (S ssDNA) as a \"universal glue\" can adsorb onto GO easily and provide the growth site to synthesize CdS QDs, CdSe QDs, CdTe QDs and CdTeSe QDs with distinctively sizes, shapes and properties. And, adapting this method, the other graphene oxide based hybrid materials which were easily synthesized in aqueous solution, including oxides, core shell structure QDs and metal nanocrystal, would be possible. This method provided a universal strategy for synthesis and function realization of graphene based nanomaterials.", "author_names": [ "Jidong Wang", "Zehua Gao", "Shengquan He", "Penghui Jin", "Daoqing Ma", "Yabiao Gao", "Libin Wang", "Shumin Han" ], "corpus_id": 212406313, "doc_id": "212406313", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "A universal growth strategy of DNA programmed quantum dots on graphene oxide surface.", "venue": "Nanotechnology", "year": 2020 }, { "abstract": "We developed a fluorescent aptamer/graphene oxide (GO) based biosensor to detect sulfamethazine (SMZ) residues in animal derived foods. The SMZ bound aptamers were identified and screened with an improved GO SELEX technique using non immobilizing ssDNA library. After seven rounds of selection, six SMZ aptamers were sequenced and analyzed for secondary structure, and their affinity and specificity were assessed by binding assays. The truncated aptamer (SMZ1S: 5' CGTTAGACG 3' with a unique stem loop structure showed the highest affinity K d 24.6 nM) to SMZ and was used to develop a GO based fluorescent aptasensor. The binding mechanism between SMZ1S and SMZ was further analyzed by molecular docking. Under optimal conditions, the fluorescent aptasensor showed low detection limits (0.35 ng/mL) and a wide dynamic linear range (from 2 to 100 ng/mL) The aptasensor was also validated against real samples spiked with SMZ, which showed a fluorescence recovery from 93.9 to 108.8% and a coefficient of variation of 12.7% Taken together, these results suggest that this novel aptasensor can be used to sensitively, selectively, and accurately detect SMZ residues in foods. Schematic illustration of fluorescent aptasensor based on aptamer/graphene oxide complex detection of of SMZ.", "author_names": [ "Qiming Kou", "Ping Wu", "Qi Sun", "Chenxi Li", "Lei Zhang", "Haixing Shi", "Juan Wu", "Yarong Wang", "Xueling Yan", "Tao Le" ], "corpus_id": 226309446, "doc_id": "226309446", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Selection and truncation of aptamers for ultrasensitive detection of sulfamethazine using a fluorescent biosensor based on graphene oxide", "venue": "Analytical and Bioanalytical Chemistry", "year": 2020 }, { "abstract": "Abstract Graphene oxide (GO) membrane, possessing well aligned laminar interlayer channels and oxygen bearing groups, offers great potentials as proton conductor in fuel cells. Yet, the scarcity and non uniform distribution of proton conducting sites in the interlayer channels often lead to low conductivity and hinder the use of GO membranes for proton conduction. Single strand deoxyribonucleic acid (ssDNA) molecules bear abundant phosphate and amidogen groups which can act as proton conducting sites. The sequentially arranged phosphate and amidogen groups are in a linear molecule chain, which accords with the ideal arrangement of proton conducting sites. Herein, we intercalated ssDNA into GO interlayer channels via a pre assembly process to create high efficient proton conducting channels. GO nanosheets offer well aligned 2D physical channels and ssDNA provides large amount of sequentially arranged proton conducting sites, which synergistically enhance proton conduction. The DNA@GO 3 membrane shows a proton conductivity of 564.8 mS cm 1 at 80 degC and 98% RH, which is 4.4 fold higher than that of pristine GO membrane and among the highest of the reported GO based membranes. The H2/O2 single fuel cell performance is improved by nearly 3 folds in terms of maximum power density.", "author_names": [ "Pengfei Yang", "Hong Wu", "Niaz Ali Khan", "Benbing Shi", "Xueyi He", "Li Cao", "Xunli Mao", "Rui Zhao", "Ming Qiu", "Zhongyi Jiang" ], "corpus_id": 216356632, "doc_id": "216356632", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Intrinsic proton conductive deoxyribonucleic acid (DNA) intercalated graphene oxide membrane for high efficiency proton conduction", "venue": "", "year": 2020 }, { "abstract": "Abstract A facile strategy has been constructed for the highly efficient discrimination of single nucleotide polymorphisms (SNPs) based on magnetic functionalized graphene oxide (GO@Fe3O4) modified poly(dimethylsiloxane) microchip system coupled with electrochemical detection. A methylene blue labeled single stranded DNA (P1) can complete complementary with target mircoRNA 21 (T1) to form a perfectly matched DNA/RNA heteroduplex (P1T1) while the hybridization of the P1 with single base mismatched sequence of mircoRNA 21 (M1) can form a loose DNA/ms RNA heteroduplex (P1M1) The p stacking interaction between the loose DNA/ms RNA heteroduplex and the GO is much stronger than that of the perfectly matched DNA/RNA heteroduplex. Moreover, GO can enhance the unwinding of unstable DNA/ms RNA through strong interaction between GO and single stranded DNA (ssDNA) and consequently increase the retention time of single base mismatch microRNA 21 in the GO@Fe3O4 based microchip system. Therefore, the GO@Fe3O4 based microchip system exhibited high performance for the separation and detection of microRNA 21 and single base mismatch microRNA 21, which provide a powerful protocol for SNPs discrimination within a short analytical time. More importantly, this platform can be used for other small molecules and proteins assay in various systems by simply changing the sequence of the probe DNA.", "author_names": [ "Cheng-Rong Zhang", "Ruping Liang", "Lu-Lu Wu", "Zhijing Wei", "Zhi Zhu", "Jian-Ding Qiu" ], "corpus_id": 213279598, "doc_id": "213279598", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "Discrimination of single nucleotide polymorphisms by magnetic functionalized graphene oxide based microchip system", "venue": "", "year": 2020 }, { "abstract": "The binding reaction of reduced graphene oxide silver nanocomposites (rGO AgNCs) with calf thymus single stranded DNA (ssDNA) was studied by ultraviolet visible absorption, fluorescence spectroscopy and circular dichroism (CD) using berberine hemisulphate (BR) dye as a fluorescence probe. The absorbance of ssDNA increases, but the fluorescence intensity is quenched with the addition of rGO AgNCs. The binding of rGO AgNCs with ssDNA was able to increase the quenching effects of BR and ssDNA, and induce the changes in CD spectra. All of the evidence indicated that there was a relatively strong interaction between ssDNA and rGO AgNCs. The data obtained from fluorescence experiments revealed that the quenching process of ssDNA caused by rGO AgNCs is primarily due to complex formation, i.e. static quenching. The increasing trend of the binding equilibrium constant (Ka) with rising temperature indicated that the binding process was an endothermic reaction. The calculated thermodynamic parameters showed that the binding process was thermodynamically spontaneous, and hydrophobic association played predominant roles in the binding of ssDNA to the surface of rGO AgNCs.", "author_names": [ "Xi Li", "Lin-qing Yang", "Yunfei Wang", "Zhongyu Du", "Xuyan Mao", "Dezhi Sun", "Jialei Liu", "Yu Zhou", "Xiangyu Xu" ], "corpus_id": 214188764, "doc_id": "214188764", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Studies on binding of single stranded DNA with reduced graphene oxide silver nanocomposites.", "venue": "IET nanobiotechnology", "year": 2020 }, { "abstract": "In this paper, we present a simple and label free colorimetric biosensor for detection of the nopaline synthase (NOS) terminator in genetically modified (GM) plants. The \"signal on\" colorimetric biosensor was developed using a nanocomposite consisted of gold nanoparticles doped magnetic Fe3O4 nanoparticles (Fe3O4@Au NP) capture probe DNA (cDNA) and hemin functionalized reduced graphene oxide nanosheets (H GN) The nanocomposite was successfully prepared by means of Au S bonds and the strong p interactions between cDNA and H GN. The sensing approach is based on the excellent peroxidase mimicking activity of H GN and its different electrostatic interactions with single stranded DNA (ssDNA) and double stranded DNA (dsDNA) In presence of the target NOS, the cDNA in the nanocomposite will hybridize with its complementary sequence, and form dsDNA structure. Due to the weak p interactions between dsDNA and H GN, a portion of H GN will be released from the surface of Fe3O4@Au NPs and transferred into solution. After magnetic separation was performed, the supernatant was incubated with 3,3',5,5' tetramethylbenzidine (TMB) in the presence of H2O2. The released H GN can catalyze the oxidation reaction of TMB and turn the colorless solution blue. This \"signal on\" colorimetric biosensor shows a broad linear range of 0.5 100 nM for the target NOS, with a 0.19 nM detection limit. The application of the biosensor for determination of NOS segments in samples of GM and non GM tomatoes shows that it can discriminate between GM and non GM plants. The reliability of the method for samples of NOS spiked GM tomato suggests satisfactory recoveries in the range of 93.6% 94.2%", "author_names": [ "Xiaodong Cao", "Zihao Xia", "Wuwen Yan", "Shudong He", "Xuan Xu", "Zhaojun Wei", "Yongkang Ye", "Haisong Zheng" ], "corpus_id": 219537565, "doc_id": "219537565", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "Colorimetric biosensing of nopaline synthase terminator using Fe3O4@Au and hemin functionalized reduced graphene oxide.", "venue": "Analytical biochemistry", "year": 2020 }, { "abstract": "A light addressable potentiometric sensor (LAPS) is a kind of silicon based semiconductor sensor, and surface modification is a fundamental problem for its application in biological fields. Graphene oxide (GO) based biochemically activated LAPS were proposed, called GO LAPS. The GO LAPS were applied to monitoring single strand DNA (ssDNA) probe immobilization and its hybridization with complementary ssDNA molecules of different chain lengths (30, 21 and 14 base pairs, respectively) It was discovered that the curves of LAPS' currents versus analyte concentrations for ssDNA probe binding and the target ssDNA hybridization were different. Explanations were proposed based on the semiconductor's surface electric field effect and the electrical properties of ssDNA molecule. Moreover, comparisons between GO LAPS and LAPS without GO modification were carried out. Enhanced response currents of GO LAPS were reported experimentally and analyzed theoretically based on X ray photoelectron spectroscopy (XPS) of GO LAPS. The limitation of target ssDNA monitoring was 1 pM to 10 nM, which suggested that this LAPS based platform could be developed as a sensitive means for short chain ssDNA detection.", "author_names": [ "Yunfang Jia", "Xuebo Yin", "Jia Zhang", "Shuang Zhou", "Meng Song", "Ke-li Xing" ], "corpus_id": 8555428, "doc_id": "8555428", "n_citations": 29, "n_key_citations": 1, "score": 0, "title": "Graphene oxide modified light addressable potentiometric sensor and its application for ssDNA monitoring.", "venue": "The Analyst", "year": 2012 }, { "abstract": "In this work, a new platform for effective sensing cysteine (Cys) was developed based on fluorescence resonance energy transfer (FRET) between FAM tagged single stranded DNA (FAM ssDNA) and graphene oxide (GO) Due to the noncovalent assembly between FAM ssDNA and GO, fluorescence quenching of the FAM took place because of FRET. This method relied on the competitive ligation of Ag( by Cys and \"cytosine cytosine\" (C C) mismatches in a FAM labeled DNA strand of the self hybridizing strand. At first, enough amount of Ag( was introduced to bind \"C C\" mismatches and form double stranded DNA (dsDNA) which had weak affinity to GO and kept FAM away from GO surface. However, the presence of Cys removed Ag( away from \"cytosine Ag( cytosine\" (C Ag( C) base pairs, leading to the formation of ssDNA again and FRET, and then fluorescence of the FAM ssDNA was efficiently quenched. The fluorescence intensity decrease was found to be proportional to the increase of concentration of Cys in both aqueous buffer (2 200 nM) and human serum (5 200 nM) and the sensitivity of the proposed method towards Cys was much higher than that of other reported assays for Cys.", "author_names": [ "Hongli Liu", "Yuhui Wang", "Aiguo Shen", "Xiaodong Zhou", "Jiming Hu" ], "corpus_id": 36457508, "doc_id": "36457508", "n_citations": 29, "n_key_citations": 1, "score": 0, "title": "Highly selective and sensitive method for cysteine detection based on fluorescence resonance energy transfer between FAM tagged ssDNA and graphene oxide.", "venue": "Talanta", "year": 2012 }, { "abstract": "A conceptually new class of DNA logic gate and biosensor using the complex of a graphene oxide DNA duplex as a scaffold was reported, achieved by means of formation of the triple stranded DNA structure mediated by Recombinational protein A (RecA) ssDNA nucleoprotein filaments with graphene oxide.", "author_names": [ "Longhua Tang", "Dongyang Li", "Jinghong Li" ], "corpus_id": 205842106, "doc_id": "205842106", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "Formation of a graphene oxide DNA duplex based logic gate and sensor mediated by RecA ssDNA nucleoprotein filaments.", "venue": "Chemical communications", "year": 2013 }, { "abstract": "Rapid detection of foodborne pathogens is crucial as ingestion of contaminated food products may endanger human health. Thus, the objective of this study was to develop a biosensor using reduced graphene oxide carbon nanotubes (rGO CNT) nanocomposite via the hydrothermal method for accurate and rapid label free electrochemical detection of pathogenic bacteria such as Salmonella enterica. The rGO CNT nanocomposite was characterized using Fourier transform infrared spectroscopy, Raman spectroscopy, X ray diffraction and transmission electron microscopy. The nanocomposite was dropped cast on the glassy carbon electrode and further modified with amino modified DNA aptamer. The resultant ssDNA/rGO CNT/GCE aptasensor was then used to detect bacteria by using differential pulse voltammetry (DPV) technique. Synergistic effects of aptasensor was evident through the combination of enhanced electrical properties and facile chemical functionality of both rGO and CNT for the stable interface. Under optimal experimental conditions, the aptasensor could detect S. Typhimurium in a wide linear dynamic range from 101 until 108 cfu mL 1 with a 101 cfu mL 1 of the limit of detection. This aptasensor also showed good sensitivity, selectivity and specificity for the detection of microorganisms. Furthermore, we have successfully applied the aptasensor for S. Typhimurium detection in real food samples.", "author_names": [ "Jimmy Nelson Appaturi", "Thiruchelvi Pulingam", "Kwai Lin Thong", "Shalini Muniandy", "Noraini Ahmad", "Bey Fen Leo" ], "corpus_id": 204918600, "doc_id": "204918600", "n_citations": 30, "n_key_citations": 0, "score": 1, "title": "Rapid and sensitive detection of Salmonella with reduced graphene oxide carbon nanotube based electrochemical aptasensor.", "venue": "Analytical biochemistry", "year": 2019 } ]

[ { "abstract": "We compare the ability of four popular hybrid density functionals (B3LYP, B3PW91, HSE, and PBE0) for predicting band gaps of semiconductors and insulators over a large benchmark set using a consistent methodology. We observe no significant statistical difference in their overall performance, although the screened hybrid HSE is more accurate for typical semiconductors. HSE can improve its accuracy for large band gap materials without affecting that of semiconductors by including a larger portion of Hartree Fock exchange in its short range. Given that screened hybrids are computationally much less expensive than their global counterparts, we conclude that they are a better option for the black box prediction of band gaps.", "author_names": [ "Alejandro J Garza", "Gustavo E Scuseria" ], "corpus_id": 38568679, "doc_id": "38568679", "n_citations": 214, "n_key_citations": 0, "score": 1, "title": "Predicting Band Gaps with Hybrid Density Functionals.", "venue": "The journal of physical chemistry letters", "year": 2016 }, { "abstract": "Density functional theory within the local or semilocal density approximations (DFT LDA/GGA) has become a workhorse in electronic structure theory of solids, being extremely fast and reliable for energetics and structural properties, yet remaining highly inaccurate for predicting band gaps of semiconductors and insulators. Accurate prediction of band gaps using firstprinciples methods is time consuming, requiring hybrid functionals, quasi particle GW, or quantum Monte Carlo methods. Efficiently correcting DFT LDA/GGA band gaps and unveiling the main chemical and structural factors involved in this correction is desirable for discovering novel materials in high throughput calculations. In this direction, we use DFT and machine learning techniques to correct band gaps and band edge positions of a representative subset of ABO3 perovskite oxides. Relying on results of HSE06 hybrid functional calculations as target values of band gaps, we find a systematic band gap correction of ~1.5 eV for this class of materials, where ~1 eV comes from downward shifting the valence band and ~0.5 eV from uplifting the conduction band. The main chemical and structural factors determining the band gap correction are determined through a feature selection procedure.", "author_names": [ "Wei Li", "", "Xianglin Xiao", "Zhiqiang Zhang", "Anderson Janotti1", "Rajasekaran Sanguthevar", "Bharat Medasani" ], "corpus_id": 221370626, "doc_id": "221370626", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Predicting band gaps and band edge positions of oxide perovskites using DFT and machine learning.", "venue": "", "year": 2020 }, { "abstract": "Density functional theory (DFT) has become a standard method for ab initio calculations of material properties. However, it has a number of shortcomings, particularly in predicting key properties, such as band gap and optical spectra, which are dependent on excited states. To treat such properties, more accurate approaches such as GW or DFT with hybrid functionals (including HSE, PBE0, and B3LYP, to name a few) can be employed; however, these approaches are unfeasible for many large and/or complex systems due to their high computational cost and large memory requirements. In this work, we investigate the ability to train neural networks of the traditional DFT charge density computed with a standard PBE functional to accurately predict HSE band gaps. We show that a single network PBE charge density functional can predict the HSE band gap of seven different materials silicon, gallium arsenide, molybdenum disulfide, germanium, tin phosphate, titanium phosphate, and zirconium phosphate under a wide variety of conditions with an RSME of 172.6 meV, which is 34\\ better accuracy than standard regression between the PBE and HSE band gaps. This approach, which, in principle, can be used to map PBE charge densities to band gaps or other properties computed with any higher accuracy method, has the potential to decrease computational costs, increase prediction accuracy, and enable accurate high throughput screening for a wide variety of complex materials systems.", "author_names": [ "Levi C Lentz", "Alexie Kolpak" ], "corpus_id": 208767628, "doc_id": "208767628", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Predicting HSE band gaps from PBE charge densities via neural network functionals.", "venue": "Journal of physics. Condensed matter an Institute of Physics journal", "year": 2019 }, { "abstract": "Accurately modeling the electronic structure of materials is a persistent challenge to high throughput screening. A promising means of balancing accuracy against computational cost are non self consistent calculations with hybrid density functional theory, where the electronic band energies are evaluated using a hybrid functional from orbitals obtained with a less demanding (semi )local functional. We have quantified the performance of this technique for predicting the physical properties of sixteen tetrahedral semiconductors with bandgaps from 0.2 5.5 eV. Provided the base functional predicts a non metallic electronic structure, bandgaps within 5 of the PBE0 and HSE06 gaps can be obtained with an order of magnitude reduction in computing time. The positions of the valence and conduction band extrema and the Fermi level are well reproduced, further enabling calculation of the band dispersion, density of states, and dielectric properties using Fermi's Golden Rule. While the error in the non self consistent total energies is ~50 meV atom 1, the energy volume curves are reproduced accurately enough to obtain the equilibrium volume and bulk modulus with minimal error. We also test the dielectric dependent scPBE0 functional and obtain bandgaps and dielectric constants to within 2.5 of the self consistent results, which amount to a significant improvement over self consistent PBE0 for a similar computational cost. We identify cases where the non self consistent approach is expected to perform poorly, and demonstrate that partial self consistency provides a practical and efficient workaround. Finally, we perform proof of concept calculations on CoO and NiO to demonstrate the applicability of the technique to strongly correlated open shell transition metal oxides.", "author_names": [ "Jonathan M Skelton", "David S D Gunn", "Sebastian Metz", "Stephen C Parker" ], "corpus_id": 218470210, "doc_id": "218470210", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Accuracy of hybrid functionals with non self consistent Kohn Sham orbitals for predicting the properties of semiconductors.", "venue": "Journal of chemical theory and computation", "year": 2020 }, { "abstract": "The performance of two modern density functionals, HSE06 and TB mBJ, on predicting electronic structures of metal oxides, chalcogenides and nitrides, is studied in terms of band gaps, band structure and projected density of states. Contrary to GGA, hybrid functionals and GGA+U, both new functionals are able to predict band gaps with an appreciable accuracy of 25% and thus allow the screening of various classes of (mixed) metal oxides at modest computational cost. The calculated electronic structures are largely unaffected by the choice of basis functions and software implementation.", "author_names": [ "Wen-Qing Li", "Christian F J Walther", "Agnieszka Beata Kuc", "Thomas Heine" ], "corpus_id": 119191807, "doc_id": "119191807", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Efficient Estimation of Band Gaps in Transition Metal Oxides and Chalcogenides using Density Functional Theory", "venue": "", "year": 2013 }, { "abstract": "The present work introduces an efficient screening technique to take advantage of the fast spatial decay of the short range Hartree Fock (HF) exchange used in the Heyd Scuseria Ernzerhof (HSE) screened Coulomb hybrid density functional. The screened HF exchange decay properties and screening efficiency are compared with traditional hybrid functional calculations on solids. The HSE functional is then assessed using 21 metallic, semiconducting, and insulating solids. The examined properties include lattice constants, bulk moduli, and band gaps. The results obtained with HSE exhibit significantly smaller errors than pure density functional theory (DFT) calculations. For structural properties, the errors produced by HSE are up to 50% smaller than the errors of the local density approximation, PBE, and TPSS functionals used for comparison. When predicting band gaps of semiconductors, we found smaller errors with HSE, resulting in a mean absolute error of 0.2 eV (1.3 eV error for all pure DFT functionals) In addition, we present timing results which show the computational time requirements of HSE to be only a factor of 2 4 higher than pure DFT functionals. These results make HSE an attractive choice for calculations of all types of solids.", "author_names": [ "Jochen Heyd", "Gustavo E Scuseria" ], "corpus_id": 45579733, "doc_id": "45579733", "n_citations": 1309, "n_key_citations": 13, "score": 0, "title": "Efficient hybrid density functional calculations in solids: assessment of the Heyd Scuseria Ernzerhof screened Coulomb hybrid functional.", "venue": "The Journal of chemical physics", "year": 2004 }, { "abstract": "Band structure calculations based on density functional theory (DFT) with local or gradient corrected exchange correlation potentials are known to severely underestimate the band gap of semiconducting and insulating materials. Alternative approaches have been proposed: from semiempirical setups, such as the so called DFT+U, to hybrid density functionals using a fraction of nonlocal Fock exchange, to modifications of semilocal density functionals. However, the resulting methods appear to be material dependent and lack theoretical rigor. The rigorous many body perturbation theory based on GW methods provides accurate results but at a very high computational cost. Hereby, we show that a linear correlation between the electronic band gaps obtained from standard DFT and GW approaches exists for most materials and argue that (1) this is a strong indication that the problem of predicting band gaps from standard DFT calculation arises from the assignment of a physical meaning to the Kohn Sham energy levels rather.", "author_names": [ "Angel Morales-Garcia", "Rosendo Valero", "Francesc Illas" ], "corpus_id": 104050405, "doc_id": "104050405", "n_citations": 89, "n_key_citations": 2, "score": 0, "title": "An Empirical, yet Practical Way To Predict the Band Gap in Solids by Using Density Functional Band Structure Calculations", "venue": "", "year": 2017 }, { "abstract": "Significance Density functionals with Hartree Fock exchange have been widely used for a wide range of chemical applications, but the nonlocal character of exchange makes long range exchange computationally expensive for solid state calculations with periodic boundary conditions, and full exchange is nonphysical for condensed phase systems. Here, we present a screened exchange (SX) density functional, M06 SX, that is especially designed to have good accuracy for both solid state physics and chemical applications with less computational cost than full Hartree Fock exchange. The M06 SX functional gives accuracy comparable to functionals with full Hartree Fock exchange for predicting chemical properties of molecules, while also being practical with good accuracy for plane wave calculations on band gaps and lattice constants of solids. Screened exchange hybrid density functionals are especially recommended for solid state systems because they combine the advantages of hybrid functionals with the correct physics and lower computational cost associated with the attenuation of Hartree Fock exchange at long range. We present a screened exchange hybrid functional, M06 SX, that combines the functional form of the local revM06 L functional with a percentage of short range nonlocal Hartree Fock exchange. The M06 SX functional gives good results not only for a large set of training data but also for several databases quite different from the training data. The mean unsigned error (MUE) of the M06 SX functional is 2.85 kcal/mol for 418 atomic and molecular energies (AME418) in Minnesota Database 2019, which is better than all five other screened exchange hybrid functionals tested in this work. The M06 SX functional also gives especially good results for semiconductor band gaps, molecular dissociation energies, noncovalent interactions, barrier heights, and electronic excitation energies excluding long range charge transfer excitations. For the LC18 lattice constants database, the M06 SX functional gives an MUE of only 0.034 A. Therefore, the M06 SX functional is well suited for studying molecular chemistry as well as solid state physics.", "author_names": [ "Pragya Verma", "Lujia Zhang", "Yaqi Li", "Zhonghua Liu", "Donald G Truhlar", "Xiao He" ], "corpus_id": 210708466, "doc_id": "210708466", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "M06 SX screened exchange density functional for chemistry and solid state physics", "venue": "Proceedings of the National Academy of Sciences", "year": 2020 }, { "abstract": "The open access material databases allowed us to approach scientific questions from a completely new perspective with machine learning methods. Here, on the basis of open access databases, we focus on the classical band gap problem for predicting accurately the band gap of a crystalline compound using a machine learning approach with newly developed tuplewise graph neural networks (TGNN) which is devised to automatically generate input representation of crystal structures in tuple types and to exploit crystal level properties as one of the input features. Our method brings about a highly accurate prediction of the band gaps at hybrid functionals and GW approximation levels for multiple material data sets without heavy computational cost. Furthermore, to demonstrate the applicability of our prediction model, we provide a data set of GW band gaps for 45835 materials predicted by TGNN posing higher accuracy than standard density functional theory calculations.", "author_names": [ "Gyoung S Na", "Seunghun Jang", "Yea-Lee Lee", "Hyunju Chang" ], "corpus_id": 227521489, "doc_id": "227521489", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Tuplewise Material Representation Based Machine Learning for Accurate Band Gap Prediction.", "venue": "The journal of physical chemistry. A", "year": 2020 }, { "abstract": "The performance of a wide variety of commonly used density functionals, as well as two screened hybrid functionals (HSE06 and TB mBJ) on predicting electronic structures of a large class of en vogue materials, such as metal oxides, chalcogenides, and nitrides, is discussed in terms of band gaps, band structures, and projected electronic densities of states. Contrary to GGA, hybrid functionals and GGA+U, both HSE06 and TB mBJ are able to predict band gaps with an appreciable accuracy of 25% and thus allow the screening of various classes of transition metal based compounds, i.e. mixed or doped materials, at modest computational cost. The calculated electronic structures are largely unaffected by the choice of basis functions and software implementation, however, might be subject to the treatment of the core electrons.", "author_names": [ "Wen-Qing Li", "Christian F J Walther", "Agnieszka Beata Kuc", "Thomas Heine" ], "corpus_id": 29795785, "doc_id": "29795785", "n_citations": 69, "n_key_citations": 0, "score": 0, "title": "Density Functional Theory and Beyond for Band Gap Screening: Performance for Transition Metal Oxides and Dichalcogenides.", "venue": "Journal of chemical theory and computation", "year": 2013 } ]

[ { "abstract": "Alumina (Alalt;subagt;2alt;/subagt;Oalt;subagt;3alt;/subagt; films of different thicknesses have been grown at different low temperatures (100 250 alt;supagt;oalt;/supagt;C) by atomic layer deposition on n type Si substrate. The robustness of the Alalt;subagt;2alt;/subagt;Oalt;subagt;3alt;/subagt; film as a barrier has been investigated based on Al/Alalt;subagt;2alt;/subagt;Oalt;subagt;3alt;/subagt;/Si metal insulator semiconductor structures. The electron transport through the Alalt;subagt;2alt;/subagt;Oalt;subagt;3alt;/subagt; layer was fitted well by the Fowler Nordheim tunneling mechanism, from which the barrier heights (conduction band offset between Si and Alalt;subagt;2alt;/subagt;Oalt;subagt;3alt;/subagt; were deduced. It was discovered that the growth temperature and film thickness both influenced the carrier transport and barrier height. The Al/Alalt;subagt;2alt;/subagt;Oalt;subagt;3alt;/subagt;/Si structure with an ultrathin 3 nm Alalt;subagt;2alt;/subagt;Oalt;subagt;3alt;/subagt; fabricated at 150 alt;supagt;oalt;/supagt;C showed the largest barrier height, the lowest tunneling current density (4.9 x 10alt;supagt; 8alt;/supagt; A/cmalt;supagt;2alt;/supagt; at 5 MV/cm) and the highest breakdown field strength of 18 MV/cm. Using Au to replace Al as the electrode could suppress the tunneling current significantly. The Alalt;subagt;2alt;/subagt;Oalt;subagt;3alt;/subagt; films were also examined by X ray photoelectron spectroscopy to determine their chemical constituents.", "author_names": [ "Pengfei Ma", "Wenhao Guo", "Jiaming Sun", "Jia-cheng Gao", "Guanqun Zhang", "Qian Xin", "Yuxiang Li", "Aimin Song" ], "corpus_id": 199070552, "doc_id": "199070552", "n_citations": 2, "n_key_citations": 0, "score": 1, "title": "Electron transport mechanism through ultrathin Al2O3 films grown at low temperatures using atomic layer deposition", "venue": "Semiconductor Science and Technology", "year": 2019 }, { "abstract": "Abstract This paper presents a systematic study of HfAlO alloy films, which were prepared by doping HfO2 with different amounts of Al using atomic layer deposition at low growth temperature (150 degC) The chemical constituents of the various HfAlO films were determined by X ray photoelectron spectroscopy. Carrier transport through the HfAlO layer presented a good fit with the Poole Frenkel emission and Fowler Nordheim tunnelling mechanisms in different voltage ranges. Barrier heights (conduction band offset) between the HfAlO films and Si substrate, which were derived from the Fowler Nordheim fittings, increased with increasing Al content in the alloy films, and the leakage current was suppressed well owing to the higher barrier. The 10 nm HfAlO dielectric layer, which was grown by the repeated deposition of 1 cycle each of HfO2 and Al2O3 (defined as H1A1) showed a high gate capacitance of 723 nF/cm2, a high breakdown voltage of 8.0 V, a small leakage current, and a smooth surface. HfAlO films doped with different amounts of Al2O3 in HfO2 were employed to study their effects on the operation of amorphous indium gallium zinc oxide (a IGZO) thin film transistors (TFTs) The a IGZO TFTs based on the H1A1 gate dielectric showed desirable properties including a high Ion/off ratio of 1.7 x 107, a small subthreshold swing of 176 mV/decade, and low operating voltage of 2.0 V.", "author_names": [ "Pengfei Ma", "Jiaming Sun", "Guanqun Zhang", "Guangda Liang", "Qian Xin", "Yuxiang Li", "Aimin Song" ], "corpus_id": 141505195, "doc_id": "141505195", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Low temperature fabrication of HfAlO alloy dielectric using atomic layer deposition and its application in a low power device", "venue": "Journal of Alloys and Compounds", "year": 2019 }, { "abstract": "Abstract Preparation of ultrathin alumina (Al2O3) films through Plasma Enhanced Atomic Layer Deposition (PE ALD) at low substrate temperature is discussed. The present work aims to investigate the physical mechanism of the PE ALD deposition process and also the characteristics of the ultrathin alumina films on silicon <100> wafer deposited using the technique. The deposition was performed using trimethyl aluminum (Al (CH3)3) as the precursor and argon gas for purging. During deposition, the target temperature was kept constant at 80, 100 and 150 degC and the pressure was 1.3 x 10 2 Pa. Two deposition cycles were tested, 400 and 800 cycles. As for understanding the process, the films deposited with and without oxygen plasma were compared. Various thin film characterization techniques, including Atomic Force Microscope (AFM) ellipsometry, Raman spectrometry measurement, X ray diffraction (XRD) and indentation technique, were applied for investigating the film properties. A transmission electron microscope (TEM) equipped with high angle annular dark field imaging line scan modes and energy dispersive X ray spectroscopy acquisition was used for imaging thin film cross sections. We found that the number of deposition cycles did not affect the substrate surface roughness as evidenced by AFM images. The mechanical property, the hardness of the film deposited with 800 cycles and plasma was the best. Raman spectroscopy measurements showed that a Al O Si phase exists when the films were deposited at 100 degC and 150 degC for 400 and 800 cycles under oxygen plasma atmosphere. While no Al O Si phase existed after the same number of ALD deposition cycle without plasma. Results from XRD measurements indicated that the films deposited at 100 degC and 150 degC for 400 and 800 cycles under oxygen plasma atmosphere has an Al O structure. TEM images clearly displayed the interface between the thin films, SiO2 interface layers and Si substrates. As for the sample deposited at 80 degC, an Al2O3 film was hardly seen, but when increasing the deposition temperature to 100 degC and 150deg, films started to build on top of the substrate. However, for all deposition conditions, TEM revealed that the amounts of carbon atoms in the reaction site remained relatively high.", "author_names": [ "Duangkhae Bootkul", "P Jitsopakul", "S Intarasiri", "Dheerawan Boonyawan" ], "corpus_id": 103456678, "doc_id": "103456678", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Qualifying ultrathin alumina film prepared by plasma enhance atomic layer deposition under low temperature operation", "venue": "", "year": 2017 }, { "abstract": "An ultrathin, 5 nm, Al2O3 film grown by atomic layer deposition was used as a gate dielectric for amorphous indium gallium zinc oxide (a IGZO) thin film transistors (TFTs) The Al2O3 layer showed a low surface roughness of 0.15 nm, a low leakage current, and a high breakdown voltage of 6 V. In particular, a very high gate capacitance of 720 nF/cm2 was achieved, making it possible for the a IGZO TFTs to not only operate at a low voltage of 1 V but also exhibit desirable properties including a low threshold voltage of 0.3 V, a small subthreshold swing of 100 mV/decade, and a high on/off current ratio of 1.2 x 107. Furthermore, even under an ultralow operation voltage of 0.6 V, well behaved transistor characteristics were still observed with an on/off ratio as high as 3 x 106. The electron transport through the Al2O3 layer has also been analyzed, indicating the Fowler Nordheim tunneling mechanism.", "author_names": [ "Pengfei Ma", "Lulu Du", "Yiming Wang", "Ran Jiang", "Qian Xin", "Yuxiang Li", "Aimin Song" ], "corpus_id": 59368433, "doc_id": "59368433", "n_citations": 38, "n_key_citations": 1, "score": 0, "title": "Low voltage operation of IGZO thin film transistors enabled by ultrathin Al2O3 gate dielectric", "venue": "", "year": 2018 }, { "abstract": "ZnO has intrinsic semiconductor conductivity because of an unintentional doping mechanism resulting from the growth process that is mainly attributable to oxygen vacancies (VO) positioned in the bandgap. ZnO has multiple electronic states that depend on the number of vacancies and the charge state of each vacancy. In addition to the individual electron states, the vacancies have different vibrational states. We developed a high temperature precursor vapor mask technique using Al2O3 to pattern the atomic layer deposition of ZnO and Al:ZnO layers on ZnO based substrates. This technique was used to create a memristor device based on Al:ZnO thin films having metallic and semiconducting and insulating transport properties ZnO. We demonstrated that adding combination of Al2O3 and TiO2 barrier layers improved the resistive switching behavior. The change in the resistance between the high and low resistivity states of the memristor with a combination of Al2O3 and TiO2 was approximately 157% The devices were exposed to laser light from three different laser diodes. The 450 nm laser diode noticeably affected the combined Al2O3 and TiO2 barrier, creating a high resistivity state with a 2.9% shift under illumination. The high resistivity state shift under laser illumination indicates defect shifts and the thermodynamic transition of ZnO defects.", "author_names": [ "Rajeh Mundle", "Christian G Carvajal", "Aswini K Pradhan" ], "corpus_id": 206674628, "doc_id": "206674628", "n_citations": 25, "n_key_citations": 0, "score": 0, "title": "ZnO/Al:ZnO Transparent Resistive Switching Devices Grown by Atomic Layer Deposition for Memristor Applications.", "venue": "Langmuir the ACS journal of surfaces and colloids", "year": 2016 }, { "abstract": "Minimizing the recombination losses of charge carriers at Si and other semiconductor surfaces is an important topic for many electronic and photonic devices. It is a particularly important issue in the field of crystalline Si photovoltaics as recombination losses cannot be tolerated for efficient solar cells. Surface recombination can be reduced by passivating the surface by dielectric films that lower the (impact of the) density of surface defect states. Thermally grown SiO2 films have traditionally provided the best surface passivation on a variety of Si surfaces with a wide range of doping levels. However the high temperatures and the long oxidation times required have prevented their widespread use in industrial solar cells. State of the art passivation of such solar cells, in particular the n type emitter at the front side of p type cells, is currently provided by hydrogenated amorphous silicon nitride (a SiNx:H) a thin film material generally deposited by plasma enhanced CVD (PECVD) Advances in solar cell technology require however the introduction of new solar cell passivation schemes. The development and study of surface passivation films is therefore currently a very active field of research. In this contribution recent results will be presented which demonstrate that excellent surface passivation (on par or superior to thermal SiO2) can be obtained by Al2O3 prepared by atomic layer deposition (ALD) These films can be ultrathin when employing plasma ALD (down to 5 nm) with Al(CH3)3 and O2 plasma or thermal ALD (down to 10 nm) with Al(CH3)3 and H2O. The key distinguishing property of Al2O3 is the fact that the films can contain a very high density of negative fixed charges ~5x10 cm at the interfacial region (with typically 1 2 nm interfacial SiOx) between the Al2O3 and the Si [1] These fixed charges lead to a surface space region lowering the electron density at the surface causing \"field effect\" passivation. Together with a significant reduction of the defect state density <10 eV cm, \"chemical\" passivation) Al2O3 leads to ultralow recombination velocities on n pand p type Si surfaces [2] The merits of ALD are the fact that it yields extremely uniform films, its precise thickness control, and the possibility of processing at low substrate temperatures <400 oC) [3] Another benefit of ALD that can be of importance for solar cells is the fact that it leads to very conformal films on demanding 3 D topologies, including very rough and non planar surfaces for light trapping and wrap through technologies, respectively. To extend the applicability of ALD for crystalline Si photovoltaics, also for applications that not benefit from the field effect passivation by negative fixed charges, an ALD process has been developed for SiO2 employing SiH2(N(C2H5)2)2 (Air Liquide SAM.24) and O2 plasma. The ALD process with this easy to apply precursor (high vapor pressure, Fig. 1) leads to high quality SiO2 films over a wide temperature range (Fig. 2) The synthesis and passivation quality of this ALD SiO2 will be addressed (Fig. 3) and possible functionalities in surface passivation schemes will be discussed. Figure 1: Relationship between pressure and temperature of TMA [Al(CH3)3] and SAM.24 [SiH2(N(C2H5)2)2] precursors.", "author_names": [ "G Gijs Dingemans", "Cristian A A van Helvoirt", "M M Mandoc", "Richard van de Sanden", "Wilhelmus M M Kessels" ], "corpus_id": 102206432, "doc_id": "102206432", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Atomic Layer Deposition of Al2O3 and SiO2 for Passivation of Si Surfaces", "venue": "", "year": 2011 }, { "abstract": "Single and few layers of semiconducting transition metal dichalcogenides (MX2) hold promise as twodimensional (2D) channel material for future low power logic applications [1] Semiconducting MX2 have significant band gaps, as opposed to graphene where a band gap is absent. Besides their atomic scale thickness, the MX2 surface is chemically inert and lacks dangling bonds. Therefore, few charge traps and scattering centers are expected to inhibit charge transport. For these 2D materials to be integrated into large scale integrated circuits, a large area deposition technique becomes indispensable. The ALD principle ensures growth control at the atomic level, which is essential to control the deposition of single and few layered MX2. The feasibility of growing thin films of MX2 by atomic layer deposition (ALD) has been shown in limited reports [2,3] Nevertheless, growth control down to a single monolayer still has to be proven. Furthermore, to ensure a layered crystalline structure, high temperature anneal treatments are necessary [2] Finally, also the surface chemistry is not well understood, in particular the control of the partial reduction or oxidation of the metal in the MX2 ALD process [4] In this work, we demonstrate a plasma enhanced ALD (PEALD) process for WS2 films, using WF6 and H2S in combination with H2 plasma. Deposition is performed on 300mm Si substrates covered with either 20 nm TiN by physical vapor deposition (PVD) or 30 nm ALD grown and annealed Al2O3 layers. Deposition was first investigated on TiN substrates because of the known reactivity of WF6 and TiN [5] The initial WF6 reaction, forming metallic W and volatile TiF4, is confirmed to be self limiting at temperatures between 250 and 350oC (Rutherford backscattering Spectrometry, RBS) However, even though nucleation is enabled, sequential exposures of WF6 and H2S precursors do not yield a steady state WS2 growth component at temperatures between 300 and 450degC (RBS, Fig. 1a) The deposition stops after ~20 cycles, resulting in the formation of a tungsten subsulfide layer (WSx, with x=~0.7) with ~1.6E+15 W atoms/cm2. We propose that the reduction of W6+ (in WF6) does not occur through reaction with H2S. The steady state growth of tungsten disulfide (WS2) is enabled by PEALD, using reaction cycles consisting of WF6, H2 plasma and H2S exposures (RBS, Fig. 1a) After the initial growth enhancement, both W and S content increase linearly with the number of reaction cycles. The S content increases almost two times faster than the W content, indicating WS2 deposition with a better stoichiometry. The deposition occurs in a broad temperature window, between 250 and 450oC. Interestingly, the PEALD sequence also yields nearly stoichiometric WS2 when applied on Al2O3 substrates. On polycrystalline Al2O3, up to 6 monolayers of WS2 have been grown, with a S to W ratio of 1.8 2 and good thickness uniformity over the 300mm substrate. The WS2 signatures are clearly observed in the Raman spectrum (Fig. 1b) A polycrystalline layered 2D structure is indicated by X ray diffraction and Transmission Electron Microscopy. The WS2 planes are mainly oriented parallel to the substrate surface. The impact of the crystallinity and roughness of the Al2O3 layers on the nucleation, growth and 2D structure of WS2 is being further analyzed.", "author_names": [ "Benjamin Groven", "M H Heyne", "Karel P S Haesevoets", "Johan Meersschaut", "Thomas Nuytten", "Pascal R Verdonck", "Sven Van Elshocht", "Marc M Heyns", "Iuliana P Radu", "Annelies Delabie", "Matty Caymax" ], "corpus_id": 211559774, "doc_id": "211559774", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Plasma enhanced atomic layer deposition of two dimensional WS2 from WF6, H2S and H2 plasma", "venue": "", "year": 2015 }, { "abstract": "The method of atomic layer deposition (ALD) is considered one of the primary candidates for the uniform and conformal deposition of ultrathin films vital for the continuous miniaturization in the semiconductor industry and related high technology markets. By the virtue of two selflimiting surface reactions, the ALD technique yields an ultimate control of film growth in the sense that a submonolayer of material is deposited per so called ALD cycle. With established materials being at the verge of industrial implementation, efforts are continuously undertaken to optimize and develop new ALD configurations and processes. So far, the main emphasis within the field of ALD has been on the materials characterization of the films by means of ex situ analysis. The research described in this thesis aims at the development of the relatively new configuration of plasma assisted ALD and at in situ diagnostics studies of the (plasmaassisted) ALD processes. In plasma assisted ALD, a plasma is used to activate the reactants in the gas phase in order to supply additional reactivity to the ALD chemistry. Plasma assisted ALD is researched to provide benefits in the development of new ALD processes and materials. In particular, the opportunities to improve and tune the film properties, and to deposit films at reduced substrate temperatures have been addressed in this thesis. This work has been accompanied by studies using various in situ diagnostics, from which fundamental insight into the reaction mechanisms governing the ALD processes can be obtained. Moreover, in situ techniques provide the opportunity to monitor, optimize, and control the ALD process. In this work the use of in situ spectroscopic ellipsometry, transmission infrared spectroscopy, mass spectrometry, and optical emission spectroscopy has been demonstrated in studies of the plasma assisted ALD processes of metal nitrides and metal oxides. The results of the film characterization obtained by these techniques have been corroborated and complemented by extensive ex situ analysis. In particular, the combination of in situ spectroscopic ellipsometry and the layer by layer ALD growth has been explored comprehensively. The merits of this in situ technique during ALD have been demonstrated by addressing various aspects relevant to ALD processes and materials. A large part of the work has concentrated on the plasma assisted ALD process of the metal nitrides TiN and TaN. The merits of plasma assisted ALD were observed in the deposition TiN films with excellent conductivity and low impurity content, even at low deposition temperatures. Furthermore, it was shown that by variation of the plasma condition in the ALD process of TaN, the film properties could be tailored from conductive, cubic TaNx;x??1 to semiconductive, amorphous Ta3N5. These aspects were clearly demonstrated by in situ spectroscopic ellipsometry, where the transition in TaNx phase could be distinguished by monitoring the energy dispersion in the optical constants. For the conductive films, the light absorption by free conduction electrons could be probed and that enabled extraction of the electrical film properties from the ellipsometry data. The latter was valuable to demonstrate electron impurity scattering and finite size effects in TiN films. Furthermore, fundamental insight into the reaction mechanisms of plasma assisted ALD process of TaN was obtained by detection of the volatile reaction by products by mass spectrometry and optical emission spectroscopy. The possibilities for plasma assisted ALD to improve the material properties and to deposit at reduced temperatures have been demonstrated for the process of Al2O3. The Al2O3 films were deposited at substrate temperatures down to room temperature and these films yielded good moisture permeation barrier properties as relevant for encapsulation purposes. The fundamental reaction mechanisms of this plasma assisted ALD process were elucidated by transmission infrared spectroscopy in order to understand and further improve the film properties obtained at these reduced deposition temperatures. It was established that the surface chemistry is ruled by CH3 and OH surface groups created by the Al(CH3)3 precursor adsorption and the combustionlike reactions during the O2 plasma step, respectively. Moreover, infrared spectroscopy provided insight into the influence of deposition temperature on the material properties. It was shown that by prolonging the plasma exposure, i.e. by supplying more plasma reactivity to the ALD process, the surface chemistry at low temperatures was enhanced and the impurity content in the Al2O3 was reduced. In conclusion, the knowledge gained through the in situ diagnostic studies in this work is relevant to further develop the ALD technique. The insight obtained into the reaction mechanisms and the material properties of the ALD films in this work are particularly useful to further exploit the possibilities and opportunities of the plasma assisted ALD technique in the synthesis of novel (complex) materials.", "author_names": [ "E Erik Langereis" ], "corpus_id": 135878457, "doc_id": "135878457", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Plasma assisted atomic layer deposition an in situ diagnostic study", "venue": "", "year": 2008 }, { "abstract": "Ultra thin Al2O3 films were deposited by plasma enhanced atomic layer deposition (PEALD) as Cu diffusion barrier on low k (k=2.5) material. The thermal stability and electrical properties of the Cu/low k system with Ta, Ta/Al2O3 and Ru/Ta layers with different thickness were compared after annealing. The TEM and EDX results reveal that the ultrathin Al2O3 films are thermally stable and have excellent Cu diffusion barrier performance. The I V and TDDB electrical measurements further confirm that the ultra thin Al2O3 film is a potential Cu diffusion barrier in copper/low k interconnect. Corresponding Author: Xin Ping Qu, Professor, With the continuing scaling down of the line pitch in very large scale integrated circuits, ultrathin Cu diffusion barriers are necessary to mitigate the increase in the effective resistivity of the Cu interconnects due to grain boundary scattering and interface scattering. Conformal deposition of thin films in high aspect ratio trenches using traditional physical vapor deposition (PVD) technique is becoming difficult [1] Atomic layer deposition (ALD) is considered as a promising method to get excellent conformal films with thickness control at atomic level owing to its intrinsic self limited growth feature [2] ALD grown metals or nitrides such as Ru [3 4] and TaN films[5,6] have been widely studied as Cu diffusion barriers or adhesion layers. ALD grown oxides, such as TiO2[7] Ta2O5 [8] and Al2O3 [9] have also been reported as Cu diffusion barriers due to their excellent uniformity and thermal stability. Qi Xie et.al reported the excellent thermal stability of ALD TiO2.[7] P. Majumder et. al. reported that the ultrathin Al2O3 layer deposited by thermal ALD as diffusion barrier between Cu and Si substrate had excellent thermal stability.[9] However, these oxide layers were all directly deposited onto Si and the very primary properties of diffusion barriers to Cu were measured. Systematic study of ALD oxide films as Cu diffusion barrier on the low k dielectric has been rarely reported. In this work, ultra thin Al2O3 films were deposited by plasma enhanced atomic layer deposition (PEALD) together with Ta adhesion layer, its properties as a Cu diffusion barrier on the low k dielectric (k=2.5) were studied. The low k films (Novellus CORAL, k=2.5) were deposited on the 12\" p type Si wafers with a thickness of 220 nm. The wafers were cut into small pieces and then were cleaned in an ultrasonic cleaner with 2 propanol solution before loading to the loadlock chamber. After in situ annealing at 250 deg C for 20 minutes in the high vacuum ALD chamber, 11 or 21 cycles ~1.2 A/cycle) Al2O3 films were grown by plasma enhanced atomic layer deposition (PEALD) using trimethylaluminium (TMA) and remote O2 plasma (200W) as precursors. The growth temperature was 250deg C. After deposition, samples were taken out and sent into a PVD chamber. The details of the ALD growth can be seen elsewhere.[7] Then the Cu(50 nm)/Ta(5 nm) film stacks were deposited by DC magnetron sputtering. The thin Ta film was used as a glue layer to promote adhesion between the Cu and Al2O3 barrier layers. To form the patterned metal insulatorsemiconductor (MIS) structures, a shadow mask was used when depositing the Cu/Ta stacks. For comparison, the Cu/Ta stack was also directly deposited onto the low k substrates. A Ti(40 nm)/Pt(30 nm) bi layer was deposited as backside electrode by sputtering. Furnace annealing was conducted in the N2 atmosphere at 400 degC for 30 minutes. After annealing, energy dispersive X ray (EDX) transmission electron microscope (TEM) time dependent dielectric breakdown (TDDB) and dielectric breakdown measurements were used to characterize the thermal stability and electrical reliability of the Cu/barrier/low k/Si system. The capacitance voltage (C V) measurements were carried out using an HP 4192A impedance analyzer to evaluate the effective k value of the system. The XTEM images of the as deposited Cu/Ta/Al2O3 (22cycle) /low k/Si samples and the one annealed at 400 degC/30min were shown in Fig. 1(a) and (b) For the asdeposited sample, the thickness of the Ta and Al2O3 layer is about 5 nm and 2.5 nm, respectively. The interface between the Ta and Al2O3 layer is clear. The contrast between the Al2O3 layer and the low k dielectric is not obvious due to the amorphous oxide structure for both Al2O3 and low k. For the annealed sample, the Ta and Al2O3 layer become mixed and the thickness of the barrier is 7.1 nm. The barrier is continuous but the interfaces of Cu/barrier and barrier/low k are obscure. Fig.2 shows the corresponding EDX depth profiles of these two samples. It can be seen that here is no Cu signal in the low k dielectric after annealing. For comparison, we also prepared other two kinds of samples, one is sputtered Cu/Ta (5 nm) and the other is sputtered Cu/ALD Ru (7 nm)/ALD TaN(5 nm) on the low k dielectrics. All the samples were annealed at 400 degC for 30min. The experimental detail of ALD growth of the Ru/TaN bi layer barrier can be seen elsewhere [4] Fig.3 (a) and (b) show the XTEM images of the Cu/Ta/low k/Si and Cu/Ru/TaN/low k/Si samples annealed at 400 degC for 30min. For the Cu/Ta/low k/Si sample, after annealing at 400 degC, there appeared a diffusion region between the Ta layer and low k. The EDX results, not shown here, revealed that there were strong Cu signals, about 10% in the diffusion region. For the Cu/ low k sample with ALD Ru/TaN bilayer as diffusion barrier (Fig.3(b) after annealing at 400 degC for 30 minutes, the Ru/TaN barrier was markedly destroyed and there was a diffusion region around 50 nm thick between the barrier layer and low k. The EDX results (not shown here) revealed that Cu signals almost appeared in every detect point, including the outside of the diffusion region. The failure of the ALD Ru/TaN stack is believed to be due to the diffusion of the Ta precursor to the porous low k dielectric during the ALD process. The diffusion of Ru precursor into the ULK during the ALD process was also observed by Heo et.al. [3] Although in the ALD deposition of Al2O3, the TMA precursor may also diffuse into the porous low k, but Al2O3 is very easy to form and it can act as a barrier to prevent the further penetration of precursor. Our results demonstrate that the thermal stability of the Ta(5 nm) /Al2O3(2.5 nm) barrier stack is not only better than the Ta film itself, but also the thick ALD Ru(7nm)/TaN(5 nm) The surface morphologies of Cu on the Ta/low k and Ta/Al2O3 (2.5 nm)/low k substrates are observed by SEM. As shown in Fig.4, after annealing at 400 degC for 30 min in N2, the Cu on the Ta/low k substrate experiences severe agglomeration; but for the samples with Ta/Al2O3 stack, there are no pinholes on the Cu surface. Agglomeration of the Cu films can be caused by reaction of barrier with moisture outgassed from the low k substrate, as well as the degraded Cu adhesion with barrier due to the oxidation of the barrier. [10 12] Thin Al2O3 films deposited by ALD used as superior moisture and oxygen barriers for organic devices has been reported. [13] Moisture barrier is also important for low k dielectrics, since the oxidation of Cu lines induced by the absorption and outgas of moisture in dielectric may degrade the electrical properties of the Cu interconnects. [14 15] Therefore, in our case, the ALD oxide layer can also suppress the moisture outgassed from the low k dielectric and enhance the Cu adhesion on Ta. Since Al2O3 is a kind of high k dielectrics (k ~9.0) [16] its effect on the effective dielectric constant of the Cu/low k system was evaluated. The C V measurements were carried out for the Cu/Ta/Al2O3(1.3 nm)/low k/Si, Cu/Ta/low k/Si and Cu/Ta/TaN(5 nm)/low k/Si MIS capacitor. The original k value was 2.55 after IPA cleaning. After sputtered deposition of the metal stacks, the measured effective k values (ke) of all the capacitors were all increased. The ke values for the Cu/Ta/low k/Si and Cu/Ta/Al2O3(1.3 nm) /low k samples were the same (2.8) and lower than that of the Cu/Ta/TaN(5 nm)/low k/Si (3.0) The increase of the effective k value is mainly due to the damage of the low k dielectric during the deposition and annealing process as well as the oxidation of the TaN barrier. These results indicate that using an ultra thin Al2O3 films as Cu diffusion barriers doesn't affect much on the k value of the low k dielectric. The electrical properties of the Cu gated MIS structures were measured. Figure 5(a) shows the leakage current densities of the the as deposited MIS capacitors with Ta(5 nm) with Ta(5 nm)/Al2O3(1.3 nm) and Ta(5 nm)/Al2O3(2.5 nm) as diffusion barriers =and those after annealing at 400 degC for 30 minutes in N2. The leakage current densities for all the as deposited and annealed samples were similar under the applied electric field of 1MV/cm. Further we compared the breakdown voltages for these samples. Figure 5(b) shows the cumulative failure distribution of breakdown electric field (Eb) of the capacitors with different diffusion barriers after annealing at 400 degC for 30 minutes in N2. For capacitors with the Ta(5 nm)/2.5 nm Al2O3 stack, Eb is mainly around 9 MV/cm; for those with 5 nm Ta layer and Ru/TaN, Eb is lower than 3 MV/cm. Although the Eb is similar for the samples with 1.3 nm or 2.5 nm Al2O3 layer, but the TDDB measurements (figure not shown here) show that the TDDB of the annealed MIS capacitor with 1.3 nm Al2O3 is about 2.3x10 4 s under a stressing field of 7.7 MV/cm; for the MIS capacitor with 2.5 nm Al2O3 layer, the TDDB exceeds 1.7x10 5 s under an higher EM of 8.6 MV/cm. Although under RT, copper is difficult to migrate under low electric field, it can move very rapidly under a high electric filed through defects in the diffusion barrier. The presence of Cu in the dielectrics would greatly reduce dielectric life time. [17] Our results further indicate that the Al2O3 film is an excellent barrier for Cu metallization and the thickness of the Al", "author_names": [ "S F Ding", "Qi Xie", "Fei Yu Chen", "Hai-Sheng Lu", "Shao-Ren Deng", "Christophe Detavernier", "Xin-Ping Qu" ], "corpus_id": 54602772, "doc_id": "54602772", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Excellent thermal stability by using PEALD ultra thin Al2O3 film with Ta as Cu diffusion barrier on low k dielectrics", "venue": "", "year": 2011 }, { "abstract": "Understanding conduction mechanisms (CMs) through a thin dielectric oxide is important in state of the art Complementary Metal Oxide Semiconductor (CMOS) technology. This is because when an Electric field (E) is applied across the dielectric film; an undesired current appears which degrades the behavior of the device, thus shortening its life span. One of the most widely used dielectric in microelectronics is Aluminum Oxide (Al2O3) because it presents a large bandgap ~8.8 eV) and relatively high dielectric constant (k~9) it also presents great thermal stability and can passivate important interfaces with other electronic materials thus enhancing the performance of electron devices. This work reviews the conduction mechanisms in Metal Insulator Semiconductor (MIS) devices fabricated using ultra thin Al2O3 (5nm and 10 nm) deposited by Atomic Layer Deposition (ALD) at relatively low processing temperatures. After gate patterning, thermal treatment was performed using Forming Gas (H2/N2) at 450deg C for 30 minutes. MIS devices were then electrically characterized using standard I V and C V measurements, taking the devices to dielectric breakdown; afterwards, experimental measurements were compared with semi empirical tunneling models like Direct tunneling (DT) Ohmic Conduction (OC) Poole Frenkel emission (PF) and Fowler Nordheim tunneling (FN) in order to determine the precise conduction mechanisms and their corresponding physical parameters. After dielectric breakdown, Schottky diode conduction is obtained, thus demonstrating the nature of the post breakdown event. Once these well known semi empirical models were validated through standard equations, SILVACO simulations were made in order to further validate the proposed models. Afterwards, physical parameters before and after thermal annealing such as effective mass (m) barrier height (before and after breakdown) and trap energy level were extracted. Finally, only one self consistent equation containing all physical parameters and conduction models is obtained.", "author_names": [ "Molina Reyes Joel", "Uribe Vargas Hector Manuel", "Carlos Zuniga", "Wilfrido Calleja" ], "corpus_id": 43932751, "doc_id": "43932751", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "COMPARISON OF THE EXPERIMENTAL CARRIER TRANSPORT IN MIS DEVICES FABRICATED WITH ULTRA THIN Al 2 O 3 WITH STANDARD CONDUCTION MODELS AND SIMULATIONS", "venue": "", "year": 2018 } ]

[ { "abstract": "1. SEMICONDUCTORS, JUNCTIONS AND MOFSET OVERVIEW 2. THE TWO TERMINAL MOS STRUCTURE 3. THE THREE TERMINAL MOS STRUCTURE 4. THE FOUR TERMINAL MOS STRUCTURE 5. MOS TRANSISTORS WITH ION IMPLANTED CHANNELS 6. SMALL DIMENSION EFFECTS 7. THE MOS TRANSISTOR IN DYNAMIC OPERATION LARGE SIGNAL MODELING 8. SMALL SIGNAL MODELING FOR LOW AND MEDIUM FREQUENCIES 9. HIGH FREQUENCY SMALL SIGNAL MODELS 10.MOFSET MODELING FOR CIRCUIT SIMULATION", "author_names": [ "Yannis P Tsividis" ], "corpus_id": 137446586, "doc_id": "137446586", "n_citations": 3154, "n_key_citations": 317, "score": 1, "title": "Operation and modeling of the MOS transistor", "venue": "", "year": 1987 }, { "abstract": "All existing transistors are based on the use of semiconductor junctions formed by introducing dopant atoms into the semiconductor material. As the distance between junctions in modern devices drops below 10 nm, extraordinarily high doping concentration gradients become necessary. Because of the laws of diffusion and the statistical nature of the distribution of the doping atoms, such junctions represent an increasingly difficult fabrication challenge for the semiconductor industry. Here, we propose and demonstrate a new type of transistor in which there are no junctions and no doping concentration gradients. These devices have full CMOS functionality and are made using silicon nanowires. They have near ideal subthreshold slope, extremely low leakage currents, and less degradation of mobility with gate voltage and temperature than classical transistors.", "author_names": [ "J P Colinge", "Chi-Woo Lee", "Aryan Afzalian", "Nima Dehdashti Akhavan", "Ran Yan", "Isabelle Ferain", "Pedram Razavi", "Brendan O'Neill", "Alan Blake", "Mary Anne White", "A Kelleher", "Brendan McCarthy", "Richard Murphy" ], "corpus_id": 14332129, "doc_id": "14332129", "n_citations": 1733, "n_key_citations": 79, "score": 0, "title": "Nanowire transistors without junctions.", "venue": "Nature nanotechnology", "year": 2010 }, { "abstract": "The authors have demonstrated a functional Pnp heterojunction bipolar transistor (HBT) using InGaAsN. The metalorganic vapor phase epitaxy (MOCVD) grown Al{sub 0.3}Ga{sub 0.7}As/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} HBT takes advantage of the narrower bandgap energy (E{sub g} 1.25eV) of In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} which is lattice matched to GaAs. Compared with the Al{sub 0.3}Ga{sub 0.7}As/GaAs material system, the Al{sub 0.3}Ga{sub 0.7}As/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} material system has a larger conduction band offset, while the valence band offset remains comparable. This characteristic band alignment is very suitable for Pnp HBT applications. The device's peak current gain is 23 and it has a turn on voltage of 0.77V, which is 0.25V lower than in a comparable Pnp Al{sub 0.3}Ga{sub 0.7}As/GaAs HBT.", "author_names": [ "Albert G Baca", "Pablo Chang", "Fan Ren" ], "corpus_id": 119009731, "doc_id": "119009731", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "InGaAsN/AlGaAs Pnp Heterojunction Bipolar Transistor", "venue": "", "year": 1999 }, { "abstract": "A pnp bipolar resonant tunneling transistor is realized using a base consisting of an n type modulation doped quantum well layer next to a double barrier tunneling structure. Electrons are injected from the quantum well base layer into the tunneling structure, leading to quantum well light emission when they recombine with holes from the emitter. This optical output, which is modulated by the base voltage, persists in the negative differential resistance region of the current voltage characteristics where the hole current is in oscillation. This opens possibilities for using this transistor as a high frequency electro optical heterodyne convertor.", "author_names": [ "Jan Genoe", "Chris Van Hoof", "Kristel Fobelets", "Robert P Mertens", "G Borghs" ], "corpus_id": 120995234, "doc_id": "120995234", "n_citations": 13, "n_key_citations": 1, "score": 0, "title": "pnp resonant tunneling light emitting transistor", "venue": "", "year": 1992 }, { "abstract": "This paper proposes a novel lateral PNP type structure that is fully compatible with existing single polysilicon BiCMOS processes and offers a valid alternative to shallow polysilicon emitter transistors. We have used both an analytical approach and a more accurate computer aided design, obtaining 0.9 GHz and 4.4 GHz cutoff frequency for 2 /spl mu/m and 0.8 /spl mu/m minimum feature transistors, respectively.", "author_names": [ "Iulian Constantin Gradinariu", "Christian Gontrand" ], "corpus_id": 110430342, "doc_id": "110430342", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "A high performance lateral PNP transistor structure", "venue": "", "year": 1996 }, { "abstract": "The microwave performance of a pnp AlGaAs/GaAs heterojunction bipolar transistor was demonstrated for the first time. Common emitter current gains of 60 were obtained using MOCVD grown structures with 100 nm thick base layers and self aligned emitter base contacts. ft and fmax values were 12 and 20 GHz respectively. Under common base configuration, 8 dB gain was obtained at 10 GHz. Device performance was characterised under CW and pulsed conditions.", "author_names": [ "Burhan Bayraktaroglu", "Natalino Camilleri", "S A Lambert" ], "corpus_id": 110446686, "doc_id": "110446686", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Microwave pnp AlGaAs/GaAs heterojunction bipolar transistor", "venue": "", "year": 1988 }, { "abstract": "A vertical pnp BJTs on thin SOI is designed and characterized by using the mixed numerical two dimensional process and device simulator (Sentaurus) The DC, frequency, and breakdown characteristics of the vertical pnp on SOI are simulated and analyzed. The peak of b is 85 at Vbe= 0.7. The maximum of the cutoff frequency ft for the pnp bipolar transistor on SOI attain 10.6 GHz, and the value of BVceo for the pnp bipolar transistor on SOI achieves 7.3V, respectively. The availability of performance pnp transistor should enable significantly improved bipolar circuit design.", "author_names": [ "Jiexin Luo", "Jing Chen", "Jianhua Zhou", "Qingqing Wu", "Xiaolu Huang", "Xi Wang" ], "corpus_id": 12501507, "doc_id": "12501507", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Design and simulation of the vertical pnp transistor on SOI", "venue": "2010 10th IEEE International Conference on Solid State and Integrated Circuit Technology", "year": 2010 }, { "abstract": "Preliminary results of the first successful operation of pnp AlGaAs/GaAs heterojunction bipolar transistors grown by molecular beam epitaxy are reported. A common emitter current gain of 50 was obtained for a base width of 0.1 mm. For collector currents larger than a certain value, a negative output differential resistance (NDR) was seen at temperatures between 360 and 83 K. The onset of collector current for NDR was found to increase with decreasing temperature from 40 mA at 360 K to 200 mA at 83 K for emitter base junction area of 10 mmx50 mm. The NDR was seen for both common base and common emitter characteristics and for both constant input currents and voltages. Increased surface recombination current at the edges of the emitter base junction at large electric fields, large currents, and high temperatures appears to be the cause for NDR.", "author_names": [ "Naresh Chand", "Tim Henderson", "Robert Fischer", "W Kopp", "Hadis Morkoc", "Lawrence Joseph Giacoletto" ], "corpus_id": 109082207, "doc_id": "109082207", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "A pnp AlGaAs/GaAs heterojunction bipolar transistor", "venue": "", "year": 1985 }, { "abstract": "Negative impedances having very stable characteristics are obtained with circuits using transistors. The physical characteristics of transistors, compactness, long life, simple power requirements, plus constancy of pertinent electrical parameters enhance their practical utility in the production of negative impedances.", "author_names": [ "John G Linvill" ], "corpus_id": 51654698, "doc_id": "51654698", "n_citations": 332, "n_key_citations": 26, "score": 0, "title": "Transistor Negative Impedance Converters", "venue": "Proceedings of the IRE", "year": 1953 }, { "abstract": "Abstract An analysis for modified lateral PNP transistors with an applied or built in electric field in the base region is performed for several different cases. Improvement in operation is obtained for the modified devices and this is shown by comparing the results with unmodified equivalent structures.", "author_names": [ "Thomas A DeMassa", "Larry Rispin" ], "corpus_id": 94857729, "doc_id": "94857729", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Analysis of modified lateral PNP transistors", "venue": "", "year": 1975 } ]

[ { "abstract": "This work clarifies the analysis of the theoretical study of noise and transmission gain characteristics of semiconductor optical amplifiers (SOAs) which are relevant in the novel local area optical communication systems. We investigated the effects of noise on AlGaAs/GaAs SOA transmission performance through the measurement of output power, optical gain, the optical signal to noise ratio, and noise figure. It was observed that noise has a dramatic effect on SOAs' operation transmission efficiency, and the performance of the amplifier structure may be limited. If the drive current and injection power at the SOA can be changed and its active region length modified, then the variation of gain, optical signal to noise ratio, and noise figure at the output of the structure can be obtained.", "author_names": [ "Hazem M M El-Hageen", "Aadel Alatwi", "Ahmed Nabih Zaki Rashed" ], "corpus_id": 225452521, "doc_id": "225452521", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "High speed signal processing and wide band optical semiconductor amplifier in the optical communication systems", "venue": "", "year": 2020 }, { "abstract": "The energy resolution of a single photon counting Microwave Kinetic Inductance Detector (MKID) can be degraded by noise coming from the primary low temperature amplifier in the detector's readout system. Until recently, quantum limited amplifiers have been incompatible with these detectors due to dynamic range, power, and bandwidth constraints. However, we show that a kinetic inductance based traveling wave parametric amplifier can be used for this application and reaches the quantum limit. The total system noise for this readout scheme was equal to ~2.1 in units of quanta. For incident photons in the 800 to 1300 nm range, the amplifier increased the average resolving power of the detector from ~6.7 to 9.3 at which point the resolution becomes limited by noise on the pulse height of the signal. Noise measurements suggest that a resolving power of up to 25 is possible if redesigned detectors can remove this additional noise source.", "author_names": [ "Nicholas Zobrist", "Byeong Ho Eom", "Peter K Day", "Benjamin A Mazin", "S R Meeker", "Bruce Bumble", "Henry G Leduc", "Gregoire Coiffard", "Paul Szypryt", "Neelay Fruitwala", "Isabel Lipartito", "Clint Bockstiegel" ], "corpus_id": 195833705, "doc_id": "195833705", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "Wide band parametric amplifier readout and resolution of optical microwave kinetic inductance detectors", "venue": "Applied Physics Letters", "year": 2019 }, { "abstract": "The invention provides a wide band amplifier with frequency compensation, wherein the working frequency range of a circuit of the amplifier can be expanded by means of frequency compensation. The wide band amplifier has a structure of an input/output circuit, wherein the circuit structure comprises a first transconductance amplifying unit, a second transconductance unit equivalent to a load circuit, two frequency compensation resistors embedded to a feedback loop of the second transconductance unit, and two capacitors equivalent to the load introduced by a post stage circuit. The first transconductance amplifying unit has a structure of an input/output circuit, and is connected in series with the second transconductance unit of the feedback circuit structure. Two frequency compensation resistors are respectively matched with a parasitic input resistor at corresponding input end of the second transconductance unit to form a capacitance resistance low pass filter circuit by which a zero point is introduced in a transmission function of the wide band amplifier to expand the frequency working range of the wide band amplifier under the effect of the loop feedback. The wide band amplifier provided by the invention is used as the base amplifier unit applied to a radio frequency simulating front end of a receiver so as to achieve amplifying of an intermediate frequency signal. The wide band amplifier can also be applied to other systems to achieve amplification of a broadband.", "author_names": [ "" ], "corpus_id": 127964913, "doc_id": "127964913", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Wide band amplifier with frequency compensation", "venue": "", "year": 2010 }, { "abstract": "RF power amplifiers are one of challenging blocks in designing radio frequency transceivers, this is due to non linearity behavior of power amplifiers that leads to inter modulation distortion. This paper presents the design of wide band power amplifier which combined with parallel coupled line band pass filter at the input and output of power amplifier to allow the only required frequency band to pass through the power amplifier. Class A topology and ATF 511P8 transistor are used in this design. Advanced Design System software used as a simulation tool to simulate the designed wide band power amplifier. The simulation results showed an input return loss (S11) which less than 10dB, and gain (S21) is higher than 10 dB over the entire frequency band and considers as flat as well. The designed amplifier is stable over the bandwidth (K>1) Inter modulation distortion is 56.919dBc which is less than 50dBc with 10dBm input power. The designed amplifier can be used for the microwave applications which include weather radar, satellite communication, wireless networking, mobile, and TV.", "author_names": [ "Mussa Mabrok", "Zahriladha Zakaria", "N Saifullah" ], "corpus_id": 69769855, "doc_id": "69769855", "n_citations": 5, "n_key_citations": 1, "score": 0, "title": "Design of Wide band Power Amplifier based on Power Combiner Technique with Low Intermodulation Distortion", "venue": "", "year": 2018 }, { "abstract": "Precision dc coupled amplifiers having risetimes of less than a nanosecond have recently been fabricated using the monolithic planar process. The design is based on a simple technique that has a broad range of applications and is characterized by a stage gain bandwidth product essentially equal to that of the transistors, and a very linear transfer characteristic, free from temperature dependence.", "author_names": [ "Barrie Gilbert" ], "corpus_id": 6584426, "doc_id": "6584426", "n_citations": 262, "n_key_citations": 8, "score": 1, "title": "A new wide band amplifier technique", "venue": "", "year": 1968 }, { "abstract": "Abstract This paper presents an Ultra Wide Band (UWB) high linear low noise amplifier. The linearity of Common Gate (CG) structure is improved based on pre distortion technique. An auxiliary transistor is used at the input to sink the nonlinear terms of source current, resulting linearity improvement. Furthermore, an inductor is used in the gate of the main amplifying transistor, which efficiently improves gain, input matching and noise performance at higher frequencies. Detailed mathematical analysis show the effectiveness of both linearity improvement and bandwidth extension techniques. Post layout simulation results of the proposed LNA in TSMC 0.18 um RF CMOS process show a gain of 13.7 dB with 3 dB bandwidth of 0.8 10.4 GHz and minimum noise figure (NF) of 3 dB. Input Third Intercept Point (IIP3) of 10.3 13 dBm is achieved which shows 8 dB improvement compared to conventional common gate structure. The core circuit occupies an area of 0.19 mm 2 including bond pads, while consuming 4 mA from a 1.8 V supply.", "author_names": [ "Roya Jafarnejad", "Abumoslem Jannesari", "Jafar Sobhi" ], "corpus_id": 114563927, "doc_id": "114563927", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "A linear ultra wide band low noise amplifier using pre distortion technique", "venue": "", "year": 2017 }, { "abstract": "Abstract In this paper, a differential multi band CMOS low noise amplifier (LNA) operated in a range of 800 1700 MHz, is proposed. In this design, the LNA is integrated wide band interference rejection (input band selection technology) and capacitive cross coupling topologies, which can improve the interference rejection and noise figure preference. Moreover, the conventional notch filter technology only rejected the specified frequency. In this experiment, by using the proposed wide band interference rejection technology, the LNA can reject unwanted signals (out of band signals) and image signals from different frequency. Thus, the LNA has good linearity and interference rejection performance. With the increasing use of frequency spectrum, the proposed technology is even more important. The post simulation results of proposed LNA show that the voltage gain is 13 17.5 dB, the noise figure (NF) is less than 3.4 dB, and the third order intercept point (IIP3) is 7.36 dBm. The LNA consumes 8.96 mW under 1.8 V supply voltage in TSMC 0.18 mm RF CMOS process.", "author_names": [ "Jhen-Ji Wang", "Duan-Yu Chen", "San-Fu Wang", "Rongshan Wei" ], "corpus_id": 111298697, "doc_id": "111298697", "n_citations": 18, "n_key_citations": 0, "score": 0, "title": "A multi band low noise amplifier with wide band interference rejection improvement", "venue": "", "year": 2016 }, { "abstract": "We report a novel hybrid optical amplifier covering S+C+L bands with 105 nm total bandwidth using a silica fiber. The principle of amplification is based on the stimulated radiative transition of Er ions for C band and on the stimulated Raman scattering for S and L band, respectively. In this letter, we analyze the amplification characteristics for two types of active fiber mediums through numerical simulation. One is a silica fiber configured with Er doped cladding and Ge doped core and the other is a medium consisting of Er doped fiber and dispersion compensating fiber. By optimizing parameters such as fiber length and pump power, we newly achieve wide band amplification with 105 nm bandwidth showing a flat gain characteristic over the entire S+C+L bands.", "author_names": [ "Hong-seok Seo", "Woon Jin Chung", "J T Ahn" ], "corpus_id": 31102285, "doc_id": "31102285", "n_citations": 28, "n_key_citations": 1, "score": 0, "title": "A novel hybrid silica wide band amplifier covering S+C+L bands with 105 nm bandwidth", "venue": "IEEE Photonics Technology Letters", "year": 2005 }, { "abstract": "Monolithic integration of a wide band amplifier with uniform gain from dc to 1 GHz is described. By choosing an essentially simple circuit both for construction and evaluation it is shown that the collective application of microwave transistor diffusions, double layer interconnections, beam leads, air isolation, and microstriplines on ceramic substrates extends the range of operation to beyond 1 GHZ. Gain values of 12 dB flat within 0.5 dB for a two stage amplifier and nearly 50 dB flat within 1 dB for cascaded amplifiers from low frequencies to 1 GHz are achieved. The direction for further technological improvements is indicated.", "author_names": [ "Justin Coughlin", "R J H Gelsing", "P J W Jochems", "H J M van der Laak" ], "corpus_id": 62168481, "doc_id": "62168481", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "A monolithic silicon wide band amplifier from DC to 1 GHz", "venue": "", "year": 1973 }, { "abstract": "A 3 mW 800 MHz amplifier with a voltage gain of 10 dB is discussed. The parasitic junction capacitance of a transistor is the major factor limiting the bandwidth particularly for low power amplifiers. In addition to the pole at the input node, the pole at the output node may become dominant in low power amplifiers, which use high speed bipolar transistors. A parasitic capacitance compensation technique to expand the bandwidth in this type of amplifier is discussed. This technique compensates for both capacitances at the input and output nodes and enhances the bandwidth and the gain bandwidth product. The measured data demonstrate that this technique expands the bandwidth to about twice that of a conventional differential amplifier. In addition, circuit simulation predicts that this technique expands the bandwidth by about 40% over a conventional peaking technique. A stable frequency response without any overpeaking or oscillation problem has been achieved by utilizing the parasitic junction capacitances of dummy transistors as the compensation capacitance.", "author_names": [ "Tsutomu Wakimoto", "Yukio Akazawa" ], "corpus_id": 62531869, "doc_id": "62531869", "n_citations": 35, "n_key_citations": 1, "score": 0, "title": "A low power wide band amplifier using a new parasitic capacitance compensation technique", "venue": "", "year": 1990 } ]

[ { "abstract": "Highly luminescent semiconductor quantum dots (zinc sulfide capped cadmium selenide) have been covalently coupled to biomolecules for use in ultrasensitive biological detection. In comparison with organic dyes such as rhodamine, this class of luminescent labels is 20 times as bright, 100 times as stable against photobleaching, and one third as wide in spectral linewidth. These nanometer sized conjugates are water soluble and biocompatible. Quantum dots that were labeled with the protein transferrin underwent receptor mediated endocytosis in cultured HeLa cells, and those dots that were labeled with immunomolecules recognized specific antibodies or antigens.", "author_names": [ "Warren C W Chan", "Shuming Nie" ], "corpus_id": 21611025, "doc_id": "21611025", "n_citations": 6268, "n_key_citations": 85, "score": 1, "title": "Quantum dot bioconjugates for ultrasensitive nonisotopic detection.", "venue": "Science", "year": 1998 }, { "abstract": "Quantum dots (QDs) are a special type of engineered nanomaterials with outstanding optoelectronic properties that make them as a very promising alternative to conventional luminescent dyes in biomedical applications, including biomolecule (BM) targeting, luminescence imaging and drug delivery. A key parameter to ensure successful biomedical applications of QDs is the appropriate surface modification, i.e. the surface of the nanomaterials should be modified with the appropriate functional groups to ensure stability in aqueous solutions and it should be conjugated with recognition elements capable of ensuring an efficient tagging of the BMs of interest. In this review we summarize the most relevant strategies used for surface modification of QDs and for their conjugation to BMs in preparation of their application in nanoplatforms for luminescent BM sensing and imaging guided targeting. The applications of conjugations of photoluminescent QDs with different BMs in both in vitro and in vivo chemical sensing, immunoassays or luminescence imaging are reviewed. Recent progress in the application of functionalized QDs in ultrasensitive detection in bioanalysis, diagnostics and imaging strategies are reported. Finally, some key future research goals in the progress of bioconjugation of QDs for diagnosis are identified, including novel synthetic approaches, the need for exhaustive characterization of bioconjugates and the design of signal amplification schemes.", "author_names": [ "Maria Diaz-Gonzalez", "Alfredo de la Escosura-Muniz", "Maria Teresa Fernandez-Arguelles", "Francisco Javier Garcia Alonso", "Jose Manuel Costa-Fernandez" ], "corpus_id": 214647352, "doc_id": "214647352", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Quantum Dot Bioconjugates for Diagnostic Applications", "venue": "Topics in Current Chemistry", "year": 2020 }, { "abstract": "A selective aptasensor was developed using the electrochemical transduction method for the ultrasensitive detection of cocaine. In this method, dendrimer quantum dot (Den QD) bioconjugate was utilized as a specific nanocomposite to efficiently fabricate the aptasensor. CdTe QD, which carries highly significant properties, was immobilized on the surface of a glassy carbon electrode (GCE) and polyamidoamine (PAMAM) dendrimer (Den) was covalently attached to the carboxyl terminated surface of the CdTe QDs. This clever combination of QD and Den provides a highly stable matrix for the increased loading of aptamer (Apt) as a cocaine molecular receptor via covalent attachment. The Apt was functionalized with AuNPs leading to the amplification of the electrochemical signal. In this study, upon the incubation of cocaine on the aptasensor surface, the peak current of the redox probe decreased due to the hindered electron transfer reaction on the sensing surface. It has shown that the proposed aptasensor can detect cocaine by electrochemical impedance spectroscopy (EIS) technique at a linear range (5.00 10 3 6.00 nM) and a capability of detection down to 1.60 pM. The excellent specificity of this sensing system is demonstrated by using some common analgesic drugs, and finally, the proposed aptasensor was successfully used to measure cocaine in the human serum sample. The proposed methodology may hold great promise for the design of other aptasensors and immunosensors based on the use of the Den QD bioconjugate as a nanocomposite with high performance.", "author_names": [ "Mahmoud Roushani", "Faezeh Shahdost-fard" ], "corpus_id": 53696126, "doc_id": "53696126", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Applicability of the Dendrimer quantum Dot (Den QD) Bioconjugate as a Novel Nanocomposite for Signal Amplification in the Fabrication of Cocaine Aptasensor", "venue": "", "year": 2019 }, { "abstract": "Exploration of quantum dots (QDs) as energy acceptors revolutionizes the current chemiluminescence resonance energy transfer (CRET) since QDs possess large Stokes shifts and high luminescence efficiency. However, the strong and high concentration of oxidant (typically H2O2) needed for luminol chemiluminescence (CL) reaction could cause oxidative quenching to QDs, thereby decreasing the CRET performance. Here we proposed the use of bienzyme QDs bioconjugate as the energy acceptor for improved CRET sensing. Two enzymes, one for H2O2 generation (oxidase) and another for H2O2 consumption (horseradish peroxidase, HRP) were bioconjugated onto the surface of QDs. The bienzyme allowed fast in situ cascaded H2O2 generation and consumption, thus alleviating fluorescence quenching of QDs. The nanosized QDs accommodate the two enzymes in a nanometric range, and the CL reaction was confined on the surface of QDs accordingly, thereby amplifying the CL reaction rate and improving CRET efficiency. As a result, CRET efficiency of 30 38% was obtained; the highest CRET efficiency by far was obtained using QDs as the energy acceptor. The proposed CRET system could be explored for ultrasensitive sensing of various oxidase substrates (here exemplified with cholesterol, glucose, and benzylamine) allowing for quantitative measurement of a spectrum of metabolites with high sensitivity and specificity. Limits of detection (LOD, 3s) for cholesterol, glucose, and benzylamine were found to be 0.8, 3.4, and 10 nM, respectively. Furthermore, multiparametric blood analysis (glucose and cholesterol) is demonstrated.", "author_names": [ "Shuxia Xu", "Xianming Li", "Chaobi Li", "Jialin Li", "Xinfeng Zhang", "Peng Wu", "Xiandeng Hou" ], "corpus_id": 206504545, "doc_id": "206504545", "n_citations": 35, "n_key_citations": 0, "score": 0, "title": "In Situ Generation and Consumption of H2O2 by Bienzyme Quantum Dots Bioconjugates for Improved Chemiluminescence Resonance Energy Transfer.", "venue": "Analytical chemistry", "year": 2016 }, { "abstract": "Herein we demonstrate the protocol of a biocatalytic precipitation (BCP) based sandwich photoelectrochemical (PEC) horseradish peroxidase (HRP) linked immunoassay on the basis of their synergy effect for the ultrasensitive detection of mouse IgG (antigen, Ag) as a model protein. The hybrid film consisting of oppositely charged polyelectrolytes and CdS quantum dots (QDs) is developed by the classic layer by layer (LbL) method and then employed as the photoactive antibody (Ab) immobilization matrix for the subsequent sandwich type Ab Ag affinity interactions. Improved sensitivity is achieved through using the bioconjugates of HRP secondary antibodies (Ab(2) In addition to the much enhanced steric hindrance compared with the original one, the presence of HRP would further stimulate the BCP onto the electrode surface for signal amplification, concomitant to a competitive nonproductive absorption that lowers the photocurrent intensity. As a result of the multisignal amplification in this HRP catalyzed BCP based PEC immunoassay, it possesses excellent analytical performance. The antigen could be detected from 0.5 pg/mL to 5.0 ng/mL with a detection limit of 0.5 pg/mL.", "author_names": [ "Wei-Wei Zhao", "Zheng-Yuan Ma", "Pei Yu", "Xiao-Ya Dong", "Jingjuan Xu", "Hong-Yuan Chen" ], "corpus_id": 206354224, "doc_id": "206354224", "n_citations": 216, "n_key_citations": 4, "score": 0, "title": "Highly sensitive photoelectrochemical immunoassay with enhanced amplification using horseradish peroxidase induced biocatalytic precipitation on a CdS quantum dots multilayer electrode.", "venue": "Analytical chemistry", "year": 2012 }, { "abstract": "An ultrasensitive photoelectrochemical immunoassay of cancer biomarker a fetoprotein (AFP) is proposed that uses titanium dioxide (TiO(2) coupled with AFP CdTe GOx bioconjugate, which featured AFP antigen and glucose oxidase (GOx) labels linked to CdTe quantum dots (QDs) for signal amplification. The synthesized CdTe QDs yielded a homogeneous and narrow size distribution, which allowed the binding of AFP and GOx on CdTe QDs. Greatly enhanced sensitivity for AFP came from a dual signal amplification strategy. First, an effective matching of energy levels between the conduction bands of CdTe QDs and TiO(2) allowed for fast electron injection from excited CdTe QDs to TiO(2) upon irradiation, which reduced the recombination process of electron hole pairs and prompted photoelectrochemical performance. Second, GOx enzyme could catalyze glucose to produce H(2)O(2) which acted as a sacrificial electron donor to scavenge the photogenerated holes in the valence band of CdTe QDs, further causing an enhanced photocurrent. Thus, on the basis of the dual signal amplification strategy, the competitive immunosensor based on the specific binding of anti AFP antibodies to AFP and AFP CdTe GOx bioconjugates was achieved. This proposed biosensor for AFP possessed largely increased linear detection range from 0.5 pg/mL to 10 mg/mL with a detection limit of 0.13 pg/mL. The proposed amplification strategy shows high sensitivity, stability, and reproducibility and can become a promising platform for other protein detection.", "author_names": [ "Yongjie Li", "Mengyao Ma", "Jun-Jie Zhu" ], "corpus_id": 23393849, "doc_id": "23393849", "n_citations": 152, "n_key_citations": 1, "score": 0, "title": "Dual signal amplification strategy for ultrasensitive photoelectrochemical immunosensing of a fetoprotein.", "venue": "Analytical chemistry", "year": 2012 }, { "abstract": "Herein, we describe an ultrasensitive specific biosensing system for detection of sarcosine as a potential biomarker of prostate carcinoma based on Forster resonance energy transfer (FRET) The FRET biosensor employs anti sarcosine antibodies immobilized on paramagnetic nanoparticles surface for specific antigen binding. Successful binding of sarcosine leads to assembly of a sandwich construct composed of anti sarcosine antibodies keeping the Forster distance (Ro) of FRET pair in required proximity. The detection is based on spectral overlap between gold functionalized green fluorescent protein and antibodies@quantum dots bioconjugate (lex 400 nm) The saturation curve of sarcosine based on FRET efficiency (F604/F510 ratio) was tested within linear dynamic range from 5 to 50 nM with detection limit down to 50 pM. Assembled biosensor was then successfully employed for sarcosine quantification in prostatic cell lines (PC3, 22Rv1, PNT1A) and urinary samples of prostate adenocarcinoma patients.", "author_names": [ "Zbynek Heger", "Natalia Cernei", "Sona Krizkova", "Michal Masarik", "Pavel Kopel", "Petr Hodek", "Ondrej Zitka", "Vojtech Adam", "Rene Kizek" ], "corpus_id": 15136835, "doc_id": "15136835", "n_citations": 35, "n_key_citations": 2, "score": 0, "title": "Paramagnetic Nanoparticles as a Platform for FRET Based Sarcosine Picomolar Detection", "venue": "Scientific reports", "year": 2015 }, { "abstract": "In this paper, we demonstrate the spectral encoding capabiliry of quantum dot nanocrystals (QDs) We mixed two direrent sizes of QDs in a resin, and two photon ercitation at various wavelengths showed that the relative intensities of the fluorescence @om two QDs varied significantly. Such a difference in level of absorption at direrent wavelengths allows one to record information only on one size of QDs, without affecting the other sized QDs. This properry can be applied to optical data storagev so thal storage dens@ can be greatly improved. Recently, three dimensional (3 D) optical storage has been receiving much attention due to its ability to overcome the current two dimensional optical storage capacity limit imposed by the diffraction limit of light [l] However, due to the problems of aberration and scattering of recording beam inside the medium, it is likely that the 3 D optical storage tecbnique'will quickly hit its capacity limit. One possible way of overcoming this issue is by incorporating other physical dimensions, which are not in spatial domain, into 3 D optical storage. In this paper, we demonstrate spectrally encoded optical data storage by using quantum dot nanocrystals (QDs) The QDs have received so much attention because of their interesting properties such as emission wavelength tunability with size, narrow emission bandwidths and discrete atom like energy level structures [2] In particular, the discrete energy level structure permits their fluorescence intensities to vary with an excitation wavelength [2] When two different sizes of QDs are mixed, the differences in energy level structures can be manifested by variation in relative intensities of the two fluorescence wavelengths with respect to the excitation wavelengths. This is shown in Figure 1, where the fluorescence spectrum of green QDs (3 nm in diameter) mixed together wiih red QDs (6 nm diameter)'are shown, excited by various near infrared wavelengths (twophoton absorption) The peak intensities of two QDs are plotted against the excitation wavelengths, shown in Figure lb. The two photon absorption of the QDs is proved in a log log plot of the fluorescence intensity with respect to the input power, which is shown in Figure IC. The figures show that at certain wavelengths, each coloured QD shows increased absorption, and therefore more interactions with excitation light such as bleaching or quenching are expected [3] Such properties can be further utilized in optical storage, where marks can be recorded on one type of QDs at a certain wavelength without affecting the other QDs. In the talk, further development of the QD based spectral encoding will be presented. Figure 1. (a) Two photon fluorescence spectrum of mixed QDs in resin at difference excitation wavelength. Note the relative change in intensities of two QDs. (b) Fluorescence peak intensities of QDs are plotted against excitation wavelengths. (c) Two photon absorption of QDs are confirmed by the log log plot References 1. D. McPhail and M. Gu, \"Use of polarization sensitivity for three dimensional optical data storage in polymer dispersed liquid crystals under two photon illumination,\" Appl. Phys. Lett. 81, ppll60 (2002) 2. W. C. W. Chan and S. Nie, \"Quantum dot bioconjugates for ultrasensitive nonisotopic detection,\" Science, 281, pp2016 2018 (1998) 3. S. A. Blanton, M. A. Hines, M. E. Schmidt, and P. Guyot Sionnest, \"Two photon spectroscopy and microscopy of 11 VI semiconductor nanocrystals,\" J. Lumines. 70, pp253 268 (1996) 0 7803 7766 4103A17 00 02003 IEEE", "author_names": [ "James W M Chon" ], "corpus_id": 199404517, "doc_id": "199404517", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "W4H4 9) 4 USE OF QUANTUM DOT NANOCRYSTALS FOR SPECTRALLY ENCODED OPTICAL DATA STORAGE", "venue": "", "year": 2004 }, { "abstract": "Foreword. Preface. List of Contributors. PART I: FUNDAMENTAL CONSIDERATIONS. Chapter 1. Chemical Sensing. Chapter 2. What to Detect? Chapter 3. Dangerous Innovations. Chapter 4. Where Should We Look For Explosive Molecules? Chapter 5. Structure of Turbulent Chemical Plumes. PART II: FIELD EXPERIENCE. Chapter 6. Detection of Trace Explosive Signatures in the Marine Environment. Chapter 7. Explosives Detection Using Ultrasensitive Electronic Vapor Sensors: Field Experience. Chapter 8. Reflections on Hunting Mines By Aroma Sensing. PART III: EXAMPLE SENSING TECHNOLOGIES. Chapter 9. Explosives Detection Based on Amplifying Fluorescence Polymers. Chapter 10. Ion Mobility Spectrometry. Chapter 11. Mass Spectrometry For Security Screening of Explosives. Chapter 12. Explosive Vapor Detection Using Microcantilever Sensors. Chapter 13. Lab On A Chip Detection of Explosives. Chapter 14. Nanoscale Sensing Assemblies Using Quantum Dot Protein Bioconjugates. Chapter 15. Remote Sensing of Explosive Materials Using Differential Reflection Spectroscopy. PART IV: SUPPLEMENTARY MATERIAL. Appendix Organizations Involved in Searching For Hidden Explosives. Definitions, Symbols and Abbreviations. Explosives Definitions. Bibliography. Index.", "author_names": [ "Ronald L Woodfin" ], "corpus_id": 92673619, "doc_id": "92673619", "n_citations": 101, "n_key_citations": 2, "score": 0, "title": "Trace chemical sensing of explosives", "venue": "", "year": 2007 }, { "abstract": "We report a method for single molecule detection and biomolecular structural mapping based on dual color imaging and automated colocalization of bioconjugated nanoparticle probes at nanometer precision. In comparison with organic dyes and fluorescent proteins, nanoparticle probes such as fluorescence energy transfer nanobeads and quantum dots provide significant advantages in signal brightness, photostability, and multicolor light emission. As a result, we have achieved routine two color superresolution imaging and single molecule detection with standard fluorescence microscopes and inexpensive digital color cameras. By using green and red nanoparticles to simultaneously recognize two binding sites on a single target, individual biomolecules such as nucleic acids are detected and identified without target amplification or probe/target separation. We also demonstrate that a powerful astrophysical method (originally developed to analyze crowded stellar fields) can be used for automated and rapid statistical analysis of nanoparticle colocalization signals. The ability to rapidly localize bright nanoparticle probes at nanometer precision has implications not only for ultrasensitive medical detection but also for structural mapping of molecular complexes in which individual components are tagged with color coded nanoparticles.", "author_names": [ "Amit Agrawal", "Rajesh P Deo", "Geoffrey D Wang", "May D Wang", "Shuming Nie" ], "corpus_id": 8240126, "doc_id": "8240126", "n_citations": 91, "n_key_citations": 1, "score": 0, "title": "Nanometer scale mapping and single molecule detection with color coded nanoparticle probes", "venue": "Proceedings of the National Academy of Sciences", "year": 2008 } ]

[ { "abstract": "Partial table of contents: Overview of Power Semiconductor Switches. Computer Simulation of Power Electronic Converters and Systems. GENERIC POWER ELECTRONIC CIRCUITS. dc dc Switch Mode Converters. Resonant Converters: Zero Voltage and/or Zero Current Switchings. POWER SUPPLY APPLICATIONS. Power Conditioners and Uninterruptible Power Supplies. MOTOR DRIVE APPLICATIONS. dc Motor Drives. Induction Motor Drives. Synchronous Motor Drives. OTHER APPLICATIONS. Residential and Industrial Applications. Optimizing the Utility Interface with Power Electronic Systems. SEMICONDUCTOR DEVICES. Basic Semiconductor Physics. Power Diodes. Power MOSFETs. Thyristors. Emerging Devices and Circuits. PRACTICAL CONVERTER DESIGN CONSIDERATIONS. Snubber Circuits. Gate and Base Drive Circuits. Design of Magnetic Components. Index.", "author_names": [ "Ned Mohan", "T M Undeland", "William P Robbins" ], "corpus_id": 109363530, "doc_id": "109363530", "n_citations": 5582, "n_key_citations": 245, "score": 1, "title": "Power Electronics: Converters, Applications and Design", "venue": "", "year": 1989 }, { "abstract": "(NOTE: Each chapter begins with an Introduction and concludes with a Summary and References. Preface. List of Principal Symbols. 1. Power Semiconductor Devices. Diodes. Thyristors. Triacs. Gate Turn Off Thyristors (GTOs) Bipolar Power or Junction Transistors (BPTs or BJTs) Power MOSFETs. Static Induction Transistors (SITs) Insulated Gate Bipolar Transistors (IGBTs) MOS Controlled Thyristors (MCTs) Integrated Gate Commutated Thyristors (IGCTs) Large Band Gap Materials for Devices. Power Integrated Circuits (PICs) 2. AC Machines for Drives. Induction Machines. Synchronous Machines. Variable Reluctance Machine (VRM) 3. Diodes and Phase Controlled Converters. Diode Rectifiers. Thyristor Converters. Converter Control. EMI and Line Power Quality Problems. 4. Cycloconverters. Phase Controlled Cycloconverters. Matrix Converters. High Frequency Cycloconverters. 5. Voltage Fed Converters. Single Phase Inverters. Three Phase Bridge Inverters. Multi Stepped Inverters. Pulse Width Modulation Techniques. Three Level Inverters. Hard Switching Effects. Resonant Inverters. Soft Switched Inverters. Dynamic and Regenerative Drive Braking. PWM Rectifiers. Static VAR Compensators and Active Harmonic Filters. Introduction to Simulation MATLAB/SIMULINK. 6. Current Fed Converters. General Operation of a Six Step Thyristor Inverter. Load Commutated Inverters. Force Commutated Inverters. Harmonic Heating and Torque Pulsation. Multi Stepped Inverters. Inverters with Self Commutated Devices. Current Fed vs Voltage Fed Converters. 7. Induction Motor Slip Power Recovery Drives. Doubly Fed Machine Speed Control by Rotor Rheostat. Static Kramer Drive. Static Scherius Drive. 8. Control and Estimation of Induction Motor Drives. Induction Motor Control with Small Signal Model. Scalar Control. Vector or Field Oriented Control. Sensorless Vector Control. Direct Torque and Flux Control (DTC) Adaptive Control. Self Commissioning of Drive. 9. Control and Estimation of Synchronous Motor Drives. Sinusoidal SPM Machine Drives. Synchronous Reluctance Machine Drives. Sinusoidal IPM Machine Drives. Trapezoidal SPM Machine Drives. Wound Field Synchronous Machine Drives. Sensorless Control. Switched Reluctance Motor (SRM) Drives. 10. Expert System Principles and Applications. Expert System Principles. Expert System Shell. Design Methodology. Applications. Glossary. 11. Fuzzy Logic Principles and Applications. Fuzzy Sets. Fuzzy System. Fuzzy Control. General Design Methodology. Applications. Fuzzy Logic Toolbox. Glossary. 12. Neural Network Principles and Applications. The Structure of a Neuron. Artificial Neural Network. Other Networks. Neural Network in Identification and Control. General Design Methodology. Applications. Neuro Fuzzy Systems. Demo Program with Neural Network Toolbox. Glossary. Index.", "author_names": [ "Bimal K Bose" ], "corpus_id": 109000242, "doc_id": "109000242", "n_citations": 3193, "n_key_citations": 296, "score": 0, "title": "Modern Power Electronics and AC Drives", "venue": "", "year": 2001 }, { "abstract": "Thank you for downloading power electronics converters applications and design. Maybe you have knowledge that, people have look numerous times for their favorite readings like this power electronics converters applications and design, but end up in harmful downloads. Rather than enjoying a good book with a cup of tea in the afternoon, instead they cope with some malicious virus inside their desktop computer.", "author_names": [ "Luca Weisz" ], "corpus_id": 114527015, "doc_id": "114527015", "n_citations": 930, "n_key_citations": 98, "score": 0, "title": "Power Electronics Converters Applications And Design", "venue": "", "year": 2016 }, { "abstract": "The harmonics are generated by the switching operation of large power converters, such as Static Compensator (STATCOM) Static Reactive Power Controller (SVC) and UPFC. These harmonics may cover a wide range of frequencies and it can cause problems of interference with communication systems. Power Line Carrier (PLC) system is one of the systems used in transmission of signals for Tele potations, Tele tripping, Tele control and speech communications. The Signal to Noise Ratio (SNR) of the PLC is based on the noise level at the input of the carrier receiver. These effects of harmonics result in overheating, extra losses in electric machines and capacitors; and over voltage due to excited resonance in the power system. The main source of disturbances resulting from harmonics has been proved to be from a high power converter. This problem becomes more complicated when harmonics are originating in many single source. These harmonics can be propagated throughout the entire interconnected power network. The interference due to large power converter will be superimposed on the background noise at lower levels causing it to reduce the SNR to an unacceptable value. This study deals with the analysis of the waveform of the converters and the methods used to reduce the noise imposed on PLC communication signal. (c) 2006 Asian Network for Scientific Information.", "author_names": [ "Sinan Mahmood Bashi", "A U M Al-Abulaziz", "Nashiren Farzilah Mailah" ], "corpus_id": 109091042, "doc_id": "109091042", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Effects of High Power Electronics Converters on PLC Signals", "venue": "", "year": 2006 }, { "abstract": "In this paper, a power control strategy is proposed for a low voltage microgrid, where the mainly resistive line impedance, the unequal impedance among distributed generation (DG) units, and the microgrid load locations make the conventional frequency and voltage droop method unpractical. The proposed power control strategy contains a virtual inductor at the interfacing inverter output and an accurate power control and sharing algorithm with consideration of both impedance voltage drop effect and DG local load effect. Specifically, the virtual inductance can effectively prevent the coupling between the real and reactive powers by introducing a predominantly inductive impedance even in a low voltage network with resistive line impedances. On the other hand, based on the predominantly inductive impedance, the proposed accurate reactive power sharing algorithm functions by estimating the impedance voltage drops and significantly improves the reactive power control and sharing accuracy. Finally, considering the different locations of loads in a multibus microgrid, the reactive power control accuracy is further improved by employing an online estimated reactive power offset to compensate the effects of DG local load power demands. The proposed power control strategy has been tested in simulation and experimentally on a low voltage microgrid prototype.", "author_names": [ "Yun Wei Li", "Ching-Nan Kao" ], "corpus_id": 18161892, "doc_id": "18161892", "n_citations": 1007, "n_key_citations": 46, "score": 0, "title": "An Accurate Power Control Strategy for Power Electronics Interfaced Distributed Generation Units Operating in a Low Voltage Multibus Microgrid", "venue": "IEEE Transactions on Power Electronics", "year": 2009 }, { "abstract": "FUNDAMENTALS OF MAGNETIC THEORY Basic Laws of Magnetic Theory Magnetic Materials Magnetic Circuits References FAST DESIGN APPROACH INCLUDING EDDY CURRENT LOSSES Fast Design Approach Examples Conclusions Appendix 2.A.1: Core Size Scale Law for Ferrites in Non Saturated Thermal Limited Design Appendix 2.A.2: Eddy Current Losses for Wide Frequency Appendix 2.A.3: MathCAD Example Files References SOFT MAGNETIC MATERIALS Magnetic Core Materials Comparison and Applications of the Core Materials in Power Electronics Losses in Soft Magnetic Materials Ferrite Core Losses with Non Sinusoidal Voltage Waveforms Wide Frequency Model of Magnetic Sheets Including Hysteresis Effects Appendix 3.A: Power and Impedance of Magnetic Sheets References COIL WINDING AND ELECTRICAL INSULATION Filling Factor Wire Length Physical Aspects of Breakdown Insulation Requirements and Standards Thermal Requirements and Standards Magnetic Component Manufacturing Sheet References EDDY CURRENTS IN CONDUCTORS Introduction Basic Approximations Losses in Rectangular Conductors Quadrature of the Circle Method for Round Conductors Losses of a Current Carrying Round Conductor in 2 D Approach Losses of a Round Conductor in a Uniform Transverse AC Field Low Frequency 2 D Approximation Method for Round Conductors Wide Frequency Method for Calculating Eddy Current Losses in Windings Losses in Foil Windings Losses in Planar Windings Appendix 5.A.1: Eddy Current 1 D Model for Rectangular Conductors Appendix 5.A.2: Low Frequency 2 D Models for Eddy Current Losses in Round Wires Appendix 5.A.3: Field Factor For Inductors References THERMAL ASPECTS Fast Thermal Design Approach (Level 0 Thermal Design) Single Thermal Resistance Design Approach (Level 1 Thermal Design) Classic Heat Transfer Mechanisms Thermal Design Utilizing a Resistance Network Contribution to Heat Transfer Theory of Magnetic Components Transient Heat Transfer Summary Appendix 6.A: Accurate Natural Convection Modeling for Magnetic Components References PARASITIC CAPACITANCES IN MAGNETIC COMPONENTS Capacitance Between Windings: Inter Capacitance Self Capacitance of a Winding: Intra Capacitance Capacitance Between the Windings and the Magnetic Material Practical Approaches for Decreasing the Effects of Parasitic Capacitances References INDUCTOR DESIGN Air Coils and Related Shapes Inductor Shapes Typical Ferrite Inductor Shapes Fringing in Wire Wound Inductors with Magnetic Cores Eddy Currents in Inductor Windings Foil Wound Inductors Inductor Types Depending on Application Design Examples of Different Types of Inductors Fringing Coefficients For Gapped Wire Wound Inductors Analitical Modeling of Combined Litz Wire Full Wire Inductors References TRANSFORMER DESIGN Transformer Design in Power Electronics Magnetizing Inductance Leakage Inductance Using Parallel Wires and Litz Wires Interleaved Windings Superimposing Frequency Components Superimposing Modes References OPTIMAL COPPER/CORE LOSS RATIO IN MAGNETIC COMPONENTS Simplified Approach Loss Minimization in the General Case Loss Minimization Without Eddy Current Losses Loss Minimization Including Low Frequency Eddy Current Losses Summary Examples References MEASUREMENTS Introduction Temperature Measurements Power Losses Measurements Measurement of Inductances Core Loss Measurements Measurement of Parasitic Capacitances Combined Measuring Instruments References APPENDIX A: RMS VALUES OF WAVEFORMS Definitions RMS Values of Some Basic Waveforms RMS Values of Common Waveforms APPENDIX B: MAGNETIC CORE DATA ETD Core Data (Economic Transformer Design Core) EE Core Data Planar EE Core Data ER Core Data UU Core Data Ring Core Data (Toroid Core) P Core Data (Pot Core) PQ Core Data RM Core Data APPENDIX C: COPPER WIRES DATA Round Wire Data American Wire Gauge Data Litz Wire Data APPENDIX D: MATHEMATICAL FUNCTIONS References INDEX", "author_names": [ "Alex Van den Bossche", "Vencislav C Valchev" ], "corpus_id": 107585866, "doc_id": "107585866", "n_citations": 289, "n_key_citations": 23, "score": 0, "title": "Inductors and Transformers for Power Electronics", "venue": "", "year": 2005 }, { "abstract": "As data rates continue to spiral upwards, electrical interconnects based on copper traces and wires are struggling to keep up and optical solutions are looking increasingly attractive.", "author_names": [ "Andrew C Alduino", "Mario Paniccia" ], "corpus_id": 119524923, "doc_id": "119524923", "n_citations": 132, "n_key_citations": 2, "score": 0, "title": "Interconnects: Wiring electronics with light", "venue": "", "year": 2007 }, { "abstract": "The electric utility industry is gradually undergoing restructuring and the main paradigm shift is the introduction of the principles of competition. With the level of future demand for electricity being unclear, power market players are reluctant to commit to long term capital investment, with the result that construction of new large scale power plants and also transmission and distribution infrastructure is typically being avoided. At the same time, power facilities are being upgraded in response to business strategies for bringing a profit in power markets and for keeping supply reliability for customers. Under such circumstances of competitive power markets, practical use of renewable and distributed energy generation offers an attractive alternative for power supply. The advantages include a short construction cycle as the supply can be located near to the demand, being less of a burden to the existing transmission network, and contributing to prevention of global warming through clean combustion using novel energy technologies such as natural gas co generation, natural gas micro turbines, or fuel cells. Distributed generations using renewable energy resources such as wind and solar energy are also attracting attention. Regarding practical use of renewal energy in Japan, a new set of requirements advents. The first is the development of a set of policies for promoting power generated from renewable energy. The second is to evaluate the influence of distributed generations from renewable energy on the quality and reliability of the electricity. The third is the establishment of the technology requirements for interconnection with the power grid. The fourth is the development of future energy supply networks such as Power parks, Microgrids, and Smart grids. In implementing future energy supply networks utilizing renewable energy, power electronic devices are widely used to interface some forms of renewable energy generations and energy storages to distribution networks, and their use is likely to increase remarkably in the near future. The development of these power electronics is benefiting from the rapid advancements in the capability of power semiconductor switching devices and in the progress being made in the design and control of variable speed drives for large motors. The most diffused application of power electronic devices is to invert the DC generated from some dispersed energy resources (e.g. photo voltaic fuel cells, micro turbines and battery storages) to existing 50/60 Hz AC. Also, power electronic devices are used to decouple rotating generates from the network and so potentially increase the efficiency of the operation of the prime mover by ensuring that they operate at their most efficient speed for the range of input power. For example, power electronics are used to support variable speed wind turbines and are also now being proposed for some forms of small hydro generation and energy storages during transients. In this article, we will discuss the role of power electronics for renewable energy utilizations and the kinds of infrastructure that should be designed and how this should be pursued in order to maintain high reliability and quality for future energy supply networks in the restructured electricity markets.", "author_names": [ "Junichi Arai", "Kenji Iba", "Toshihisa Funabashi", "Yoshitaka Nakanishi", "Kaoru Koyanagi", "Ryuichi Yokoyama" ], "corpus_id": 741351, "doc_id": "741351", "n_citations": 145, "n_key_citations": 6, "score": 0, "title": "Power electronics and its applications to renewable energy in Japan", "venue": "IEEE Circuits and Systems Magazine", "year": 2008 }, { "abstract": "1. Electromagnetic Fields and Waves 2. Rays and Optical Beams 3. Dielectric Waveguides and Optical Fibers 4. Optical Resonators 5. Interaction of Radiation and Atomic Systems 6. Theory of Laser Oscillation and Some Specific Laser Systems 7. Chromatic Dispersion and Polarization Mode Dispersion in Fibers 8. Nonlinear Optics 9. Electro Optics and AO modulators 10. Noise in Optical Detection and Generation 11. Detection of Optical Radiation 12. Periodic Structures 13. Waveguide Coupling 14. Nonlinear Optical Effects in Fibers 15. Semiconductor Lasers 16. Advanced Semiconductor Lasers 17. Optical Amplifiers 18. Classical Treatment of Quantum Optics, Quantum Noise, and Squeezing A. WAVE EQUATION IN CYLINDRICAL COORDINATES AND BESSEL FUNCTIONS B. EXACT SOLUTIONS OF THE STEP INDEX CIRCULAR WAVEGUIDE C. KRAMERS KRONIG RELATIONS D. TRANSFORMATION OF A COHERENT ELECTROMAGNETIC FIELD BY A THIN LENS E. FERMI LEVEL AND ITS TEMPERATURE DEPENDENCE F. ELECTRO OPTIC EFFECT IN CUBIC 43M CRYSTALS G. CONVERSION FOR POWER UNITS AND ATTENUATION UNITS", "author_names": [ "Amnon Yariv", "Pochi Albert Yeh" ], "corpus_id": 107100857, "doc_id": "107100857", "n_citations": 906, "n_key_citations": 70, "score": 0, "title": "Photonics optical electronics in modern communications", "venue": "", "year": 2006 }, { "abstract": "Power Quality Enhancement Using Custom Power Devices considers the structure, control and performance of series compensating DVR, the shunt DSTATCOM and the shunt with series UPQC for power quality improvement in electricity distribution. Also addressed are other power electronic devices for improving power quality in Solid State Transfer Switches and Fault Current Limiters. Applications for these technologies as they relate to compensating busses supplied by a weak line and for distributed generation connections in rural networks, are included. In depth treatment of inverters to achieve voltage support, voltage balancing, harmonic suppression and transient suppression in realistic network environments are also covered. New material on the potential for shunt and series compensation which emphasizes the importance of control design has been introduced. Power Quality Enhancement Using Custom Power Devices is appropriate for distribution engineers, graduate engineers and designers working in the area of power electronic applications for power systems. Sections of the book on power quality issues and generation connection make for a timely reference for undergraduates studying distribution engineering. Written for: Distribution engineers, graduate engineers and designers working in the area of power electronic applications for power systems, students", "author_names": [ "Arindam Ghosh", "Gerard F Ledwich" ], "corpus_id": 107426166, "doc_id": "107426166", "n_citations": 858, "n_key_citations": 56, "score": 0, "title": "Power Quality Enhancement Using Custom Power Devices", "venue": "", "year": 2002 } ]

[ { "abstract": "Part 1 Logic design: binary numbers boolean algebra and minimization combinational circuit design sequential circuit design logic circuit implementation. Part 2 Microprocessor system design: computer and microprocessor systems microprocessor instructions semiconductor main memory devices input/output circuits and operation memory management. Part 3 Further aspects of digital system design: formal sequential circuit design processor design introduction to VLSI systems design and testing engineering aspects reliability.", "author_names": [ "Barry Wilkinson" ], "corpus_id": 26943159, "doc_id": "26943159", "n_citations": 29, "n_key_citations": 0, "score": 1, "title": "Digital system design", "venue": "", "year": 1987 }, { "abstract": "", "author_names": [ "M S Harris" ], "corpus_id": 112135501, "doc_id": "112135501", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Digital system design (2nd edition) B. Wilkinson with R. Makki, Prentice Hall, Hemel Hempstead, UK, 1992, 538pp. PS19.99", "venue": "", "year": 1993 }, { "abstract": "The authors consider the effects of single event upsets (SEUs) on digital systems, and show techniques for designing reliable systems with current levels of SEU protection. Three main systems are discussed: main memory, logic, and cache memory. A design for the main and cache memory subsystems that are SEU protected is also described. With SEU defined in bit days p, and using single error correction, it is shown that for all subsystems considered, an effective upset rate which is proportional to the product of p/sup 2/ and the time between corrections, or scrub time, can be obtained. Data for memory chip size and performance derived from the gallium arsenide (GaAs) pilot lines funded by the Defense Advanced Research Projects Agency (DARPA) throughout the 1980s are used.", "author_names": [ "Sherman Karp", "Barry K Gilbert" ], "corpus_id": 62688566, "doc_id": "62688566", "n_citations": 25, "n_key_citations": 1, "score": 0, "title": "Digital system design in the presence of single event upsets", "venue": "", "year": 1993 }, { "abstract": "The design principles that drove the development of a new cardiovascular x ray digital flat panel (DFP) detector system are presented, followed by assessments of imaging and dose performance achieved relative to other state of the art FPD systems. The new system (GE Innova 2100IQTM) incorporates a new detector with substantially improved DQE at fluoroscopic (73%@1mR) and record (79%@114mR) doses, an x ray tube with higher continuous fluoro power (3.2kW) a collimator with a wide range of copper spectral filtration (up to 0.9mm) and an improved automatic x ray exposure management system. The performance of this new system was compared to that of the previous generation GE product (Innova 2000) and to state of the art cardiac digital x ray flat panel systems from two other major manufacturers. Performance was assessed with the industry standard Cardiac X ray NEMA/SCA&I phantom, and a new moving coronary artery stent (MCAS) phantom, designed to simulate cardiac clinical imaging conditions, composed of an anthropomorphic chest section with stents moving in a manner simulating normal coronary arteries. The NEMA/SCA&I phantom results showed the Innova 2100IQ to exceed or equal the Innova 2000 in all of the performance categories, while operating at 28% lower dose on average, and to exceed the other DFP systems in most of the performance categories. The MCAS phantom tests showed the Innova 2100IQ to be significantly better (p 0.05) than the Innova 2000, and significantly better than the other DFP systems in most cases at comparable or lower doses, thereby verifying excellent performance against design goals.", "author_names": [ "Barry F Belanger", "F Betraoui", "Paritosh J Dhawale", "Parasuram Gopinath", "Pal Tegzes", "Balazs P Vagvolgyi" ], "corpus_id": 108702989, "doc_id": "108702989", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Development of next generation digital flat panel catheterization system: design principles and validation methodology", "venue": "SPIE Medical Imaging", "year": 2006 }, { "abstract": "For accurate and reliable automatic control the organisation of computer systems in aircraft and applications in other multi task computer systems is more likely to be based on a number of 'cooperative' computers in an integrated manner [1] than a main central computer. Such a cooperative design should provide for the normal work load of each computer plus checking the data processing of another computer and have the ability to continue operation in case of a malfunction in one processor. To ensure that these requirements are met in a data driven operating system the basic system design parameters need careful assessment for optimised system performance especially when deadlines must be met in some control functions and an order of priorities preserved. The present paper reports progress on a computer aided system design of such linked cooperative computers under the above conditions to determine basic system parameters such as the desirable character rates for the several central processors (C.P's) and optimum cycle length of C.P. to C.P. transfers. The methods also overcomes objections [2] to some systems design procedures by allowing the results of sampled data theory to be made use of in the systems design by incorporating the sampling rate although calculated separately [3] in one of the prime design parameters of the system.", "author_names": [ "B S Thornton" ], "corpus_id": 62636137, "doc_id": "62636137", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Computer aided system design of linked cooperative digital computers for control", "venue": "", "year": 1971 }, { "abstract": "The emerging application of Gallium Arsenide digital integrated circuits to signal processing problems will require the development of architectures quite different from those used for highly parallel silicon VLSI and VHSIC components. Much higher system clock rates will be employed in GaAs based systems than will be common in silicon VLSI, placing much more stress on interchip signal protocols, and on the design of first and second level packaging, i.e. at the chip carrier and logic board levels.", "author_names": [ "Barry K Gilbert", "Daniel J Schwab" ], "corpus_id": 109139895, "doc_id": "109139895", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Will Presently Available System Design Approaches And Electrical Interconnect Rules Fulfill The Performance Requirements Of High Clock Rate Digital Signal Processors Based On Gaas?", "venue": "Photonics West Lasers and Applications in Science and Engineering", "year": 1984 }, { "abstract": "This case study describes the use of learning analytics to evaluate the transition of a postgraduate wine business course from face to face to online delivery using e learning course design principles. Traditionally, Foundations of Wine Science lectures were delivered face to face, however the decision to transition the course from semester to trimester format presented an opportunity for online delivery of lectures. This was initially achieved through audio recordings, then video lectures, supported by a range of digital learning resources intended to engage, support and enhance student learning and the student experience. Descriptive analysis of learning analytics, comprising assessment results, student evaluations of learning and teaching, and data sourced from the Learning Management System, was performed to evaluate the impact of online delivery of course content on student performance, satisfaction and engagement. The use of audio lecture recordings negatively impacted students' perception of the overall quality of the course (including course organisation, learning strategies and learning resources) The subsequent implementation of e learning designed video lectures was considered superior to audio recordings, albeit final grades were not significantly different between the delivery modes. However, student engagement was equal to, or better than face to face delivery, when content was designed specifically for an e learning environment.", "author_names": [ "Kerry L Wilkinson", "Imogen McNamara", "David I Wilson", "Karina M Riggs" ], "corpus_id": 164427016, "doc_id": "164427016", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Using Learning Analytics to Evaluate Course Design and Student Behavior in an Online Wine Business Course", "venue": "International Journal of Innovation in Science and Mathematics Education", "year": 2019 }, { "abstract": "Outer space is a very harsh environment that can cause electronics to not operate as they were originally intended. Aside from the extreme amount of radiation found in space, temperatures can also change very dramatically in a relatively small time frame. In order to test electronics that will be used in this environment, they first need to be tested on Earth under replicated conditions. Vanderbilt University designed a dewar that allows devices to be tested at these extreme temperatures while being radiated. For this thesis, a test setup that met all of the dewar's constraints was designed that would allow a 12 bit, 16 channel analog to digital converter to be tested while inside.", "author_names": [ "Zack Pannell" ], "corpus_id": 107710677, "doc_id": "107710677", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Design of a Highly Constrained Test System for a 12 bit, 16 channel Wilkinson ADC", "venue": "", "year": 2009 }, { "abstract": "Abstract An integrated passive device technology by semi insulating (SI) GaAs based fabrication has been developed to meet the ever increasing needs of size and cost reduction in wireless applications. This technology includes reliable NiCr thin film resistor, high Q spiral inductor due to thick plated Cu/Au metal process to reduce resistive loss, high breakdown voltage metal insulator metal capacitor due to a thinner dielectric thickness, lowest parasitic effect by multi air bridged metal layers, air bridges for inductor underpass and capacitor pick up, and low chip cost using only six process layers. This paper presents the Wilkinson power divider with excellent performance for a digital cellular system application. The insertion loss of this power divider is 0.53 dB and the port isolation greater than 30 dB over the entire band. Return loss in input and output ports are 20.2 dB and 35.8 dB, respectively. The Wilkinson power divider based on SI GaAs substrates is designed within a die size of 1.42 mm2.", "author_names": [ "Cong Wang", "Nam-Young Kim" ], "corpus_id": 111538224, "doc_id": "111538224", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Design of High performance Wilkinson Power Divider on SI GaAs Substrate using Integrated Passive Technology", "venue": "", "year": 2012 }, { "abstract": "In England and Wales, building regulations apply to the design and construction of new buildings, extensions and changes of use. Regulation 38 (BRE, 2019) is a requirement to provide fire safety information to the responsible person at the completion of a project, or where the building or extension is first occupied. Regulations require as built Fire Safety Information to be handed over by the design and construction teams to the responsible person to maintain and operate a building with reasonable safety. The responsible person is the owner, occupier, or manager of the building. The information would typically include; a fire safety strategy of the building that accurately reflects the fire safety precautions; and design and construction information, services information; and information about fixtures, fittings and equipment. Unfortunately, Regulation 38 has been far from successful and the required information is rarely communicated to the dutyholders in a manner that meets the intention of the authors. There is no requirement for the information to be presented to either the Fire Service or the Building Control Body for assessment. The requirement is merely for the person carrying out the work to confirm that the required information has been passed over (CIC, 2017) The guiding philosophy of legislation requires organisations to assess the potential risks associated with their work activities and to introduce effective measures to control risks. However, in reality the current regulations set the bar too low, with the industry looking to satisfy the minimum standards by the cheapest means possible, magnified by a lack of approval scrutiny. In the wake of the Grenfell Tower fire in 2017 that killed 72 people, the UK Government commissioned the Hackitt Review (2018) of building regulations and fire safety. The Hackitt Review calls for radical change in culture in the construction industry and the regulatory system that assigns responsibility and holds people accountable. It also states that the Government should mandate a digital standard of record keeping for design, construction and occupation of new Higher Risk Residential Buildings (HRRB) and refurbishments within HRRBs. A BIM driven dataset is suggested, which requires duty holders to generate a suitable evidence base through which to deliver their responsibilities and maintain safety and integrity throughout the lifecycle of a building. This paper will examine the requirements set out in the Hackitt review and explores the need for a digital record of lifecycle building information. It examines examine the role of BIM as an enabler of the digital building information record and presents a conceptual framework that enables rapid realisation of the digital by default vision, via a Safe by Default Asset Delivery framework. It outlines the potential outcomes of the safe by default approach and discusses the potential opportunities and challenges likely to be considered if the BIM enabled \"digital by default\" vision was to be realised.", "author_names": [ "Kirti Ruikar", "Peter Wilkinson", "Judith Shulz" ], "corpus_id": 211750778, "doc_id": "211750778", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "BIM enabled \"Digital by Default\" vision for fire safety", "venue": "", "year": 2019 } ]

[ { "abstract": "Field effect transistors are emerging as useful device structures for efficient light generation from a variety of materials, including inorganic semiconductors, carbon nanotubes and organic thin films. In particular, organic light emitting field effect transistors are a new class of electro optical devices that could provide a novel architecture to address open questions concerning charge carrier recombination and light emission in organic materials. These devices have potential applications in optical communication systems, advanced display technology, solid state lighting and electrically pumped organic lasers. Here, recent advances and future prospects of light emitting field effect transistors are explored, with particular emphasis on organic semiconductors and the role played by the material properties, device features and the active layer structure in determining the device performances.", "author_names": [ "Michele Muccini" ], "corpus_id": 23799488, "doc_id": "23799488", "n_citations": 742, "n_key_citations": 1, "score": 1, "title": "A bright future for organic field effect transistors", "venue": "Nature materials", "year": 2006 }, { "abstract": "Freestanding, substrate free organic field effect transistors and organic circuits with a nominal thickness of 320 nm are demonstrated by using a simple water floatation method. The devices work well in freestanding status, attached on banknotes, or bent over the blade of a knife. The ultralight devices with extreme bending stability indicate a bright future for organic electronics.", "author_names": [ "Libo Zhang", "Hanlin Wang", "Yan Zhao", "Yunlong Guo", "Wenping Hu", "Gui Yu", "Yunqi Liu" ], "corpus_id": 1019324, "doc_id": "1019324", "n_citations": 77, "n_key_citations": 0, "score": 0, "title": "Substrate free ultra flexible organic field effect transistors and five stage ring oscillators.", "venue": "Advanced materials", "year": 2013 }, { "abstract": "Manufacturing organic circuits from solution provides an opportunity to realize low cost fabrication of large area flexible electronics, such as radio frequency identity tags, sensor arrays and flexible displays. Inspired by the potential applications, significant efforts have been devoted to develop organic field effect transistors with solution processed components in the past decade. Herein, we summarize recent progresses in solution processable functional materials including organic semiconductors, electrode materials, and dielectric materials. Various solution manufacturing techniques, patterning techniques and related device engineering methods are also reviewed. Finally, all solution processed logic circuits are discussed from the point of view of practical application. All these achievements represent a big step forward and promise the solution processed OFETs a bright future.", "author_names": [ "Lei Zhang", "Chong-an Di", "Gui Yu", "Yunqi Liu" ], "corpus_id": 98326275, "doc_id": "98326275", "n_citations": 74, "n_key_citations": 0, "score": 0, "title": "Solution processed organic field effect transistors and their application in printed logic circuits", "venue": "", "year": 2010 }, { "abstract": "Today,when the information technology has accessed to the rapid development,organic field effect transistor(OFET)with the bright prospect has got the rapid process. The structure and operating principle of OFET are introduced in this paper. The application and future developments of OFET are also described.", "author_names": [ "Huang Jin-zhao" ], "corpus_id": 112605350, "doc_id": "112605350", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Reseach on Organic Field Effect Transistors", "venue": "", "year": 2007 }, { "abstract": "Abstract Since the discovery of conductivity in organic molecules in the 1980s, the field of organic electronics has witnessed immense advancement. The main reason for such growth is the possibility of designing and developing innumerable functional organic materials. Today, almost all possible optoelectronic applications have been developed using various organic materials, and many of them have been commercialized for use in day to day lives of common people. This chapter summarizes a series of functional organic materials used in high efficiency solar cell devices, bright light emitting diodes (LEDs) high mobility and high ON/OFF ratio field effect transistors (FETs) and resistive random access memory (ReRAM) devices for switching applications. This chapter will be a guide to further improve the properties of functional organic materials for better performances in future.", "author_names": [ "Ritesh Kant Gupta", "Rahul Narasimhan Arunagirinathan", "Mohammad Adil Afroz", "Rabindranath Garai", "Anwesha Choudhury", "Maimur Hossain", "Ramesh Babu Yathirajula", "Parameswar Krishnan Iyer" ], "corpus_id": 234143028, "doc_id": "234143028", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Functional materials for various organic electronic devices", "venue": "", "year": 2021 }, { "abstract": "We have fabricated ambipolar light emitting field effect transistors made of 1,4 bis(5 phenylthiophen 2 yl)benzene (AC5) single crystals, which have 35% fluorescent quantum efficiency. The obtained hole and electron mobilities were 2.9x10 1 cm2/V s and 6.7x10 3 cm2/V s, respectively. These are the highest values among AC5 transistors. Importantly, although the light emission from the crystal surface was less than the detection level of the camera, we observed bright and polarized light emission from the edge of the single crystals. This polarized edge emission is attributed to the strong self assembled light confining nature and perfectly aligned transition dipole moments, which are advantageous for future laser devices.", "author_names": [ "Yohei Yomogida", "Taishi Takenobu", "Hidekazu Shimotani", "Kosuke Sawabe", "Satria Zulkarnaen Bisri", "Takeshi Yamao", "Shu Hotta", "Yoshihiro Iwasa" ], "corpus_id": 120627777, "doc_id": "120627777", "n_citations": 41, "n_key_citations": 0, "score": 0, "title": "Green light emission from the edges of organic single crystal transistors", "venue": "", "year": 2010 }, { "abstract": "Abstract Green materials have great potential to become a primary research area for bioelectronic integration. Over the last three decades, bioelectronic applications have been getting great interest due to their low cost, flexible, nontoxic, large volume electronic components that are sustainable, biocompatible, biodegradable, and bioresorbable. Therefore the versatility of bioelectronics applications, such as organic field effect transistors and biosensors, promises a bright future. This chapter will highlight recent progress in the natural materials and some of their applications in bioelectronics devices. The key strategies and the forecast perspectives of this research field are also briefly summarized.", "author_names": [ "Tugbahan Yilmaz", "Mahmut Kus" ], "corpus_id": 234249186, "doc_id": "234249186", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Advanced applications of green materials in bioelectronics applications", "venue": "", "year": 2021 }, { "abstract": "To enhance electron injection in n type organic field effect transistors (OFETs) nonconjugated polyelectrolyte (NPE) layers are interposed between a [6,6] phenyl C61 butyric acid methyl ester (PCBM) layer and Au electrodes. A series of NPEs based on an ethoxylated polyethylenimine backbone with various counterions, including Cl Br and I improve electron mobilities up to 10 2 cm2 V 1 s 1 and yield on off ratios (Ion/Ioff) of 105 in PCBM OFETs. Ultraviolet photoelectron spectroscopy reveals that all of the NPEs lead to reduced electron injection barriers (phe) at the NPE/metal interface; this reduction in phe is consistent with dipole formation or n type doping at the electrode interface. Absorption measurements of PCBM films treated with NPEs are consistent with n doping of the PCBM. Regardless of the type of anion, thick NPE layers lead to high conductivity in the films independent of gate bias, whereas thin NPE layers lead to dramatically improved electron injection and performance. These results demonstrate that thin polyelectrolyte layers can be used to achieve controlled interfacial doping in organic semiconductors. Furthermore, this study provides valuable information about the function of NPEs, which may be exploited to improve device performance and to design new materials for future use in optoelectronic devices.", "author_names": [ "Yu Jung Park", "Myoung Joo Cha", "Yung Jin Yoon", "Shinuk Cho", "Jin Young Kim", "Jung Hwa Seo", "Bright Walker" ], "corpus_id": 139187727, "doc_id": "139187727", "n_citations": 15, "n_key_citations": 0, "score": 0, "title": "Improved Performance in n Type Organic Field Effect Transistors via Polyelectrolyte Mediated Interfacial Doping", "venue": "", "year": 2017 }, { "abstract": "Abstract Flexible pressure sensors based on organic field effect transistors (OFETs) have emerged as promising candidates for electronic skin applications. However, it remains a challenge to achieve low operating voltages of hysteresis free flexible pressure sensors. Interface engineering of polymer dielectrics is a feasible strategy toward sensitive pressure sensors based on low voltage OFETs. Here, a novel type of solution processed bilayer dielectrics is developed by combining a thick polyelectrolyte layer of polyacrylic acid (PAA) with a thin poly(methyl methacrylate) (PMMA) layer. This bilayer dielectric can provide a vertical phase separation structure from hydrophilic interface to hydrophobic interface which adjoins well to organic semiconductors, leading to improved stability and remarkably reduced leakage currents. Consequently, OFETs using the PMMA/PAA dielectrics reveal greatly suppressed hysteresis and improved mobility compared to those with a pure PAA dielectric. Using the optimized PMMA/PAA dielectric, flexible OFET based pressure sensors that show a record high sensitivity of 56.15 kPa 1 at a low operating voltage of 5 V, a fast response time of less than 20 ms, and good flexibility are further demonstrated. The salient features of high capacitance, good dielectric performance, and excellent reliability of the bilayer dielectrics promise a bright future of flexible sensors based on low voltage OFETs for wearable electronic applications.", "author_names": [ "Zhigang Yin", "Ming-Jie Yin", "Ziyang Liu", "Yangxi Zhang", "A Ping Zhang", "Qingdong Zheng" ], "corpus_id": 52333596, "doc_id": "52333596", "n_citations": 24, "n_key_citations": 0, "score": 0, "title": "Solution Processed Bilayer Dielectrics for Flexible Low Voltage Organic Field Effect Transistors in Pressure Sensing Applications", "venue": "Advanced science", "year": 2018 }, { "abstract": "In this study, NiO/PVC nano hybrid composites have been synthesized through sol gel method. Nano crystallites phases, crystallinity and electrical properties have been characterized using X ray diffraction, Fourier transfer infrared radiation, scanning electron microscopy and atomic force microscopy techniques. The dielectric constant of the samples has been calculated through measuring the capacity of samples by application of GPS 132 A. Obtained results have indicated that an NiO/PVC sample with 5 g NiO and 0.02 g PVC, equivalent to 0.4 %wt PVC, in weight synthesis, at a temperature of 80 degC has a higher dielectric constant, better surface morphology, less rough surface, less leakage current, and thus has potential to be suggested as a possible gate dielectric material for future organic field effect transistor devices.", "author_names": [ "Amir Hayati", "Ali Bahari" ], "corpus_id": 123441474, "doc_id": "123441474", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Electrical properties of NiO/PVC nano hybrid composites for organic field effect transistors", "venue": "", "year": 2015 } ]

[ { "abstract": "Abstract Diamond like carbon (DLC) is a metastable form of amorphous carbon with significant sp3 bonding. DLC is a semiconductor with a high mechanical hardness, chemical inertness, and optical transparency. This review will describe the deposition methods, deposition mechanisms, characterisation methods, electronic structure, gap states, defects, doping, luminescence, field emission, mechanical properties and some applications of DLCs. The films have widespread applications as protective coatings in areas, such as magnetic storage disks, optical windows and micro electromechanical devices (MEMs)", "author_names": [ "John Robertson" ], "corpus_id": 135487365, "doc_id": "135487365", "n_citations": 4785, "n_key_citations": 158, "score": 1, "title": "Diamond like amorphous carbon", "venue": "", "year": 2002 }, { "abstract": "Diamond is the hardest material on Earth. Nevertheless, polishing diamond is possible with a process that has remained unaltered for centuries and is still used for jewellery and coatings: the diamond is pressed against a rotating disc with embedded diamond grit. When polishing polycrystalline diamond, surface topographies become non uniform because wear rates depend on crystal orientations. This anisotropy is not fully understood and impedes diamond's widespread use in applications that require planar polycrystalline films, ranging from cutting tools to confinement fusion. Here, we use molecular dynamics to show that polished diamond undergoes an sp(3) sp(2) order disorder transition resulting in an amorphous adlayer with a growth rate that strongly depends on surface orientation and sliding direction, in excellent correlation with experimental wear rates. This anisotropy originates in mechanically steered dissociation of individual crystal bonds. Similarly to other planarization processes, the diamond surface is chemically activated by mechanical means. Final removal of the amorphous interlayer proceeds either mechanically or through etching by ambient oxygen.", "author_names": [ "Lars Pastewka", "Stefan Moser", "Peter Gumbsch", "Michael Moseler" ], "corpus_id": 5287476, "doc_id": "5287476", "n_citations": 236, "n_key_citations": 8, "score": 1, "title": "Anisotropic mechanical amorphization drives wear in diamond.", "venue": "Nature materials", "year": 2011 }, { "abstract": "This paper aims to establish the wear mechanisms of tungsten carbide (WC) and polycrystalline diamond (PCD) drills when drilling carbon fiber reinforced plastics (CFRP) stacked on top of titanium (Ti) During the drilling experiments, torque and thrust forces were measured using a dynamometer under the CFRP/Ti stacks. In addition, a Scanning Electron Microscope (SEM) and a Confocal Laser Scanning Microscope (CLSM) were periodically used to measure the wear progression of the tool surface and to analyze tool wear mechanisms. For the WC drills Ti adhesion was a predominant tool wear factor, covering the entire cutting edges. PCD drills on the other hand, showed less titanium adhesion, but had a significant amount of cutting edge chipping. Abrasion, by the carbon fiber and hard inclusions in Ti, and adhesion of titanium were found to be the dominant tool wear mechanisms. Higher torque and thrust values were observed at the higher spindle speeds which caused a significant increase in tool wear due to the higher temperature generated, especially when drilling the Ti plates.", "author_names": [ "Kyung Hee Park", "Aaron Beal", "Dave Kim", "Patrick Kwon", "Jeff Lantrip" ], "corpus_id": 136689478, "doc_id": "136689478", "n_citations": 174, "n_key_citations": 2, "score": 0, "title": "Tool wear in drilling of composite/titanium stacks using carbide and polycrystalline diamond tools", "venue": "", "year": 2011 }, { "abstract": "Abstract This paper presents an experimental machinability study of the metal matrix composites (MMCs) A356/SiC/20p with brazed polycrystalline diamond (PCD) tools or chemical vapour deposition (CVD) diamond coated tools. The experimental procedure consisted of turning operations, during which cutting force, cutting tools flank wear and surface roughness obtained in composite workpiece were measured. The obtained results showed that PCD tools are important in cutting this composite type of reduced machinability. Actually, CVD diamond coated tools show short life, as tools wear evolution becomes very fast after coating rupture.", "author_names": [ "Joao Paulo Davim" ], "corpus_id": 135609507, "doc_id": "135609507", "n_citations": 177, "n_key_citations": 4, "score": 0, "title": "Diamond tool performance in machining metal matrix composites", "venue": "", "year": 2002 }, { "abstract": "1 Refraction. 2 Reflection and Transmission. 3 Vibronic Absorption. 4 Scattering. 5 Optical Electronic Transitions. 6 Coloration of Diamond. 7 Physical Classification of Diamond. 8 Interaction with Energetic Light Beams. 9 Thermostimulated Luminescence and Tunnel Luminescence. 10 Photoconductivity. 11 Related Data. Appendix: Abbreviations, Definitions and Methods. References.", "author_names": [ "Alexander M Zaitsev" ], "corpus_id": 137922153, "doc_id": "137922153", "n_citations": 789, "n_key_citations": 58, "score": 0, "title": "Optical properties of diamond", "venue": "", "year": 2001 }, { "abstract": "Direct machining steel parts at a hardened state, known as hard turning, offers a number of potential benefits over traditional grinding in some applications. In addition, hard turning has several unique process characteristics, e.g. segmented chip formation and microstructural alterations at the machined surfaces, fundamentally different from conventional turning. Hard turning is, therefore, of a great interest to both the manufacturing industry and research community. Development of superhard materials such as polycrystalline cubic boron nitride (known as CBN) has been a key to enabling hard turning technology. A significant pool of CBN tool wear studies has been surveyed, in an attempt to achieve better processing and tooling applications, and discussed from the tool wear pattern and mechanism perspectives. Although various tool wear mechanisms, or a combination of several, coexist and dominate in CBN turning of hardened steels, it has been suggested that abrasion, adhesion (possibly complicated by tribochemical interactions) and diffusion may primarily govern the CBN tool wear in hard turning. Further, wear rate modeling including one approach developed in a recent study, on both crater and flank wear, is discussed as well. In conclusion, a summary of the CBN tool wear survey and the future work are outlined.", "author_names": [ "Yong Huang", "Y Kevin Chou", "Steven Y Liang" ], "corpus_id": 36060617, "doc_id": "36060617", "n_citations": 164, "n_key_citations": 2, "score": 0, "title": "CBN tool wear in hard turning: a survey on research progresses", "venue": "", "year": 2007 }, { "abstract": "Understanding friction and wear at the nanoscale is important for many applications that involve nanoscale components sliding on a surface, such as nanolithography, nanometrology and nanomanufacturing. Defects, cracks and other phenomena that influence material strength and wear at macroscopic scales are less important at the nanoscale, which is why nanowires can, for example, show higher strengths than bulk samples. The contact area between the materials must also be described differently at the nanoscale. Diamond like carbon is routinely used as a surface coating in applications that require low friction and wear because it is resistant to wear at the macroscale, but there has been considerable debate about the wear mechanisms of diamond like carbon at the nanoscale because it is difficult to fabricate diamond like carbon structures with nanoscale fidelity. Here, we demonstrate the batch fabrication of ultrasharp diamond like carbon tips that contain significant amounts of silicon on silicon microcantilevers for use in atomic force microscopy. This material is known to possess low friction in humid conditions, and we find that, at the nanoscale, it is three orders of magnitude more wear resistant than silicon under ambient conditions. A wear rate of one atom per micrometre of sliding on SiO(2) is demonstrated. We find that the classical wear law of Archard does not hold at the nanoscale; instead, atom by atom attrition dominates the wear mechanisms at these length scales. We estimate that the effective energy barrier for the removal of a single atom is approximately 1 eV, with an effective activation volume of approximately 1 x 10( 28) m.", "author_names": [ "Harish Bhaskaran", "Bernd Gotsmann", "Abu Sebastian", "Ute Drechsler", "Mark A Lantz", "Michel Despont", "Papot Jaroenapibal", "Robert W Carpick", "Yun Chen", "Kumar Sridharan" ], "corpus_id": 5174068, "doc_id": "5174068", "n_citations": 192, "n_key_citations": 7, "score": 0, "title": "Ultralow nanoscale wear through atom by atom attrition in silicon containing diamond like carbon.", "venue": "Nature nanotechnology", "year": 2010 }, { "abstract": "Abstract In the present work, the tribological mechanism of diamond like carbon (DLC) films was investigated. DLC films were coated on metallic substrates (M50 steel, Ti 6Al 4V alloy and AISI 440C steel) by methane ion beam deposition. Pin on disc experiments showed that the DLC films possess excellent wear resistance and exhibit low values of friction coefficient (f", "author_names": [ "Yan Liu", "Ali Erdemir", "E I Meletis" ], "corpus_id": 137666739, "doc_id": "137666739", "n_citations": 467, "n_key_citations": 7, "score": 0, "title": "A study of the wear mechanism of diamond like carbon films", "venue": "", "year": 1996 }, { "abstract": "This paper presents the prediction and evaluation of thrust force in drilling of carbon composite material. In order to extend tool life and improve quality of hole drilling, a better understanding of uncoated and coated tool behaviors is required. This paper describes the development of a phenomenological model between the thrust force, the drilling parameters and the tool wear. The experimental results indicate that the feed rate, the cutting speed and the tool wear are the most significant factors affecting the thrust force. The model can then be used for tool wear monitoring. The model presented here is verified by experimental tests.", "author_names": [ "Dragos Iliescu", "Daniel Gehin", "M E Gutierrez", "F Girot" ], "corpus_id": 109509606, "doc_id": "109509606", "n_citations": 205, "n_key_citations": 0, "score": 0, "title": "Modeling and tool wear in drilling of CFRP", "venue": "", "year": 2010 }, { "abstract": "The demand for increasing productivity when machining heat resistant alloys has resulted in the use of new tool materials such as cubic boron nitride (CBN) or ceramics. However, CBN tools are mostly used by the automotive industry in hard turning, and the wear of those tools is not sufficiently known in aerospace materials. In addition, the grade of these tools is not optimized for superalloys due to these being a small part of the market, although expanding (at 20% a year) So this investigation has been conducted to show which grade is optimal and what the wear mechanisms are during finishing operations of Inconel 718. It is shown that a low CBN content with a ceramic binder and small grains gives the best results. The wear mechanisms on the rake and flank faces were investigated. Through SEM observations and chemical analysis of the tested inserts, it is shown that the dominant wear mechanisms are adhesion and diffusion due to chemical affinity between elements from workpiece and insert.", "author_names": [ "Jean Philippe Costes", "Yoann Guillet", "Gerard Poulachon", "Michel Dessoly" ], "corpus_id": 55975016, "doc_id": "55975016", "n_citations": 182, "n_key_citations": 7, "score": 0, "title": "Tool life and wear mechanisms of CBN tools in machining of Inconel 718", "venue": "", "year": 2007 } ]

[ { "abstract": "Using the density functional theory (DFT) of the first principle and Generalized gradient approximation method, the electronic structures and optical properties of the InxGa1 xN crystals with different x (x 0.25, 0.5, 0.75, 1) have been calculated in this paper. The influence of the electronic structure on the properties has been analyzed. Then the influence of doping quantity on the characteristics has been summarized, which also indicates the trend of complex dielectric function, absorption spectrum and transitivity. With the increase of x, the computational result shows that the optical band gap (i.e.Eg) of the InxGa1 xN crystal tends to be narrow, then the absorption spectrum shifts to the low energy direction. And the Fermi energy slightly moves to the bottom of conduction band which would cause the growth of conductivity by increasing x. In a word, the InxGa1 xN compound can be achieved theoretically the adjustable Eg and photoelectric performance with x, which will be used in making various optoelectronic devices including solar cell and sensors.", "author_names": [ "Xuewen Wang", "Wenwen Liu", "Chunxue Zhai", "Jiangni Yun", "Zhiyong Zhang" ], "corpus_id": 210836637, "doc_id": "210836637", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "DFT Calculation on the Electronic Structure and Optical Properties of InxGa1 xN Alloy Semiconductors", "venue": "", "year": 2019 }, { "abstract": "In 2014, we moved from XE 2100 with Standard SIS rules to XN 9000 with GFHC recommendations for slide review. The aim of our study was to evaluate the potential impact of the new Sysmex(r) automation with implementation of GFHC rules on our review rate, turnaround time (TAT) workload and on CD34+ stem cells enumeration. We conducted a retrospective observational study from September 2013 through August 2014, in CHU Dinant Godinne UCL Namur. With the GFHC recommendations and the new Sysmex(r) automation, we significantly reduced our review rate by nearly 30% considering all units (35.8% vs 25.9% and up to 73% when excluding oncology haematology department (17.5% vs 4.7% We also noticed significantly shorter TAT for CBC measurement (median for routine samples: 76.4 vs 56.8 minutes, p 0.0001; urgent samples: 18.9 vs 15.2 minutes, p 0.023) slide review (median: 54.9 vs 36.4 minutes, p 0.0001) and CD34+ enumeration performed on peripheral blood samples (p 0.001) and on apheresis samples (p 0.026) In conclusion, GFHC recommendations implemented on the new Sysmex(r) XN 9000 resulted in a significant reduction in review rate and in TAT. This is particularly of interest for the clinicians with subsequent potential faster patient management.", "author_names": [ "Anne Tamigniau", "Nicolas Bailly", "Bernard Chatelain", "Francois Mullier" ], "corpus_id": 4318778, "doc_id": "4318778", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "From XE 2100 to XN 9000, from SIS Standard to GFHC recommendations for slide review: potential impact on review rate and turnaround time.", "venue": "Annales de biologie clinique", "year": 2017 }, { "abstract": "We have applied the pseudo potential plane wave method to study the structural, elastic, electronic, lattice dynamic and optical properties of GaN and AlN in the wurtzite lattice and BN with zinc blende structure. We have found that all elastic constants depend strongly on hydrostatic pressure, except for C44 in wurtzite AlN and GaN that shows a weaker dependence. AlN and GaN present a direct band gap G G, whereas BN has an indirect band gap G X. The indirect G K band gap in AlN occurs at about 35 GPa. The top of the valence bands reflects the p electronic character for all structures. There is a gap between optical and acoustic modes only for wurtzite phases AlN and GaN. All peaks in the imaginary part of the dielectric function for the wurtzite lattice GaN and AlN move towards lower energies, while those in the zinc blende BN structure shift towards higher energies with increasing pressure. The decrease of the static dielectric constant and static refractive index in zinc blende BN is weaker and it can be explained by its higher elastic constants.", "author_names": [ "M Qaiser Fatmi", "Brahim Ghebouli", "M A Ghebouli", "Zien K Hieba" ], "corpus_id": 122555489, "doc_id": "122555489", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "First principles study of structural, elastic, electronic, lattice dynamic and optical properties of XN (X=Ga, Al and B) compounds under pressure", "venue": "", "year": 2011 }, { "abstract": "Abstract First principles calculations of plane wave ultra soft pseudo potential method based on the density functional theory (DFT) were used to study lattice constants, band structure, density of states and optical properties of wurtzite InxGa1 xN alloys. The calculated results indicate that the lattice constant gradually increases, the conduction band shifts to low energy direction and the band gap becomes narrower with the increase in In doped concentration. Meanwhile, the dielectric function moves towards low energy direction, which is red shift. The first dielectric peak appears near 2.0 eV, and the maximum dielectric peak close to 4.76 eV is found. There are two intersection points at about 5.6 and 9.2 eV. When the photon energy is less than 5.6 eV or higher than about 9.2 eV, the absorption coefficient of InxGa1 xN in low doping concentration (less than 50% is smaller than that of high doping concentration of InxGa1 xN. However, when the photon energy is located between 5.6 and 9.2 eV, the absorption spectra of InxGa1 xN in low doping concentration are greater than those of high doping concentration. Therefore, the study result shows that InxGa1 xN alloys can be applied as solar cell and the transparent conductive materials.", "author_names": [ "Ruan Xingxiang", "Zhang Fuchun", "Zhang Weihu" ], "corpus_id": 138096408, "doc_id": "138096408", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "First Principles Investigation on Electronic Structure and Optical Properties of Wurtzite InxGa1 xN Alloys", "venue": "", "year": 2015 }, { "abstract": "2018 Published by Elsevier B.V. Radiotherapy and Oncology xxx (2018) xxx xxx Filling the gap in cancer care in underserved regions worldwide requires global collaboration and concerted effort to share creative ideas, pool talents and develop sustainable support from governments, industry, academia and non governmental organizations. Comprehensive cancer care, which fits within and strengthens the broader healthcare system, ranges from prevention to screening, to curative treatment, to palliative care and to long term follow up. Radiation therapy is an essential component for curative and palliative cancer care and can serve as a stable focal point physically and for personnel around which regional cancer and health care programs can be established. To build capacity with high quality capability and with the credibility to conduct research to understand specific diseases and treatment outcomes requires a complex systems approach toward both expertise and technology. To move forward in the aspirational goal of substantially reducing the global burden of cancer as part of the Sustainable Development Goals of the United Nations [1] a workshop was convened on November 7 8, 2016 by the International Cancer Expert Corps (ICEC) [2] and hosted by CERN [3] Entitled 'Design Characteristics and Implementation of a Novel Linear Accelerator for Challenging Environments\" a major focus was on innovative radiation oncology technology opportunities. Cobalt 60 units are still in use but, while newer units are increasingly sophisticated, they do not provide the full treatment capability ofmodern linacs and require ongoing security and ever increasing costs for disposal of radioactive materials. While there has been substantial progress in radiation oncology technology development, significant opportunity remains for improvement and innovation in the combination of technology and processes used to deliver basic and advanced radiation therapy in lowand middle income countries. Most specifically, the adoption of a collaborative approach that ties together broad expertise and perspectives by connecting global need, oncology expertise, and deep capacity in technology innovation was reinforced by this workshop and subsequent efforts and has resulted in a framework for collaboration to address the unacceptable gap in global cancer care. The magnitude of the problem It is estimated that the annual global cancer incidence will rise from 15 million cases in 2015 to as many as 25 million cases in 2035, 65 70% of which will occur in lowand middle income countries (LMICs) [4] where there is a severe shortfall in radiation", "author_names": [ "David A Pistenmaa", "Manjit Dosanjh", "U Jr Amaldi", "David A Jaffray", "Eduardo Zubizarreta", "Katherine Holt", "Yolande Lievens", "Yakov Pipman", "C Norman Coleman" ], "corpus_id": 49314171, "doc_id": "49314171", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Changing the global radiation therapy paradigm.", "venue": "Radiotherapy and oncology journal of the European Society for Therapeutic Radiology and Oncology", "year": 2018 }, { "abstract": "Abstract Several approaches have been tried by researchers for improvement of the InxGa1 xN/GaN QW red LEDs, where due the strong polarization fields, the electron hole wave functions are separated spatially. In this paper, we have studied the type II InGaN ZnSnN2/GaN QW diodes and compared the results with the conventional InGaN/GaN QW diodes for red emission. It reveals that the overlap of electron hole wave functions are increased more than three times that of the conventional InGaN/GaN QWs. In the active region with lower In content, hole confinement increases due to higher valance band offset in the type II structure and the electron hole wave functions move towards the center of the well. The entire red region of the visible spectrum can be covered with suitable width, position of the ZnSnN2 layer and In content in the InGaN layer. The computations have been carried out through the self consistent solutions of the Schrodinger and Poisson equations.", "author_names": [ "Anup Gorai" ], "corpus_id": 102560723, "doc_id": "102560723", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Red light emitting diodes based on the type II InGaN ZnSnN2/GaN quantum wells", "venue": "", "year": 2018 }, { "abstract": "The instrument prepared for these observations was a reflecting telescope, of two feet focal length, of the Gregorian form, magnifying about 65 times, and so constructed in its machinery as to move in a move in a plane parallel to the horizon, and also, when required, to move in a plane parallel to the equator.", "author_names": [ "James Short" ], "corpus_id": 186211908, "doc_id": "186211908", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "XXX. Observations of the transit of Mercury over the sun, May 6, 1753; by Mr. J. Short, F. R. S", "venue": "Philosophical Transactions of the Royal Society of London", "year": 1753 }, { "abstract": "Right now it can not be questionable that competition in banking industry become more tight start from small scale bank up to big scale. Bank XXX is one of private bank with big scale, get the effect so its position going down from second place to third place because it is moved by BRI in 2008. Fund product is owned by bank XXX is still good enough although it is already supported by technology, network and marketing that are classified good enough, bank XXX is still difficult to compete with big scale banks such as bank Mandiri, BRI and BNI. Customers rather choose bank Mandiri, BRI and BNI to make saving so bank XXX always make riset and observation in order to settle current competition. Based on qualitative observation and external environment analysis with value chain analysis and internal environment analysis with five competitive forces method so it can be concluded that good saving product is saving product that fullfil criterias such as can be accepted by every people grade, give several benefits in one saving product, give security, pleasure good interest rate and can be combined with other saving products or credit produts.", "author_names": [ "", "Maman Setiawan" ], "corpus_id": 155982140, "doc_id": "155982140", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "PERUMUSAN PRODUK DANA YANG BAIK UNTUK BANK XXX", "venue": "", "year": 2013 }, { "abstract": "Abstract In [1, 2] Nekrasov applied the Bethe/Gauge correspondence to derive the \\mathfrak{su} su (2) XXX spin chain coordinate Bethe wavefunction from the IR limit of a 20 \\mathcal{N} N (2, 2) supersymmetric A 1 quiver gauge theory with an orbifold type codimension 2 defect. Later, Bullimore, Kim and Lukowski implemented Nekrasov's construction at the level of the UV A 1 quiver gauge theory, recovered his result, and obtained further extensions of the Bethe/Gauge correspondence [3] In this work, we extend the construction of the defect to A M quiver gauge theories to obtain the \\mathfrak{su} su (M 1) XXX spin chain nested coordinate Bethe wavefunctions. The extension to XXZ spin chain is straightforward. Further, we apply a Higgsing procedure to obtain more general A M quivers and the corresponding wavefunctions, and interpret this procedure (and the Hanany Witten moves that it involves) on the spin chain side in terms of Izergin Korepin type specializations (and re assignments) of the parameters of the coordinate Bethe wavefunctions.", "author_names": [ "Omar Foda", "Masahide Manabe" ], "corpus_id": 195767208, "doc_id": "195767208", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Nested coordinate Bethe wavefunctions from the Bethe/Gauge correspondence", "venue": "Journal of High Energy Physics", "year": 2019 }, { "abstract": "Host factors are critically important in governing the susceptibility and severity of most viral infections. The importance of these host factors is governed by the prevalence of the virus and the availability of effective therapeutic and/or preventive measures. This review highlights 2 such host factors that were initially judged to be important but over time have moved in opposite directions: hepatitis C virus and the IL28B locus as well as HIV and the D32 CCR5 mutation (Clin Ther. 2019; XX:XXX XXX) (c) 2019 Elsevier HS Journals, Inc.", "author_names": [ "Ravi Jhaveri" ], "corpus_id": 201750597, "doc_id": "201750597", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "\"Here Today, Gone Tomorrow\" or \"Here Today, Stay a Long While\" The Divergent Paths of 2 Host Factors Important in Viral Infections.", "venue": "Clinical therapeutics", "year": 2019 } ]

[ { "abstract": "In the past three decades, organic semiconductor field effect transistors (OFETs) have drawn intense attention as promising candidates for drive circuits of flat panel display, radio frequency identifications, chemical/bio sensors, and other devices. Generally, the key parameters of OFETs, carrier mobility, threshold voltage, and on/off current ratio are closely related to the degree of order and surface/interface electronic structure of organic semiconductor (OSC) films. The ordering of films is crucially determined by the molecule substrate interactions. On inert substrates (such as SiO2) OSC films can hardly reach a high degree of ordering without growth templates, while traditional single crystal surfaces usually force the OSC molecules to deviate from their favorite assemble manner resulting in an unstable structure. Recently, the rise of two dimensional materials (2D) provides a possible solution. The in plane lattice of 2D materials can offer possible epitaxy templates for OSCs while the weak van der Waals (vdWs) interaction between OSC and 2D layers allows for more flexibility to realize the epitaxy growth of OSCs with their favored assemble manner. In addition, the various band structures tuned by the layer numbers of 2D materials encourage widely modified OSC electronic structures by interface doping between the OSC and 2D layers, which benefits the structure by obtaining high performance OFETs. In this review, we emphasize and discuss the recent advances of OSC 2D hybrid OFETs. The OSC 2D heterostructures not only promote OFET device performances by film morphology/structure optimization and channel electronic structure modification, but also offer platforms for basic organic solids physics investigation and further functional optoelectronic devices.", "author_names": [ "Zi Wang", "Lizhen Huang", "Lifeng Chi" ], "corpus_id": 222179959, "doc_id": "222179959", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Organic Semiconductor Field Effect Transistors Based on Organic 2D Heterostructures", "venue": "Frontiers in Materials", "year": 2020 }, { "abstract": "Novel device architectures based on heterostructures of graphene with semiconductor layers have recently attracted considerable interest due to their potential in a wide range of electronic and photonic applications. The key concept in these devices is to exploit the work function tunability of graphene via external gate field to modulate the current flow across the graphene semiconductor junction by adjusting the Schottky barrier height. Transistor devices based on a vertical heterojunction of graphene with inorganic semiconductors (n and p type Silicon) [1] oxide semiconductor (n type indium gallium zinc oxide) [2,3] and flakes of 2D layered materials (molybdenum disulfide, tungsten disulfide) [4 7] have been successfully fabricated with a high on/off ratio, overcoming the limitation of planar graphene field effect devices. We demonstrate, for the first time, low voltage complementary p and n channel vertical organic thin film transistors (VOTFTs) based on the graphene organic semiconductor heterojunctions with simple, scalable and low temperature fabrication process. VOTFT device with thin layer of prototypical n type organic semiconductor C60 exhibits high on current densities in the range of 10 mA/cm2 with the driving voltage of only 1 V suppressing the output current of traditional planar organic field effect transistors. It can also operate at the bias as low as 200 mV with high on/off ratio ~103) For low power logic application, complementary VOTFT devices with prototypical p type organic semiconductors (CuPc, Pentacene, a 6T, Rubrene) are also investigated.", "author_names": [ "Htay Htay Hlaing", "F Carta", "Robert A Barton", "Chang-Yong Nam", "Nicholas Petrone", "James C Hone", "Ioannis Kymissis" ], "corpus_id": 43549018, "doc_id": "43549018", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Low power organic electronics based on gate tunable injection barrier in vertical graphene organic semiconductor heterostructures", "venue": "72nd Device Research Conference", "year": 2014 }, { "abstract": "2D transition metal dichalcogenides are promising channel materials for the next generation electronic device. Here, vertically 2D heterostructures, so called van der Waals solids, are constructed using inorganic molybdenum sulfide (MoS2 few layers and organic crystal 5,6,11,12 tetraphenylnaphthacene (rubrene) In this work, ambipolar field effect transistors are successfully achieved based on MoS2 and rubrene crystals with the well balanced electron and hole mobilities of 1.27 and 0.36 cm2 V 1 s 1 respectively. The ambipolar behavior is explained based on the band alignment of MoS2 and rubrene. Furthermore, being a building block, the MoS2 /rubrene ambipolar transistors are used to fabricate CMOS (complementary metal oxide semiconductor) inverters that show good performance with a gain of 2.3 at a switching threshold voltage of 26 V. This work paves a way to the novel organic/inorganic ultrathin heterostructure based flexible electronics and optoelectronic devices.", "author_names": [ "Xuexia He", "Wai Leong Chow", "Fucai Liu", "Bengkang Tay", "Zheng Liu" ], "corpus_id": 13474500, "doc_id": "13474500", "n_citations": 21, "n_key_citations": 0, "score": 0, "title": "MoS2 /Rubrene van der Waals Heterostructure: Toward Ambipolar Field Effect Transistors and Inverter Circuits.", "venue": "Small", "year": 2017 }, { "abstract": "La presente tesis doctoral se centra en la fabricacion, optimizacion, caracterizacion y aplicacion de capas activas compuestas de una mezcla de semiconductor organico y un polimero aislante (OSC:PS) en transistores organicos de efecto de campo (EGOFET) con puerta electrolitica. El EGOFET esta considerado como una prometedora plataforma de deteccion en el campo de la bioelectronica debido a su capacidad de operar en medios electroliticos. Hasta la fecha, aunque en varios proyectos de investigacion se ha demostrado su alto potencial como plataforma de deteccion, existe algunos problemas que deben resolverse, tales como su baja movilidad del portador de carga, lentos tiempo de respuesta y una degradacion rapida que dificultan su aplicacion practica. En este contexto, la tesis se divide en tres bloques, que van desde la fabricacion de los dispositivos hasta sus aplicaciones. La primera parte de la tesis tiene como objetivo la fabricacion de dispositivo robustos y eficientes empleando dos estrategias: (i) la optimizacion de la mezclas de polimero aislante y semiconductor organico (OSC) y (ii) el uso de una tecnica basada en la deposicion de capas activas mediante disolucion que recibe el nombre de BAMS (bar assistance meniscus shearing) En la primera parte de la tesis (Capitulo 2) se emplearon cuatro semiconductores organicos diferentes en que se incluyen tres pequenas moleculas y un polimero semiconductor como materiales activos. Los dispositivos se han caracterizado mediante medida electricas (caracteristicas de transferencia y salida) y su analisis y compresion, la sensibilidad potenciometrica, velocidad de conmutacion (tiempo de respuesta) y estabilidad electrica en agua MilliQ y soluciones salinas (NaCl) Ademas, la segunda parte de la tesis (Capitulo 3) esta dedicada al desarrollo de un sensor de iones de mercurio basado la exposicion de los capas activas a disoluciones acuosa que contienen iones de mercurio. En este caso, se observo un cambio gradual en el potencial umbral, que era respuesta directa de la concentracion de iones a la qual se exponia la capa activa. Ademas, se realizaron pruebas de microscopia de fuerza de atomica \"Kelvin prove\" y espectroscopia electroquimica de impedancia con el objetivo de entender el mecanismo de respuesta frente al mercurio. El cual se relaciono con la oxidacion/reduccion de los iones Hg2+ y la superficie del semiconductor. Finalmente, la tercera parte de la tesis (Capitulo 4) se centra en la fabricacion de nuevos dispositivo sustituyendo el electrolito por un hidrogel (HYGOFET) Logrando dispositivo de alto rendimiento empleando un hidrogel a base de agua como dielectrico. Ademas, el HYGOFET muestra una excelente respuesta a los variacion de presion debida a la alineacion de los dipolos del agua dentro de la capa de semiconductor. Por lo tanto, el dispositivo se puede visualizar como un prototipo de sensor de presion adaptable a ropa inteligente.", "author_names": [ "Qiaoming Zhang" ], "corpus_id": 213904923, "doc_id": "213904923", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Electrolyte gated organic field effect transistors based on organic semiconductor insulating polymer blends", "venue": "", "year": 2019 }, { "abstract": "Abstract Solution processed 2D organic semiconductors (OSCs) have drawn considerable attention because of their novel applications from flexible optoelectronics to biosensors. However, obtaining well oriented sheets of 2D organic materials with low defect density still poses a challenge. Here, a highly crystallized 2,9 didecyldinaphtho[2,3 b:2',3' f]thieno[3,2 b]thiophene (C10 DNTT) monolayer crystal with large area uniformity is obtained by an ultraslow shearing (USS) method and its growth pattern shows a kinetic Wulff's construction supported by theoretical calculations of surface energies. The resulting seamless and highly crystalline monolayers are then used as templates for thermally depositing another C10 DNTT ultrathin top up film. The organic thin films deposited by this hybrid approach show an interesting coherence structure with a copied molecular orientation of the templating crystal. The organic field effect transistors developed by these hybrid C10 DNTT films exhibit improved carrier mobility of 14.7 cm2 V 1 s 1 as compared with 7.3 cm2 V 1 s 1 achieved by pure thermal evaporation (100% improvement) and 2.8 cm2 V 1 s 1 achieved by solution sheared monolayer C10 DNTT. This work establishes a simple yet effective approach for fabricating high performance and low cost electronics on a large scale.", "author_names": [ "Zhiwen Zhou", "Qisheng Wu", "Sijia Wang", "Yu-ting Huang", "Hua Guo", "Shien-Ping Feng", "Paddy Kwok Leung Chan" ], "corpus_id": 201320799, "doc_id": "201320799", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "Field Effect Transistors Based on 2D Organic Semiconductors Developed by a Hybrid Deposition Method", "venue": "Advanced science", "year": 2019 }, { "abstract": "Nonvolatile organic field effect transistor (OFET) memory devices based on pentacene/N,N' ditridecylperylene 3,4,9,10 tetracarboxylic diimide (P13)/pentacene trilayer organic heterostructures have been proposed. The discontinuous n type P13 embedded in p type pentacene layers can not only provide electrons in the semiconductor layer that facilitates electron trapping process; it also works as charge trapping sites, which is attributed to the quantum well like pentacene/P13/pentacene organic heterostructures. The synergistic effects of charge trapping in the discontinuous P13 and the charge trapping property of the poly(4 vinylphenol) (PVP) layer remarkably improve the memory performance. In addition, the trilayer organic heterostructures have also been successfully applied to multilevel and flexible nonvolatile memory devices. The results provide a novel design strategy to achieve high performance nonvolatile OFET memory devices and allow potential applications for different combinations of various organic semiconductor materials in OFET memory.", "author_names": [ "Wen Zhi Li", "Fengning Guo", "Haifeng Ling", "Peng Zhang", "Ming-dong Yi", "Laiyuan Wang", "Dequn Wu", "Linghai Xie", "Wei Huang" ], "corpus_id": 21683292, "doc_id": "21683292", "n_citations": 42, "n_key_citations": 0, "score": 0, "title": "High Performance Nonvolatile Organic Field Effect Transistor Memory Based on Organic Semiconductor Heterostructures of Pentacene/P13/Pentacene as Both Charge Transport and Trapping Layers", "venue": "Advanced science", "year": 2017 }, { "abstract": "Mingdong Yi, Linghai Xie, Wei Huang and co workers describe an organic field effect transistor memory device based on trilayer organic heterostructures in article number 1700007. The device exhibits excellent performance for nonvolatile memory applications. In addition, the heterostructures are successfully applied on multilevel and flexible nonvolatile memory devices.", "author_names": [ "Wen Zhi Li", "Fengning Guo", "Haifeng Ling", "Peng Zhang", "Ming-dong Yi", "Laiyuan Wang", "Dequn Wu", "Linghai Xie", "Wei Huang" ], "corpus_id": 10746675, "doc_id": "10746675", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Semiconductors: High Performance Nonvolatile Organic Field Effect Transistor Memory Based on Organic Semiconductor Heterostructures of Pentacene/P13/Pentacene as Both Charge Transport and Trapping Layers (Adv. Sci. 8/2017)", "venue": "Advanced Science", "year": 2017 }, { "abstract": "High structural quality of crystalline organic semiconductors is the basis of their superior electrical performance. Recent progress in quasi two dimensional (2D) organic semiconductor films challenges bulk single crystals because both demonstrate competing charge carrier mobilities. As the thinnest molecular semiconductors, monolayers offer numerous advantages such as unmatched flexibility and light transparency as well they are an excellent platform for sensing. Oligothiophene based materials are among the most promising ones for light emitting applications because of the combination of efficient luminescence and decent charge carrier mobility. Here, we demonstrate single crystal monolayers of unprecedented structural order grown from four alkyl substituted thiophene and thiophene phenylene oligomers. The monolayer crystals with lateral dimensions up to 3 mm were grown from the solution on substrates with various surface energies and roughness by drop or spin casting with subsequent slow solvent evaporation. Our data indicate that 2D crystallization resulting in single crystal monolayers occurs at the receding gas solution substrate contact line. The structural properties of the monolayers were studied by grazing incidence X ray diffraction/reflectivity, atomic force and differential interference contrast microscopies, and imaging spectroscopic ellipsometry. These highly ordered monolayers demonstrated an excellent performance in organic field effect transistors approaching the best values reported for the thiophene or thiophene phenylene oligomers. Our findings pave the way for efficient monolayer organic electronics highlighting the high potential of simple solution processing techniques for the growth of large size single crystal monolayers with excellent structural order and electrical performance competing against bulk single crystals.", "author_names": [ "Vladimir V Bruevich", "Anastasia V Glushkova", "Olena Yu Poimanova", "Roman S Fedorenko", "Yuriy N Luponosov", "Artem V Bakirov", "Maxim A Shcherbina", "Sergei N Chvalun", "Andrey Yu Sosorev", "Linda Grodd", "Souren Grigorian", "Sergei A Ponomarenko", "Dmitry Yu Paraschuk" ], "corpus_id": 58640925, "doc_id": "58640925", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Large Size Single Crystal Oligothiophene Based Monolayers for Field Effect Transistors.", "venue": "ACS applied materials interfaces", "year": 2019 }, { "abstract": "Owing to enhanced charge transport efficiency arising from the ultrathin nature, two dimensional (2D) organic semiconductor single crystals (OSSCs) are emerging as a fascinating platform for high performance organic field effect transistors (OFETs) However, \"coffee ring\" effect induced by an evaporation induced convective flow near the contact line hinders the large area growth of 2D OSSCs through a solution process. Here, we develop a new strategy of suppressing the \"coffee ring\" effect by using an organic semiconductor: polymer blend solution. With the high viscosity polymer in the organic solution, the evaporation induced flow is remarkably weakened, ensuring the uniform molecule spreading for the 2D growth of the OSSCs. As an example, wafer scale growth of crystalline film consisting of few layered 2,7 didecylbenzothienobenzothiophene (C 10 BTBT) crystals was successfully accomplished via blade coating. OFETs based on the crystalline film exhibited a maximum hole mobility up to 12.6 cm 2 *V 1 *s 1 along with an average hole mobility as high as 8.2 cm 2 *V 1 *s 1 Our work provides a promising strategy for the large area growth of 2D OSSCs toward high performance organic electronics.", "author_names": [ "Xiujuan Zhang", "Jiansheng Jie", "Xiaohong Zhang" ], "corpus_id": 220291983, "doc_id": "220291983", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Controlled 2D growth of organic semiconductor crystals by suppressing \"coffee ring\" effect", "venue": "Nano Research", "year": 2020 }, { "abstract": "", "author_names": [ "" ], "corpus_id": 138245903, "doc_id": "138245903", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Weavable, Fibrous Organic Field Effect Transistors Based on Metal Insulator Semiconductor Coaxial Microfibers using Phase Separation of Organic Semiconductor", "venue": "", "year": 2016 } ]

[ { "abstract": "Abstract Photoelectrochemical (PEC) bioanalysis is a newly developed exquisite methodology for innovative biomolecular detection. Photocathodes made by p type semiconductors have different photoelectric properties from that of n type semiconductors based photoanodes. Due to their obvious advantages and potentials, the integration of PEC bioanalysis and photocathodes has opened almost unlimited possibilities for elegant cathodic PEC bioanalysis. Currently, the impetus for advanced cathodic PEC bioanalysis has grown tremendously as demonstrated by increased research papers. Using illustrative examples, this review discusses specifically on this topic, with the aim to cover the basic concept, major signaling strategies, the state of the art in this field, and the future prospects based on our own opinions.", "author_names": [ "Yi-Tong Xu", "Peng Qu" ], "corpus_id": 107645091, "doc_id": "107645091", "n_citations": 33, "n_key_citations": 0, "score": 1, "title": "Cathodic photoelectrochemical bioanalysis", "venue": "TrAC Trends in Analytical Chemistry", "year": 2019 }, { "abstract": "A ZnAgInS quantum dot (QD) decorated BiOI microsphere (BiOI ZAIS) heterostructure was first proposed and successfully employed for sensitive cathodic photoelectrochemical (PEC) bioanalysis. Specifi.", "author_names": [ "Chun-Qin Zhao", "Shou-Nian Ding", "Jia-hui Xu", "Hong-Yuan Chen" ], "corpus_id": 228822172, "doc_id": "228822172", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "ZnAgInS Quantum Dot Decorated BiOI Heterostructure for Cathodic Photoelectrochemical Bioanalysis of Glucose Oxidase", "venue": "", "year": 2020 }, { "abstract": "Previously reported copper oxide based cathodic photoelectrochemical bioanalysis of cysteine had attributed the decrease of the photocurrents to the binding of cysteine onto the CuO surface. However, our latest investigation found that the previous explanation was not correct. This Letter presents the in depth study of such phenomena and a new insight into the underlying mechanism. Specifically, the unique redox reaction between the CuO photocathode and cysteine produced [Cys Cu(I) and cystine, and the insoluble complex blocked the partial contact between the photoelectrode and the dissolved O2 containing electrolyte and reduced the effective working area of the photocathode, leading to the decrease of photocurrent.", "author_names": [ "Yi-Li Liu", "Yuancheng Zhu", "Ling-bo Qu", "Ran Yang", "Xiao-Dong Yu", "Wei-Wei Zhao" ], "corpus_id": 197001156, "doc_id": "197001156", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Unique Redox Reaction between CuO Photocathode and Cysteine: Insight into the Mechanism for Cathodic Photoelectrochemical Bioanalysis", "venue": "ACS Applied Bio Materials", "year": 2019 }, { "abstract": "This report outlines the first exploration of graphene oxide (GO) itself as a light harvesting material with an innovative in situ chemical redox and functionalization (CRF) strategy for versatile and high throughput cathodic photoelectrochemical (PEC) bioanalysis.", "author_names": [ "Tiantian Gu", "Mengmeng Gu", "Yi-Li Liu", "Yuming Dong", "Li-Bang Zhu", "Zaijun Li", "Guang-Li Wang", "Wei-Wei Zhao" ], "corpus_id": 199437406, "doc_id": "199437406", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "In situ chemical redox and functionalization of graphene oxide: toward new cathodic photoelectrochemical bioanalysis.", "venue": "Chemical communications", "year": 2019 }, { "abstract": "This work reports the liposome mediated in situ formation of the AgI/Ag/BiOI Z scheme heterojunction on foamed nickel electrode for signal on cathodic photoelectrochemical (PEC) bioanalysis. Specifically, in a proof of concept study, Ag nanoparticle encapsulated liposomes were initially confined via the sandwich immunobinding and then processed to release numerous Ag+ ions, which were then directed to react with the BiOI/Ni electrode, resulting in the in situ generation of a AgI/Ag/BiOI Z scheme heterojunction on the electrode. The enhanced cathodic signal could be correlated to the target concentration, which thus underlays a novel signal on cathodic liposomal PEC bioanalysis strategy. Different from previous anodic liposomal PEC bioanalysis, this work features the first cathodic liposomal PEC bioanalysis on the basis of the in situ formation of a Z scheme heterojunction. More generally, integrated with various biorecognition events, this protocol could serve as a common basis for addressing numerous targets of interest.", "author_names": [ "Si-Yuan Yu", "Li-Ping Mei", "Yi-Tong Xu", "Tie-Ying Xue", "Gaochao Fan", "Deman Han", "Guangxu Chen", "Wei-Wei Zhao" ], "corpus_id": 73470196, "doc_id": "73470196", "n_citations": 32, "n_key_citations": 0, "score": 0, "title": "Liposome Mediated in Situ Formation of AgI/Ag/BiOI Z Scheme Heterojunction on Foamed Nickel Electrode: A Proof of Concept Study for Cathodic Liposomal Photoelectrochemical Bioanalysis.", "venue": "Analytical chemistry", "year": 2019 }, { "abstract": "We report herein the energy transfer (ET) between semiconducting polymer dots (Pdots) and gold nanoparticles (Au NPs) in a photoelectrochemical (PEC) system and its feasibility for cathodic bioanalysis application. Specifically, COOH capped Pdots were first fabricated and then assembled onto the indium tin oxide (ITO) surface, followed by the modification of single strand (ss) DNA probe (pDNA) After the DNA hybridization with the Au NP tethered complementary ssDNA (Au NP tDNA) the Au NPs were brought into the close proximity of Pdots. Upon light stimulation, photoluminescence (PL) was annihilated, fluorescence was attenuated, and the photocurrent intensity was evidently decreased. This ET based PEC DNA sensor exhibited a linear range from 1 fM to 10 pM with a detection limit of 0.97 fM at a signal to noise ratio of 3. The present work first exploited the ET between Pdots and Au NPs, and we believe this phenomenon will spark new interest in the study of various Pdots based ET influenced PEC systems and thus catalyze increasing studies for specific bioanalytical purposes.", "author_names": [ "Xiao-Mei Shi", "Li-Ping Mei", "Qian Wang", "Wei-Wei Zhao", "Jing-Juan Xu", "Hong-Yuan Chen" ], "corpus_id": 3830081, "doc_id": "3830081", "n_citations": 24, "n_key_citations": 0, "score": 0, "title": "Energy Transfer between Semiconducting Polymer Dots and Gold Nanoparticles in a Photoelectrochemical System: A Case Application for Cathodic Bioanalysis.", "venue": "Analytical chemistry", "year": 2018 }, { "abstract": "Abstract In this study, we report the development of indirect Z scheme heterojunction to construct a cathodic photoelectrochemical (PEC) sensor for highly selective detection of endogenous H2S using AgCl Ag core shell nanostructures coupled with porous carbon nitride (PCN) as cathode materials. As an electron mediator, Ag on the Z scheme heterojunction transformed to Ag2S in the presence of H2S, resulting in the destruction of original charge carrier migration pathway. Meanwhile, photo induced charges on the then formed AgCl Ag2S/PCN cannot be as effectively separated as they are on AgCl Ag/PCN due to the straddling energy band alignments. A decrease in cathodic signal may be expected. Consequently, the H2S concentration could be quantitated by such corresponding decrease, which thus underlines a novel signal off cathodic PEC bioanalysis strategy. More importantly, the 'Z scheme' PEC sensor based on AgCl Ag/PCN exhibits analytical performance with high sensitivity, showing its potential to be applied to the areas of biomedical and health care etc.", "author_names": [ "Dong Liang", "Junjun Luo", "Yaliang Huang", "X San Liang", "Zaichun Zhou", "Jianxiu Wang", "Xiaoqing Qiu" ], "corpus_id": 225028160, "doc_id": "225028160", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Z Scheme cathodic photoelectrochemical sensors for detection of hydrogen sulfide based on AgCl Ag coupled with porous carbon nitride", "venue": "", "year": 2020 }, { "abstract": "Abstract Cathodic photoelectrochemical (PEC) bioanalysis has been drawing more attention in recent years due to the advantages of excellent anti interference capability. l cysteine (Cys) is an essential sulfur containing amino acid and has been intensively addressed as targets in previous anodic PEC bioanalysis. Herein a novel and simple cathodic PEC l cysteine (Cys) sensor is reported, on the basis of facile electrochemical fabrication of CuO/Cu2O heterojunction photocathode and the selective interaction between the copper and Cys via the formation of Cu S bond. The as prepared sensor exhibited excellent biosensing performance in terms of high sensitivity, selectivity and stability. In such a sensor, the binding induced decrease of cathodic photocurrent can be related to target concentration from 0 and 1.5 mM. This cathodic PEC Cys sensor exempted the use of expensive equipment and required no laborious sensor development procedures. We hope it can inspire more interest for further development of simple and practical PEC sensor toward important biomolecules.", "author_names": [ "Si-Yuan Yu", "Yuan Gao", "Fengzao Chen", "Gaochao Fan", "Deman Han", "Chengshuang Wang", "Wei-Wei Zhao" ], "corpus_id": 108910770, "doc_id": "108910770", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "Fast electrochemical deposition of CuO/Cu2O heterojunction photoelectrode: Preparation and application for rapid cathodic photoelectrochemical detection of L cysteine", "venue": "Sensors and Actuators B: Chemical", "year": 2019 }, { "abstract": "In this study, a coumarin appended cyclometalated iridium (III) complex was prepared and demonstrated to be an efficient photoelectrochemical (PEC) active species with stable and reproducible cathodic photocurrent illuminated by visible light. A gold nanoparticles (AuNPs) based PEC probe was assembled using the as prepared iridium (III) complex as signal reporter. Integrating aptamer/protein proximity binding triggered strand displacement and catalytic hairpin assembly (CHA) amplification strategy, an enzyme free and sensitive PEC assay was developed. Benefiting from superior photon to current conversion character of the iridium (III) complex and effective amplification strategy, the proposed assay exhibited enhanced sensitivity for thrombin detection with a detection limit of 23 fM. It also showed a high specificity in serum samples. This study further demonstrated that cyclometalated iridium (III) complexes could be adopted as favorable photoactive material for bioanalysis by improving their ability of absorbance in the visible region.", "author_names": [ "Chunxiang Li", "Yueyuan Cai", "Mengmeng Pang", "Xiaoming Zhou", "Xiliang Luo", "Zhenyu Xiao" ], "corpus_id": 204815381, "doc_id": "204815381", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "A coumarin appended cyclometalated iridium(III) complex for visible light driven photoelectrochemical bioanalysis.", "venue": "Biosensors bioelectronics", "year": 2019 }, { "abstract": "Most of the photoelectrochemical (PEC) bioassays need to immobilize biomolecules on electrodes, which lead to tedious modification processes, damaged biomolecules, as well as crippled sensitivity/accuracy and low throughput of the performances. To overcome these drawbacks, we now introduce an exquisitely split mode (which separates the bioreaction (performed in microplates) from the PEC detection (conducted in PEC cell) cathodic photoelectrochemistry for probing versatile biocatalytic events with high throughput. Specifically, the enzymatically in situ generated 1,2 bezoquinone was covalently attached onto the PbSe quantum dots (QDs) modified indium tin oxide (ITO) (ITO/PbSe) photocathode through the connector of chitosan (CS) And the attached 1,2 bezoquinone acted as an efficient electron acceptor to promote the cathodic photocurrent of the ITO/PbSe electrode, enabling us to probe quinones generating oxidoreductase (by taking horseradish peroxidase (HRP) as a model) coupled biocatalytic cascades including the alkaline phosphatase (ALP)/HRP and the glucose oxidase (GOx)/HRP cascades. Quantitative probing for ALP activity in a wide linear range of 5.0 x 10 3 to 10 U/L with the detection limit of 1.2 x 10 3 U/L was realized. While a wide linear range of 5.0 x 10 8 to 1.0 x 10 4 moL/L with a quite low detection limit of 1.0 x 10 8 moL/L was obtained for the glucose assay. In addition, this testing protocol was also extended to an immunoassay (taking carcinoembryonic antigen (CEA) as an example) using HRP as a catalytic tracer. The developed bioassays show high sensitivity and good selectivity for CEA detection in the linear range from 0.1 pg/mL to 100 ng/mL with a detection limit of 0.02 pg/mL. Moreover, the proposed detection has distinctive merits because it not only avoids the adverse effects of the surface confined biomolecules for crippling the signal transduction, but also it has enhanced throughput.", "author_names": [ "Hong Wang", "Fang Yuan", "Xiuming Wu", "Yuming Dong", "Guang-Li Wang" ], "corpus_id": 73726047, "doc_id": "73726047", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Enzymatic in situ generation of covalently conjugated electron acceptor of PbSe quantum dots for high throughput and versatile photoelectrochemical bioanalysis.", "venue": "Analytica chimica acta", "year": 2019 } ]

[ { "abstract": "Thin film solar cells made from earth abundant, non toxic materials are needed to replace the current technology that uses Cu(In,Ga)(S,Se)2 and CdTe, which contain scarce and toxic elements. One promising candidate absorber material is tin monosulfide (SnS) In this report, pure, stoichiometric, single phase SnS films were obtained by atomic layer deposition (ALD) using the reaction of bis(N,N' diisopropylacetamidinato)tin(II) [Sn(MeC(N iPr)2)2] and hydrogen sulfide (H2S) at low temperatures (100 to 200 degC) The direct optical band gap of SnS is around 1.3 eV and strong optical absorption (a 104 cm 1) is observed throughout the visible and near infrared spectral regions. The films are p type semiconductors with carrier concentration on the order of 1016 cm 3 and hole mobility 0.82 15.3 cm2V 1s 1 in the plane of the films. The electrical properties are anisotropic, with three times higher mobility in the direction through the film, compared to the in plane direction.", "author_names": [ "Prasert Sinsermsuksakul", "Jaeyeong Heo", "Wontae Noh", "Adam S Hock", "Roy G Gordon" ], "corpus_id": 51861645, "doc_id": "51861645", "n_citations": 327, "n_key_citations": 6, "score": 0, "title": "Atomic Layer Deposition of Tin Monosulfide Thin Films", "venue": "", "year": 2011 }, { "abstract": "The authors present a new method for preparing thin films of SnO2 by atomic layer deposition (ALD) using alternating exposures to tetrakis(dimethylamino) tin and hydrogen peroxide. This method avoids problems of corrosion and agglomeration associated with the halogenated compound, SnCl4. Tin oxide films were successfully deposited on a variety of substrates using deposition temperatures of 50 300degC at an average growth rate of 1.2A/cycle. They use in situ quartz crystal microbalance and quadrupole mass spectrometry measurements to explore the mechanism for SnO2 ALD. Scanning electron microscopy of SnO2 films deposited on Si(100) show that the SnO2 films are smooth, conformal, and nearly featureless, while atomic force microscopy yields a surface roughness of only 0.84nm for a film with a thickness of 92nm. X ray diffraction reveals that the SnO2 films are amorphous. Films deposited on glass yielded a resistivity of ~0.3Ocm and an optical transmission of 94% for a film thickness of 140nm. X ray photoelectr.", "author_names": [ "Jeffrey W Elam", "David A Baker", "Alexander J Hryn", "Alex B F Martinson", "Michael J Pellin", "Joseph T Hupp" ], "corpus_id": 14742059, "doc_id": "14742059", "n_citations": 119, "n_key_citations": 4, "score": 1, "title": "Atomic layer deposition of tin oxide films using tetrakis(dimethylamino) tin", "venue": "", "year": 2008 }, { "abstract": "Atomic layer deposition (ALD) of tin oxide (SnOx) films was achieved using a newly synthesized tin precursor and hydrogen peroxide. We obtained highly pure, conductive SnOx films at temperatures as low as 50 degC, which was possible because of high chemical reactivity between the new Sn precursor and hydrogen peroxide. The growth per cycle is around 0.18 nm/cycle in the ALD window up to 150 degC, and decreased at higher temperatures. Self limited growth was demonstrated for both the Sn and O precursors. Thickness is linear in the number of cycles, with an induction period of not more than a few cycles. Rutherford backscattering spectroscopy (RBS) and X ray photoelectron spectroscopy (XPS) measurements showed that the composition ratio of O/Sn is ~2 and that the films do not contain any detectable carbon or nitrogen impurities. X ray and electron diffraction analyses identified crystallites of SnO2 with the rutile structure and average grain size 5 10 nm. The density of the films is 83% of the bulk rutile phas.", "author_names": [ "Jaeyeong Heo", "Adam S Hock", "Roy G Gordon" ], "corpus_id": 3073040, "doc_id": "3073040", "n_citations": 108, "n_key_citations": 3, "score": 0, "title": "Low Temperature Atomic Layer Deposition of Tin Oxide", "venue": "", "year": 2010 }, { "abstract": "In this work we present a low cost and scalable technique, via ambient pressure chemical vapor deposition (CVD) on polycrystalline Ni films, to fabricate large area approximately cm2) films of single to few layer graphene and to transfer the films to nonspecific substrates. These films consist of regions of 1 to approximately 12 graphene layers. Single or bilayer regions can be up to 20 mum in lateral size. The films are continuous over the entire area and can be patterned lithographically or by prepatterning the underlying Ni film. The transparency, conductivity, and ambipolar transfer characteristics of the films suggest their potential as another materials candidate for electronics and opto electronic applications.", "author_names": [ "Alfonso Reina", "Xiaoting Jia", "John T Ho", "Daniel Nezich", "Hyungbin Son", "Vladimir Bulovic", "Mildred S Dresselhaus", "Jing Kong" ], "corpus_id": 2796618, "doc_id": "2796618", "n_citations": 4937, "n_key_citations": 87, "score": 0, "title": "Large area, few layer graphene films on arbitrary substrates by chemical vapor deposition.", "venue": "Nano letters", "year": 2009 }, { "abstract": "The deposition of conformal coatings into porous silicon layers was successfully demonstrated. Tin oxide films were formed from SnCl 4 and H 2 O precursors by atomic layer epitaxy. The influence of the porous substrate structure on the deposition parameters was analyzed from the viewpoint of formation mechanism, growth rate, and layer composition. The SnO x covered porous substrates were characterized by means of Rutherford backscattering, secondary ion mass spectrometry, cross sectional transmission electron microscopy, and ellipsometry. The mesoporous structure of the Si substrate uniquely determines the gas phase diffusion and physisorption of the precursors. The processing parameters favoring chemisorption are more critical for porous silicon than those for a flat surface. Even a small decrease in the deposition temperature results in a considerable increase in the growth rate through gas phase reactions, and the process becomes chemical vapor deposition like. Conformal step coverage was obtained on extremely high (140 :1) aspect ratio pores if the deposition conditions were chosen such that chemisorption was the growth rate determining step in the process.", "author_names": [ "Csaba Ducso", "Nguyen Quoc Khanh", "Zsolt Endre Horvath", "Istvan Barsony", "Mikko Utriainen", "Sari Lehto", "Minna Nieminen", "Lauri Niinisto" ], "corpus_id": 98154410, "doc_id": "98154410", "n_citations": 46, "n_key_citations": 0, "score": 0, "title": "Deposition of tin oxide into porous silicon by atomic layer epitaxy", "venue": "", "year": 1996 }, { "abstract": "Atomic layer deposition (ALD) is a process for depositing highly uniform and conformal thin films by alternating exposures of a surface to vapours of two chemical reactants. ALD processes have been successfully demonstrated for many metal compounds, but for only very few pure metals. Here we demonstrate processes for the ALD of transition metals including copper, cobalt, iron and nickel. Homoleptic N,N' dialkylacetamidinato metal compounds and molecular hydrogen gas were used as the reactants. Their surface reactions were found to be complementary and self limiting, thus providing highly uniform thicknesses and conformal coating of long, narrow holes. We propose that these ALD layers grow by a hydrogenation mechanism that should also operate during the ALD of many other metals. The use of water vapour in place of hydrogen gas gives highly uniform, conformal films of metal oxides, including lanthanum oxide. These processes should permit the improved production of many devices for which the ALD process has previously not been applicable.", "author_names": [ "Booyong S Lim", "Antti Rahtu", "Roy G Gordon" ], "corpus_id": 21887076, "doc_id": "21887076", "n_citations": 502, "n_key_citations": 3, "score": 0, "title": "Atomic layer deposition of transition metals", "venue": "Nature materials", "year": 2003 }, { "abstract": "films have been fabricated using many different technologies, including sputtering [1] chemical vapor deposition [2] spray pyrolysis [3] and atomic layer deposition (ALD) [4] [5] Amongst these ALD produces unique film properties compared with other methods. In particular dense films of high aspect ratio and fewer defects are achieved. ALD is also an ideal technology for the deposition of ultrathin films with high conformality and precise thickness control [6] ALD is a dense thin film growth technology using an alternating self controlled chemical process between the gas precursor and a solid surface in order to deposit materials in an atomic layer by layer fashion. This methodology can produce films with very precise control over film thickness and composition. This technology allows precise coatings to be applied on other surfaces of powder and porous materials. Plasma enhanced ALD (PEALD) is a promising technology for obtaining high quality metal oxide films at relatively low temperatures compared with commercial CVD. Interestingly, the comparative study of the growth of tin oxide films by ALD and chemical vapor deposition was reported [7] The films were of the tetragonal rutile type for both cases. Thin films grown by ALD were found to be close to being perfect single crystals, containing a low density of defects and were almost atomically smooth. The CVD films had a much rougher film morphology and exhibited both grain boundaries and twin formation. Tin oxide thin films have been fabricated previously by ALD using halogenated precursors, SnCl", "author_names": [ "Woon-Seop Choi" ], "corpus_id": 56028910, "doc_id": "56028910", "n_citations": 26, "n_key_citations": 0, "score": 1, "title": "The Fabrication of Tin Oxide Films by Atomic Layer Deposition using Tetrakis(Ethylmethylamino) Tin Precursor", "venue": "", "year": 2009 }, { "abstract": "Titanium nitride (TiN) films were deposited by a plasma assisted atomic layer deposition (PA ALD) process, based on TiCl 4 precursor dosing and remote H 2 N 2 plasma exposure, at temperatures ranging from 100 to 400degC. The plasma, the PA ALD process, and the resulting TiN material properties were extensively investigated. The plasma was studied by optical emission spectroscopy and Langmuir probe, revealing an ion density of 10 9 cm 3 and an electron temperature of 3.5 eV just above the substrate. Under floating conditions there is thus a considerable ion flux towards the substrate per ALD cycle with a typical ion energy of 15 eV. TiN film growth was studied by in situ spectroscopic ellipsometry, revealing self limiting surface reactions for the complete temperature range. At 100degC the growth rate of 0.3 A/cycle was found to be significantly lower than the growth rate of 0.6 A/cycle at 400degC. The stoichiometry of the films varied with the plasma exposure time, while the Cl content was mostly affected by the deposition temperature (2.1 atom at 100degC to 0.07 atom at 400degC) Resistivities as low as 71 mO cm were obtained at a temperature of 400degC, while at 100degC a fair resistivity of 209 mO cm was reached. These results show that PA ALD with TiCl 4 and H 2 N 2 plasma is well suited for low temperature deposition of high quality TiN films.", "author_names": [ "Sbs Stephan Heil", "E Erik Langereis", "Fred Roozeboom", "Van de Sanden", "Wmm Erwin Kessels" ], "corpus_id": 95853683, "doc_id": "95853683", "n_citations": 91, "n_key_citations": 2, "score": 0, "title": "Low Temperature Deposition of TiN by Plasma Assisted Atomic Layer Deposition", "venue": "", "year": 2006 }, { "abstract": "The authors deposited thin films of tin oxide on substrates of silicon and stainless steel by using atomic layer deposition (ALD) with tetraethyltin precursors. In this process, the authors used various coreactants such as water, oxygen, remote oxygen plasma, hydrogen peroxide, and ozone. The growth rates of films were studied as functions of the deposition temperature, the pulse times of the precursor and coreactant, and the number of ALD cycles, and the optimal growth conditions were determined. The film growth rates were found to be 0.025, 0.045, and 0.07 nm per cycle within the optimal growth conditions and ALD temperature windows for H2O2, O3, and O2 plasma, respectively. Using H2O or O2 did not prompt film growth. The films deposited using O3 and H2O2 had good continuity and low roughness, while the morphology of a coating prepared using oxygen plasma depended greatly on the deposition temperature. The films produced at temperatures below 300 degC were amorphous, irrespective of the coreactant used. X.", "author_names": [ "Denis V Nazarov", "Maxim Yu Maximov", "Pavel Alexandrovich Novikov", "Anatoly A Popovich", "Aleksey Silin", "Vladimir M Smirnov", "Natalia P Bobrysheva", "Olga M Osmolovskaya", "M G Osmolovsky", "A M Rumyantsev" ], "corpus_id": 100055099, "doc_id": "100055099", "n_citations": 24, "n_key_citations": 0, "score": 0, "title": "Atomic layer deposition of tin oxide using tetraethyltin to produce high capacity Li ion batteries", "venue": "", "year": 2017 }, { "abstract": "Silicon or glass substrates exposed to sequential pulses of tetraethyltin (TET) and ozone (O3) were coated with thin films of SnO2. Self limiting deposition was found using 8 s pulse times, and a uniform thickness per cycle (TPC) of 0.2 nm/cycle was observed in a small, yet reproducible, temperature window from 290 to 320 degC. The as deposited, stoichiometric SnO2 films were amorphous and transparent above 400 nm. Interspersing pulses of diethylzinc and O3 among the TET:O3 pulses resulted in deposition of zinc tin oxide films, where the fraction of tin, defined as [at. Sn/(at. Sn at. Zn) was controlled by the ratio of TET pulses, specifically nTET:(nTET nDEZ) where nTET and nDEZ are the number of precursor/O3 subcycles within each atomic layer deposition (ALD) supercycle. Based on film thickness and composition measurements, the TET pulse time required to reach saturation in the TPC of SnO2 on ZnO surfaces was increased to >30 s. Under these conditions, film stoichiometry as a function of the T.", "author_names": [ "Ellis J Warner", "Forrest Johnson", "Stephen A Campbell", "Wayne L Gladfelter" ], "corpus_id": 97870689, "doc_id": "97870689", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Atomic layer deposition of tin oxide and zinc tin oxide using tetraethyltin and ozone", "venue": "", "year": 2015 } ]

[ { "abstract": "The I III VI 2 group semiconductors are of great importance due to their applications in solar cell fabrication. Spray pyrolysis is a very cheap and inexpensive method of depositing thin films of large area. We have deposited CuInSe 2(1 x) S 2x on glass substrate at 350 0 C by varying the proportion parameter x by this method. Resistivity, Hall coefficient and carrier concentration were measured at room temperature by Van der Pauw Hall method. From these results we conclude that resistivity and Hall coefficient increases as composition parameter x increases. While Hall mobility and carrier concentration decreases as x increases.The resistivity, Hall coefficient and carrier concentration fallow the parabolic variation.", "author_names": [ "Yashwantrao D Tembhurkar" ], "corpus_id": 136385121, "doc_id": "136385121", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Resistivity, Hall Coefficient and Carrier Concentration of Cuinse2(1 X)S2x Thin Films by Spray Pyrolysis", "venue": "", "year": 2017 }, { "abstract": "Copper indium selenide CuInSe2(CISe) thin films were deposited by chemical spray pyrolysis (CSP) method of CuInS2(CIS) and subsequent selenization process. To study the effects of solution concentration, we prepared different precursors solution of CIS including different amount of indium salts from 0.025 to 0.100 M with In/Cu 1.25 and S/In 4. These results propose that solution concentration is critical for inflecting the morphological, optical, electrical, and electrochemical characteristics of solution processed CISe films and device performance. The studied morphological properties of deposited samples were homogenous, crack free with large grains in indium salt concentrations more than 0.075 M. The deposited film thickness depends on the spray precursor concentration and increases for higher concentration. In addition with increasing of indium precursor concentration from 0.025 to 0.100 M in spray solution, the optical bandgap of deposited film decreases from 1.40 to 1.35 eV. Also the films mobility and carrier density were notably influenced by any change in the solution concentration. Electrical and electrochemical properties showed a decrease in carrier density from 1020 to 1017 cm 3 and the increase in mobility of order 10 7 to 10 2 cm2/V s, respectively, for 0.025 M, 0.100 M CISe films. All films exhibited p type conductivity owing to different concentrations. However, it seems that the concentration of the ideal solution is 0.100 molars.", "author_names": [ "Maryam Hashemi", "Seyed Mohammad Bagher Ghorashi", "Fariba Tajabadi", "Nima Taghavinia" ], "corpus_id": 226202488, "doc_id": "226202488", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Investigation of precursors concentration in spray solution on the optoelectronic properties of CuInSe2 thin films deposited by spray pyrolysis method", "venue": "Journal of Materials Science: Materials in Electronics", "year": 2020 }, { "abstract": "Cu2SnSe3 based compounds with a diamond like structure are promising thermoelectric materials. However, the relatively high lattice thermal conductivity limits further improvement in their thermoelectric performance. In this work, two compounds including In2Se3 and CuInSe2 are employed to alloy with Cu2SnSe3 aiming to decrease lattice thermal conductivity and their corresponding effects are compared. It is found that alloying with CuInSe2 is more beneficial to reduce lattice thermal conductivity and maintain the power factor, as evidenced by a higher quality factor B. Subsequently, both In and Ga doping is performed to regulate the carrier concentration of (Cu2SnSe3)0.80(CuInSe2)0.2. Finally, (Cu2Sn0.97Ga0.03Se3)0.80(CuInSe2)0.20 displays a decent zT of ~0.98 at 823 K, a nearly six fold higher value compared to that of the pristine sample. Additionally, a zTave of ~0.35 over 300 823 K is obtained in (Cu2Sn0.97Ga0.03Se3)0.80(CuInSe2)0.20, which is among the best reported p type Cu2SnSe3 based compounds. The result proves that alloying with CuInSe2 combined with carrier concentration optimization is a valid strategy to improve the thermoelectric performance of Cu2SnSe3 based compounds.", "author_names": [ "Guoyu Wang", "Xiao Zhang", "Yuling Huang", "Xiaoyuan Zhou" ], "corpus_id": 225255097, "doc_id": "225255097", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Synergistic effect of CuInSe2 alloying on enhancing the thermoelectric performance of Cu2SnSe3 compounds", "venue": "", "year": 2020 }, { "abstract": "Abstract The absorption spectra of as grown and copper annealed n CuInSe 2 samples were obtained at room temperature. A shift of the absorption edge to higher energy for the annealed sample as compared to its value in the as grown sample, is observed in the measurements. This behaviour can be explained as due to the fact that n CuInSe 2 becomes degenerate at relatively low electron concentration because of its small electron effective mass.", "author_names": [ "Carlos Rincon", "Gerardo Sanchez Perez" ], "corpus_id": 97221703, "doc_id": "97221703", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Influence of the carrier concentration on the optical absorption edge of n CuInSe2", "venue": "", "year": 1984 }, { "abstract": "Silver alloying and KF post deposition treatments are explored as approaches to increase the efficiency of low bandgap CuInSe₂ (CIS) solar cells. The KF treatment prevents a loss in <italic>V</italic>_OC when CIS has a thinner CdS layer, and also increases the carrier concentration of these devices. Compared with CIS devices, Ag alloyed CIS (ACIS) devices have lower efficiencies due to a lower carrier concentration which decreases <italic>V</italic>_OC When ACIS is exposed to the KF treatment, the resulting devices have reduced <italic>V</italic>_OC and fill factor <italic>FF</italic> compared with untreated devices; however, thinning the CdS layer with KF treated ACIS improves <italic>V</italic>_OC ACIS+KF films show an unidentified compound in Raman spectra and the resulting solar cells have a dominant interface recombination mechanism and light to dark crossover. An electron microscopy study of the growth and coverage of CdS reveals that KF treated samples in this study have faster CdS growth and ACIS+KF has complete CdS coverage with less than half of the normal deposition time. Improved coverage of CdS layers on KF treated samples is also verified by X ray photoelectron spectroscopy. Finally, using a heat treatment and an anti reflection layer enables CIS+KF solar cells to obtain a high 16.0% efficiency for CIS with a <italic>V</italic>_OC 526 mV and <italic>J</italic>_SC 41.0 mA/cm²", "author_names": [ "Nicholas H Valdes", "Jinwoo Lee", "William N Shafarman" ], "corpus_id": 131777167, "doc_id": "131777167", "n_citations": 3, "n_key_citations": 1, "score": 0, "title": "Ag Alloying and KF Treatment Effects on Low Bandgap CuInSe2 Solar Cells", "venue": "IEEE Journal of Photovoltaics", "year": 2019 }, { "abstract": "", "author_names": [ "R Pal", "Kalyan Kumar Chattopadhyay", "Subhadra Chaudhuri", "Arun Kumar Pal" ], "corpus_id": 100353954, "doc_id": "100353954", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Dependence of electrical conductivity, carrier concentration, band gap and grain size of CuInSe2 films on the composition", "venue": "", "year": 1993 }, { "abstract": "Chalcopyrite structured semiconductor CuInSe2 has received considerable attention owing to its promising electrical and optical properties for nonlinear optical instruments and photovoltaic solar cells. In view of these interesting properties of CuInSe2, it is thought to be worthwhile to study the high pressure electrical transport behavior of this compound. Herein, we use in situ Hall effect measurements, temperature dependent electrical resistivity measurements, and first principles calculations to conduct a comprehensive study on the carrier behavior and the band structure of CuInSe2 under high pressure. The resistivity shows an obvious increase with pressure and reaches the maximum value at 7.2 GPa, indicating that pressure enlarges the band gap which has been confirmed by the result of the subsequent band structure calculations. Dramatic changes in electrical transport parameters, such as Hall coefficient, Hall mobility, carrier concentration, and electrical resistivity, are detected at 7.2 GPa, whic.", "author_names": [ "Meiyan Ye", "Ruilian Tang", "Shuailing Ma", "Qiang Tao", "Xuefeng Wang", "Yuanjie Li", "Pinwen Zhu" ], "corpus_id": 201221009, "doc_id": "201221009", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Electrical Transport Properties and Band Structure of CuInSe2 under High Pressure", "venue": "The Journal of Physical Chemistry C", "year": 2019 }, { "abstract": "Abstract Na has been believed to improve the device parameters of open circuit voltage (VOC) and fill factor (FF) presumably by increasing the carrier concentration (NA) of vacuum processed Cu(In,Ga)Se2 films. In solution processed CI(G)Se devices as well, Na reportedly increases VOC and FF but this improvement is not correlated with the increase in NA, suggesting a different physical mechanism associated with Na in solution based routes. In this contribution, experimental results on the role of Na addition in solution processed CISe films and devices were reported, in which Na addition had no influence on NA nor on film composition in spite of the notable increase in the device efficiency. On the contrary, Na was found to mitigate the interfacial recombination by reducing the undesirable surface defects. Along with this understanding, Na addition in our air processable route resulted in a CISe device with 12.83% efficiency, which is comparable to the current world record efficiency of solution processed CISe devices.", "author_names": [ "Shanza Rehan", "Jihyun Moon", "Tae Gun Kim", "Jihye Gwak", "Juran Kim", "Jeong Won Kim", "William Jo", "Seung Kyu Ahn", "Sejin Ahn" ], "corpus_id": 103290682, "doc_id": "103290682", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Role of Na in solution processed CuInSe2 (CISe) devices: A different story for improving efficiency", "venue": "", "year": 2018 }, { "abstract": "In this study CuInSe2 and CuInS2 thin films were prepared onto ITO glass substrate using the electrodeposition technique in aqueous solution. The electrodeposited films were characterized by X ray diffraction (XRD) scanning electron microscopy (SEM) and energy dispersive X ray analysis. The annealing effects on electrodeposited precursors were investigated. The chalcopyrite structure of CuInSe2/CuInS2 showed an enhancement of crystallinity after subsequent selenization/sulfurization treatment in Se/S atmosphere, respectively. XRD and SEM studies revealed a dramatic improvement of the crystalline quality of CIS films after annealing treatments. Mott Schottky measurements were used to assess the conductivity type of the films and their carrier concentration. The prepared samples underwent an etching process to remove the binary accumulated Cu2 x(Se,S) phases shown in FESEM pictures. This etching process has shown a noticeable decrease in both, the flat band potential, Vfb (V) and the number of acceptors, NA (cm 3) in selenized CuInSe2 and sulfurized CuInS2 samples.", "author_names": [ "Suzan Saber", "M Mollar", "Amany M El Nahrawy", "Nagwa Mohamed Aly Khattab", "A H Eid", "Mohamed Mahmoud Abo-Aly", "B Mari" ], "corpus_id": 102956171, "doc_id": "102956171", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Annealing study of electrodeposited CuInSe2 and CuInS2 thin films", "venue": "", "year": 2018 }, { "abstract": "We investigate the dopant concentration and majority carrier mobility in epitaxial CuInSe2thin films for different copper to indium ratios and selenium excess during growth. We find that all copper poor samples are n type, and that hopping conduction in a shallow donor state plays a significant role for carrier transport. Annealing in sodium ambient enhances gallium in diffusion from the substrate wafer and changes the net doping of the previously n type samples to p type. We suggest that sodium incorporation from the glass might be responsible for the observed p type doping in polycrystalline Cu poor CuInSe2 solar cell absorbers.", "author_names": [ "Florian Werner", "Diego Colombara", "Michele Melchiorre", "Nathalie Valle", "Brahime El Adib", "Conrad Spindler", "Susanne Siebentritt" ], "corpus_id": 102132182, "doc_id": "102132182", "n_citations": 24, "n_key_citations": 0, "score": 0, "title": "Doping mechanism in pure CuInSe2", "venue": "", "year": 2016 } ]

[ { "abstract": "Nanomaterials and Nanostructures: Progress Towards Monodisperse Single Walled Carbon Nanotubes (Mark C Hersam) The Rise of Graphene (A K Geim K S Novoselov) Multiferroics: Progress and Prospects in Thin Films (R Ramesh Nicola A Spaldin) Inorganic Nanotubes and Fullerene Like Nanoparticles (R Tenne) The Role of Interparticle and External Forces in Nanoparticle Assembly (Younjin Min et al. Complex Thermoelectric Materials (G Jeffrey Snyder Eric S Toberer) Solid State Nanopores (Cees Dekker) Engineering Atomic and Molecular Nanostructures at Surfaces (Johannes V Barth et al. Molecular Machines and Devices: Making Molecular Machines Work (Wesley R Browne Ben L Feringa) Molecular Logic and Computing (A Prasanna de Silva Seiichi Uchiyama) Harnessing Biological Motors to Engineer Systems for Nanoscale Transport and Assembly (Anita Goel Viola Vogel) Designed DNA Molecules: Principles and Applications of Molecular Nanotechnology (Anne Condon) DNA Nanomachines (Jonathan Bath Andrew J Turberfield) Nanoelectronics: Nanoelectronics from the Bottom Up (Wei Lu Charles M Lieber) The Emergence of Spin Electronics in Data Storage (Claude Chappert et al. Nanoionics Based Resistive Switching Memories (Rainer Waser Masakazu Aono) Technology and Metrology of New Electronic Materials and Devices (Eric Vogel) Carbon Based Electronics (Phaedon Avouris et al. Electron Transport in Molecular Junctions (N J Tao) Molecular Spintronics using Single Molecule Magnets (Lapo Bogani Wolfgang Wernsdorfer) Nanophotonics: Light in Tiny Holes (C Genet T W Ebbesen) Nano Optics from Sensing to Waveguiding (Surbhi Lal et al. Semiconductor Quantum Light Sources (Andrew J Shields) Biomimetics of Photonic Nanostructures (Andrew R Parker Helen E Townley) Nanobiotechnology and Nanomedicine: Nanoparticle Therapeutics: An Emerging Treatment Modality for Cancer (Mark E Davis et al. Neuroscience Nanotechnology: Progress, Opportunities and Challenges (Gabriel A Silva) The Potential and Challenges of Nanopore Sequencing (Daniel Branton et al. Atomic Force Microscopy as a Multifunctional Molecular Toolbox in Nanobiotechnology (Daniel J Muller Yves F Dufrene) Immunological Properties of Engineered Nanomaterials (Marina A Dobrovolskaia Scott E McNeil) Injectable Nanocarriers for Biodetoxification (Jean Christophe Leroux) Selected Applications: Applications of Dip Pen Nanolithography (Khalid Salaita et al. Biosensing with Plasmonic Nanosensors (Jeffrey N Anker et al. Materials for Electrochemical Capacitors (Patrice Simon Yury Gogotsi) Future Lab on a Chip Technologies for Interrogating Individual Molecules (Harold Craighead) Science and Technology for Water Purification in the Coming Decades (Mark A Shannon et al.", "author_names": [ "Peter Rodgers" ], "corpus_id": 106685952, "doc_id": "106685952", "n_citations": 270, "n_key_citations": 6, "score": 1, "title": "Nanoscience and technology a collection of reviews from nature journals", "venue": "", "year": 2009 }, { "abstract": "", "author_names": [ "Gino Rinaldi" ], "corpus_id": 108497531, "doc_id": "108497531", "n_citations": 8, "n_key_citations": 2, "score": 0, "title": "Nanoscience and Technology: A Collection of Reviews from Nature Journals", "venue": "", "year": 2010 }, { "abstract": "", "author_names": [ "Bohumil Kratochvil" ], "corpus_id": 103172093, "doc_id": "103172093", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Recenze: Peter Rodgers (ed. Nanoscience and Technology A Collection of Reviews from Nature Journals", "venue": "", "year": 2010 }, { "abstract": "ABSTRACT Background: The majority of reviews related to Physical Education Pedagogy (PEP) refer to the English speaking world. Some of these assert the need to obtain more data and provide reviews of what has been investigated in languages other than English to be able to assess the current state of the field internationally. Purpose: The aim of this study was to identify, categorise, and analyse articles on PEP published in Spanish sport science journals during the last decade (2005 2014) Participants and setting: A total of 13 journals were selected: 8 were indexed in the Scopus databases, and 5 were added based on expert judgement due to their importance in the field of Spanish PEP. Research design: The study uses a quantitative approach that is exploratory and descriptive in nature and includes document research techniques. Data collection: The identification of all articles published between 2005 and 2014 (both inclusive) was performed. The search yielded 3258 published articles, from which articles whose content was not related to PEP were eliminated. The final sample was 534 articles. Data analysis: The articles that comprise the final sample were analysed and classified according to their content and article type. Findings: Of the 3258 articles published in the last decade in these journals, only 534 (16.39% address content in the PEP field of study. With regard to sub areas, half of the research conducted pertains to teaching (50.00% followed by curriculum (25.66% The combination of both sub areas comprises the third largest percentage (9.74% Teacher education is the least addressed sub area, with 8.80% and its intersections with teaching and curriculum in no case exceed 3% In terms of article type, 38.39% are theoretical studies, historical studies, or essays. One fourth (25.09% are quantitative empirical research, and one fifth (22.47% refer to experiences in education or innovation. These three article types are predominant, comprising 85.95% of the total. The remaining articles are divided into studies related to qualitative empirical research (7.68% those conducting empirical research using a mixed methodology (quantitative and qualitative) (5.06% and a testimonial for review articles (1.31% Conclusions: In the decade studied, an increase in the gap between the number of articles published in Spanish journals specialising in physical education and sport and the percentage of articles related to PEP is observed. Of these journals, those publishing the most articles on PEP were included by expert judgement and are not indexed in Scopus. The implication is an academically worrying state for the field in the Spanish context, differing significantly from the English context.", "author_names": [ "Pere Molina", "Alejandro Martinez-Baena", "Miguel Villamon" ], "corpus_id": 152074747, "doc_id": "152074747", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Physical Education Pedagogy: an analysis of research published in Spanish journals (2005 2014)", "venue": "", "year": 2017 }, { "abstract": "Our world is changing fast. Microbes, once considered our adversaries, are now recognized as partners. Well, not all microbes, but a vast number that live in the unique niches of our bodies and, in particular, the gut. Recently, we have come to appreciate how our normal microbiota contribute to our health, and how disruption of this partnership can open the way for disease (both infectious and non infectious) This Joint Virtual Issue on 'Immunology and the Microbiome' celebrates this partnership and is a joint initiative by the immunological societies of Australia and New Zealand (ASI) and Britain (BSI) and their journals, Immunology Cell Biology and Immunology, respectively. This collection contains six recent articles from each journal (three reviews and three original research articles) that highlight specific aspects of the microbiome immune partnership. Focusing on the articles from Immunology, there are key central themes that arise: the changing nature of this relationship over time, how diet influences the microbiota and consequently the immune system, and how individual components of the innate and adaptive immune systems interact with the gut microbiome to regulate and balance the complex network. To start this collection off, Zhao et al. begin at the beginning the education of the adaptive immune system by gut microbial antigens (Fig. 1 1) This education starts at birth with the first major seeding of flora from the mother; colonization begins and so does the development of adaptive cells. Zhao et al. detail how these processes are intertwined with the neonate's immune system regulating the microbial community and the microbes shaping the developing immune cells. This period is a critical 'window of opportunity' which impacts one's health and homeostasis throughout life. Within the large community of microbes, specific microbes can support the differentiation or expansion of different functional immune subsets such as the support of regulatory T (Treg) cell expansion by specific Clostridium clusters and Bacteroides fragilis or the induction of T helper type 17 cells by epithelial adhesive bacteria like Escherichia coli O157. Zhao et al. conclude by discussing how the mis education of adaptive immune cells during this critical period promotes the development of chronic inflammatory diseases such as Crohn's disease and multiple sclerosis (MS) and end by highlighting how the potential of probiotics or prebiotics to 'normalize' the gut microbiota presents an attractive therapeutic strategy. Partnerships take a lot of work; they need the right fuel to keep them alive and to enable both partners to benefit. That is how probiotics and prebiotics work seeding the right microbes and then providing the right nutrients to fuel them. Gudi et al. and Haase et al. investigate how specific microbial partnerships are fueled and sustained such that their metabolites can regulate chronic inflammatory diseases such as MS. The complex dietary polysaccharide, yeast b glucan (YBG) is a prebiotic that Gudi et al. investigate in their original article (Fig. 1 2) and they find that administration of YBG expands FoxP3 IL10 IL 17 T cells ex vivo and modulates the T cell compartment in vivo, leading to suppression of type 1 diabetes in non obese diabetic mice. Key to this effect is the finding that YBG enhances, not suppresses, local cytokine production including interleukin (IL) 10, tumor necrosis factor a, and IL 17 with a targeted decrease in some cytokines (e.g. interferon c) Promoting the growth of the 'right' kind of bacteria has flow on effects not only locally but also systemically, by the production of immune modifying microbial metabolites as discussed by Haase et al. (Fig. 1 3) In particular, the ability of these microbially produced compounds such as short chain fatty acids or tryptophan metabolites to alter neuroinflammation in diseases such as MS speaks to the importance of the microbiota gut brain axis in maintaining health and homeostasis throughout the body. This axis involves not just the immune system but is a complex network encompassing enteroendocrine cells, vagal nerve signals, as well as astrocytes and microglia within the brain with short chain fatty acids exerting their effects through stimulation of retinoic acid production, histone deacetylase inhibition and direct activation of free fatty acid receptors like GPR43, GPR41 and GPR109A. This review centers on the specific benefits of short chain fatty acids and tryptophan metabolites, but these microbially derived products are only subset of metabolites that contributes to immune homeostasis and the development of a beneficial microbial partnership. Immune control of the microbial populations in the gut is essential to the maintenance of a healthy gut microbiome, and control of gut microbes by gut eosinophils and secretory IgA (sIgA) are the focus of the articles by Singh et al. and Hoces et al. Using mice deficient in eosinophils (i.e. DdblGATA 1 mice) Singh and his colleagues report that an absence of eosinophils did not alter gut architecture, barrier integrity or sIgA levels; however, the loss of eosinophils significantly changed microbial diversity with the greatest effects found in the mucus associated communities (Fig. 1 4) Although these investigators did not find that these changes in", "author_names": [ "Anne Camille La Flamme", "Simon W F Milling" ], "corpus_id": 221324006, "doc_id": "221324006", "n_citations": 3, "n_key_citations": 1, "score": 0, "title": "Immunological partners: the gut microbiome in homeostasis and disease", "venue": "Immunology", "year": 2020 }, { "abstract": "BackgroundThere is wide agreement that there is a lack of attention to health in municipal environmental policy making, such as urban planning and regeneration. Explanations for this include differing professional norms between health and urban environment professionals, system complexity and limited evidence for causality between attributes of the built environment and health outcomes. Data from urban health indicator (UHI) tools are potentially a valuable form of evidence for local government policy and decision makers. Although many UHI tools have been specifically developed to inform policy, there is poor understanding of how they are used. This study aims to identify the nature and characteristics of UHI tools and their use by municipal built environment policy and decision makers.MethodsHealth and social sciences databases (ASSIA, Campbell Library, EMBASE, MEDLINE, Scopus, Social Policy and Practice and Web of Science Core Collection) will be searched for studies using UHI tools alongside hand searching of key journals and citation searches of included studies. Advanced searches of practitioner websites and Google will also be used to find grey literature. Search results will be screened for UHI tools, and for studies which report on or evaluate the use of such tools. Data about UHI tools will be extracted to compile a census and taxonomy of existing tools based on their specific characteristics and purpose. In addition, qualitative and quantitative studies about the use of these tools will be appraised using quality appraisal tools produced by the UK National Institute for Health and Care Excellence (NICE) and synthesised in order to gain insight into the perceptions, value and use of UHI tools in the municipal built environment policy and decision making process. This review is not registered with PROSPERO.DiscussionThis systematic review focuses specifically on UHI tools that assess the physical environment's impact on health (such as transport, housing, air quality and greenspace) This study will help indicator producers understand whether this form of evidence is of value to built environment policy and decision makers and how such tools should be tailored for this audience.Systematic review registrationN/A.", "author_names": [ "Helen Pineo", "Ketevan Glonti", "Harry Rutter", "Nicole S Zimmermann", "Paul Wilkinson", "Michael Davies" ], "corpus_id": 3834566, "doc_id": "3834566", "n_citations": 14, "n_key_citations": 1, "score": 0, "title": "Characteristics and use of urban health indicator tools by municipal built environment policy and decision makers: a systematic review protocol", "venue": "Systematic Reviews", "year": 2017 }, { "abstract": "Academic research aims to provide solutions for many current problems. The data collection and analysis presented in this study addresses the extent to which such benefit could be realised in practice. This research reviews the limitations of research publishing in Saudi Arabia by focusing on the nature of academic journals, in terms of their numbers and purpose, the barriers that academic staff faced when they wished to publish. This research uses questionnaire tool. The data are tabulated and analysed in a systematic method to show findings in accordance with required objectives. The most prominent findings from this study are the lack of academic staff encouragement to conduct and publish research, lack of financial support to the research publishing sector, lack of a research publishing infrastructure. An interesting finding is that unlike many other countries, there is no culture of volunteering for work that does not provide direct financial benefit. This could be an important factor affecting the adoption of an online open publishing approach. This research ultimately aims at proposing and implementing suitable processes and policies to solve these problems and to identifying means of overcoming the research publishing barriers in Saudi Arabia.", "author_names": [ "Jumaan Abdulqader Alzahrani" ], "corpus_id": 74359164, "doc_id": "74359164", "n_citations": 24, "n_key_citations": 2, "score": 0, "title": "Overcoming Barriers to Improve Research Productivity in Saudi Arabia", "venue": "", "year": 2011 }, { "abstract": "Purpose The purpose of this article is to analyze the link based web site impact measure known as the web impact factor (WIF) It is a quantitative tool for evaluating and ranking web sites, top level domains and sub domains. The paper also aims to discuss the WIF's advantages and disadvantages, data collection problems, and validity and reliability of WIF results.Design/methodology/approach A key to webometric studies has been the use of large scale search engines, such as Yahoo! and AltaVista that allow measurements to be made of the total number of pages in a web site and the total number of back links to the web site. These search engines provide similar possibilities for the investigation of links between web sites/pages to those provided by the academic journals citation databases from the Institute of Scientific Information (ISI) But the content of the web is not of the same nature and quality as the databases maintained by the ISI.Findings This paper reviews how the WIF has been developed a.", "author_names": [ "Alireza Noruzi" ], "corpus_id": 206375121, "doc_id": "206375121", "n_citations": 68, "n_key_citations": 6, "score": 0, "title": "The web impact factor: a critical review", "venue": "Electron. Libr.", "year": 2006 }, { "abstract": "This survey introduces a two volume, 1,900 page reprint collection of articles recently published by Elsevier/North Holland journals. Volume 1 begins with a comprehensive overview of the empirical evidence, followed by introductions to the econometrics of event studies and various techniques for dealing with corporate self selection issues. It then delves into classic issues such as the nature of aggregate merger activity (merger waves) market valuation effects of merger announcements (the stock price performance of bidder and target firms) and the nature of the sources of merger gains in the context of industrial rganization (much of it involving estimating the effects of mergers on industry competitors) The volume ends with a review of restructuring transactions other than takeovers, such as divestitures, spinoffs, leveraged buyouts and other highly leveraged transactions.Volume 2 presents a series of specific deal related topics and provides reviews of both theory and associated empirical evidence. It begins with surveys of principles for optimal bidding in specific auction settings, followed by a review of actual takeover premiums and their determinants. It then showcases recent empirical contributions on topics such as toehold bidding and winner's curse (does overbidding exist? bidding for distressed targets (do bankruptcy auctions cause fire sales? effects of deal protection devices (do termination agreements and poison pills affect takeover premiums? large shareholder voting on takeover outcomes (does institutional activism matter? deal financing issues (does it matter how the bidder finances any cash payment for the target) managerial compensation effects of takeovers (what's in it for the CEO) governance spillovers from cross border mergers (are there any? and, finally, the returns to merger arbitrage activity (market efficiency and limits to arbitrage)", "author_names": [ "B Espen Eckbo" ], "corpus_id": 168746708, "doc_id": "168746708", "n_citations": 9, "n_key_citations": 1, "score": 0, "title": "Corporate Takeovers: Modern Empirical Developments", "venue": "", "year": 2011 }, { "abstract": "The central role of the ribonucleic acids (RNA) in mediating the expression of information encoded in DNA in living cells is now well established. Research in this area of biology continues at a remarkable rate, and new and significant information appears almost daily in a wide range of journals, published symposia and specialist reviews. The diverse nature of this information makes it difficult for the newcomer to the field of RNA biochemistry to obtain a general view of established concepts, current activity, and new advances. Moreover, the reviews available are frequently concerned with insular aspects of these Ubiquitous molecules, or in the case of text books, the subject is treated as part of a general outline of proper ties of nucleic acids and thus may be superficial. The authors of the chapters in this collection attempt to provide a comprehensive, though not overly detailed, outline of the biologi cal roles of RNA. They have written for students with basic training in biochemistry, but otherwise with a wide variety of biological interests plant physiology, virology, organelle bio chemistry, genetics, cell biology, differentiation and development. Viral RNA, which was dealt with as a separate chapter in the first edition, has been deleted from this edition because it is an unman ageably large single topic, and at the same time is addressed in a number of ways in many different places in the book.\"", "author_names": [ "Peter R Stewart", "David S Letham" ], "corpus_id": 2405353, "doc_id": "2405353", "n_citations": 60, "n_key_citations": 1, "score": 0, "title": "The Ribonucleic Acids", "venue": "Springer New York", "year": 1977 } ]

[ { "abstract": "The features of high resolution and high bandwidth are in an increasing demand considering to the wide range application fields based on high performance data converters. In this paper, a modeling of high resolution hybrid analog to digital converter (ADC) is proposed to meet those requirements, and a 16 bit two step pipelined successive approximation register (SAR) analog to digital converter (ADC) with first order continuous time incremental sigma delta modulator (ISDM) assisted is presented to verify this modeling. The combination of high bandwidth two step pipelined SAR ADC with low noise ISDM and background comparator offset calibration can achieve higher signal to noise ratio (SNR) without sacrificing the speed and plenty of hardware. The usage of a sub ranging scheme consists of a coarse SAR ADC followed by an fine ISDM, can not only provide better suppression of the noise added in 2nd stage during conversion but also alleviate the demands of comparator's resolution in both stages for a given power budget, compared with a conventional Pipelined SAR ADC. At 1.2 V/1.8 V supply, 33.3 MS/s and 16 MHz input sinusoidal signal in the 40 nm complementary metal oxide semiconductor (CMOS) process, the post layout simulation results show that the proposed hybrid ADC achieves a signal to noise distortion ratio (SNDR) and a spurious free dynamic range (SFDR) of 86.3 dB and 102.5 dBc respectively with a total power consumption of 19.2 mW.", "author_names": [ "Bo Gao", "Xiantao Li", "Jie Sun", "Jianhui Wu" ], "corpus_id": 212775537, "doc_id": "212775537", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Modeling of High Resolution Data Converter: Two Step Pipelined SAR ADC based on ISDM", "venue": "", "year": 2020 }, { "abstract": "The analog frontend (AFE) coupling circuit is a crucial processing element for data acquisition systems based on analog to digital converters (ADCs) Currently, high speed and high resolution ADCs are predominantly designed with differential input stages. Conventional high speed ADC drivers are mainly AC coupled by employing transformers (Baluns) or fully differential amplifiers (FDAs) with blocking capacitors. However, the results of this study indicate that a certain degree of DC offset error exists and manifests itself as the baseline error in the presence of power dividers connecting several DC coupled channels that implement high dynamic range (HDR) signal conditioning. The study involves a theoretical analysis and explanation of the baseline offset error. The offset error can potentially lead to unexpected out of range issues for sampling devices, including high speed ADCs and switched capacitor array ASICs. High performance FDAs are adopted, and an offset free DC coupled AFE circuit is proposed to address the aforementioned issue using two stage amplification and a resistive attenuator. The proposed methodology is verified via circuit simulations and hardware design. Thus, the baseline offset problem can be accurately solved using the proposed circuit by minimizing the neglectable error. The proposed circuit facilitates improvements in the high precision measurement of HDR signals in many nuclear physics experiments and some applications in the DC coupling scheme with FDAs involving resistive power dividers.", "author_names": [ "Yafei Du", "Jun Wu", "Chen Yuan", "Chuanfei Zhang", "Yinong Liu" ], "corpus_id": 216299243, "doc_id": "216299243", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Offset free DC coupled analog frontend circuit for high dynamic range signals", "venue": "", "year": 2020 }, { "abstract": "An arbiter based simple phase decision circuit (PDC) optimized for high resolution phase to digital converter made up of an analog phase frequency detector and a time to digital converter for all digital phase locked loops is proposed. It can distinguish very small phase difference between two pulses even though it consumes lower power and has smaller input to output delay than the previously reported PDC. Proposed PDC is realized using 130 nm CMOS process and demonstrated by transistor level simulations. A 5 bit P2D having no offset nor deadzone using the PDC is also demonstrated. A harmonic lock free and small phase offset delay locked loop for fixing the P2D resolution regardless of PVT variations is also proposed and demonstrated.", "author_names": [ "Kwang-Chun Choi", "Min-Hyeong Kim", "Woo-Young Choi" ], "corpus_id": 62652804, "doc_id": "62652804", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "An Offset and Deadzone Free Constant Resolution Phase to Digital Converter for All Digital PLLs", "venue": "", "year": 2013 }, { "abstract": "Aim Here, we describe the web based tool EpHLA Converter, a free program designed to reduce the complexity of the problem to predict high resolution HLA typing. Methods Our program allows one to determine the most probable high resolution HLA class I and II genotypes using as data input just low or medium resolution HLA A, B, C, DRB1, DRW, DQA1 and DQB1 typing and the population it came from. Allelic conversion is based on public databases (NMDP, IMGT) queries and allele frequencies determined from either reference populations or private HLA typing databases. The program was developed to run independently or to be integrated to third part programs including the recently developed EpHLA program to analyze epitopic HLA serum reactivity. We validated the EpHLAConverter to HLA class II inference by using three different approaches: (i) We determined the percentage of matched results between the 100 predicted high resolution typing with the actual high resolution typing to HLA DRB1, (ii) the concordance to predict HLA DQA1 and HLA DQB1 assignments by using NMDP published DRB1/DQB1/DQA1 associations and (iii) by computing the time spent in the conversion from medium to high resolution HLA A, B and DRB1 typing for database with more than 10,000 typings each one. Results Percentage matched predicted High Resolution vs. Actual High resolution typing for HLA DRB1 and DQB1 was 94% and 83% respectively. Besides, we showed that our tool is able to safely convert HLA typing databases with 10,000 typings HLA A, B DRB1 in 191 minutes (more than five inferences per second) The limitation of the EpHLA Converter program is if the allele DRB1 is uncommon, the association HLA DRB1/DQA1/DQB1 will not be able to be inferred because the association is not listed on the available frequencies tables. Conclusions Our data demonstrates that EpHLA Converter has an excelent accuracy rate to predict DRB1 and DRB1/DQA1/DQB1 association at high resolution level.", "author_names": [ "Jose Renato Pereira de Moura Barroso", "Semiramis Jamil Hadad do Monte", "Adalberto Socorro da Silva", "Herton Luiz Alves Sales Filho", "Anaregina S Araujo", "Antonio Vanildo de Sousa Lima", "Deylane Menezes Teles e Oliveira", "Rubens de Sousa Santana", "Marayza Gomes Carvalho", "L C D da M Sousa" ], "corpus_id": 80827215, "doc_id": "80827215", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "13 P EpHLA CONVERTER: A TOOL FOR AUTOMATIC INFERENCE OF HIGH RESOLUTION HLA FOR SOLID ORGAN TRANSPLANTATION", "venue": "", "year": 2013 }, { "abstract": "The sampling rate plays a key role in wireless applications at very high frequency range. Flash analog to digital converter (ADC) betters the slow converter counterparts in this regard but bulky at inevitable high resolutions. A state of the art Divide and Collate (DnC) algorithm is proposed to design the flash ADC at subranging levels. The offset voltage is kept at a minimum through the comparators used for novel coarse and fine conversion separately. The kick back noise is also reduced by using sample and hold switches at the input. The 10 bit ADC architecture is designed with 45 nm CMOS technology and analyzed in the SPECTRE environment. A trivial variation in the transconductance with temperature is observed and consequently the offset drift with temperature is found to be 0.015 mV/*C. The design improves the INL by 0.42 LSB and DNL by 0.3 LSB. Signal tonoise and distortion (SNDR) ratio and spurious free dynamic range (SFDR) are 51.8 dB and 62 dB respectively at a frequency range near the Nyquist rate with a supply voltage of 1 V and input frequency of 500 MHz. Subranging scheme minimizes the comparator requirements which is reflected in the 44% reduction in the power dissipation.", "author_names": [ "Farhana Begum", "Sandeep Mishra", "Anup Dandapat" ], "corpus_id": 202548677, "doc_id": "202548677", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Low Power 10 Bit Flash Analog to Digital Converter with Divide and Collate Subranging Conversion Scheme", "venue": "", "year": 2019 }, { "abstract": "An offset free switched capacitor gain stage is described. By combining the gain stage with a binary weighted capacitor array, a D/A converter is obtained. A cascaded design of an offset free D/A converter with greatly reduced capacitor ratio is also described.", "author_names": [ "R Gregorian" ], "corpus_id": 111308322, "doc_id": "111308322", "n_citations": 33, "n_key_citations": 4, "score": 1, "title": "High resolution switched capacitor D/A converter", "venue": "", "year": 1981 }, { "abstract": "A low noise 8.95~11GHz all digital frequency synthesizer (ADPLL) with a metastability free first order noise shaping time to digital converter (TDC) and a high frequency resolution digitally controlled oscillator (DCO) is presented. An input stage for TDC is proposed to solve the problem of metastability and a specific technique is used to power down the high speed counter as soon as the ADPLL is about to lock for power saving consideration. The ADPLL is fabricated in 65nm CMOS technology and the core area is 0.385mm2. With about 8.5ms locking time, the measured phase noise performance at 1MHz offset is 106.4dBc/Hz from a carrier of 10GHz. The ADPLL core consumes 17.52mW from a supply of 1V.", "author_names": [ "Chen Jiang", "Junren Liu", "Yumei Huang", "Zhiliang Hong" ], "corpus_id": 32968151, "doc_id": "32968151", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "A low noise, 8.95 11GHz all digital frequency synthesizer with a metastability free time to digital converter and a sleepy counter in 65nm CMOS", "venue": "2012 Proceedings of the ESSCIRC (ESSCIRC)", "year": 2012 }, { "abstract": "This work proposes a calibration free 14b 70MS/s 0.13um CMOS ADC for high performance integrated systems such as WLAN and high definition video systems simultaneously requiring high resolution, low power, and small size at high speed. The proposed ADC employs signal insensitive 3 D fully symmetric layout techniques in two MDACs for high matching accuracy without any calibration. A three stage pipeline architecture minimizes power consumption and chip area at the target resolution and sampling rate. The input SHA with a controlled trans conductance ratio of two amplifier stages simultaneously achieves high gain and high phase margin with gate bootstrapped sampling switches for 14b input accuracy at the Nyquist frequency. A back end sub ranging flash ADC with open loop offset cancellation and interpolation achieves 6b accuracy at 70MS/s. Low noise current and voltage references are employed on chip with optional off chip reference voltages. The prototype ADC implemented in a 0.13um CMOS is based on a 0.35um minimum channel length for 2.5V applications. The measured DNL and INL are within 0.65LSB and l.80LSB, respectively. The prototype ADC shows maximum SNDR and SFDR of 66dB and 81dB and a power consumption of 235mW at 70MS/s. The active die area is", "author_names": [ "Kyoung-Jun Moon", "Kyung-Hoon Lee", "Seung-Hoon Lee" ], "corpus_id": 64390675, "doc_id": "64390675", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A Calibration Free 14b 70MS/s 0.13um CMOS Pipeline A/D Converter with High Matching 3 D Symmetric Capacitors", "venue": "", "year": 2006 }, { "abstract": "Analog to Digital converters (ADCs) used in instrumentation and measurements often require high absolute accuracy, including excellent linearity and negligible dc offset. Incremental converters provide a solution for such measurement applications, as they retain most of the advantages of conventional converters, and yet they are capable of offset free and accurate conversion. Most of the previous research on incremental converters was for single channel and dc signal applications, where they can perform extremely accurate data conversion with more than 20 bit resolution. In this paper, a design technique for implementing multiplexed incremental data converters to convert narrow bandwidth ac signals is discussed. A design methodology to optimize the signal to quantization+thermal noise ratio of multiplexed IDC is presented. It incorporates the operation principle, topology, and digital decimation filter design. The theoretical results are verified by simulation results.", "author_names": [ "Sung-Hwan Bae", "Changki Lee" ], "corpus_id": 113488342, "doc_id": "113488342", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Multi Channel AD Converters with High Resolution and Low Speed", "venue": "", "year": 2008 }, { "abstract": "Sample and hold amplifier less (SHA less) pipelined analog to digital converters (ADCs) are well suited for high resolution, high speed and low power applications. Apart from the comparator static offset, a dynamic offset is induced due to the timing skew and bandwidth mismatch between the multiplying digital to analog converter and the comparator input paths in the first stage, which brings a serious design challenge. This brief presents a novel background calibration technique for these offsets. First, the comparator's static offset and dynamic offset are discussed and analyzed. Then, a new evaluation technique is proposed to synchronously extract the values of the static offset and dynamic offset through the residue output at decision points. In this brief, the new calibration method is validated using behavioral models. The effective number of bits is improved from 5.04 bits to 11.96 bits, while the spurious free dynamic range is improved by 50.7 dB from our simulation. Thanks to the background calibration, comparator offset errors exceeding the built in redundancy of the architecture become acceptable. The proposed method relaxes comparator design requirements effectively. More importantly, the calibration can maximize the input frequency of the SHA less pipelined ADCs.", "author_names": [ "Congyi Zhu", "Jun Lin", "Zhongfeng Wang" ], "corpus_id": 67871454, "doc_id": "67871454", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Background Calibration of Comparator Offsets in SHA Less Pipelined ADCs", "venue": "IEEE Transactions on Circuits and Systems II: Express Briefs", "year": 2019 } ]

[ { "abstract": "The ultimate device miniaturization would be to use individual molecules as functional devices. Single wall carbon nanotubes (SWNTs) are promising candidates for achieving this: depending on their diameter and chirality, they are either one dimensional metals or semiconductors. Single electron transistors employing metallic nanotubes and field effect transistors employing semiconducting nanotubes have been demonstrated. Intramolecular devices have also been proposed which should display a range of other device functions. For example, by introducing a pentagon and a heptagon into the hexagonal carbon lattice, two tube segments with different atomic and electronic structures can be seamlessly fused together to create intramolecular metal metal, metal semiconductor, or semiconductor semiconductor junctions. Here we report electrical transport measurements on SWNTs with intramolecular junctions. We find that a metal semiconductor junction behaves like a rectifying diode with nonlinear transport characteristics that are strongly asymmetric with respect to bias polarity. In the case of a metal metal junction, the conductance appears to be strongly suppressed and it displays a power law dependence on temperatures and applied voltage, consistent with tunnelling between the ends of two Luttinger liquids. Our results emphasize the need to consider screening and electron interactions when designing and modelling molecular devices. Realization of carbon based molecular electronics will require future efforts in the controlled production of these intramolecular nanotube junctions.", "author_names": [ "Zhen Yao", "Henk W Ch Postma", "Leon Balents", "Cees Dekker" ], "corpus_id": 941712, "doc_id": "941712", "n_citations": 1320, "n_key_citations": 10, "score": 1, "title": "Carbon nanotube intramolecular junctions", "venue": "Nature", "year": 1999 }, { "abstract": "Leveraging the unique properties of single walled carbon nanotube (SWNT) intramolecular junctions (IMJs) in innovative nanodevices and next generation nanoelectronics requires controllable, repeatable, and large scale preparation, together with rapid identification and comprehensive characterization of such structures. Here we demonstrate SWNT IMJs through directly growing ultralong SWNTs on trenched substrates. It is found that the trench configurations introduce axial strain in partially suspended nanotubes, and promote bending deformation in the vicinity of the trench edges. As a result, the lattice and electronic structure of the nanotubes can be locally modified, to form IMJs in the deformation regions. The trench patterns also enable pre defining the formation locations of SWNT IMJs, facilitating the rapid identification. Elaborate Raman characterization has verified the formation of SWNT IMJs and identified their types. Rectifying behavior has been observed by electrical measurements on the as prepared semiconducting semiconducting (S S) junction.", "author_names": [ "Jianing An", "Zhaoyao Zhan", "Gengzhi Sun", "Hari Mohan", "Jinyuan Zhou", "Young-jin Kim", "Lianxi Zheng" ], "corpus_id": 17090907, "doc_id": "17090907", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Direct Preparation of Carbon Nanotube Intramolecular Junctions on Structured Substrates", "venue": "Scientific reports", "year": 2016 }, { "abstract": "In this letter, graded pillared graphene structures with carbon nanotube graphene intramolecular junctions are demonstrated to exhibit ultrahigh thermal rectification. The designed graded two stage pillared graphene structures are shown to have rectification values of 790.8 and 1173.0% at average temperatures 300 and 200 K, respectively. The ultrahigh thermal rectification is found to be a result of the obvious phonon spectra mismatch before and after reversing the applied thermal bias. This outcome is attributed to both the device shape asymmetry and the size asymmetric boundary thermal contacts. We also find that the significant and stable standing waves that exist in graded two stage pillared graphene structures play an important role in this kind of thermal rectifier, and are responsible for the ultrahigh thermal rectification of the two stage ones as well. Our work demonstrates that pillared graphene structure with SWCNT graphene intramolecular junctions is an excellent and promising phononic device.", "author_names": [ "Xueming Yang", "Dapeng Yu", "Bing-Yang Cao", "Albert C To" ], "corpus_id": 206434554, "doc_id": "206434554", "n_citations": 21, "n_key_citations": 0, "score": 0, "title": "Ultrahigh Thermal Rectification in Pillared Graphene Structure with Carbon Nanotube Graphene Intramolecular Junctions.", "venue": "ACS applied materials interfaces", "year": 2017 }, { "abstract": "Highly efficient carbon based 1D light emitting devices require multi quantum well heterostructures with sensitive optical properties. However, carbon nanotubes (CNTs) based composites become much worse than expected and most of their applications such as field emission are thwarted because dispersing CNTs among one another is difficult. We demonstrate that such sensitive optical and limited field emission properties can be attained and improved, respectively, through the use of ZnO nanocrystal selective quantum well heterostructures grown on carbon nanotubes to fabricate carbon zinc oxide (CZO) nanotubes. ZnO can be effectively and uniformly decorated on the carbon nanotubes intramolecular junctions with abundant functional groups and also with large surface adsorption area produced by CNTs surface plasma pre treatments at room temperature. The cathodoluminescence (CL) spectrum of the CZO nanotubes exhibits a weak UV emission peak and two distinct strong green emission peaks at 2.51 eV and at 2.4 eV, attributed to zinc rich ZnO band to donor transitions and oxygen rich ZnO band to acceptor transitions, respectively. Furthermore, the CZO nanotubes reach an extremely low turn on field of 0.1 V mm 1, low threshold field of 3.1 V mm 1, but high field enhancement factor b of 110 x 103. The field emission properties are dramatically enhanced by ZnO quantum dots decorated on the carbon nanotube intramolecular junctions, which not only provide extra electron emission paths and higher carrier concentrations, but also protect the emitter from ion bombardment during operation.", "author_names": [ "Chia-Te Hu", "Jyh Ming Wu", "Jien-Wei Yeh", "Han Chang Shih" ], "corpus_id": 98979383, "doc_id": "98979383", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "ZnO quantum dots decorated on optimized carbon nanotube intramolecular junctions exhibit superior field emission properties", "venue": "", "year": 2016 }, { "abstract": "The longitudinal vibration band gaps in periodic (n, 0) (2n, 0) single walled carbon nanotube(SWCNT) intramolecular junctions(IMJs) are investigated based on the finite element calculation. The frequency ranges of band gaps in frequency response functions(FRF) simulated by finite element method (FEM) show good agreement with those in band structure obtained by simple spring mass model. Moreover, a comprehensive parametric study is also conducted to highlight the influences of the geometrical parameters such as the size of unit cell, component ratios of the IMJs and diameters of the CNT segments as well as geometric imperfections on the first band gap. The results show that the frequency ranges and the bandwidth of the gap strongly depend on the geometrical parameters. Furthermore, the influences of geometrical parameters on gaps are nuanced in IMJs with different topological defects. The existence of vibration band gaps in periodic IMJs lends a new insight into the development of CNT based nano devices in.", "author_names": [ "Jiaqian Li", "Hai-jun Shen" ], "corpus_id": 96906115, "doc_id": "96906115", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Analysis of longitudinal vibration band gaps in periodic carbon nanotube intramolecular junctions using finite element method", "venue": "", "year": 2015 }, { "abstract": "The dispersion of longitudinal and transverse waves in (n,0) (2n,0) intramolecular junctions (IMJs) are investigated using an atomistic finite element method (FEM) The transient responses of IMJs with different connection types subjected to harmonic incident wave were modelled using three dimensional elastic beams of carbon bonds and point masses. The linkage between the force field constants of molecular mechanics and input parameters of beam and mass elements was established through the molecular structural mechanics approach. The wave dispersion simulated by FEM shows good agreement with that of the non local elastic model in a wide frequency range up to the terahertz region. It is shown that both the microstructure of conical part (connection part) and the coupling of longitudinal vibration and transverse vibration brought by the conicity play important roles in the dispersion of longitudinal and transverse wave in a single walled IMJ. The amplitude decay of longitudinal wave depended on the distance propagating; the wavelength and the structure in connection part are examined. The results show that the dispersion of the decay of the wave amplitude in IMJ with less pentagon heptagon defects has a better agreement with analytical results of macroscopic conical shell.", "author_names": [ "Jiaqian Li", "Hai-jun Shen" ], "corpus_id": 96575544, "doc_id": "96575544", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Wave propagation in carbon nanotube intramolecular junctions: finite element calculations", "venue": "", "year": 2015 }, { "abstract": "Abstract The mechanical properties of single walled carbon nanotubes with one dimensional intramolecular junctions (CNT IMJs) are investigated, using first principles density functional theory calculations. The effects of pentagon heptagon (5 7) defects (a pair of five and seven membered rings) at a junction on the Young's modulus, tensile strength, and breaking strain of CNT IMJs are discussed from the viewpoint of charge density and interatomic distance. Our calculations indicate that the deformation concentration on a seven membered ring causes the strength and elongation of CNT IMJs to decrease. It is found that the tensile strength and breaking strain of CNT IMJs depend on the position of 5 7 defects, while these properties of CNT IMJs are not significantly affected by the number of 5 7 defects. The applicability of the AIREBO classical interatomic potential in the simulation of the tensile deformation in CNT IMJs is also discussed.", "author_names": [ "Yusuke Kinoshita", "Motoyuki Murashima", "Masaki Kawachi", "Nobutada Ohno" ], "corpus_id": 136536920, "doc_id": "136536920", "n_citations": 18, "n_key_citations": 0, "score": 0, "title": "First principles study of mechanical properties of one dimensional carbon nanotube intramolecular junctions", "venue": "", "year": 2013 }, { "abstract": "We present results of a reverse non equilibrium molecular dynamics study of thermal transport in single walled carbon nanotube (SWCNT) graphene junctions comprised of carbon carbon (C C) bonds with either sp2 or mixed sp2/sp3 hybridization. In both cases, a finite interfacial thermal resistance is observed at the SWCNT graphene junctions for thermal transport in the out of plane direction. The interfacial thermal resistance at the junctions is attributed to the combined effects of scattering of the phonons at the SWCNT graphene junctions due to the presence of distorted sp2 bonds in the junction region and the change in dimensionality of the medium along the phonon transport path as the phonons propagate from SWCNT pillars (quasi 1D) to graphene sheet (2D) and then again to SWCNTs. Moreover, the thermal resistance is found to depend on the C C bond hybridization at the intramolecular junctions with mixed sp2/sp3 hybridization showing a higher interfacial resistance when compared to pure sp2 bonding. Therm.", "author_names": [ "Jungkyu Park", "Vikas Prakash" ], "corpus_id": 119476807, "doc_id": "119476807", "n_citations": 23, "n_key_citations": 1, "score": 0, "title": "Phonon scattering and thermal conductivity of pillared graphene structures with carbon nanotube graphene intramolecular junctions", "venue": "", "year": 2014 }, { "abstract": "Abstract Carbon nanotube based intramolecular junctions can function as rectifying diodes and switches in circuits and thus possesses the promising potential to be applied in nano scale electronic devices. Due to their slender and unsymmetrical geometry, intramolecular junctions are prone to buckling under compression and the resulting structural instability will eventually leads to structural or electrical failure. Thus, it is important to explore the mechanical behaviors of intramolecular junctions subject to compressive loads. In this study, molecular dynamical simulations are carried out to investigate the compressive behaviors of intramolecular junctions at finite temperature, while carbon nanotubes are also studied as reference. The simulation results indicate that the strain rate effect is negligible within relatively low loading rate range but the critical strain increases significantly under higher loading rate. At an extremely high strain rate, the intramolecular junctions will crush immediately. It is also predicted that local deformation will be introduced at high environmental temperature. Moreover, with increasing tube length, the instability mode of the intramolecular junctions transfers from shell buckling to column buckling and the critical aspect ratio is lower than that of carbon nanotubes due to presence of the Stone Wales defects.", "author_names": [ "Ming Li", "Zhan Kang", "Peiying Yang", "Xianhong Meng", "Yanjun Lu" ], "corpus_id": 136650602, "doc_id": "136650602", "n_citations": 22, "n_key_citations": 0, "score": 0, "title": "Molecular dynamics study on buckling of single wall carbon nanotube based intramolecular junctions and influence factors", "venue": "", "year": 2013 }, { "abstract": "Nitrogen doped carbon nanotubes (CN x /carbon nanotube intramolecular junctions were prepared by a simple continuous chemical vapour deposition (CVD) method at 650 degC. The catalyst was obtained by calcination of a layered double hydroxide precursor containing Fe and Mg. By switching between hexane and ethylenediamine repeatedly in the CVD process, multiple intramolecular junctions composed of CN x with a bamboo like structure and empty hollow carbon nanotubes were observed, and such different structures at both sides of the junctions indicated some interesting properties and offered potential applications for future nanodevices. Keywords: Nitrogen doped carbon nanotubes, junction, chemical vapour deposition", "author_names": [ "Yong Cao", "Bingtao Liu", "Qingze Jiao", "Yun-Peng Zhao" ], "corpus_id": 93325619, "doc_id": "93325619", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Preparation of CN x /Carbon Nanotube Intramolecular Junctions by Switching Gas Sources in Continuous Chemical Vapour Deposition", "venue": "", "year": 2011 } ]

[ { "abstract": "Abstract This review highlights the recent research advances in active nanostructured anode materials for the next generation of Li ion batteries (LIBs) In fact, in order to address both energy and power demands of secondary LIBs for future energy storage applications, it is required the development of innovative kinds of electrodes. Nanostructured materials based on carbon, metal/semiconductor, metal oxides and metal phosphides/nitrides/sulfides show a variety of admirable properties for LIBs applications such as high surface area, low diffusion distance, high electrical and ionic conductivity. Therefore, nanosized active materials are extremely promising for bridging the gap towards the realization of the next generation of LIBs with high reversible capacities, increased power capability, long cycling stability and free from safety concerns. In this review, anode materials are classified, depending on their electrochemical reaction with lithium, into three groups: intercalation/de intercalation, alloy/de alloy and conversion materials. Furthermore, the effect of nanoscale size and morphology on the electrochemical performance is presented. Synthesis of the nanostructures, lithium battery performance and electrode reaction mechanisms are also discussed. To conclude, the main aim of this review is to provide an organic outline of the wide range of recent research progresses and perspectives on nanosized active anode materials for future LIBs.", "author_names": [ "Subrahmanyam Goriparti", "Ermanno Miele", "Francesco de Angelis", "Enzo Di Fabrizio", "Remo Proietti Zaccaria", "Claudio Capiglia" ], "corpus_id": 98149878, "doc_id": "98149878", "n_citations": 1415, "n_key_citations": 10, "score": 2, "title": "Review on recent progress of nanostructured anode materials for Li ion batteries", "venue": "", "year": 2014 }, { "abstract": "In order to address power and energy demands of mobile electronics and electric cars, Li ion technology is urgently being optimized by using alternative materials. This article presents a review of our recent progress dedicated to the anode and cathode materials that have the potential to fulfil the crucial factors of cost, safety, lifetime, durability, power density, and energy density. Nanostructured inorganic compounds have been extensively investigated. Size effects revealed in the storage of lithium through micropores (hard carbon spheres) alloys (Si, SnSb) and conversion reactions (Cr(2)O(3) MnO) are studied. The formation of nano/micro core shell, dispersed composite, and surface pinning structures can improve their cycling performance. Surface coating on LiCoO(2) and LiMn(2)O(4) was found to be an effective way to enhance their thermal and chemical stability and the mechanisms are discussed. Theoretical simulations and experiments on LiFePO(4) reveal that alkali metal ions and nitrogen doping into the LiFePO(4) lattice are possible approaches to increase its electronic conductivity and does not block transport of lithium ion along the 1D channel.", "author_names": [ "Hong Li", "Zhaoxiang Wang", "Li-quan Chen", "Xuejie Huang" ], "corpus_id": 94907892, "doc_id": "94907892", "n_citations": 1397, "n_key_citations": 3, "score": 0, "title": "Research on Advanced Materials for Li ion Batteries", "venue": "", "year": 2009 }, { "abstract": "This review outlines the developments and recent progress in metal assisted chemical etching of silicon, summarizing a variety of fundamental and innovative processes and etching methods that form a wide range of nanoscale silicon structures. The use of silicon as an anode for Li ion batteries is also reviewed, where factors such as film thickness, doping, alloying, and their response to reversible lithiation processes are summarized and discussed with respect to battery cell performance. Recent advances in improving the performance of silicon based anodes in Li ion batteries are also discussed. The use of a variety of nanostructured silicon structures formed by many different methods as Li ion battery anodes is outlined, focusing in particular on the influence of mass loading, core shell structure, conductive additives, and other parameters. The influence of porosity, dopant type, and doping level on the electrochemical response and cell performance of the silicon anodes are detailed based on recent findings. Perspectives on the future of silicon and related materials, and their compositional and structural modifications for energy storage via several electrochemical mechanisms, are also provided.", "author_names": [ "William McSweeney", "Hugh Geaney", "Colm O'Dwyer" ], "corpus_id": 51792589, "doc_id": "51792589", "n_citations": 78, "n_key_citations": 2, "score": 0, "title": "Metal assisted chemical etching of silicon and the behavior of nanoscale silicon materials as Li ion battery anodes", "venue": "Nano Research", "year": 2015 }, { "abstract": "Carbon nanostructural materials have gained the spotlight as promising anode materials for energy storage; they exhibit unique physico chemical properties such as large surface area, short Li+ ion diffusion length, and high electrical conductivity, in addition to their long term stability. However, carbon nanostructured materials have issues with low areal and volumetric densities for the practical applications in electric vehicles, portable electronics, and power grid systems, which demand higher energy and power densities. One approach to overcoming these issues is to design and apply a three dimensional (3D) electrode accommodating a larger loading amount of active anode materials while facilitating Li+ ion diffusion. Furthermore, 3D nanocarbon frameworks can impart a conducting pathway and structural buffer to high capacity non carbon nanomaterials, which results in enhanced Li+ ion storage capacity. In this paper, we review our recent progress on the design and fabrication of 3D carbon nanostructures, their performance in Li ion batteries (LIBs) and their implementation into large scale, lightweight, and flexible LIBs.", "author_names": [ "Chiwon Kang", "Eunho Cha", "Mumukshu D Patel", "H Wu", "Wonbong Choi" ], "corpus_id": 5385656, "doc_id": "5385656", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Three Dimensional Carbon Nanostructures for Advanced Lithium Ion Batteries", "venue": "", "year": 2016 }, { "abstract": "Hollow nanostructured anode materials lie at the heart of research relating to Li ion batteries, which require high capacity, high rate capability, and high safety. The higher capacity and higher rate capability for hollow nanostructured anode materials than that for the bulk counterparts can be attributed to their higher surface area, shorter path length for Li+ transport, and more freedom for volume change, which can reduce the overpotential and allow better reaction kinetics at the electrode surface. In this article, we review recent research activities on hollow nanostructured anode materials for Li ion batteries, including carbon materials, metals, metal oxides, and their hybrid materials. The major goal of this review is to highlight some recent progresses in using these hollow nanomaterials as anode materials to develop Li ion batteries with high capacity, high rate capability, and excellent cycling stability.", "author_names": [ "Jun Liu", "Dongfeng Xue" ], "corpus_id": 235352, "doc_id": "235352", "n_citations": 170, "n_key_citations": 0, "score": 0, "title": "Hollow Nanostructured Anode Materials for Li Ion Batteries", "venue": "Nanoscale research letters", "year": 2010 }, { "abstract": "Si has been considered as one of the most attractive anode materials for Li ion batteries (LIBs) because of its high gravimetric and volumetric capacity. Importantly, it is also abundant, cheap, and environmentally benign. In this review, we summarized the recent progress in developments of Si anode materials. First, the electrochemical reaction and failure are outlined, and then, we summarized various methods for improving the battery performance, including those of nanostructuring, alloying, forming hierarchic structures, and using suitable binders. We hope that this review can be of benefit to more intensive investigation of Si based anode materials.", "author_names": [ "De-long Ma", "Zhanyi Cao", "Anming Hu" ], "corpus_id": 4145888, "doc_id": "4145888", "n_citations": 246, "n_key_citations": 1, "score": 0, "title": "Si Based Anode Materials for Li Ion Batteries: A Mini Review", "venue": "Nano micro letters", "year": 2014 }, { "abstract": "Abstract Mobile electronics have developed so rapidly that battery technology has hardly been able to keep pace. The increasing desire for lighter and thinner Li ion batteries with higher capacities is a continuing and constant goal for in research. Achieving higher energy densities, which is mainly dependent on cathode materials, has become a critical issue in the development of new Li ion batteries. In this review, we will outline the progress on nanostructured 4 V cathode materials of Li ion batteries for mobile electronics, covering LiCoO 2 LiNi x Co y Mn 1 x y O 2 LiMn 2 O 4 LiNi 0.5 Mn 1.5 O 4 and Li rich layered oxide materials. We aim to provide some scientific insights into the development of superior cathode materials by discussing the advantages of nanostructure, surface coating, and other key properties.", "author_names": [ "Xiaodong Xu", "Sanghan Lee", "Sookyung Jeong", "Youngsik Kim", "Jaephil Cho" ], "corpus_id": 59426590, "doc_id": "59426590", "n_citations": 55, "n_key_citations": 0, "score": 0, "title": "Recent progress on nanostructured 4 V cathode materials for Li ion batteries for mobile electronics", "venue": "", "year": 2013 }, { "abstract": "Transition metal oxides (TMOs) based on conversion reactions are attractive candidate anode materials for lithium ion batteries (LIBs) because of their high theoretical capacity and safety characteristics. In this review, we have summarized recent progress in the rational design and efficient synthesis of TMOs with controllable morphologies, compositions, and micro /nanostructures, along with their Li storage behaviors. Single metal oxides of manganese (Mn) iron (Fe) cobalt (Co) nickel (Ni) copper (Cu) ruthenium (Ru) chromium (Cr) molybdenum (Mo) and tungsten (W) and their common binary metal oxides have been discussed in this review. Finally, the less well known merits of conversion reactions are put forward, and the design of metal oxide electrodes making full use of these merits has been proposed.", "author_names": [ "Kangzhe Cao", "Ting Jin", "Li Yang", "Lifang Jiao" ], "corpus_id": 103382480, "doc_id": "103382480", "n_citations": 150, "n_key_citations": 1, "score": 0, "title": "Recent progress in conversion reaction metal oxide anodes for Li ion batteries", "venue": "", "year": 2017 }, { "abstract": "Computations have been widely used to explore new Li ion battery materials because of its remarkable advantages. In this review, we summarize the recent progress on computational investigation on anode materials in Li ion batteries. By introducing the computational studies on Li storage capability in carbon nanotubes, graphene, alloys and oxides, we reveal that computations have successfully addressed many fundamental problems and are powerful tools to understand and design new anode materials for Li ion batteries.", "author_names": [ "Dihua Wu", "Zhen Zhou" ], "corpus_id": 122066354, "doc_id": "122066354", "n_citations": 16, "n_key_citations": 0, "score": 0, "title": "Recent progress of computational investigation on anode materials in Li ion batteries", "venue": "", "year": 2011 }, { "abstract": "", "author_names": [ "Zheng Shiyou", "Dong Fei", "Pan Yuepeng", "Han Pan", "Yang Junhe" ], "corpus_id": 218937595, "doc_id": "218937595", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Research Progress on Nanostructured Metal Oxides as Anode Materials for Li ion Battery", "venue": "", "year": 2020 } ]

[ { "abstract": "Designing chaotic oscillators using complementary metal oxide semiconductor (CMOS) integrated circuit technology for generating multi scroll attractors has been a challenge. That way, we introduce a current mode piecewise linear (PWL) function based on CMOS cells that allow programmable generation of 2 7 scroll chaotic attractors. The mathematical model of the chaotic oscillator designed herein has four coefficients and a PWL function, which can be varied to provide a high value of the maximum Lyapunov exponent. The coefficients are implemented electronically by designing operational transconductance amplifiers that allow programmability of their transconductances. Design simulations of the chaotic oscillator are provided for the 0.35 m m CMOS technology. Post layout and process voltage temperature (PVT) variation simulations demonstrate robustness of the multi scroll chaotic attractors. Finally, we highlight the synchronization of two seven scroll attractors in a master slave topology by generalized Hamiltonian forms and observer approach. Simulation results show that the synchronized CMOS chaotic oscillators are robust to PVT variations and are suitable for chaotic secure communication applications.", "author_names": [ "Victor Hugo Carbajal-Gomez", "Esteban Tlelo-Cuautle", "Carlos Sanchez-Lopez", "Francisco Vidal Fernandez-Fernandez" ], "corpus_id": 59941865, "doc_id": "59941865", "n_citations": 13, "n_key_citations": 1, "score": 2, "title": "PVT Robust CMOS Programmable Chaotic Oscillator: Synchronization of Two 7 Scroll Attractors", "venue": "", "year": 2018 }, { "abstract": "The authors report the simulation and actual implementation of chaotic oscillator synchronization for a pair of three state variable Lorenz systems. The first oscillator performs as a driver (transmitter) while the second system is made to respond the received waveform. Specifically, one of the state variables of the driver circuit is judiciously selected to generate an RF waveform. This waveform is transmitted through a noisy channel and is used to drive the response system until both the systems of all three state variables achieve complete replacement synchronization. It is known that this synchronization is sensitive to changes in received power. To overcome this, a technique hereon called generalized projective synchronization is employed to accept an attenuated version of the transmitted waveform. A sensitivity analysis reveals that generalized projective synchronization is robust with respect to deviations in the control parameter values of the response system due to tolerances of electronic components. The potential of the generalized projective synchronization is illustrated for a bistatic radar system case, where synchronization is necessary to obtain the range Doppler information of a moving target. In this instance, the cross correlation, short time cross correlogram and cross ambiguity surface of the transmitted and synchronized waveforms are of high quality as indicated by their entropy measures.", "author_names": [ "Chandra S Pappu", "Benjamin C Flores", "Patrick S Debroux", "James E Boehm" ], "corpus_id": 22273973, "doc_id": "22273973", "n_citations": 8, "n_key_citations": 0, "score": 2, "title": "An Electronic Implementation of Lorenz Chaotic Oscillator Synchronization for Bistatic Radar Applications", "venue": "IEEE Transactions on Aerospace and Electronic Systems", "year": 2017 }, { "abstract": "In this paper, the simplest chaotic oscillator with fractional order memristor component (SCOF) is proposed. Dynamical characteristics of the proposed chaotic oscillator are investigated both analytically and numerically. The results indicate that the proposed chaotic oscillator possesses novel dynamical characteristics: double scroll chaotic attractor, four scroll chaotic attractor and coexisting attractors. The proposed SCOF system is implemented in field programmable gate arrays (FPGA) using the Adomian decomposition method to verify the numerical simulation results. Finally, control and synchronization of the simple chaotic oscillator with fractional order memristor component is studied using the linear feedback control and the unidirectional linear error feedback coupling scheme, respectively.", "author_names": [ "Karthikeyan Rajagopal", "Sifeu Takougang Kingni", "Abdul Jalil M Khalaf", "Yasser Shekofteh", "Fahimeh Nazarimehr" ], "corpus_id": 209963271, "doc_id": "209963271", "n_citations": 11, "n_key_citations": 0, "score": 1, "title": "Coexistence of attractors in a simple chaotic oscillator with fractional order memristor component: analysis, FPGA implementation, chaos control and synchronization", "venue": "The European Physical Journal Special Topics", "year": 2019 }, { "abstract": "We study synchronization of systems in which agents holding chaotic oscillators move in a two dimensional plane and interact with nearby ones forming a time dependent network. Due to the uncertainty in observing other agents' states, we assume that the interaction contains a certain amount of noise that turns out to be relevant for chaotic dynamics. We find that a synchronization transition takes place by changing a control parameter. But this transition depends on the relative dynamic scale of motion and interaction. When the topology change is slow, we observe an intermittent switching between laminar and burst states close to the transition due to small noise. This novel type of synchronization transition and intermittency can happen even when complete synchronization is linearly stable in the absence of noise. We show that the linear stability of the synchronized state is not a sufficient condition for its stability due to strong fluctuations of the transverse Lyapunov exponent associated with a slow network topology change. Since this effect can be observed within the linearized dynamics, we can expect such an effect in the temporal networks with noisy chaotic oscillators, irrespective of the details of the oscillator dynamics. When the topology change is fast, a linearized approximation describes well the dynamics towards synchrony. These results imply that the fluctuations of the finite time transverse Lyapunov exponent should also be taken into account to estimate synchronization of the mobile contact networks.", "author_names": [ "Naoya Fujiwara", "Jurgen Kurths", "Albert Diaz-Guilera" ], "corpus_id": 3648640, "doc_id": "3648640", "n_citations": 17, "n_key_citations": 0, "score": 1, "title": "Synchronization of mobile chaotic oscillator networks.", "venue": "Chaos", "year": 2016 }, { "abstract": "Memcapacitor and meminductor are two new nonlinear memory circuit components defined on the basis of memristor. In the absence of physical devices of memcapacitor and meminductor, applying their equivalent circuit models into actual circuits to explore the characteristics of memcapacitor and meminductor based nonlinear circuits is meaningful. In this paper, a nonlinear oscillating circuit is designed based on the given nonvolatile memcapacitor and meminductor models, whose memory characteristics are analyzed using POP method in detail, and a series of dynamic characteristics of the novel chaotic circuit are analyzed, including Poincare section, equilibrium point, system stability, bifurcation diagrams, Lyapunov exponent spectrums and dynamic map of the system. By analyzing the influence of parameters on system dynamics, the evolutionary law of the system is obtained, which helps to better use of this chaotic oscillator in possible application areas like communication encryption and synchronization approach dependent on the initial setting. In particular, coexisting attractors are found under different initial values, by drawing the attractive basin, four different types of attractors in the system are discovered, and from the attractive basin, the evolutionary process of the system under different initial values is obtained. Finally, the validity of the system is verified by DSP experiment, and the experimental results are consistent with the theoretical analysis.", "author_names": [ "Xiaoyuan Wang", "Jun Yu", "Chenxi Jin", "Herbert Ho-Ching Iu", "Simin Yu" ], "corpus_id": 128242901, "doc_id": "128242901", "n_citations": 19, "n_key_citations": 0, "score": 2, "title": "Chaotic oscillator based on memcapacitor and meminductor", "venue": "", "year": 2019 }, { "abstract": "In this paper, a novel kind of compound synchronization among four chaotic systems is investigated, where the drive systems have been conceptually divided into two categories: scaling drive systems and base drive systems. Firstly, a sufficient condition is obtained to ensure compound synchronization among four memristor chaotic oscillator systems based on the adaptive technique. Secondly, a secure communication scheme via adaptive compound synchronization of four memristor chaotic oscillator systems is presented. The corresponding theoretical proofs and numerical simulations are given to demonstrate the validity and feasibility of the proposed control technique. The unpredictability of scaling drive systems can additionally enhance the security of communication. The transmitted signals can be split into several parts loaded in the drive systems to improve the reliability of communication.", "author_names": [ "Junwei Sun", "Yi Shen", "Quan Yin", "Chengjie Xu" ], "corpus_id": 41149670, "doc_id": "41149670", "n_citations": 190, "n_key_citations": 1, "score": 1, "title": "Compound synchronization of four memristor chaotic oscillator systems and secure communication.", "venue": "Chaos", "year": 2013 }, { "abstract": "Abstract A novel chaotic memfractor oscillator with one unstable equilibriums is proposed. Various dynamic properties of the proposed system are derived and investigated to show the existence of chaotic oscillations. The fractional order time delayed model of the chaotic memfractor oscillator is derived considering time delay in the memcapacitor. Bifurcation of the time delayed system with its delay factor is investigated along with the parameter space bifurcation. A novel methodology for synchronizing identical time delayed systems with an uncertainty in the slave system is proposed and tested with the proposed time delayed fractional order chaotic memfractor oscillator.", "author_names": [ "Karthikeyan Rajagopal", "Anitha Karthikeyan", "Ashokkumar Srinivasan" ], "corpus_id": 125864322, "doc_id": "125864322", "n_citations": 25, "n_key_citations": 0, "score": 1, "title": "Bifurcation and chaos in time delayed fractional order chaotic memfractor oscillator and its sliding mode synchronization with uncertainties", "venue": "", "year": 2017 }, { "abstract": "The drive system can synchronize with the response system by the scaling factor in the traditional projective synchronization. This paper proposes a novel adaptive hybrid dislocated synchronization with uncertain parameters scheme for chaos synchronization using the Lyapunov stability theory. The drive system is synchronized by the sum of hybrid dislocated state variables for the response system. By designing effective hybrid dislocated adaptive controller and hybrid dislocated adaptive law of the parameters estimation, we investigate the synchronization of two identical memristor chaotic oscillator systems and two different memristor chaotic oscillator systems with uncertain parameters. Finally, the numerical simulation examples are provided to show the effectiveness of our method.", "author_names": [ "Jie Chen", "Junwei Sun", "M X Chi", "Xin-Ming Cheng" ], "corpus_id": 121593694, "doc_id": "121593694", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "A Novel Scheme Adaptive Hybrid Dislocated Synchronization for Two Identical and Different Memristor Chaotic Oscillator Systems with Uncertain Parameters", "venue": "", "year": 2014 }, { "abstract": "Abstract In this paper, we present the synchronization of a chaotic system using a discrete time recurrent high order neural network. This is done by using a Genesio Tesi oscillator circuit in discrete time embedded into an Arduino microcontroller that provides the state space variables. A discrete time recurrent neural network is designed to synchronize the dynamics of the chaotic oscillator. This neural network is trained using a time varying training algorithm where it is used the Extended Kalman Filter. Two state space variables are captured in real time in ADC inputs of a compact development system, where these signals are synchronized by the recurrent high order neural network in discrete time. The proposed work allows synchronization of interactions associated between the neural convergence and the chaotical plant state. The obtained real time results, and the statistical analyses on the synchronization process validate the possible application in chaos based communications systems.", "author_names": [ "Carlos Eduardo Castaneda", "Didier Lopez-Mancilla", "Roger Chiu", "Edgar Villafana-Rauda", "Onofre Orozco-Lopez", "Francisco J Casillas-Rodriguez", "Ricardo Sevilla-Escoboza" ], "corpus_id": 128092206, "doc_id": "128092206", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Discrete time neural synchronization between an Arduino microcontroller and a Compact Development System using multiscroll chaotic signals", "venue": "Chaos, Solitons Fractals", "year": 2019 }, { "abstract": "Abstract In this work, we further investigate the dynamics of the Genesio Tesi chaotic system which consists of a relatively simple jerk circuit with a quadratic nonlinearity. We complete and enrich the results obtained by Aceng et al. (2016) For this reason, we focus our interest in multistability generation and chaos synchronization as well. By using simulation software tools like PASCAL compiler, Orcad PSPICE and MATLAB, these properties have been characterized via common nonlinear tools including phase portraits, temporal responses, frequency responses, bifurcation diagrams and maximum lyapunov exponent plots. The analysis shows that the Genesio Tesi system under consideration is able to exhibit complex and interesting behaviors including period doubling bifurcation, chaos, periodic windows and coexistence of multiple attractors. This latter phenomenon has not been found in previous studies of the Genesio Tesi oscillator thus merits to be shared. We have also shown that Genesio Tesi systems in their chaotic states can be synchronized and used for a possible masking of information, thus illustrating its importance in engineering. Numerical findings have been validated through experimental studies.", "author_names": [ "Leopold Parfait Nguemkoua Nguenjou", "Guillaume Honore Kom", "Justin Roger Mboupda Pone", "Jacques Kengne", "Alain Tiedeu" ], "corpus_id": 125544474, "doc_id": "125544474", "n_citations": 12, "n_key_citations": 0, "score": 1, "title": "A window of multistability in Genesio Tesi chaotic system, synchronization and application for securing information", "venue": "AEU International Journal of Electronics and Communications", "year": 2019 } ]

[ { "abstract": "In industries, for adjustable speed operation various types of drives are used. These drives are categorized in to AC drives and DC drives. DC drives were popular due to its overall performance, efficiency, static and dynamic characters. However it is suffers from major drawback of higher initial cost and maintenance cost. The advancements in semiconductor devices have made significant contribution in AC drives and also made AC drives equally competitive to DC drives. The AC drives are fed from either Voltage Source Inverter (VSI) or Current Source Inverter (CSI) VSI fed drives has proven to be more efficient, with higher reliability and faster dynamic response, compared CSI fed drives and capable of running motors without de rating. Hence fed drives VSI saves money with higher efficiencies, minimizing install time, eliminating interconnect power cabling costs, and reducing building floor space. The VSI drive PWM inverter along with rectifier and capacitor filter circuit from the basic structure of any AC drives.", "author_names": [], "corpus_id": 209421523, "doc_id": "209421523", "n_citations": 2, "n_key_citations": 0, "score": 1, "title": "VOLTAGE SOURCE INVERTER FED INDUCTION MOTOR DRIVES", "venue": "", "year": 2014 }, { "abstract": "This paper presents a predictive current control method and its application to a voltage source inverter. The method uses a discrete time model of the system to predict the future value of the load current for all possible voltage vectors generated by the inverter. The voltage vector which minimizes a quality function is selected. The quality function used in this work evaluates the current error at the next sampling time. The performance of the proposed predictive control method is compared with hysteresis and pulsewidth modulation control. The results show that the predictive method controls very effectively the load current and performs very well compared with the classical solutions", "author_names": [ "Jose R Rodriguez", "Jorge Pontt", "Cesar A Silva", "Pablo Correa", "Pablo Lezana", "Patricio Cortes", "Ulrich Ammann" ], "corpus_id": 35514796, "doc_id": "35514796", "n_citations": 1319, "n_key_citations": 69, "score": 0, "title": "Predictive Current Control of a Voltage Source Inverter", "venue": "IEEE Transactions on Industrial Electronics", "year": 2004 }, { "abstract": "The new direct self control (DSC) is a simple method of signal processing that gives converter fed three phase machines an excellent dynamic performance. To control the torque of, say, an induction motor, it is sufficient to process the measured signals of the stator currents and the total flux linkages only. In the basic version of DSC, the power semiconductors of a three phase voltage source inverter are directly switched on and off via three Schmitt triggers, comparing the time integrals of line to line voltages to a reference value of desired flux, if the torque has not yet reached an upper limit value of a two limit torque control. Optimal performance of drive systems is accomplished in steady state as well as under transient conditions by combination of several two limit controls.", "author_names": [ "Manfred Depenbrock" ], "corpus_id": 110665508, "doc_id": "110665508", "n_citations": 1751, "n_key_citations": 75, "score": 0, "title": "Direct self control (DSC) of inverter fed induction machine", "venue": "", "year": 1988 }, { "abstract": "A six phase six step voltage fed induction motor is presented. The inverter is a transistorized six step voltage source inverter, while the motor is a modified standard three phase squirrel cage motor. The stator is rewound with two three phase winding sets displaced from each other by 30 electrical degrees. A model for the system is developed to simulate the drive and predict its performance. The simulation results for steady state conditions and experimental measurements show very good correlation. It is shown that this winding configuration results in the elimination of all air gap flux time harmonics of the order (6v 1, v 1,3,5, Consequently, all rotor copper losses produced by these harmonics as well as all torque harmonics of the order (6v, v 1,3,5, are eliminated. A comparison between the measured instantaneous torque of both three phase and six phase six step voltage fed induction machines shows the advantage of the six phase system over the three phase system in eliminating the sixth harmonic dominant torque ripple.", "author_names": [ "Mohamed A Abbas", "Roland W Christen", "Thomas M Jahns" ], "corpus_id": 18919079, "doc_id": "18919079", "n_citations": 232, "n_key_citations": 7, "score": 0, "title": "Six Phase Voltage Source Inverter Driven Induction Motor", "venue": "IEEE Transactions on Industry Applications", "year": 1984 }, { "abstract": "In this paper modelling and simulation of control strategy for Z source inverter is presented. The performance of single phase induction motor is studied with the control of single phase Z source inverter using Simple boost controller. This controller senses the motor speed feedback signal and consequently provides the pulse width modulated (PWM) signal that sets the gate voltage of the inverter, which in turn provides the required voltage for the desired speed. The proposed drive system is simulated using MATLAB/Simulink. The simulation results were compared with the experimental results.", "author_names": [ "Selva santhose Kumar" ], "corpus_id": 212492002, "doc_id": "212492002", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Z Source Inverter Fed Induction Motor", "venue": "", "year": 2013 }, { "abstract": "", "author_names": [ "D S Reddy", "M V Lakshmi Prakash", "V Subrahmanyam" ], "corpus_id": 114219544, "doc_id": "114219544", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Analysis of voltage source inverter fed induction motor", "venue": "", "year": 1987 }, { "abstract": "This paper describes the experimental results of a test to drive two induction motors through a VVVF inverter by 25kW class proton membrane type fuel cells (PEMFCs) The experiments are aimed at verifying the compatibility between the drive system for the railway vehicle traction and FCs. This paper describes test results of powering, powering off procedure, and simulated slip readhesion control test, respectively. Through the experiments, we obtained useful knowledge required in designing the fuel cell drive system.", "author_names": [ "Takemasa Furuya", "Keiichiro Kondo", "Takamitsu Yamamoto" ], "corpus_id": 109516478, "doc_id": "109516478", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Experimental Study on a Voltage Source Inverter fed Induction Motor Traction System Connected to Fuel Cell", "venue": "", "year": 2006 }, { "abstract": "Induction motor efficiency can be significantly improved (specially under light loads) by reducing the motor air gap flux. Flux can be indirectly controlled by adjusting both stator voltage and frequency. This paper describes the development and implementation of a controller for a voltage source inverter fed induction motor with online efficiency optimization. The system was tested for a small power induction motor and results are presented.<ETX>", "author_names": [ "Carlos Couto", "J Santana Martins" ], "corpus_id": 108413508, "doc_id": "108413508", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Control of a voltage source inverter fed induction motor with on line efficiency optimization", "venue": "Proceedings of 1994 IEEE International Conference on Industrial Technology ICIT '94", "year": 1994 }, { "abstract": "This paper develops an real time inverter fault diagnosis method for induction motor drives based on the subtractive clustering analysis of the stator current vector and a quick mean current vector calculation method. A subtractive clustering algorithm for analyzing the mean current vectors under both normal and faulty inverter condition is conducted off line to verify the effectiveness of the mean current vectors for the inverter fault diagnosis. The amplitude and angle of the different mean current vector cluster are used to determine the fault modes. Furthermore, a single data shifting method is introduced to build up an array for the mean current vector calculation in the on line fault diagnosis process. The simulation results verify that, based on the proposed method, the inverter faults can be detected within 1/4 period of fundamental frequency or even shorter time in both speed opened loop and closed loop induction motor drive system.", "author_names": [ "Yufan Guan", "Dan Sun", "Yikang He" ], "corpus_id": 22857867, "doc_id": "22857867", "n_citations": 33, "n_key_citations": 0, "score": 0, "title": "Mean Current Vector Based Online Real Time Fault Diagnosis for Voltage Source Inverter fed Induction Motor Drives", "venue": "2007 IEEE International Electric Machines Drives Conference", "year": 2007 }, { "abstract": "An electrical stability analysis of a voltage source inverter fed induction motor drive system is presented assuming an infinite inertia load. With a quasisquare wave scheme this system is characterised as a linear time varying system and its stability is investigated using Liapunov's first method for stability, and also by a Routh Hurwitz technique. The stability of each of the six individual modes is also investigated by evaluating the eigenvalues of the corresponding A matrices. The stability boundaries for the complete drive system are presented for various input filter parameter values.", "author_names": [ "Musse Mohamud Ahmed", "J A Taufiq", "Christopher J Goodman", "M Lockwood" ], "corpus_id": 110075422, "doc_id": "110075422", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "Electrical instability in a voltage source inverter fed induction motor drive at constant speed", "venue": "", "year": 1986 } ]

[ { "abstract": "Spectral line broadening in semiconductor lasers is studied experimentally through the gain saturation characteristics of 1.5 mm InGaAsP traveling wave laser amplifiers. Wide signal gain spectrum under the injection of an intense saturating signal is measured using a weak probe signal. The saturated signal gain spectrum is found to coincide exactly with the unsaturated spectrum under a less biased condition, thus verifying that the semiconductor laser gain saturates homogeneously over the entire gain spectrum. Cross saturation characteristics between the two signal channels having identical input powers are also investigated and found to be in good agreement with theoretical calculations based on the homogeneous gain model. The degree of gain saturation is confirmed to be uniquely determined by the total output power from both channels.", "author_names": [ "Takaaki Mukai", "Kyo Inoue", "Tadashi Saitoh" ], "corpus_id": 121842210, "doc_id": "121842210", "n_citations": 33, "n_key_citations": 3, "score": 0, "title": "Homogeneous gain saturation in 1.5 mm InGaAsP traveling wave semiconductor laser amplifiers", "venue": "", "year": 1987 }, { "abstract": "We have proposed a novel approximate analytical expression for saturation intensity for tapered traveling wave semiconductor laser amplifier structures. The application of this analytical expression of saturation intensity has been demonstrated by considering the effect of gain saturation on polarization sensitivity of two tapered amplifier structures, linear and exponential tapered amplifier structures. It is found that polarization sensitivity of the tapered amplifier structure is several decibels higher than that of passive tapered waveguides in unsaturated condition. Polarization sensitivity of the two tapered amplifier structures has also been investigated in a highly saturated condition. The combined effects of mode conversion and gain saturation on fundamental TE gain have also been investigated using the proposed analytical expression for saturation intensity.", "author_names": [ "Hooshang Ghafouri-Shiraz", "P W Tan", "W M Wong" ], "corpus_id": 25837373, "doc_id": "25837373", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "A novel analytical expression of saturation intensity of InGaAsP tapered traveling wave semiconductor laser amplifier structures", "venue": "IEEE Photonics Technology Letters", "year": 1998 }, { "abstract": "This paper presents a theoretical and experimental study in terms of small signal gain, signal gain saturation, and noise characteristics of a 1.5 mm GaInAsP traveling wave amplifier (TWA) realized through the application of SiO x film antireflection coatings. This TWA, having a residual facet reflectivity of 0.04 percent, exhibits a wide, flat signal gain spectrum and a saturation output power of +7 dBm at a 20 dB signal gain. The TWA also has a noise figure of 5.2 dB, which is the smallest value reported for semiconductor laser amplifiers. The experimental results are confirmed to be in good agreement with the theoretical predictions based on the multimode traveling wave rate equations in conjunction with the photon statistic master equation analysis, which takes into account the amplifier material and device structural parameters. Signal gain undulation, saturation output power, and noise figure are also theoretically evaluated as functions of the facet reflectivity. The superior performance of the TWA demonstrates that the device is favorable for use in linear optical repeaters in fiber transmission systems.", "author_names": [ "Tadashi Saitoh", "Takaaki Mukai" ], "corpus_id": 123504195, "doc_id": "123504195", "n_citations": 139, "n_key_citations": 4, "score": 1, "title": "1.5 um GaInAsP traveling wave semiconductor laser amplifier", "venue": "", "year": 1987 }, { "abstract": "The optical nonlinearity in a semiconductor laser gain medium is investigated through copropagating nearly degenerate four wave mixing (NDFWM) in a 1.5 mu m InGaAsP traveling wave laser amplifier (TWA) The FWM signal output powers vary symmetrically with the sign of probe detuning with respect to the pump frequency, while the pump and probe output powers vary asymmetrically. The NDFWM conversion efficiency from the probe input to the FWM signal output is a maximum of 8.3 dB around zero detuning and has positive gain in the range of +or 6 GHz. This demonstrates highly efficient nonlinear interaction due to both large optical gain and large third order susceptibility. The NDFWM efficiency is also investigated in connection with the TWA gain saturation characteristics and is found to be a maximum for operation around the saturation intensity of the TWA.", "author_names": [ "Takaaki Mukai", "Tadashi Saitoh" ], "corpus_id": 122679952, "doc_id": "122679952", "n_citations": 82, "n_key_citations": 2, "score": 0, "title": "Detuning characteristics and conversion efficiency of nearly degenerate four wave mixing in a 1.5 mu m traveling wave semiconductor laser amplifier", "venue": "", "year": 1990 }, { "abstract": "We developed a Time Domain Traveling Wave model to properly study the dynamics of a hybrid lasers realized by coupling a III V Reflective Semiconductor Optical Amplifier with a Silicon Photonics mirror providing a narrow effective reflectivity <10GHz) In free running operation mode, we show that for realistic values of the Henry factor stable single mode emission only occurs around the maximum of the reflectivity slope. Very interestingly for applications, in presence of optical feedback, we access a regime of ultra stability with respect to unwanted reflections or to self oscillations triggered by a photon photon resonance phenomenon.", "author_names": [ "Lorenzo Luigi Columbo", "J T Bovington", "Dominic Francis Siriani", "Sebastian Romero-Garcia", "Mariangela Gioannini" ], "corpus_id": 216242003, "doc_id": "216242003", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Time domain traveling wave model of optical feedback tolerant hybrid laser design for silicon photonics applications (Conference Presentation)", "venue": "", "year": 2020 }, { "abstract": "Nearly degenerate four wave mixing (NDFWM) in a traveling wave semiconductor laser amplifier is demonstrated by simultaneously injecting two lights of slightly different frequencies in the same direction. A new frequency light at an expected frequency for NDFWM is observed with the same order of output as that of the injected light. The output power ratio of the three beams is strongly dependent on the sign of the frequency detuning. Theoretical analysis, in which the carrier rate equation is coupled with nonlinear Maxwell's equations, explains the experimental results well. The observed behaviors are attributed to a unique third order nonlinearity stemming from saturation induced refractive index change in the semiconductor gain medium.", "author_names": [ "Kyo Inoue", "Takaaki Mukai", "Tadashi Saitoh" ], "corpus_id": 121608146, "doc_id": "121608146", "n_citations": 87, "n_key_citations": 1, "score": 0, "title": "Nearly degenerate four wave mixing in a traveling wave semiconductor laser amplifier", "venue": "", "year": 1987 }, { "abstract": "Near traveling wave semiconductor laser amplifiers for amplification and detection of optical signals are discussed. Measurements of gain, responsivity, and bandwidth are presented and compared with theory. The system performance of the laser amplifier detector is evaluated by a digital transmission experiment. The importance of using low reflectivity amplifiers with high responsivity and weakly wavelength dependent devices is revealed by computer simulations. The various noise contributions of the laser amplifier detector are analyzed. Expected sensitivity values are given, and it is shown that there exists an optimum amplifier gain with respect to sensitivity.", "author_names": [ "Mats Gustavsson", "Anders Karlsson", "Lars Thylen" ], "corpus_id": 111180092, "doc_id": "111180092", "n_citations": 64, "n_key_citations": 2, "score": 0, "title": "Traveling wave semiconductor laser amplifier detectors", "venue": "", "year": 1990 }, { "abstract": "Optical pulses with durations ranging from 0.49 to 21 ps are amplified by a traveling wave semiconductor laser amplifier. The pulse energy gain is determined by pulse energy only. The dependence of pulse energy gain on output pulse energy does not change in the pulse duration range. The saturation characteristics are successfully explained by a four level system model.<ETX>", "author_names": [ "Tadashi Saitoh", "Haruyasu Itoh", "Yoshio Noguchi", "Shoichi Sudo", "Takaaki Mukai" ], "corpus_id": 10215977, "doc_id": "10215977", "n_citations": 18, "n_key_citations": 0, "score": 0, "title": "Pulse energy gain saturation in subpico and picosecond pulse amplification by a traveling wave semiconductor laser amplifier", "venue": "IEEE Photonics Technology Letters", "year": 1989 }, { "abstract": "All optical frequency conversion over the entire gain spectrum of a traveling wave semiconductor laser amplifier is analyzed by numerical solution of a nonlinear wave equation system. The wavelength dependence of the gain coefficient g, the linewidth enhancement factor alpha the differential gain dg/dN, and the gain saturation effect are contained in the model. The method yields a high conversion efficiency and a converted signal output power up to 10 dBm is obtainable. It is shown that the input signal power can vary by three orders of magnitude with nearly no degradation of the conversion efficiency. By means of the input powers, the conversion efficiency can be maximized. The dependence of the conversion efficiency is analyzed for fixed input powers. Simultaneous conversion of an optical data signal to several wavelengths is analyzed. The requirements for the output filter are outlined.", "author_names": [ "Nikolaus Schunk" ], "corpus_id": 121836951, "doc_id": "121836951", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "All optical frequency conversion in a traveling wave semiconductor laser amplifier", "venue": "", "year": 1991 }, { "abstract": "An equivalent lumped element electric circuit model for traveling wave semiconductor laser amplifier has been developed using the rate equation for carriers. SPICE simulation of the circuits gives results in close agreement with the experimental data and values from sophisticated analyses. The modulation bandwidth and transient response were examined by including parasitic elements in the intrinsic model. (c) 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1558 1561, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22483", "author_names": [ "Abhirup Das Barman", "Ipsita Sengupta", "P K Basu" ], "corpus_id": 111145146, "doc_id": "111145146", "n_citations": 11, "n_key_citations": 1, "score": 0, "title": "A simple spice model for traveling wave semiconductor laser amplifier", "venue": "", "year": 2007 } ]

[ { "abstract": "As the semiconductor industry advances to ever smaller technology nodes, the power distribution network (PDN) is becoming an essential design factor to ensure system performance and reliability. The time domain simulations typically utilize the chip power model (CPM) generated by Ansys RedHawk, as the current load. The typical CPM only includes current consumption in a few clock cycles, which includes the high frequencies components (several hundreds of MHz) but losing mid to low frequencies. This paper describes a modulated CPM (MCPM) design and signoff process for PDN. The first step is frequency domain analysis of PDN to identify the die package resonance frequency. Then the chip gate level simulation is performed over an extended period of time to generate the VPD (Value Change Dump plus) file, with realistic low to mid frequency current components. This information is then used to modulate the CPM as the current load for the system level time domain noise simulations. This PI analysis flow was validated using a set of three test cases, with reasonable simulation measurement correlation achieved. This analysis flow enables more effective power/ground plane layout optimization and capacitor optimization in a timely manner.", "author_names": [ "Di Hu", "Yongxue Yu", "Antonio Ferrario", "Olivier Bayet", "Lin Shen", "Ravi Nimmagadda", "F Bonardi", "Francis Matus" ], "corpus_id": 182741, "doc_id": "182741", "n_citations": 4, "n_key_citations": 0, "score": 1, "title": "System power noise analysis using modulated CPM", "venue": "2015 IEEE Symposium on Electromagnetic Compatibility and Signal Integrity", "year": 2015 }, { "abstract": "Abstract The proposed system of a 450 nm blue GaN (Gallium Nitride) laser diode directly modulated by pre leveled 16 Quadrature Amplitude Modulation(QAM) Orthogonal Frequency Divisional Multiplexing (OFDM)data is implemented to achieve high transmission capacity upto 10.02 Gbits/sec. The simulation analysis will be done under sea water and tap water to enable underwater wireless optical communication(UOWC) over a distance of upto 12 m. The UWOC tap water provide an allowable bit rate decrease from 16.57 to 14.67 Gbps with the transmission distance significantly increased from 2 m to 6 m, exhibit bit/distance decay ratio of 0.236 Gbps/m. By performing Underwater Optical Wireless Communication (UOWC) in sea water, the impurities in sea water scattered the light causing attenuation of the blue laser power. This reduces the transmission capacity with a slightly higher decay ratio 0.410 Gbps/m. There are other noise sources in the sea produced by creatures or by natural and man made activities. All these noise are also taken into consideration so that the ambient noise are eliminated with the help of digital signal processing.", "author_names": [ "Kalimuthu Krishnan", "Sabitha Gauni", "C T Manimegalai", "V Malsawmdawngliana" ], "corpus_id": 126806726, "doc_id": "126806726", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Ambient noise analysis in underwater wireless communication using laser diode", "venue": "Optics Laser Technology", "year": 2019 }, { "abstract": "The compact intensity modulated frequency modulated continuous wave (FMCW) laser range sensor has a low signal tonoise ratio(SNR) because the transmitting power is limited by heat dissipation conditions, and the detection performance is reduced in degraded visual environments. To increase the transmitting power and keep the heat low, the SNR enhancement technique using synchronized dual laser sources is proposed. This paper established a mathematical model of the echo signal of the dual laser sources, made a comparative analysis of the single and dual channel laser beat signal. Aimed at the problem of unsynchronization of the two modulated signals caused by the drive circuit, a phase synchronization algorithm based on sampling feedback was proposed and verified by simulation. Finally, a synchronized dual channel laser ranging system was built in the laboratory for experiments. Compared with a single channel laser, the synchronized dual channel laser transmitting power is doubled, and the echo signal SNR can be increased by 2.2dB. The experimental results indicate that the proposed SNR enhancement technique can effectively solve the problem of low SNR in compact intensity modulated FMCW laser range sensor.", "author_names": [ "Zhi Yong Tao", "Zhonghua Huang", "Zhongming Xiu" ], "corpus_id": 235716577, "doc_id": "235716577", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Signal to noise ratio enhancement in compact intensity modulated FMCW laser range sensor using synchronized dual laser sources", "venue": "International Conference on Digital Image Processing", "year": 2021 }, { "abstract": "In the proposed system, a 450nm blue laser diode is directly modulated by 16 Quadrature Amplitude Modulation (QAM) data which are orthogonal. The simulation is done by assuming underwater with ambient noise present in the underwater covering a distance of 20 meters. Due to the presence of noise and attenuation of the wireless medium, the optical power is decreased to a great extent. The photodetector converts the weak optical signal to electrical signal. The phase and amplitude of the signal is change caused by noise present in it. A Butterworth filter is implemented to obtain the original signal at the receiver side. It is shown that the output binary data has change due phase due to the corruption of the noise.", "author_names": [ "", "K Kalimuthu", "Sabitha Gauni" ], "corpus_id": 55806159, "doc_id": "55806159", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Underwater optical wireless communication analysis using blue laser diode", "venue": "", "year": 2018 }, { "abstract": "In recent times there has been a wide interest in micro grids. One area of concern in micro grids is the generation of harmonics by active devices such as converters and FACTS devices used for reactive power compensation. The currently available literature focuses on the number of operations and fundamental cycles for estimating harmonics. This usually results in a trade off between accuracy of estimation and the choice of digital filter parameters. In this work a novel orthogonal frequency division multiplexing (OFDM) principle modified as per the power system scenario has been proposed. Odd harmonics up to 31st order are measured by demodulation as if the power signal is OFDM modulated. All these harmonics are measured using only one cycle of voltage signal. Instantaneous detection of harmonics is made possible using the Discrete Wavelet Transform (DWT) instead of the fast Fourier transforms used in conventional OFDM. DWT is also used for noise elimination before the harmonics are analyzed and the performance of proposed method is analyzed using PSNR under different noise conditions.", "author_names": [ "Srihari Mandava", "Ramesh Varadarajan" ], "corpus_id": 67078005, "doc_id": "67078005", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Analysis of Power System Harmonics Using PSNR Metric", "venue": "", "year": 2018 }, { "abstract": "The system carries out the Measurement of reactor kinetic parameters and absolute power of zero Power Reactor in the delayed critical state,using reactor noise analysis technology.Two g compensation ionization chambers are placed symmetrically close to the core.After being detected in the chambers,the reactor neutron noise signal shall be modulated and collected by measurement system.Then the noise signal shall be analysed by the software based on Labview to get cross power spectral densities.The kinetic parameters are obtained from Nonlinear least squares fitting of cross power spectral densities.Absolute power of zero power reactor shall be obtained by algorithm.After field measurement,kinetic parameters and absolute power are identical with reactor operation parameters.", "author_names": [ "Liu Cai-xue" ], "corpus_id": 113823184, "doc_id": "113823184", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "The Design of Absolute Power Measurement System of Zero Power Reactor Based on Reactor Noise Analysis Technology", "venue": "", "year": 2009 }, { "abstract": "Heart rhythm is modulated by the autonomic nervous system in order to adapt to changing cardiovascular loads. The resulting heart rate variability (HRV) is considered as one of the most promising non invasive markers of the activity of the autonomic nervous system. In this work, the possibility to analyze HRV with wavelet transform was investigated. Specifically, three methods of wavelet transform (CWT, CWTFT and DWT) were compared. DWT showed to be the best one because of the simplicity of decomposition, and quality of reconstruction, high time resolution as well as the shortest computation time and lowest CPU power consumption. DWT showed to have high noise robustness, excellent temporal and good frequency resolution and small influence of the mother wavelet type. ULF, HF and LF components of HRV were assessed using DWT transform. LF/HF ratio was extracted from HRV signal during voluntary breathing apneas and compared to the respiration signal. An increase in LF/HF ratio corresponding to the times of breathing apnea could be observed, indicating that the proposed method could reveal specific changes in the HRV and that LF/HF ratio could serve as a good indicator of breathing apnea.", "author_names": [ "Una Pale", "Florian Thurk", "Eugenijus Kaniusas" ], "corpus_id": 16210143, "doc_id": "16210143", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Heart rate variability analysis using different wavelet transformations", "venue": "2016 39th International Convention on Information and Communication Technology, Electronics and Microelectronics (MIPRO)", "year": 2016 }, { "abstract": "A new approach to estimate the direction of arrival (DOA) in a Time Modulated Array (TMA) system with a bipolar squared periodic time modulating sequence is proposed in this letter. Using such a sequence can increase the power of harmonic components of the received signal. Based on this fact, we formulated a new parameter pertaining to the ratio of the upper and lower sideband first harmonic components of the received signal, to improve the accuracy of the DOA estimation in a low signal to noise ratio (SNR) environment. A numerical analysis was performed to verify the effectiveness of the proposed DOA estimation method.", "author_names": [ "Young-Woo Youn", "Jeongphill Kim", "Sangyeol Oh" ], "corpus_id": 236405167, "doc_id": "236405167", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Time Modulated Array System Controlled With Bipolar Squared Periodic Sequence for Direction of Arrival Estimation", "venue": "IEEE Wireless Communications Letters", "year": 2021 }, { "abstract": "Critical to real time oscillations monitoring is early detection when otherwise dormant natural modes become a serious threat to grid stability. The next urgent issue is to determine the frequency and damping of the problematic modes when the signal is embedded in noise and the system contains closely spaced natural modes. The present paper addresses the detection issue using the Teager Kaiser energy operator (TKEO) which has shown to be a fast predictor of the instability onset time when applied to the output signals of an orthogonal filter bank. In the system stability context, linear filter decomposition (LFD) is preferred rather than empirical mode decomposition (EMD) well known for its tendency to generate artificial modes with no physical meaning. A narrowband LFD with a less than 0.2 Hz bandwidth is achieved in the range 0.05 to 3 Hz through a cosine modulated filter bank design. The effectiveness of the scheme in accurately detecting and tracking the frequency and damping of oscillatory modes is demonstrated using Monte Carlo simulations of three closely spaced modes and a detailed analysis of an actual event recorded by Hydro Quebec's WAMS in 2006.", "author_names": [ "I Kamwa", "Ashok Kumar Pradhan", "Geza Joos" ], "corpus_id": 34589921, "doc_id": "34589921", "n_citations": 81, "n_key_citations": 5, "score": 0, "title": "Robust Detection and Analysis of Power System Oscillations Using the Teager Kaiser Energy Operator", "venue": "IEEE Transactions on Power Systems", "year": 2011 }, { "abstract": "In this paper, MIMO is paired up with OFDM improve the performance of wireless transmission systems. Multiple antennas are employed both at the transmitting as well as receiving ends. The performance of an OFDM system is measured, considering multipath delay spread, channel noise, Rayleigh fading channel and distortion. In this paper, bits are generated and then mapped with modulation schemes such as QPSK, 8PSK, and QAM. Then, the mapped data is divided into blocks of 120 modulated data where a training sequence of the data is inserted both at the beginning and ending parts of the block. The equalization is used to determine the variation to the rest of data. The singular value decomposition (SVD) and water filling algorithm have been employed to measure the performance of the MIMO OFDM integrated systems. Therefore, the capacity is increased by transmitting different streams of data through different antennas at a same carrier frequency. Any inter symbol interference (ISI) produced after the transmission is recovered by using spatial sampling integrated with the signal processing algorithm. Furthermore, the performance remains the same with different combinations of transmitting and receiving antennas.", "author_names": [ "K Pavan Kumar Reddy", "K Ramanjaneyulu", "DR K Veeraswamy", "Dr Ch Srinivasa Rao" ], "corpus_id": 212531367, "doc_id": "212531367", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "POWER ALLOCATION ANALYSIS OF MIMO OFDM SYSTEM USING SVD AND WATER FILLING ALGORITHM", "venue": "", "year": 2013 } ]

[ { "abstract": "Conductive polymers combine the attractive properties associated with conventional polymers and unique electronic properties of metals or semiconductors. Recently, nanostructured conductive polymers have aroused considerable research interest owing to their unique properties over their bulk counterparts, such as large surface areas and shortened pathways for charge/mass transport, which make them promising candidates for broad applications in energy conversion and storage, sensors, actuators, and biomedical devices. Numerous synthetic strategies have been developed to obtain various conductive polymer nanostructures, and high performance devices based on these nanostructured conductive polymers have been realized. This Tutorial review describes the synthesis and characteristics of different conductive polymer nanostructures; presents the representative applications of nanostructured conductive polymers as active electrode materials for electrochemical capacitors and lithium ion batteries and new perspectives of functional materials for next generation high energy batteries, meanwhile discusses the general design rules, advantages, and limitations of nanostructured conductive polymers in the energy storage field; and provides new insights into future directions.", "author_names": [ "Ye Shi", "Lele Peng", "Yu Ding", "Yu Zhao", "Guihua Yu" ], "corpus_id": 1124013, "doc_id": "1124013", "n_citations": 434, "n_key_citations": 1, "score": 1, "title": "Nanostructured conductive polymers for advanced energy storage.", "venue": "Chemical Society reviews", "year": 2015 }, { "abstract": "", "author_names": [ "Ye Shi", "Lele Peng", "Yu Ding", "Yu Zhao", "Guihua Yu" ], "corpus_id": 197220833, "doc_id": "197220833", "n_citations": 30, "n_key_citations": 0, "score": 0, "title": "Nanostructured Conductive Polymers for Advanced Energy Storage", "venue": "", "year": 2015 }, { "abstract": "This review examines high performingenergy storage devices for high power applications including heavy electric vehicles, energy efficient cargo ships and locomotives, aerospace andstationary grid system.Such devices require systematic design and fabrication of composite nanostructured carbon based material and conductive polymers. Electrochemical capacitors based on nanostructured carbon can complement or replace batteries in electrical energy storage and harvesting applications whenever high power delivery or uptake is needed. Composite device of pseudo capacitive polymericmaterials and nanostructured carbon with the latest generation of nanostructured lithium electrodes has brought the energy density of electrochemical capacitors closer to that of batteries without compromising its specific power density, high capacitance and lifetime cycling stability.Energy storage devices' widespread applications in industrial, hybrid electric vehicles and commodity electronics could be facilitated through careful selection of electrolyte electrode system. Good understanding of charging mechanism is key to improving device's performance. Charging mechanism includes sequential ion desolations in pores smaller than the solvated ions through ion exchange or ion adsorption. This leads to higher capacitance for such storage devices. This has opened the door to designing advanced high energy density devices with fast charging and discharging times using a variety of electrolytes and nanostructured carbon polymer composite.", "author_names": [ "Shehu Isah" ], "corpus_id": 86867770, "doc_id": "86867770", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Advanced materials for energy storage devices", "venue": "", "year": 2018 }, { "abstract": "This review examines high performing energy storage devices for high power applications including heavy electric vehicles, energy efficient cargo ships and locomotives, aerospace and stationary grid system. Such devices require systematic design and fabrication of composite nanostructured carbon based material and conductive polymers. Electrochemical capacitors based on nanostructured carbon can complement or replace batteries in electrical energy storage and harvesting applications, when high power delivery or uptake is needed. Composite device of pseudo capacitive polymeric materials and nanostructured carbon with the latest generation of nanostructured lithium electrodes has brought the energy density of electrochemical capacitors closer to that of batteries without compromising its specific power density, high capacitance and lifetime cycling stability. Energy storage devices' widespread applications in industrial, hybrid electric vehicles and commodity electronics could be facilitated through careful selection of electrolyte electrode system. Good understanding of charging mechanism is key to improving device's performance. Charging mechanism includes sequential ion desolations in pores smaller than the solvated ions through ion exchange or ion adsorption. This leads to higher capacitance for such storage devices. This has opened the door to designing advanced high energy density devices with fast charging and discharging times using a variety of electrolytes and nanostructured carbon polymer composite.", "author_names": [ "Shehu Isah" ], "corpus_id": 116055587, "doc_id": "116055587", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Advanced Materials for Energy Storage Devices (Review)", "venue": "", "year": 2018 }, { "abstract": "This review highlights the synthesis, structure modification, morphology, and properties of nano manganese dioxide (MnO2) Though MnO2 has been widely employed for electrode materials due to its superior electrochemica1 performance, abundant storage, low cost, and environmental friendly nature, the usage in bioapplications and dye mineralisation studies have started since few decades only. Currently, nano MnO2 plays an important role in solar cell devices and gas sensing as it can be easily tunable into desired polymerphic structure and morphology. Herein, the use of nano MnO2 as advanced material in energy, gas sensing, biological application and wastewater remediation are described. Based on the recent research, the available preparation procedures, surface modification and applications of nanostructured MnO2 are systematically presented. Also, structure stabilization and performance improvement of nano MnO2 by doping or composite formation with metals, carbon materials, and conductive polymers are summerised. According to the latest research progress, new trends and strategies of nano MnO2 towards specific applications besides energy storage application are focused in this review, as well as a brief overview of the challenges and future perspectives of MnO2, synthetic methodologies, and their state of the art applications in different fields are presented.", "author_names": [ "Ayonbala Baral", "Lakkoji Satish", "Guoying Zhang", "Shaohua Ju", "Malay Kumar Ghosh" ], "corpus_id": 227132097, "doc_id": "227132097", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "A Review of Recent Progress on Nano MnO2: Synthesis, Surface Modification and Applications", "venue": "Journal of Inorganic and Organometallic Polymers and Materials", "year": 2020 }, { "abstract": "Over the past decades, flexible and wearable energy storage devices have received tremendous interest due to the development of smart electronic products, such as Apple Watch, Google Glass, and sport wristbands. Fiber shaped electrochemical energy storage devices (FEESDs) derived from fibrous electrodes are standing out as a result of the excellent flexibility and breathability compared with the planar counterparts. Textiles and fabrics can be simply achieved by spinning and weaving FEESDs, which perfectly match with an arbitrary uneven and mobile surface, revealing enormous potentialities in wearable electronics. Combining mechanical features with the electrically conductive properties and biocompatibility, conductive polymers (CPs) have emerged as a promising candidate for smart textile products including medical textiles, protective clothing, touch screen displays, and flexible fabric power supplies. In this context, this review summarizes the material design of CPs for fibrous electrodes and provides a critical discussion on their applications in flexible energy storage devices. Meanwhile, basic principles are briefly presented, including the conduction mechanism of conductive polymers, fibrous electrode design, and the evaluation of the electrochemical/mechanical performance for fibrous devices. Last, possibilities and challenges for the development of CP derived FEESDs are outlined as well.", "author_names": [ "Xiaoqing Li", "Xiaojuan Chen", "Zhaoyu Jin", "Panpan Li", "Dan Xiao" ], "corpus_id": 228960366, "doc_id": "228960366", "n_citations": 8, "n_key_citations": 1, "score": 0, "title": "Recent progress in conductive polymers for advanced fiber shaped electrochemical energy storage devices", "venue": "", "year": 2021 }, { "abstract": "Polyaniline (PANI) is considered one of the most preferred electrically conductive polymers (CPs) which is widely studied as an electrode material in designing next generation energy storage devices due to their chemical stability, fast redox reactions between the polymer and the electrolytes, high electrical conductivity, excellent electrochemical performance, and low cost. However, the inferior stability of PANI limits its application. In this work, the benefit of carbon dots (CDots) as light weight and spherical carbon based electrodes and fillers that allow the maintenance of the nanostructure of PANI while easing the ionic transport was studied together with the effect of manganese(ii) (Mn2+ doping on the overall capacitive properties of PANI. The integration of N doped spherical, nanosized carbon dots (N CDots) in the copolymerization of nanostructured PANI in the presence of varying concentrations of Mn2+ as a dopant synergistically improved the overall conductivity and specific surface area of the PANI based electrode and showed surface double layer ion exchange. Pseudocapacitance mechanisms were observed when the dopant concentration was kept at a molar percentage of Mn2+ to aniline of 1, which displayed exceptionally high specific capacitances of up to 595 F g 1. The asymmetric supercapacitor devices made with N CDot and nanostructured hybrid electrodes could reveal the great potential in the development of cheap yet efficient battery sized supercapacitor devices. In addition to extensive electrochemical performance, advanced EPR spectroscopy revealed detailed information regarding the defect structures of electrode materials in terms of understanding the conduction behavior of defect centers.", "author_names": [ "Melis Ozge Alas", "Ahmet Gungor", "Rukan Genc", "Emre Erdem" ], "corpus_id": 174815550, "doc_id": "174815550", "n_citations": 39, "n_key_citations": 0, "score": 0, "title": "Feeling the power: robust supercapacitors from nanostructured conductive polymers fostered with Mn2+ and carbon dots.", "venue": "Nanoscale", "year": 2019 }, { "abstract": "Nanostructured conductive polymers have been widely researched for various applications such as energy storage and conversion, chemical/biological sensors, and biomedical devices. Recently, novel synthetic methods which adopt doping molecules as cross linker have been developed to prepare conductive polymer gels (CPGs) with cross linked network and 3D hierarchically porous nanostructures. The CPGs, as well as their derived carbon frameworks, exhibit high electrical conductivity, large surface area, structural tunability, and hierarchical porosity for rapid mass/charge transport, which contribute to their high performance when applied for energy storage and conversion devices. This Perspective highlights the key features of CPGs and their derived carbon frameworks, discusses their possibilities in terms of rational synthesis and energy related applications, and proposes future directions for their technological development.", "author_names": [ "Ye Shi", "Guihua Yu" ], "corpus_id": 101127672, "doc_id": "101127672", "n_citations": 164, "n_key_citations": 0, "score": 0, "title": "Designing Hierarchically Nanostructured Conductive Polymer Gels for Electrochemical Energy Storage and Conversion", "venue": "", "year": 2016 }, { "abstract": "Three dimensional (3D) nanostructured conducting polymer hydrogels represent a group of high performance electrochemical energy storage materials. Here, we demonstrate a molecular self assembly approach toward controlled synthesis of nanostructured polypyrrole (PPy) conducting hydrogels, which was \"cross linked\" by a conjugated dopant molecule trypan blue (TB) to form a 3D network with controlled morphology. The protonated TB by ion bonding aligns the free sulfonic acid groups into a certain spatial structure. The sulfonic acid group and the PPy chain are arranged by a self sorting mechanism to form a PPy nanofiber structure by electrostatic interaction and hydrogen bonding. It is found that PPy hydrogels doped with varying dopant concentrations and changing dopant molecules exhibited controllable morphology and tunable electrochemical properties. In addition, the conjugated TB dopants promoted interchain charge transport, resulting in higher electrical conductivity (3.3 S/cm) and pseudocapacitance for the TB doped PPy, compared with PPy synthesized without TB. When used as supercapacitor electrodes, the TB doped PPy hydrogel reaches maximal specific capacitance of 649 F/g at the current density 1 A/g. The result shows that PPy nanostructured hydrogels can be tuned for potential applications in next generation energy storage materials.", "author_names": [ "Chunying Yang", "Pengfei Zhang", "Amit Nautiyal", "Shihua Li", "Na Liu", "Jialin Yin", "Kuilin Deng", "Xinyu Zhang" ], "corpus_id": 58638237, "doc_id": "58638237", "n_citations": 31, "n_key_citations": 0, "score": 0, "title": "Tunable Three Dimensional Nanostructured Conductive Polymer Hydrogels for Energy Storage Applications.", "venue": "ACS applied materials interfaces", "year": 2019 }, { "abstract": "Conductive polymers are attractive organic materials for future high throughput energy storage applications due to their controllable resistance over a wide range, cost effectiveness, high conductivity >103 S cm 1) light weight, flexibility, and excellent electrochemical properties. In particular, conductive polymers can be directly incorporated into energy storage active materials, which are essential for building advanced energy storage systems (ESSs) (i.e. supercapacitors and rechargeable batteries) This review summarizes the synthesis of conductive polymers with different chemical structures in various ways and also addresses their widespread applications for a broader range of ESSs. Moreover, we introduce recent progress in ESS development, including new electroactive polymers, new approaches (i.e. flexible, stretchable, binder free, hybrid, etc. and new functions (e.g. color changeable electrochromic materials for displays)", "author_names": [ "Jeonghun Kim", "Jaewoo Lee", "Jungmok You", "Min-Sik Park", "Shahriar Al Hossain", "Yusuke Yamauchi", "Jung Ho Kim" ], "corpus_id": 138032825, "doc_id": "138032825", "n_citations": 160, "n_key_citations": 0, "score": 0, "title": "Conductive polymers for next generation energy storage systems: recent progress and new functions", "venue": "", "year": 2016 } ]