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[ { "abstract": "Soliton microcombs offer the prospect of advanced optical metrology and timing systems in compact form factors. In these applications, the pumping of microcombs directly from a semiconductor laser without amplification or triggering components is desirable to reduce system power and to simplify system design. At the same time, low repetition rate microcombs are required in many comb applications as an interface to detectors and electronics, but their increased mode volume makes them challenging to pump at low power. Here 10 GHz repetition rate soliton microcombs are directly pumped by low power <20 mW) diode lasers. High Q silica microresonators are used for this low power operation and are packaged into fiber connectorized modules that feature temperature control for improved long term frequency stability.", "author_names": [ "Myoung-Gyun Suh", "Christine Y Wang", "Cort N Johnson", "Kerry J Vahala" ], "corpus_id": 89620775, "doc_id": "89620775", "n_citations": 10, "n_key_citations": 0, "score": 1, "title": "Directly pumped 10 GHz microcomb modules from low power diode lasers.", "venue": "Optics letters", "year": 2019 }, { "abstract": "Microcombs provide a path to broad bandwidth integrated frequency combs with low power consumption, which are compatible with wafer scale fabrication. Yet, electrically driven, photonic chip based microcombs are inhibited by the required high threshold power and the frequency agility of the laser for soliton initiation. Here we demonstrate an electrically driven soliton microcomb by coupling a III V material based (indium phosphide) multiple longitudinal mode laser diode chip to a high Q silicon nitride microresonator fabricated using the photonic Damascene process. The laser diode is self injection locked to the microresonator, which is accompanied by the narrowing of the laser linewidth, and the simultaneous formation of dissipative Kerr solitons. By tuning the laser diode current, we observe transitions from modulation instability, breather solitons, to single soliton states. The system operating at an electronically detectable sub 100 GHz mode spacing requires less than 1 Watt of electrical power, can fit in a volume of ca. 1 cm3, and does not require on chip filters and heaters, thus simplifying the integrated microcomb.Chip based frequency combs promise many applications, but full integration requires the electrical pump source and the microresonator to be on the same chip. Here, the authors show such integration of a microcomb with 100 GHz mode spacing without additional filtering cavities or on chip heaters.", "author_names": [ "Arslan S Raja", "Andrey S Voloshin", "Hairun Guo", "Sofya E Agafonova", "Junqiu Liu", "Alexander S Gorodnitskiy", "Maxim Karpov", "Nikolay G Pavlov", "Erwan Lucas", "Ramzil R Galiev", "Artem E Shitikov", "John D Jost", "Michael L Gorodetsky", "Tobias J Kippenberg" ], "corpus_id": 53451200, "doc_id": "53451200", "n_citations": 112, "n_key_citations": 4, "score": 0, "title": "Electrically pumped photonic integrated soliton microcomb", "venue": "Nature Communications", "year": 2019 }, { "abstract": "In conclusion, we have built and characterized a SCOWA based system that produces low noise, 10 GHz pulse trains with output power up to 0.39 W, with an external amplification stage, using only electrically pumped diodes. The timing jitter is ~6 fs. Given that the shot noise can potentially be reduced if the total output power is considered, the timing jitter integrated to the Nyquist frequency can be as low as ~7 8 with the current mode locked laser.", "author_names": [ "Josue Davila-Rodriguez", "C Williams", "Peter J Delfyett", "Jason Plant", "Paul W Juodawlkis" ], "corpus_id": 29141269, "doc_id": "29141269", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "All diode generation and amplification of 10 GHz pulse trains from coupled cavity mode locked lasers using Slab Coupled Waveguide Amplifiers", "venue": "IEEE Avionics, Fiber Optics and Photonics Digest CD", "year": 2012 }, { "abstract": "We demonstrate the first self referenced full stabilization of a diode pumped solid state laser (DPSSL) frequency comb with a GHz repetition rate. The Yb:CALGO DPSSL delivers an average output power of up to 2.1 W with a typical pulse duration of 96 fs and a center wavelength of 1055 nm. A carrier envelope offset (CEO) beat with a signal to noise ratio of 40 dB (in 10 kHz resolution bandwidth) is detected after supercontinuum generation and f to 2f interferometry directly from the output of the oscillator, without any external amplification or pulse compression. The repetition rate is stabilized to a reference synthesizer with a residual integrated timing jitter of 249 fs [10 Hz 1 MHz] and a relative frequency stability of 10 12/s. The CEO frequency is phase locked to an external reference via pump current feedback using home built modulation electronics. It achieves a loop bandwidth of ~150 kHz, which results in a tight CEO lock with a residual integrated phase noise of 680 mrad [1 Hz 1 MHz] We present a detailed characterization of the GHz frequency comb that combines a noise analysis of the repetition rate frep, of the CEO frequency fCEO, and of an optical comb line at 1030 nm obtained from a virtual beat with a narrow linewidth laser at 1557 nm using a transfer oscillator. An optical comb linewidth of about 800 kHz is assessed at 1 s observation time, for which the dominant noise sources of frep and fCEO are identified.", "author_names": [ "Sargis Hakobyan", "Valentin Johannes Wittwer", "Pierre Brochard", "Kutan Gurel", "Stephane Schilt", "Aline S Mayer", "Ursula Keller", "Thomas Sudmeyer" ], "corpus_id": 46815121, "doc_id": "46815121", "n_citations": 32, "n_key_citations": 0, "score": 0, "title": "Full stabilization and characterization of an optical frequency comb from a diode pumped solid state laser with GHz repetition rate.", "venue": "Optics express", "year": 2017 }, { "abstract": "Pulses as short as 8.1 fs were generated from a blue laser diode pumped Kerr lens mode locked Ti:sapphire oscillator, with an average power of 27 mW and a repetition rate of 120.6 MHz. The full width at half maximum exceeds 146 nm, benefitting from the dispersion management by a combination of a low dispersion fused silica prism pair and a series of double chirped mirrors. To the best of our knowledge, this is the first time to generate sub 10 fs pulses from a laser diode directly pumped Ti:sapphire oscillator.", "author_names": [ "Han Liu", "Geyang Wang", "Jianwang Jiang", "Wenlong Tian", "Dacheng Zhang", "Hainian Han", "Shaobo Fang", "Jiangfeng Zhu", "Zhiyi Wei" ], "corpus_id": 225613690, "doc_id": "225613690", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Sub 10 fs pulse generation from a blue laser diode pumped Ti:sapphire oscillator", "venue": "", "year": 2020 }, { "abstract": "Photonics chip based soliton microcombs have been used in many applications including LIDAR, spectroscopy, coherent communication and astronomical spectrometer calibration [1] Current initiated soliton microcombs have been demonstrated [2, 3] recently, signifying improvements in the fabrication of high Q Si3N4 microresonators. However, both approaches suffer from limited input laser power, thus only demonstrated single soliton at repetition rates above 149 GHz, which are challenging to detect with commercially available photodetectors. Here we demonstrate a single soliton generation in 100 GHz FSR Si3N4 microresonators fabricated using the photonic Damascene reflow process [4] yielding the intrinsic Q factor exceeding 15 million [5] Using a compact hybrid laser with narrow linewidth, low relative intensity noise 160 dBc/Hz at foffset=100 kHz) and high output power up to 100 mW [6] different comb states are observed by simply changing the current of the laser diode, without the need of complex tuning mechanism such as a single sideband modulator [7] As the laser noise is directly transferred to the soliton comb line, this low noise laser can be utilized in applications where the phase noise is a critical parameter, e.g. low noise microwave generation or coherent communication. The experimental setup shown in Fig. 1 (a) consists of an ULN laser operated by a current source and temperature controllers to tune its frequency and power. After the light is coupled into the Si3N4 photonic chip via double inverse nano tapers [8] the temperature of FBG/GC is changed to align the laser wavelength to the resonance of the microresonator. The laser diode current is increased 330 mA) until soliton existence range is sufficiently long. This is indicated by transmission signal directly observed after the chip on the photodetector (Fig. 1 c) Due to high Q factor of the Si3N4, the soliton state can be accessed via simply frequency forward tuning [9] without the need of any complex soliton tuning mechanism. Further, different comb states are observed, i.e. modulation instability, multi soliton state and single soliton state, via laser diode current tuning. The coherence properties of the soliton comb teeth is asserted by performing a heterodyne beatnote measurement using a reference laser with a short time linewidth of 10 kHz (Fig. 1b) The soliton spectrum is fitted with a sech2 function corresponding to a 3 dB bandwidth of 19.3 nm and a 131.5 fs pulse.", "author_names": [ "Arslan S Raja", "Junqiu Liu", "Nicolas Volet", "Rui Wang", "Jijun He", "Erwan Lucas", "Romain Bouchand", "Paul Adrian Morton", "John E Bowers", "Tobias J Kippenberg" ], "corpus_id": 204822858, "doc_id": "204822858", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Photonic Chip Based Soliton Microcomb Driven by a Compact Ultra Low Noise Laser", "venue": "2019 Conference on Lasers and Electro Optics Europe European Quantum Electronics Conference (CLEO/Europe EQEC)", "year": 2019 }, { "abstract": "Single frequency stable, narrow linewidth diode pumped solid state (DPSS) lasers are commonly used in many applications and science areas, like high resolution spectroscopy, optical metrology, gravity wave detection [1] fundamental physics and others. Many of them require optical amplification of the DPSS seed laser to obtain higher output power while maintaining the excellent optical properties of the laser beam (e.g. Coherent Power Summation for military applications) In Ref.[2] the miniature, single frequency stable DPSS laser operating at 1064 nm and patented structure of the monolithic microchip resonator Nd:YVO4/YVO4/YVO4 were described (Fig.1a) However, from commercial point of view the DPSS seed laser needs to be inexpensive, mechanically and optically stable for wide temperature range, easy to assemble and service. Here, the comparison of the 0.3 mm long a cut Nd:YVO4 crystal resonator (Fig. 1b) with dielectric mirrors directly deposited onto the outer crystal surfaces (short resonator SR) and described in Ref.[3] the 8.5mm long microchip resonator Nd:YVO4/YVO4/YVO4 (long resonator LR) is presented for the first time. Both resonators were examined in the same DPSS laser module, providing the same conditions for their operation and they were pumped through a 3.5 mm long GRIN lens collimator (Casix) by a linearly polarized 1W multimode 808 nm laser diode (QA 808 1000 030, Axcel Photonics) In comparison to the LR, the SR configuration provides only 27% less power conversion efficiency (at only 0.3mm resonator/gain crystal thickness) due to back reflection from HR@808nm coating of the pump beam. However, for the 808 nm pump power lower than 250 mW, the SR ensures slightly more output power than LR configuration due to 10 times lower power threshold (Fig. 1c) The pure single longitudinal mode operation was obtained for both configurations (Fig. 1e) nonetheless the SR provides almost 9 times wider temperature range (14 32 degC 550mW of pump power) where laser resonator works in single mode (SM) regime (Fig. 1d) than the LR chip (21.2 23.2 degC 550mW of pump power) Additionally, the SR configuration does not need a crystals bonding process and it is around 25% cheaper (excluding bonding costs) compared to the LR. Whereas, the output beam divergence becomes around 4 times higher for the SR and it is more sensitive to angular aligning of the pump beam causing that transverse mode distribution can occur. Presented results and comparison were carried out within a commercial TANGO project \"Development, optimization and integration of the single frequency seed laser operating at 1064 nm with medium power fiber amplifier\" (TANGO1/266345/NCBR/2015) financed by National Centre for Research and Development (NCBiR) Poland and statutory funds of the Faculty of Electronics (0401/0030/18)", "author_names": [ "Grzegorz Dudzik", "Karol Krzempek", "Krzysztof M Abramski" ], "corpus_id": 204822372, "doc_id": "204822372", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Comparison of Nd:YVO4 Based Monolithic Microchip Laser Resonators for Single Frequency Stable, CW Diode Pumped Laser Sources", "venue": "2019 Conference on Lasers and Electro Optics Europe European Quantum Electronics Conference (CLEO/Europe EQEC)", "year": 2019 }, { "abstract": "An all diode pumped Nd:YAG burst mode laser was demonstrated. A diode laser side pumped Nd:YAG laser with Qswitcher, as laser oscillator, was employed to produce burst pulse directly. When the diode laser worked at 10Hz and Qswitcher was operated at 10kHz, a maximum burst energy of 456mJ was obtained in the master oscillator with the highest optical efficiency of ~30% Each burst included 19 pulses in the pumping duration of 2ms. A master oscillator and power amplifier architecture was adapted to scale the burst energy to meet PLIF system applications. The burst energy of 456mJ obtained from laser oscillator was amplified to 2.2J by use of three diode laser side pumped Nd:YAG modules as laser amplifiers. The energy extraction efficiency of each stage was achieved to ~13% ~22% and ~24% respectively. The single pulse energy of 1064nm laser at 10 kHz reached to ~116 mJ with pulse width of 9.8 ns and a peak power of ~11.8 MW. The performances of pulse burst laser we constructed can be better and improved greatly by use of more amplifiers.", "author_names": [ "Xudong Li", "Guichuan Xu", "Renpeng Yan", "Wentao Wu", "Zhixiang Liu", "Xiaolin Wen", "Deying Chen" ], "corpus_id": 125603080, "doc_id": "125603080", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A 2.2J all diode pumped Nd:YAG burst mode laser at repetition rate of 10kHz", "venue": "Other Conferences", "year": 2018 }, { "abstract": "Broad area lasers with narrow spectra are required for many pumping applications and for wavelength beam combination. Although monolithically stabilized lasers show high performance, some applications can only be addressed with external frequency stabilization, for example when very narrow spectra are required. When conventional diode lasers with vertical far field angle, ThV 95% 45deg (95% power) are stabilized using volume holographic gratings (VHGs) optical losses are introduced, limiting both efficiency and reliable output power, with the presence of any bar smile compounding the challenge. Diode lasers with designs optimized for extremely low vertical divergence (ELOD lasers) directly address these challenges. The vertical far field angle in conventional laser designs is limited by the waveguiding of the active region itself. In ELOD designs, quantum barriers are used that have low refractive index, enabling the influence of the active region to be suppressed, leading to narrow far field operation from thin vertical structures, for minimal electrical resistance and maximum power conversion efficiency. We review the design process, and show that 975 nm diode lasers with 90 mm stripes that use ELOD designs operate with ThV 95% 26deg and reach 58% power conversion efficiency at a CW output power of 10 W. We demonstrate directly that VHG stabilized ELOD lasers have significantly lower loss and larger operation windows than conventional lasers in the collimated feedback regimes, even in the presence of significant 1 mm) bar smile. We also discuss the potential influence of ELOD designs on reliable output power and options for further performance improvement.", "author_names": [ "P A Crump", "Steffen Knigge", "Andre Maassdorf", "Frank Bugge", "Stefan Hengesbach", "Ulrich Witte", "Hans Dieter Hoffmann", "Bernd Kohler", "Ralf Hubrich", "Heiko Kissel", "Jens Biesenbach", "Gotz Erbert", "Guenther Traenkle" ], "corpus_id": 121982251, "doc_id": "121982251", "n_citations": 20, "n_key_citations": 1, "score": 0, "title": "Low loss smile insensitive external frequency stabilization of high power diode lasers enabled by vertical designs with extremely low divergence angle and high efficiency", "venue": "Photonics West Lasers and Applications in Science and Engineering", "year": 2013 }, { "abstract": "It is widely known that a diode pumped solid state laser (DPSSL) has very limited modulation bandwidth. Recently, we directed our attention toward the opportunities for directly modulating a DPSSL to generate high speed green light signals, with high power and superior beam quality, which are highly desirable in underwater wireless optical communication. The constraint imposed by the limited modulation bandwidth of a DPSSL is circumvented with the strategy of orthogonal frequency division multiplexing and power loading. With a compact DPSSL dismantled from a low cost laser pointer, we achieve net bit rates of 108.55 Mb/s for the 64 quadrature amplitude modulation (QAM) signal at a bit error rate (BER) of 6.42x10 4 and 89.55 Mb/s for the 32 QAM signal at a BER of 4.81x10 4, respectively, over a 2 m underwater channel. When the underwater transmission distance is increased to 6 m, the BERs are still below the forward error correction (FEC) limit of 3.8x10 3.", "author_names": [ "Jing Xu", "Meiwei Kong", "Aobo Lin", "Yuhang Song", "Jun Han", "Zhiwei Xu", "Bo Wu", "Shiming Gao", "Ning Deng" ], "corpus_id": 46754673, "doc_id": "46754673", "n_citations": 22, "n_key_citations": 0, "score": 0, "title": "Directly modulated green light diode pumped solid state laser for underwater wireless optical communication.", "venue": "Optics letters", "year": 2017 } ]

[ { "abstract": "This review reports on the basic mechanism of photocatalysis and different ways of enhancing the photocatalytic efficiency. It further examines enhancement of the photocatalytic property using the different combinations of semiconductor oxides (TiO2, ZnO, stratified WO3/TiO2, WO3/ZnO) TiO2, ZnO semiconductors have been widely used from the recent few decades in the photocatalytic degradation process, but the main drawback of these materials is able to utilize the UV part of the solar spectrum. So many researchers tried to utilize a major portion of the solar spectrum using different strategies such as doping, applying external bias, stratified films, etc. The main aim of this review is providing different strategies for enhancing the photocatalytic efficiency.", "author_names": [ "Y M Hunge", "A A Yadav", "Babasaheb M Mohite" ], "corpus_id": 219482676, "doc_id": "219482676", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Basics of Photocatalysis and Different Strategy for Enhancing the Photocatalytic Efficiency", "venue": "", "year": 2020 }, { "abstract": "Presently, world is facing the problem of environmental pollution, which is associated to the air, water and soil pollution. This is mainly due to a continually rising of population and increase of demands for source water. Due to rapid civilization and industrialization, many pollutants such as various toxic compounds, dyes, sulfates are dumped into water.1,2 Water is an indispensable source of life. It is the major solvent, for all biochemical processes. The discharged waste water from the industries contains the organic, inorganic and microbial contaminants that are hazardous to human, aquatic and biotic life. The removal of organic contaminants form water is of prime importance.3 Degradation of pollutants is of paramount importance as far as potable water is concerned.", "author_names": [ "Y M Hunge", "A A Yadav" ], "corpus_id": 134163044, "doc_id": "134163044", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Basics and advanced developments in photocatalysis a review", "venue": "", "year": 2018 }, { "abstract": "", "author_names": [ "Tsukasa Torimoto" ], "corpus_id": 138521851, "doc_id": "138521851", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Photoelectrochemistry and Photocatalysis 3: Basics and Applications of Photoelectrodes", "venue": "", "year": 2016 }, { "abstract": "Presently, the most challenging issue is the elimination of contaminants existing in polluted water due to their adverse effect on human health and environment. Photocatalysis is one of the best, renewable, and green approach that remedies the water pollution problems. It has gained momentum since water splitting by Fujishima and Honda under UV irradiation, and remarkable progress has been made with the assistance of nanotechnology to resolve energy and pollution problems. Interestingly, its simplicity and low cost make it suitable and affordable for practical application in water purification. Chapter 1 describes the basic mechanism of heterogenous photocatalysis, degradation of toxic pollutants, and principles of semiconductor based heterogeneous photocatalysis. Further, reactions, that is, generation of charge carriers, recombination losses, and degradation of pollutants, under illumination of solar light have been described in detail. The parameters required for efficient photocatalysts, such as optimum band gap energy, rapid transportation of photoelectrons, suitable band positions, and intrinsic electron mobility, have been summarized. Hence, this chapter consists of fundamental details about heterogeneous photocatalysis.", "author_names": [ "Rajendra C Pawar", "Caroline Sunyong Lee" ], "corpus_id": 100340014, "doc_id": "100340014", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Basics of Photocatalysis", "venue": "", "year": 2015 }, { "abstract": "Abstract Heterogeneous photocatalysis as a sustainable and promising strategy has been intensively investigated for different applications, including solar fuel production and degradation of environmental pollutants. However, it is still challenging to develop highly active, selective, and durable photocatalysts for practical applications. In this chapter, after introducing a brief history of photocatalysis, we first present a comprehensive review on the thermodynamics and dynamics of photocatalysis, which could help the readers deeply understand the fundamental principles of photocatalytic processes. Then, we systematically summarize the basics for the surface/interface science of photocatalysis, including adsorption, surface redox reactions, and interfacial charge separation. Finally, the design principles, modification strategies, and the characterization and evaluation methods of semiconductor photocatalysts are summarized. By addressing these pertinent and important topics in heterogeneous photocatalysis, this chapter is expected to provide a useful reference for researchers in designing and exploring advanced photocatalytic materials for different applications.", "author_names": [ "Xin Li", "Jiaguo Yu", "Chuanjia Jiang" ], "corpus_id": 216478564, "doc_id": "216478564", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Principle and surface science of photocatalysis", "venue": "", "year": 2020 }, { "abstract": "Photocatalysis is a process in which the rate of photoreaction is accelerated in presence of a catalyst. It has gained much interest due to its ability to completely mineralise a variety of organic compounds into carbon dioxide and water. This paper describes the basics of heterogeneous photocatalysis, mainly on TiO2 and the application of the photocatalytic process to water purification, mainly to remove phenol as well as special emphasis on the effects of; solution pH, dissolved oxygen, catalyst load, initial phenol concentration and UV radiation on the photoactivity. Photocatalytic degradation of phenol was conducted in 1 L solutions of phenol (20 mg/L) in ultrapure water in a batch system. Catalyst concentration was constant at 8 mg/L Titanium dioxide (TiO2) Concentration of phenol was monitored on a Waters High Performance Liquid Chromatograph (HPLC) and Gas ChromatogramMass Spectrometer (GC MS) Results showed that photo degradation is an effective method for the removal of phenol from wastewaters. The efficiency of the process depends strongly on the experimental conditions.", "author_names": [ "Lindelwa Jay", "Evans M N Chirwa" ], "corpus_id": 208075962, "doc_id": "208075962", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "The Effect of Reaction Conditions on the Degradation of Phenol by UV/TiO2 Photocatalysis", "venue": "", "year": 2019 }, { "abstract": "Photocatalysis is a process in which the rate of photoreaction is accelerated in presence of a catalyst. It has gained much interest due to its ability to completely mineralise a variety of organic compounds into carbon dioxide and water. This paper describes the basics of heterogeneous photocatalysis, mainly on TiO2 and the application of the photocatalytic process to water purification, mainly to remove phenol as well as special emphasis on the effects of; solution pH, dissolved oxygen, catalyst load, initial phenol concentration and UV radiation on the photoactivity. Photocatalytic degradation of phenol was conducted in 1 L solutions of phenol (20 mg/L) in ultrapure water in a batch system. Catalyst concentration was constant at 8 mg/L Titanium dioxide (TiO2) Concentration of phenol was monitored on a Waters High Performance Liquid Chromatograph (HPLC) and Gas Chromatogram Mass Spectrometer (GC MS) Results showed that photo degradation is an effective method for the removal of phenol from wastewaters. The efficiency of the process depends strongly on the experimental conditions.", "author_names": [ "Lindelwa Jay", "Evans M N Chirwa" ], "corpus_id": 208752610, "doc_id": "208752610", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "The Effect of Reaction Conditions on the Degradation of Phenol by UV/TiO 2 Photocatalysis", "venue": "", "year": 2019 }, { "abstract": "Abstract In order to support the future hydrogen economy, photocatalytic water splitting technology, based on nanosized semiconductors, has significant potential for the production of hydrogen using solar energy with a low environmental impact. Despite the numerous attempts to prepare materials able to efficiently use solar energy during the past decades, the solar to hydrogen energy conversion efficiency is currently far too low for the technology to be economically profitable. This chapter depicts the basics of photocatalytic water splitting and organic photoreforming and surveys metal based semiconductor nanomaterials (i.e. metal oxides, metal (oxy)sulfides and metal (oxy)nitrides, etc. used as photocatalysts for hydrogen production in aqueous solution under UVA or visible radiation. Special attention is paid to recent developments for enhancing the effectiveness of the most common metal based semiconductors. The main experimental factors affecting performance and design of photocatalytic materials are critically discussed.", "author_names": [ "Laura Clarizia", "Danilo Russo", "Ilaria Di Somma", "Roberto Andreozzi", "Raffaele Marotta" ], "corpus_id": 104177602, "doc_id": "104177602", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Metal based semiconductor nanomaterials for photocatalysis", "venue": "", "year": 2018 }, { "abstract": "Studies on localized surface plasmon resonance (LSPR) of noble metals (mainly gold and silver) regarding solar driven photocatalysis have been attracting enormous interests over the past two decades. As research on LSPR continues to expand, recently, aluminum (Al) with respect to plasmonic enhanced photocatalysis beyond such noble metals has attracted considerable attention. Al as an abundant and relatively inexpensive metal holds great promise for plasmonic photocatalysis with outstanding light harvesting capacity and performance in virtue of its unique optical characteristics. Herein, a short review is given on the related basics of LSPR, and the key factors including the size, shape, and oxide formation of Al nanostructures, which significantly influence the optical response of Al. In particular, photocatalytic applications in artificial photoredox processes with regard to plasmonic Al are outlined. In addition, some perspectives on the opportunity and challenge for future development of this research field are offered.", "author_names": [ "Yan Chen", "Xin Xin", "Nan Zhang", "Yi-Jun Xu" ], "corpus_id": 100318595, "doc_id": "100318595", "n_citations": 24, "n_key_citations": 0, "score": 0, "title": "Aluminum Based Plasmonic Photocatalysis", "venue": "", "year": 2017 }, { "abstract": "Overall water splitting based on particulate photocatalysts is an easily constructed and cost effective technology for the conversion of abundant solar energy into clean and renewable hydrogen energy on a large scale. This promising technology can be achieved in a one step excitation system using a single photocatalyst or via a Z scheme process based on a pair of photocatalysts. Ideally, such photocatalysis will proceed with charge separation and transport unaffected by recombination and trapping, and surface catalytic processes will not involve undesirable reactions. This review summarizes the basics of overall water splitting via both one step excitation and Z scheme processes, with a focus on standard methods of determining photocatalytic performance. Various surface engineering strategies applied to photocatalysts, such as cocatalyst loading, surface morphology control, surface modification and surface phase junctions, have been developed to allow efficient one step excitation overall water splitting. In addition, numerous visible light responsive photocatalysts have been successfully utilized as H2 evolution or O2 evolution photocatalysts in Z scheme overall water splitting. Prototype particulate immobilization systems with photocatalytic performances comparable to or drastically higher than those of particle suspension systems suggest the exciting possibility of the large scale production of low cost renewable solar hydrogen.", "author_names": [ "Zheng Wang", "Can Li", "Kazunari Domen" ], "corpus_id": 53523213, "doc_id": "53523213", "n_citations": 633, "n_key_citations": 0, "score": 0, "title": "Recent developments in heterogeneous photocatalysts for solar driven overall water splitting.", "venue": "Chemical Society reviews", "year": 2019 } ]

[ { "abstract": "Epitaxial heterostructures based on oxide perovskites and III V, II VI and transition metal dichalcogenide semiconductors form the foundation of modern electronics and optoelectronics 1 7 Halide perovskites an emerging family of tunable semiconductors with desirable properties are attractive for applications such as solution processed solar cells, light emitting diodes, detectors and lasers 8 15 Their inherently soft crystal lattice allows greater tolerance to lattice mismatch, making them promising for heterostructure formation and semiconductor integration 16 17 Atomically sharp epitaxial interfaces are necessary to improve performance and for device miniaturization. However, epitaxial growth of atomically sharp heterostructures of halide perovskites has not yet been achieved, owing to their high intrinsic ion mobility, which leads to interdiffusion and large junction widths 18 21 and owing to their poor chemical stability, which leads to decomposition of prior layers during the fabrication of subsequent layers. Therefore, understanding the origins of this instability and identifying effective approaches to suppress ion diffusion are of great importance 22 26 Here we report an effective strategy to substantially inhibit in plane ion diffusion in two dimensional halide perovskites by incorporating rigid p conjugated organic ligands. We demonstrate highly stable and tunable lateral epitaxial heterostructures, multiheterostructures and superlattices. Near atomically sharp interfaces and epitaxial growth are revealed by low dose aberration corrected high resolution transmission electron microscopy. Molecular dynamics simulations confirm the reduced heterostructure disorder and larger vacancy formation energies of the two dimensional perovskites in the presence of conjugated ligands. These findings provide insights into the immobilization and stabilization of halide perovskite semiconductors and demonstrate a materials platform for complex and molecularly thin superlattices, devices and integrated circuits. An epitaxial growth strategy that improves the stability of two dimensional halide perovskites by inhibiting ion diffusion in their heterostructures using rigid p conjugated ligands is demonstrated, and shows near atomically sharp interfaces.", "author_names": [ "Enzheng Shi", "Biao Yuan", "Stephen B Shiring", "Yao Gao", "", "Yunfan Guo", "Cong Su", "Minliang Lai", "Peidong Yang", "Jing Kong", "Brett M Savoie", "Yi Yu", "Letian Dou" ], "corpus_id": 216649846, "doc_id": "216649846", "n_citations": 63, "n_key_citations": 0, "score": 1, "title": "Two dimensional halide perovskite lateral epitaxial heterostructures", "venue": "Nature", "year": 2020 }, { "abstract": "Using detailed first principles calculations, we investigated the behaviour of interface vacancies in a lateral heterostructure (LHS) constructed by arsenene (As) and antimonene (Sb) which has been demonstrated to have many unique properties but with a large lattice mismatch [Q. Sun, Y. Dai, Y. Ma, N. Yin, W. Wei, L. Yu and B. Huang, 2D Mater. 2016, 3, 035017] Our calculated results show that the energetics, kinetics and electronic properties of the atomic vacancies are greatly modified at the interface of the As Sb LHS. Two mechanisms are demonstrated to govern the migration of interfacial DV 585s based on the dissociation/recombination of SVs and the exchange of atoms adjacent to the vacant sites, respectively. DV 5 585 is identified as the lowest energy atomic vacancy at the interface. The easy formation of DV 5 585 due to the release of the compressed stress in the Sb block suggests that, in LHSs with a large lattice mismatch, much attention should be paid to the potentially large concentration of detrimental interfacial vacancies close to the compressed building blocks, where the proper selection of temperature and careful control of the atomic chemical potential are essential. Meanwhile the unexpected half metal states induced by DV 3 585 o and DV 4 585 o rooted in the unpaired As atoms driven by the tensile stress reveal that decorating atomic vacancies in the stretched building blocks may provide an effective way to achieve the functionalization of LHSs with a large lattice mismatch. In addition, we reveal a single atom triggered transition between the metal and semiconductor in SV As 1 decorated As Sb LHS. Thus, by manipulating the Sb atom at the interface, the defect of SV As 1 may be used as an atomic switch to control the on off states of a circuit at the nanoscale, making As Sb LHS a promising candidate for application in nanoelectronic devices. Our theoretical work enriches the fundamental understanding of intrinsic defects at the interface of As Sb LHSs, and provides significant insight towards defect and interface engineering in LHSs with a large lattice mismatch, which are of great relevance for the manipulation of the LHS properties for the design of novel nanodevices.", "author_names": [ "Lei Ao", "Zhihua Xiong" ], "corpus_id": 210247363, "doc_id": "210247363", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Insights into the vacancy behaviour at the interface of As Sb lateral heterostructures", "venue": "", "year": 2020 }, { "abstract": "Lateral TMD heterostructures create atomically thin p n junctions. These 1D interfaces offer tremendous potential to probe effects such as ultrafast charge transfer, strong coupling and strain at the interface [4 5] A particularly interesting heterostructure is Type II MoS2/ WS2. MoS2 and WS2, due to very small lattice mismatch (1.3% form clean and smooth zig zag interfaces over large areas [6]", "author_names": [ "Sandhya Susarla", "Luiz H G Tizei", "Steffi Y Woo", "Alberto Zobelli", "Odile Stephan", "Pulickel M Ajayan" ], "corpus_id": 201331482, "doc_id": "201331482", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Low Loss EELS of Lateral MoS2/WS2 Heterostructures", "venue": "Microscopy and Microanalysis", "year": 2019 }, { "abstract": "We demonstrate that 3.5% in plane lattice mismatch between GaN (0001) epitaxial layers and SiC (0001) substrates can be accommodated without triggering extended defects over large areas using a grain boundary free AlN nucleation layer (NL) Defect formation in the initial epitaxial growth phase is thus significantly alleviated, confirmed by various characterization techniques. As a result, a high quality 0.2 mm thin GaN layer can be grown on the AlN NL and directly serve as a channel layer in power devices, like high electron mobility transistors (HEMTs) The channel electrons exhibit a state of the art mobility of >2000 cm2/V s, in the AlGaN/GaN heterostructures without a conventional thick C or Fe doped buffer layer. The highly scaled transistor processed on the heterostructure with a nearly perfect GaN SiC interface shows excellent DC and microwave performances. A peak RF power density of 5.8 W/mm was obtained at VDSQ 40 V and a fundamental frequency of 30 GHz. Moreover, an unpassivated 0.2 mm GaN/AlN/SiC stack shows lateral and vertical breakdowns at 1.5 kV. Perfecting the GaN SiC interface enables a GaN SiC hybrid material that combines the high electron velocity thin GaN with the high breakdown bulk SiC, which promises further advances in a wide spectrum of high frequency and power electronics.We demonstrate that 3.5% in plane lattice mismatch between GaN (0001) epitaxial layers and SiC (0001) substrates can be accommodated without triggering extended defects over large areas using a grain boundary free AlN nucleation layer (NL) Defect formation in the initial epitaxial growth phase is thus significantly alleviated, confirmed by various characterization techniques. As a result, a high quality 0.2 mm thin GaN layer can be grown on the AlN NL and directly serve as a channel layer in power devices, like high electron mobility transistors (HEMTs) The channel electrons exhibit a state of the art mobility of >2000 cm2/V s, in the AlGaN/GaN heterostructures without a conventional thick C or Fe doped buffer layer. The highly scaled transistor processed on the heterostructure with a nearly perfect GaN SiC interface shows excellent DC and microwave performances. A peak RF power density of 5.8 W/mm was obtained at VDSQ 40 V and a fundamental frequency of 30 GHz. Moreover, an unpassivated 0.2 mm GaN/A.", "author_names": [ "Jr-Tai Chen", "Johan Bergsten", "Jun Novi Lu", "Erik Janzen", "Mattias Thorsell", "Lars Hultman", "Niklas Rorsman", "O Kordina" ], "corpus_id": 52211166, "doc_id": "52211166", "n_citations": 23, "n_key_citations": 0, "score": 0, "title": "A GaN SiC hybrid material for high frequency and power electronics", "venue": "", "year": 2018 }, { "abstract": "We have proposed a 1.3 mm wavelength InGaAs(P)/InGaP double heterostructure laser that increases the band gap difference by using a wide band gap InGaP cladding layer. Epitaxial lateral overgrowth (ELO) has been investigated with liquid phase epitaxy to produce a high crystal quality ternary InGaP layer that has a large lattice mismatch on a GaAs (111)B substrate. In a previous study, we were able to produce a large area of In 0.8 Ga 0.2 P on a GaAs (111 )B substrate. However, there were a number of cracks and the crystal quality of the epitaxial layer was poor. In this study, we succeeded in reducing the number of defects in ELO layers by using a spin on diffusion source instead of a sputtering SiO 2 mask for ELO. We also attempted to grow a second InGaP layer over the first InGaP ELO layer. We were able to obtain an InGaP epitaxial layer with a mismatch to the GaAs substrate.", "author_names": [ "Shigeo Hayashi", "Maki Nangu", "Tomoaki Morikuni", "Soichi Owa", "N Shin-ichi Takahashi" ], "corpus_id": 95789846, "doc_id": "95789846", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Lattice mismatched InGaP/GaAs (111)B liquid phase epitaxy with epitaxial lateral overgrowth", "venue": "", "year": 2009 }, { "abstract": "We report on the fabrication of a near broken InAs/Al0.5Ga0.5Sb vertical TUNNEL field effect transistor (TFET) The epitaxial structure is grown on a GaAs (001) substrate thanks to large mismatch accommodation at the GaSb/GaAs interface. The fabrication process involves an anisotropic and selective wet chemical etching of the InAs channel to form a V shaped mesa with lateral side gates. This new architecture provides a large ON current at room temperature while enabling an efficient pinch off thanks to a reduced body thickness near the tunneling interface. With low temperature measurements, we identify the different mechanisms limiting the subthreshold slope at room temperature. At 77 K, where the impact of defects is reduced, a minimum subthreshold slope of 71 mV/decade is achieved for VDS 0.1 V with an ION/IOFF current ratio larger than 6 decades demonstrating that a good trade off between ON current and switching efficiency could be obtained with a near broken gap heterostructure based n TFET.", "author_names": [ "V K Chinni", "M Zaknoune", "C Coinon", "Laurence Morgenroth", "David Troadec", "Xavier Wallart", "Ludovic Desplanque" ], "corpus_id": 22237913, "doc_id": "22237913", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "V Shaped InAs/Al0.5Ga0.5Sb Vertical Tunnel FET on GaAs (001) Substrate With I $_{\\text {ON}\\text {433}\\mu$ A. \\mu$ m \\text {1} at V $_{\\text {DS} \\text {0.5} V", "venue": "IEEE Journal of the Electron Devices Society", "year": 2017 }, { "abstract": "", "author_names": [ "Lianbi Li" ], "corpus_id": 139628132, "doc_id": "139628132", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Growth Mode and Characterization of Si/SiC Heterostructure of Large Lattice Mismatch", "venue": "", "year": 2018 }, { "abstract": "Photocarrier recombination remains a big barrier for the improvement of solar energy conversion efficiency. For 2D materials, construction of heterostructures represents an efficient strategy to promote photoexcited carrier separation via an internal electric field at the heterointerface. However, due to the difficulty in seeking two components with suitable crystal lattice mismatch, most of the current 2D heterostructures are vertical heterostructures and the exploration of 2D lateral heterostructures is scarce and limited. Here, lateral epitaxial heterostructures of BiOCl Bi2 O3 at the atomic level are fabricated via sonicating assisted etching of Cl in BiOCl. This unique lateral heterostructure expedites photoexcited charge separation and transportation through the internal electric field induced by chemical bonding at the lateral interface. As a result, the lateral BiOCl Bi2 O3 heterostructure demonstrates superior CO2 photoreduction properties with a CO yield rate of about 30 umol g 1 h 1 under visible light illumination. The strategy to fabricate lateral epitaxial heterostructures in this work is expected to provide inspiration for preparing other 2D lateral heterostructures used in optoelectronic devices, energy conversion, and storage fields.", "author_names": [ "Li Wang", "Xue Zhao", "Dongdong Lv", "Chuangwei Liu", "Weihong Lai", "Chunyi Sun", "Zhongmin Su", "Xun Xu", "Weichang Hao", "Shi Xue Dou", "Yi Du" ], "corpus_id": 226031054, "doc_id": "226031054", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Promoted Photocharge Separation in 2D Lateral Epitaxial Heterostructure for Visible Light Driven CO2 Photoreduction.", "venue": "Advanced materials", "year": 2020 }, { "abstract": "Electrical generation and detection of pure spin currents without the need of magnetic materials are key elements for the realization of full electrically controlled spintronic devices. In this framework, achieving a large spin to charge conversion signal is crucial, as considerable outputs are needed for plausible applications. Unfortunately, the values obtained so far have been rather low. Here we exploit the spin Hall effect by using Pt, a non magnetic metal with strong spin orbit coupling, to generate and detect pure spin currents in a few layer graphene channel. Furthermore, the outstanding properties of graphene, with long distance spin transport and higher electrical resistivity than metals, allow us to achieve in our graphene/Pt lateral heterostructures the largest spin to charge output voltage at room temperature reported so far in the literature. Our approach opens up exciting opportunities towards the implementation of spin orbit based logic circuits and all electrical control of spin information without magnetic field.Spintronic devices with full electrical control rely on electrical generation and detection of spin currents in the absence of magnetic materials. Here, the authors use Pt, a non magnetic metal, to generate and detect pure spin currents in a few layer graphene channel, achieving a remarkable spin to charge voltage signal at room temperature.", "author_names": [ "Wenjing Yan", "Edurne Sagasta", "M'ario Ribeiro", "Yasuhiro Niimi", "Luis E Hueso", "Felix Casanova" ], "corpus_id": 3638887, "doc_id": "3638887", "n_citations": 28, "n_key_citations": 0, "score": 0, "title": "Large room temperature spin to charge conversion signals in a few layer graphene/Pt lateral heterostructure", "venue": "Nature Communications", "year": 2017 }, { "abstract": "The synthesis of lateral heterostructures assembled by atomically thin materials with distinct intrinsic properties is important for future heterojunction embedded two dimensional (2D) devices. Here we report an etching assisted chemical vapor deposition method to synthesize large area continuous lateral graphene/hexagonal boron nitride (Gr/h BN) heterostructures on carbon containing copper foils. The h BN film is first synthesized on the copper foil, followed by hydrogen etching, and then epitaxial graphene domains are grown to form continuous lateral heterostructures. Analyses, including Raman spectroscopy, atomic force microscopy, scanning electron microscopy, x ray photoelectron spectroscopy, and ultraviolet visible absorption spectroscopy, are used to characterize the coexistence of both materials and the highly continuous nature of this lateral heterostructure. This facile and scalable synthesizing method enables the potential usage of Gr/h BN heterostructure in both fundamental studies and related 2D devices.", "author_names": [ "Pingping Zhuang", "Weiyi Lin", "Harry Chou", "Anupam Roy", "Weiwei Cai", "Sanjay K Banerjee" ], "corpus_id": 53292190, "doc_id": "53292190", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Growth of lateral graphene/h BN heterostructure on copper foils by chemical vapor deposition.", "venue": "Nanotechnology", "year": 2019 } ]

[ { "abstract": "Semiconductor physics is the basis of semiconductor science and integrated circuits. And this course is one of the main basic courses for undergraduates majoring in electronic engineering. Under the background of new engineering course construction and talent training, in this paper, we introduce a teaching platform with multi dimensional structure for \"Semiconductor Physics\" which consists of multi dimensional structure of theory teaching, virtual labs and simulations, and multi dimensional experimental teaching subsystem. The teaching achievements in the course \"Semiconductor Physics\" are awarded by our university. As a consequence, the teaching mode proposed in this paper can be served as a guidance for the education in electrical engineering and information science field.", "author_names": [ "Xia Wu", "Wanling Deng", "Zhi Luo", "Junkai Huang" ], "corpus_id": 225363740, "doc_id": "225363740", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Teaching Reform Studies of the Course \"Semiconductor Physics\" Under the Mode of Compound New Engineering Talent Training", "venue": "", "year": 2020 }, { "abstract": "After thirty years of rapid development, China has become the second largest economy in the world. In order to strengthen economic cooperation with countries along the Belt and Road and assume more responsibilities as a major power, China has put forward the Belt and Road Initiative, which puts great pressure on the demand for Business English talents in society. However, at present, there is a shortage of high level Business English talents in China. The traditional Business English talent training model cannot meet the needs of the business industry, which results in the serious disconnection between the cultivation of business talents and the market demand. Under the background of the Belt and Road Initiative, how to cultivate Business English talents has become a strategic issue. This research firstly combs the research of Business English talent training objectives and training model from the perspective of ESP Needs Analysis Theory, and then discusses the drawbacks of the current Business English training model from such aspects as curriculum setting, teaching system, and evaluation system, and gives suggestions in order to explore an appropriate Business English training model that meets the needs of the Belt and Road Initiative.", "author_names": [ "Guihang Guo", "Haimei Jin" ], "corpus_id": 159089322, "doc_id": "159089322", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Exploring Business English Talent Training Model under the Background of the Belt and Road Initiative", "venue": "Higher Education Studies", "year": 2019 }, { "abstract": "As a kind of new education ideal and mode, the \"innovation and entrepreneurship\" education points out the direction of the path for training of applied talents of colleges and universities in a certain future period. This paper explores the integration mode of innovation and entrepreneurship education ideas based on the reform conditions of cultivation schemes for professional talents of design major in Baoshan College, the newly constructed local college from three aspects including training objective, training standards and curriculum system and proposes that the revision of talent training scheme oriented by major and the construction of curriculum system based on learning are the realization path worthy of further exploration. Keywords innovation and entrepreneurship education; ability structure; local colleges", "author_names": [ "Haiyan Li", "Dongqiang Zhang" ], "corpus_id": 150806723, "doc_id": "150806723", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Exploration on the \"Innovation and Entrepreneurship\" Talent Training Program of Design Class in Local Colleges and Universities", "venue": "", "year": 2019 }, { "abstract": "As an important part of the university enterprise cooperation, the embedded talent training has played a significant role in the talent training. On the purpose of cultivating applied talents to adapt to the development of related industries, Nanjing University of Information Science Technology carried out the teaching reform of the embedded talent training with the cooperation of Jiangsu Ruipin Information Technology Co. Ltd. By constructing the curriculum system for embedded talent training, strengthening the construction of teachers' team, and improving the practice training conditions, the quality of the talent training has been comprehensively improved.", "author_names": [ "Chen Haixiu", "Chen Weifeng", "Liu Yunping", "Zhang Zi-jia", "Hou Yan" ], "corpus_id": 208830452, "doc_id": "208830452", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Exploration and Practice of Embedded Talent Training in Measurement and Control Technology and Instrument Specialty", "venue": "", "year": 2019 }, { "abstract": "The purpose of the work is to propose a talent training system of new engineering specialty integrated with the engineering education certification standards. Firstly the talent training system is constructed according to the establishment of training objectives, graduation requirements, curriculum knowledge system, engineering ability training system and the improvement of continuous improvement mechanisms based on the quality evaluation system. Then the automation, information and electrical specialties have practiced the proposed talent training system in the College of Electrical and Information Engineering of Beihua University. At last the disciplines have received connotative development. Keywords New engineering; Engineering education certification; Talent training system; Connotative development", "author_names": [ "Jing Bai", "Zhenxiong Zhou", "Tiecheng Pu", "Hongxi Wang" ], "corpus_id": 208840168, "doc_id": "208840168", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Construction of the Talent Training System of New Engineering Specialty in Engineering Education Certification", "venue": "", "year": 2019 }, { "abstract": "According to the needs and characteristics of military representative positions in the new era, this paper analyzes the necessity of undergraduate talent training in equipment procurement management, systematically expounds the status quo of undergraduate talent training in equipment procurement management, and puts forward the tentative idea of undergraduate talent training mode for equipment procurement management with the targeted countermeasures and suggestions.", "author_names": [ "Zhongyi Cai", "Huachun Xiang", "Lili Wang", "Yuhui Wang" ], "corpus_id": 169398545, "doc_id": "169398545", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Research on Undergraduate Talent Training Model of Equipment Procurement Management Major based on Job Demand", "venue": "", "year": 2019 }, { "abstract": "In order to cultivate application oriented talents of urban rail transit, individualized talent training mode is an important measure. In view of the existing problems in the training of rail transit professionals, the research group proposed the framework of individualized talent training under the background of new engineering, planned the matrix corresponding to graduation requirements and knowledge, ability and quality, and then set up the curriculum system and built the multi evaluation system in the implementation process. The developed solution has been put into practice and will be tested in the future teaching practice activities in order to constantly improve the personalized talent training model.", "author_names": [ "Zhaoli Wu", "Hai Xiang Li", "Junying Qi" ], "corpus_id": 235051060, "doc_id": "235051060", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Research and Practice of individualized talent Training Mode for rail transit majors from the perspective of new engineering", "venue": "", "year": 2020 }, { "abstract": "ABSTRACT Wang, H. and Wei, A. M. 2020. Talent demand and training strategy of oceangoing cruise company based on customized talent development model. In: Gong, D. Zhang, M. and Liu, R. (eds. Advances in Coastal Research: Engineering, Industry, Economy, and Sustainable Development. Journal of Coastal Research, Special Issue No. 106, pp. 233 236. Coconut Creek (Florida) ISSN 0749 0208. With the rapid development of China's national economy and foreign trade, the oceangoing cruise industry has had huge development potential in China, with a corresponding requirement for cruise talent. However, the gap in talent from international cruise companies has seriously affected the development needs of domestic companies. Based on a customized talent development model, this paper studies the talent demand of ocean cruise companies and seeks high quality talent training strategies for ocean cruise companies. The research results show that there exist many problems in China's cruise talent training in terms of different levels, categories, and contents; the training of customized talent in China includes internal training, intermediary training, and college education training; the strategies of training marine talent need to be carried out from the system level, the process level, and the environmental level. The research findings provide a theoretical basis for talent training in the marine system.", "author_names": [ "Hui Wang", "Ai-Min Wei" ], "corpus_id": 220468800, "doc_id": "220468800", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Talent Demand and Training Strategy of Oceangoing Cruise Company Based on Customized Talent Development Model", "venue": "Journal of Coastal Research", "year": 2020 }, { "abstract": "In response to the increasing demand for cross domain digital talent, the researchers in this study designed and tested cross domain digital courses for medical students. These Artificial Intelligence (AI) courses were made available throughout the semester via an innovative blended learning model. Fourteen students took part in a one credit, an 18 week online and offline blended learning model course entitled Application of Data Science in Medical Fields. The instructors for the physical courses comprised both academics and industry professionals. The final presentation, students put what they learnt into practice in a contemporary medical environment. The course not only helped students develop problem solving skills but also strengthened the connections between academic subjects and AI related technology. As a result of this research, medical university students achieved significant academic improvement after participating in the course. Students' rated their satisfaction levels for course contents and materials an average of four out of five.", "author_names": [ "Yu-Han Huang", "Hsin-Jung Wu", "Chung-Han Yeh", "Chwen-Pyng Wang", "Lee-Hwa Lu", "I-Chang Tsai" ], "corpus_id": 232236801, "doc_id": "232236801", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Innovative Training Model of Cross Domain Digital ICT Talent Development for Training Application of Data Analysis in Medical Field", "venue": "2020 IEEE International Conference on Teaching, Assessment, and Learning for Engineering (TALE)", "year": 2020 }, { "abstract": "Taking the computer science and technology of Yunnan University as an example, the ideas and methods of training excellent talents are expounded in this paper. This major trains excellent talents from four points: classified training based on course group, collaborative education based on school enterprise cooperation, computer professional certification and construction of practice innovation base. By setting up three course groups and dividing each course group into application type and research type, the individualized classified training of students can be realized. Through school enterprise cooperation and education project, the industry enterprises deeply participate in the training process, and the students become industry recognized talents. Through Certified Software Professional (CSP) organized by China Computer Federation (CCF) talents are trained according to industry standards. Through the construction of practice and innovation base, we will change to \"learning by doing\" which centers on students and focuses on students' active practice, and strengthen the cultivation of students' engineering ability and innovation ability. It can provide reference for the construction of computer talent training in relevant universities.", "author_names": [ "Guowu Yuan", "Gaifang Luo", "Xutao Yang", "Kun Yue", "Wenhua Qian" ], "corpus_id": 234986501, "doc_id": "234986501", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Construction and Practice of Excellence Talent Training System for Computer Science and Technology in Yunnan University", "venue": "", "year": 2020 } ]

[ { "abstract": "Abstract High voltage LiNi 0.5 Mn 1.5 O 4 has been considered as one of the most promising cathode candidate for LIBs due to its excellent energy density and power density, but the attack of HF on the material and dissolution of Mn ions into electrolyte can cause structure collapse and serious capacity fading of the cathode. In this work, a semiconductor of LaFeO 3 was coated on the surface of polyhedral LiNi 0.5 Mn 1.5 O 4 via a wet chemical method. LaFeO 3 coated at the surface of LiNi 0.5 Mn 1.5 O 4 significantly protects the cathode from the corrosion of HF and alleviates the dissolution of Mn ions into organic liquid electrolyte during (dis)charge processes. The 2.0 wt% LaFeO 3 coated LiNi 0.5 Mn 1.5 O 4 cathode exhibits much better cycling stability, rate capability, and elevated temperature stability than the pristine: capacity retention of 97.71% at 1 C after 100 cycles vs. that of 90.96% rate capability of 111.9 and 99.6 mAh g 1 at high C rates of 5 C and 10 C vs. that of 90.6 and 76.4 mAh g 1 respectively; and high temperature capacity retention of 93.29% at 1 C after 100 cycles vs. that of 69.9% Present study provides a facile method to mitigate the dissolution of Mn ions into electrolyte for LiNi 0.5 Mn 1.5 O 4 resulting in excellent cycling performance and rate capability.", "author_names": [ "Jirong Mou", "Yunlong Deng", "Lihua He", "Qiaoji Zheng", "Na Jiang", "Dunmim Lin" ], "corpus_id": 102625142, "doc_id": "102625142", "n_citations": 47, "n_key_citations": 0, "score": 0, "title": "Critical roles of semi conductive LaFeO 3 coating in enhancing cycling stability and rate capability of 5 V LiNi 0.5 Mn 1.5 O 4 cathode materials", "venue": "", "year": 2018 }, { "abstract": "Abstract Z scheme g C3N4/LaFeO3 heterojunction photocatalysts were prepared by calcining the uniformly mixed g C3N4 nanosheets and LaFeO3 nanoparticles at 300 degC for 1 h. The as prepared g C3N4/LaFeO3 composites were systematically characterized by XRD, SEM, TEM, XPS, UV vis DRS, PL spectroscopy, EIS and photocurrent response. It is demonstrated that LaFeO3 nanoparticles (average size: ca. 35 nm) are uniformly assembled onto the surface of g C3N4 nanosheets through chemical bonding, leading to the formation of g C3N4/LaFeO3 heterojunctions. The photocatalytic, Fenton and photo Fenton performances of the samples were investigated by degrading RhB using simulated sunlight as the light source. Compared to bare LaFeO3 and g C3N4, the g C3N4/LaFeO3 composites exhibit significantly enhanced photocatalytic and photo Fenton degradation of the dye, and the maximum activity is observed for the 15%g C3N4/LaFeO3 composite. Moreover, the photo Fenton performance of the composites is much higher than the photocatalytic or Fenton performances. The much improved photo fenton activity is ascribed to the efficient separation of photogenerated electron hole pairs due to the Z scheme electron transfer and the synergistic effect between LaFeO3 and g C3N4. *OH radicals were examined by PL spectroscopy using TPA as a probe molecule, clearly revealing the *OH generation, and moreover, the *OH yield and the dye degradation rate show a similar variation between different cases of the catalysis process. This suggested that *OH is the dominant reactive species causing the dye degradation. The underlying photo Fenton mechanism of the composites is discussed.", "author_names": [ "Yongchun Ye", "Hua Yang", "Xiangxian Wang", "Wangjun Feng" ], "corpus_id": 103408882, "doc_id": "103408882", "n_citations": 87, "n_key_citations": 2, "score": 0, "title": "Photocatalytic, Fenton and photo Fenton degradation of RhB over Z scheme g C3N4/LaFeO3 heterojunction photocatalysts", "venue": "", "year": 2018 }, { "abstract": "Au and Cl comodified LaFeO3 nanoparticles were prepared by a citric sol gel method through the addition of HAuCl4 into precursor. As evidenced by XRD and TEM, the addition of HAuCl4 suppressed the", "author_names": [ "Ensi Cao", "Aiting Wu", "Huihu Wang", "Yongjia Zhang", "Wentao Hao", "Li Hui Sun" ], "corpus_id": 104460075, "doc_id": "104460075", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Enhanced Ethanol Sensing Performance of Au and Cl Comodified LaFeO3 Nanoparticles", "venue": "ACS Applied Nano Materials", "year": 2019 }, { "abstract": "Perovskite type lanthanum iron oxide, LaFeO3, is a p type semiconductor that can achieve overall water splitting using visible light while maintaining photostability. These features make LaFeO3 a p.", "author_names": [ "Garrett P Wheeler", "Valentin Urena Baltazar", "T J Smart", "Andjela Radmilovic", "Yuan Ping", "Kyoung-Shin Choi" ], "corpus_id": 199067612, "doc_id": "199067612", "n_citations": 18, "n_key_citations": 0, "score": 0, "title": "Combined Theoretical and Experimental Investigations of Atomic Doping To Enhance Photon Absorption and Carrier Transport of LaFeO3 Photocathodes", "venue": "Chemistry of Materials", "year": 2019 }, { "abstract": "Perovskite type oxides lanthanum ferrite (LaFeO3) photocatalysts were successfully prepared by a facile and cost effective sol gel method using La(NO)3 and Fe(NO)3 as metal ion precursors and citric acid as a complexing agent at different calcination temperatures. The properties of the resulting LaFeO3 samples were characterized by powder X ray diffraction (XRD) energy dispersive X ray spectroscopy (EDXS) UV Vis diffuse reflectance spectroscopy (DRS) X ray photoelectron spectroscopy (XPS) Fourier transform infrared spectra (IR) transmission electron microscopy (TEM) N2 adsorption/desorption and photoelectrochemical tests. The photoactivity of the LaFeO3 samples was tested by monitoring the photocatalytic degradation of Rhodamine B (RhB) and 4 chlorophenol (4 CP) under visible light irradiation, the highest photocatalytic activity was found for LaFeO3 calcined at 700 *C, which attributed to the relatively highest surface area (10.6 m2/g) In addition, it was found from trapping experiments that the reactive species for degradation were superoxide radical ions (O2) and holes (h+ Photocurrent measurements and electrochemical impedance spectroscopy (EIS) proved the higher photo induced charge carrier transfer and separation efficiency of the LaFeO3 sample calcined at 700 *C compared to that that calcined at 900 *C. Band positions of LaFeO3 were estimated using the Mott Schottky plots, which showed that H2 evolution was not likely.", "author_names": [ "Mohammed Ismael", "Michael Wark" ], "corpus_id": 119096955, "doc_id": "119096955", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Perovskite type LaFeO 3 Photoelectrochemical Properties and Photocatalytic Degradation of Organic Pollutants Under Visible Light Irradiation", "venue": "", "year": 2019 }, { "abstract": "", "author_names": [ "Liu Qing Sheng Liu Qing-sheng", "Tan Cheng Liang Tan Cheng-liang", "Cheng Hua Jin Cheng Hua-jin", "Duan Xu Duan Xu", "Chang Qing Chang Qing", "Chen Jiang An Chen Jiang-an" ], "corpus_id": 213402274, "doc_id": "213402274", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "(Mg, Cr)Gong Xian LaFeO 3 Ji Fu He Fen Ti De Neng Dai Jie Gou Ji Qi Re Fu She Xing Neng", "venue": "", "year": 2019 }, { "abstract": "Preparation and characterization of Al2O3 dopped LaFeO3 thick film ceramics for ethanol gas sensor applications has been conducted. LaFeO3 ceramics were made by co precipitation method with doping variation of Al2O3 0% and 3.75% mole of the main ingredients LaFeO3 (La2O3 and Fe2O3) Screen printing technique was employed to make thick film ceramics of LaFeO3 and Al2O3 dopped LaFeO3. The ceramics were calcined at temperature of 60 0C. The analysis results of the characteristics of crystals using X Ray Difraction (XRD) showed that the made ceramics made had cubic phase with a lattice parameter a=b=c=39.52nm. The addition of 3.75% mole of Al2O3 did not change the crystal phase and lattice parameter values of LaFeO3. The crystallite size of LaFeO3 was 52.17nm while the crystallite size of Al2O3 doped LaFeO3 was 44.52nm. The analysis results of morphological structure ceramics of LaFeO3 and Al2O3 doped LaFeO3 using Scanning Electron Microscopy (SEM) possessed a grain size of each 0:40 mm and 0.25mm. The electrical characterization results of LaFeO3 thick film ceramics indicated the sensitivity of the sensor increased along with the addition of ethanol gas concentration. The maximum sensitivity value of LaFeO3 thick film ceramics ceramic thick film LaFeO3 and Al2O3 doped LaFeO3 at 300ppm was 4.34 at 330 0C and 6.08 at 3500C. The thick film ceramics with the addition of 3.75% mole of Al2O3 has a higher sensitivity and potential to be used as ethanol gas sensor.", "author_names": [ "Endi Suhendi", "Neng Astri Lidiawati", "Dani Gustaman Syarif", "Andhy Setiawan" ], "corpus_id": 145025847, "doc_id": "145025847", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Synthesis and Characterization of Al 2 O 3 Doped LaFeO 3 Thick Film Ceramics for Ethanol Gas Sensing Application", "venue": "", "year": 2019 }, { "abstract": "", "author_names": [ "Chenyi Gu", "Min Gu", "Zhoushen Yuan", "Yuefeng Nie", "Peng Wang", "Xiaoqing Pan" ], "corpus_id": 188671242, "doc_id": "188671242", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Atomic Resolutin Study of Charge Transfer at the LaTiO 3 /LaFeO 3 Interface", "venue": "", "year": 2019 }, { "abstract": "", "author_names": [ "Takuya Okamoto", "Kyoya Hiraoka", "Takehiro Teraji", "Kodai Sakamoto", "Nobuyuki Iwata" ], "corpus_id": 204306177, "doc_id": "204306177", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Influence of Oxidation Degree of CaFeO x and LaFeO 3 Thickness on Magnetic Property of LaFeO 3 /CaFeO x Superlattices and Multilayers", "venue": "", "year": 2019 }, { "abstract": "The physical properties of perovskite oxides are strongly influenced by their stoichiometry and one of the key features of these materials is the tunability of their functionality by controlling the interplay between the compositional and structural properties. Here, the effects on the photoelectrochemical (PEC) water splitting properties of ferroelectric LaFeO3 thin films obtained at different oxygen partial pressures during growth are reported in conjunction with the morphological, optical and structural features. The LaFeO3 thin films have been deposited by pulsed laser deposition on Nb:SrTiO3 substrates. The strong dependence of the photocurrent values Jphoto on the growth conditions is revealed by the photoelectrochemical measurements. Strong variations of the lateral coherence lengths L| of LaFeO3/Nb:SrTiO3 with the oxygen partial pressure values are noticed from the X ray diffraction (XRD) analysis. All the films are heteroepitaxial with small tensile strain levels detected in the crystalline structure, but only for a narrow interval of oxygen partial pressures the LFO/STON thin films show high quality crystalline structure with large lateral coherence length L| and photoelectrochemical currents.", "author_names": [ "Florin Andrei", "Iulian Boerasu", "Ruxandra Birjega", "Antoniu Moldovan", "Maria Dinescu", "Valentin Ion", "Cristian N Mihailescu", "Nicu Doinel Scarisoreanu", "Victor Leca" ], "corpus_id": 209704735, "doc_id": "209704735", "n_citations": 3, "n_key_citations": 1, "score": 1, "title": "The effects of the oxygen content on the photoelectrochemical properties of LaFeO3 perovskite thin films obtained by pulsed laser deposition", "venue": "Applied Physics A", "year": 2019 } ]

[ { "abstract": "A current sensing analog to digital converter (CADC) targeting biomedical applications is proposed in this paper. The proposed architecture consists of a leaky integrate and fire (LIF) neuron model inspired from neuromorphic circuits along with digital control circuits and error correction circuit to enhance INL/DNL performance. The architecture is tuned for input signal ranging from 1 uA to 64 uA with power supply of 1/1.8 V for digital and analog blocks respectively. The design is implemented in 0.18 um CMOS 1P4M triple well process of Tower Jazz Semiconductor's technology. Total power consumption of the circuit is 1. 95 mW 48.86 mW respectively and achieves FoM of 331.6 71.24 pJ/conversion step for the cases with and without error correction for 6 bits operation.", "author_names": [ "Navin Singhal", "M Santosh", "S C Bose", "Abhijit Karmakar" ], "corpus_id": 231850853, "doc_id": "231850853", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Neuromorphic Approach based Current Sensing Analog to Digital Converter for Biomedical Applications", "venue": "2020 IEEE 17th India Council International Conference (INDICON)", "year": 2020 }, { "abstract": "We propose a modelling framework using the fuzzy neural algorithm for generating various scenarios for better decision making. The model framework and the architecture responsible for daily decision making enhances information management system in transportation and logistics processes. This application augments the capability of 'Control Tower' as a visualization tool to decision making, finding possibilities, self learning and prevention of unwanted situations.", "author_names": [ "Rakesh Verma", "Saroj Koul", "Gurpreet Singh" ], "corpus_id": 226266623, "doc_id": "226266623", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Intelligent Decision Making: Using Control Tower at a Logistics Company", "venue": "2020 IEEE International Conference on Computing, Power and Communication Technologies (GUCON)", "year": 2020 }, { "abstract": "In a series of recent launch tests, North Korea has been improving the firepower of its missiles that can target South Korea. North Korea's missiles and submarines are capable of threatening targets in South Korea and are likely faster and more covert than the systems previously seen in North Korea. The advanced threats require that ROK Navy should not only detect them earlier than ever but also response quicker than ever. In addition to increasing threats, the number of young man that can be enlisted for military service has been dramatically decreasing. To deal with these difficulty, ROK navy has been making various efforts to acquire a SMART warship having enhanced defense capability with fewer human resources. For quick response time with fewer operators, ROK Navy should improve the efficiency of systems and control tower mounted on the ship by promoting the Ship System Integration. Total Ship Computing Environment (TSCE) is a method of providing single computing environment for all ship systems. Though several years have passed since the first proposal of TSCE, limited information has been provided and domestic research on the TSCE is still in its infancy. In this paper, we apply TSCE with open architecture (OA) to solve the problems that ROK Navy is facing in order to meet the requirements for the SMART ship. We first review the level of Ship System Integration of both domestic and foreign ships. Then, based on analyses of integration demands for SMART warship, we apply real time OA to design architecture for TSCE from functional view and physical view. Simulation result shows that the proposed architecture has faster response time than the response time of the existing architecture and satisfies its design requirements.", "author_names": [ "Gang-Soo Park", "Byeong-Chun Yoo", "Kyeongtaek Kim", "Bong-Wan Choi" ], "corpus_id": 226361596, "doc_id": "226361596", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A Methodology for the Ship System Integration with Open Architecture Focusing on the Total Ship Computing Environment based Architecture Building and Validation", "venue": "", "year": 2020 }, { "abstract": "Abstract In this paper we present a study on the mitigation of dynamic responses of a 10 MW monopile offshore wind turbine under coupled wind wave earthquake excitations. We have developed and validated the generic seismic coupled analysis and structural control architecture tool to overcome the limitation of numerical tools when examining the wind wave earthquake coupling effects. We investigated the dynamic responses of a 10 MW monopile offshore wind turbine under different loading combinations and found that the earthquake loading increases the tower top displacement and pile cap moment by 47.6% and 95.1% respectively, compared to the wind wave only condition. It is found that the earthquake induced vibration in the fore aft direction is mitigated by the wind and wave loadings due to the energy dissipated by the aerodynamic and hydrodynamic damping. In addition, the tower responses are dominated by the earthquake excitation. In order to alleviate the tower vibration induced by the earthquake, we implemented the structural control capability within the tool using tuned mass dampers. The tuned mass dampers with appropriately selected design parameters achieve a larger mitigation on the tower top displacement for the earthquake only condition compared to the coupled loading scenario. The reason is that the tuned mass damper is only effective in mitigating tower vibration, and it is not capable of reducing the tower elastic deformation which is the major contribution of the tower displacement for the coupled loading condition. In addition, we have found that a heavier tuned mass damper requires a lower tuned frequency to achieve a larger mitigation. A configuration for the mitigation control of the 10 MW offshore wind turbine is suggested by using a 5% mass ratio of the tuned mass damper.", "author_names": [ "Yang Yang", "Musa Bashir", "Chun Xiang Li", "Constantine Michailides", "Jin Wang" ], "corpus_id": 219744360, "doc_id": "219744360", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Mitigation of coupled wind wave earthquake responses of a 10 MW fixed bottom offshore wind turbine", "venue": "", "year": 2020 }, { "abstract": "[Introduction] In order to solve the control problem of Tower Concentrated Solar Power. Method Firstly based on the astronomical algorithms for calculating the position of the sun. Secondly, this article studied the main control technology of solar field control system, including system architecture, hardware and software design, feedback measurement program based on image processing. At last, it made an overall design and planning for the whole plant control system, and proposed a signal interface between solar field control system and DCS. Result This article invented a high precision and easy engineering implementation algorithm for heliostats tracking and controlling, which will reduce engineering cost and shorten the construction period. Conclusion The research is structural integrity and easy to be realized, it improves accuracy of heliostats tracking and controlling with a lower cost.", "author_names": [ "Tao Qiu", "Canling Xu", "Wei Wang" ], "corpus_id": 229561244, "doc_id": "229561244", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Research on Control System of Tower Concentrated Solar Power Plant", "venue": "", "year": 2020 }, { "abstract": "Abstract The aim of this work is to deploy an advanced Nonlinear Model Predictive Control (NMPC) approach for reducing the tower fatigue of a wind turbine (WT) tower while guaranteeing efficient energy extraction from the wind. To achieve this, different Artificial Neural Network (ANN) architectures are trained and tested in order to estimate the tower fatigue as a surrogate of the traditional Rainflow Counting (RFC) method. The ANNs receive data stemming from the tower top oscillation velocity and the previous fatigue state to directly estimate the fatigue progression. The results are compared to select the most convenient architecture for control implementation. Once an ANN is selected, an economic tracking NMPC (etNMPC) solution to reduce the fatigue of the WT tower is deployed in real time. The closed loop results are then compared to a baseline controller from a renowned WT simulation tool and a classic etNMPC implementation with indirect fatigue minimisation to demonstrate the improvement achieved with the proposed strategy. Finally, conclusions regarding computational cost and real time deployment capabilities are discussed, as well as future lines of research.", "author_names": [ "Julio Luna", "Ole Falkenberg", "Sebastien Gros", "Axel Schild" ], "corpus_id": 204144662, "doc_id": "204144662", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Wind turbine fatigue reduction based on economic tracking NMPC with direct ANN fatigue estimation", "venue": "", "year": 2020 }, { "abstract": "With the increasing importance of data, visibility has reached widespread importance within the logistics industry. Current efforts however focus on granular visibility, taking into consideration a small piece of the pool of available data. Being able to analyze and integrate available data in real time also known as Control Tower, however, remains uncharted territory. This thesis aims to 1) clarify the concept of control tower within the supply chain sector by providing a standardized definition, 2) provide a generalizable reference architecture for the supply chain control tower to assist transition toward it, 3) design a prototype for real time incident data collection and monitoring. The main goal of this research is as follows: To improve by designing a that in order to Conducting stakeholder analysis as well as literature review has helped in designing the reference architecture for the supply chain control tower that covers essential elements. The reference architecture has been validated by applying it to a logistics case. This has formed the basis for the design of the incident handling tool at Emon Group. The tool has been successfully implemented and used. Our tool helps with 1) real time data acquisition, 2) consolidated data storage, 3) real time incident monitoring. Since the data acquisition part has been of an issue prior to our research, a preliminary analysis of available data has been performed to 1) generate insight when possible, 2) detect improvement areas for our prototype. Our prototype has been validated by using expert opinion. The validation has been performed in two phases. First, the MoSCoW model has been filled to understand design requirements prior to the implementation. The final artifact has been assessed based on the MoSCoW requirements and interviews. The contribution of our work to the academic community is in two folds. First, a standard definition for the concept has been provided. Our work clarified the difference among types and elements of control tower which has caused enormous issues previously. Second, a generalizable reference architecture has been provided. The reference architecture elaborates on the common vocabulary and elements necessary for implementation. This work can also be a starting point for practitioners. We have started moving toward implementing the desired components of the architecture. The prototype has been designed to collect data and assist the real time exception detection. Our prototype can be further improved by expanding its coverage to the external processes of collaborative organizations.", "author_names": [ "Maryam Azani" ], "corpus_id": 237134424, "doc_id": "237134424", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Supply Chain Control Tower Reference Architecture for Exception Monitoring and Real Time Incident Management", "venue": "", "year": 2020 }, { "abstract": "The topic of solar control in architecture goes back over the relation between the shape and the light, which is a finely architectonic relationship. It is not a purely technical issue. The plastic properties of the architecture are emphasized by the light and the shadow. Le Corbusier's almost unrecognized work is the Tower of Shadows, built at the center of the Chandigarh's capitol as a part of the Fosse de la Consideration. The Tower of Shadows represents the construction of a method. It is a significant reference for the architectural design issues, in particular for the architects evermore called to solve the requests posed by the energy issues of which the solar control has a constitutive role. The contemporary challenges suggest us to get back to the architectural principles that should not be contradicted as Le Corbusier and other main exponents of the twentieth century had theorized. The Tower of Shadows in Chandigarh makes clear the principles and reasons that are at the base of the relationship between architecture and nature, in particular the relation with the sunlight. This construction, even in its elementary skeleton, alludes to an architecture. It is a manifesto.", "author_names": [ "Stefano Perego" ], "corpus_id": 216295875, "doc_id": "216295875", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Les conditions de la nature sont retrouvee: The Tower of Shadow in Chandigarh and Other Le Corbusier's Masterpieces", "venue": "", "year": 2020 }, { "abstract": "The work describes the use of VPL to optimize fundamental natural frequency of structures based on the example of steel lattice towers. For this purpose, a universal programming tool in Python using FEM was created, which allows the optimization of any bar structure in terms of its natural frequency. The capabilities of the tool are illustrated in several examples. It has been shown that by changing the tower geometry it is possible to obtain its higher spatial rigidity with a small increase in mass, it is possible to control the frequencies and forms of natural vibrations. Finally, the possibilities of further development of VPL applications in optimization of fundamental natural frequency of constructions and generative architecture were discussed.", "author_names": [ "Artur Wirowski" ], "corpus_id": 232097500, "doc_id": "232097500", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Optimization of Fundamental Natural Frequency of Structures Using VPL on the Example of Truss Towers", "venue": "", "year": 2020 }, { "abstract": "OBJECTIVE Designed to measure a diversity of executive functioning (EF) through classical neuropsychological tests, the Delis Kaplan Executive Function Scale (D KEFS) allows for the investigation of the neural architecture of EF. We examined how the D KEFS Tower, Verbal Fluency, Design Fluency, Color Word Interference, and Trail Making Test tasks related to frontal lobe volumes, quantifying the regional specificity of EF components. METHOD Adults from the Nathan Kline Institute Rockland Sample (NKI RS) an open access community study of brain development, with complete MRI (3T scanner) and D KEFS data were selected for analysis (N 478; ages 20 85) In a mixed effects model predicting volume, D KEFS task, D KEFS score, region of interest (ROI; 13 frontal, 1 occipital control) were entered as fixed effects with intercepts for participants as random effects. RESULTS \"Unitary\" EF (aggregate of D KEFS scores) was positively associated with superior frontal, rostral middle frontal, and lateral orbitofrontal volumes; a negative association was observed with frontal pole volume z score slope range 0.040 to 0.051) \"Diverse\" EF skills (individual D KEFS task scores) were differentially associated with two or three ROIs, respectively, but to a stronger extent z score slope range 0.053 to 0.103) CONCLUSIONS The neural correlates found for the D KEFS support the prefrontal modularity of both unitary (aspects of EF ability common to all tasks) and diverse EF. Our findings contribute to emerging evidence that aggregate measurements of EF may serve broader but less robust frontal neural correlates than distinct EF skills. (PsycINFO Database Record (c) 2019 APA, all rights reserved)", "author_names": [ "Ryan A Mace", "Abigail B Waters", "Kayle S Sawyer", "Taylor Turrisi", "David A Gansler" ], "corpus_id": 202564029, "doc_id": "202564029", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Components of executive function model regional prefrontal volumes.", "venue": "Neuropsychology", "year": 2019 } ]

[ { "abstract": "Parasitic inductances in power semiconductor packages affect the device switching speeds. The self inductance of the source terminal has been considered to be the main factor that limits the switching speed, but mutual inductances among the three terminals also influence the speed. This paper proposes a method to measure the source self inductance and the mutual inductances in the package using time domain reflectometry (TDR) and time domain transmissometry (TDT) that reveals the limitation of the switching speed. The measurement results agreed well with those of Q3D simulation.", "author_names": [ "H Iida", "Kazunori Hasegawa", "Ichiro Omura" ], "corpus_id": 195885223, "doc_id": "195885223", "n_citations": 2, "n_key_citations": 0, "score": 1, "title": "Mutual inductance influence to switching speed and TDR measurements for separating self and mutual inductances in the package", "venue": "2019 31st International Symposium on Power Semiconductor Devices and ICs (ISPSD)", "year": 2019 }, { "abstract": "The general method of calculation described in this paper is applicable to the calculation of the self and mutual inductance of thin walled solenoids of general shape with parallel axes in both coaxial and non coaxial relative positions. The method is based on the solution of integral equation, the validity of which is defined in the text and additionally the physical interpretation of each section of the equation is documented. The manner of utilization of the method is demonstrated for the cases known in systems with a circular solenoid and subsequently applied to the case of two solenoids of rectangular shape in a general relative position. In these cases, a similarly detailed algorithm is compiled and the measurements are then compared with the calculation results.", "author_names": [ "Vitezslav Pankrac" ], "corpus_id": 40138143, "doc_id": "40138143", "n_citations": 14, "n_key_citations": 1, "score": 0, "title": "The Algorithm for Calculation of the Self and Mutual Inductance of Thin Walled Air Coils of General Shape With Parallel Axes", "venue": "IEEE Transactions on Magnetics", "year": 2012 }, { "abstract": "The self inductance expressions given by Yu and Han (1987) for air core circular coils with rectangular cross sections, thin solenoids, and disk coils can be solved only by the numerical integration methods. We propose as an alternative a combined analytic and numeric approach. The approach brings some improvement in the calculations of self inductance of thin wall solenoids and disk coils that can be encountered in superconducting magnetic energy storage (SMES) problems. We also give a method for the calculation of mutual inductance of disk coils and of thin wall solenoids. The results are obtained in an analytical form over the complete elliptic integrals of the first and second kind and Heuman's Lambda function. It is important to mention that the kernels of these integrals are always continuous functions on intervals of integration, so singularities are avoided. The results enable one to calculate the self inductance and the mutual inductance of any thin air core coil precisely and fast. For practical applications, the results are so simple to use that we recommend them to avoid the problems of solving the singular cases.", "author_names": [ "Slobodan Babic", "Cevdet Akyel" ], "corpus_id": 122874381, "doc_id": "122874381", "n_citations": 130, "n_key_citations": 6, "score": 0, "title": "Improvement in calculation of the self and mutual inductance of thin wall solenoids and disk coils", "venue": "", "year": 2000 }, { "abstract": "This paper has presented an excitation circuit for self oscillating fluxgate DC current sensors with symmetrical bi excitation structures. It consists of two excitation windings, a multivibrator, an inverter, sampling resistors and an adder. The two sets of excitation currents will together produce circumferential magnetic fields in the ferromagnetic core. The strength of the magnetic field in the magnetic core is deduced according to the ampere loop law. And it is proved that the excitation current is still in line with the average current model when the mutual inductance effect has been taken into account and the circuit parameters are symmetrical. A relevant simulation for the degree of the circuit parameters' influence has also been performed to verify the results.", "author_names": [ "Yang Liu", "Yuan Lin", "Qinhong Lan", "Dong F Wang", "Ziqi Zhao", "Xuesong Shang", "Yipeng Hou", "Huan Liu", "Xu Yang" ], "corpus_id": 54455377, "doc_id": "54455377", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Excitation Circuit Design and Theoretical Model for Self Oscillating Fluxgate Current Sensors Considering Mutual Inductance Effect", "venue": "2018 IEEE 13th Annual International Conference on Nano/Micro Engineered and Molecular Systems (NEMS)", "year": 2018 }, { "abstract": "This paper extends a previous formula for the mutual inductance between single turn coils to include all coils in air with rectangular cross sections, without any restrictions on the dimensions (including overlapping coils) The formula is compared with a wide spectrum of examples from the literature and agreement is excellent in every case. Experimental results are presented to validate the formula for both solenoid and disk coils. The formula is relevant to coreless transformers, inductive coupling, wireless power transfer, and leakage inductance in resonant converters.", "author_names": [ "William Gerard Hurley", "Maeve Duffy", "Jun Xiong Zhang", "Ignacio Lope", "Bettina Kunz", "Werner Hugo Wolfle" ], "corpus_id": 44603758, "doc_id": "44603758", "n_citations": 39, "n_key_citations": 1, "score": 0, "title": "A Unified Approach to the Calculation of Self and Mutual Inductance for Coaxial Coils in Air", "venue": "IEEE Transactions on Power Electronics", "year": 2015 }, { "abstract": "The accurate estimation of the phase inductance is essential for proper machine design and efficient control strategy development. Within this paper two different analytical estimation methods for the airgap self inductance are compared and improved by introducing the airgap mutual inductance. Moreover, a more accurate new expression is proposed where the stator slotting is included. A validation has been carried out with FEM simulations in FLUX2D(r) where the new method offers 20% more accurate results than those achieved with other methods proposed in the literature.", "author_names": [ "A L Rodriguez", "D J Gomez", "Irma Villar", "Amaia Lopez-de-Heredia", "Ion Etxeberria-Otadui" ], "corpus_id": 13819101, "doc_id": "13819101", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "New improved estimation method for airgap self and mutual inductance in electric machines", "venue": "2013 15th European Conference on Power Electronics and Applications (EPE)", "year": 2013 }, { "abstract": "This paper presents a qualitative modeling for magnetization curve of self excited induction generator and effect of mutual inductance. During self excitation the variation in the value of magnetizing inductance, increases until it reaches a peak value and decreases until it attains saturated value then increasing at lower voltage and then decreasing at higher voltage as presented. The application of fuzzy clustering method and a rule processing to extract the qualitative properties curve magnetizing of self excited induction generator.", "author_names": [ "Mohamed Barara", "Mohamed Akherraz", "Ahmed Abbou", "Mohamed Moutchou", "Mohammed Larbi Elhafyani" ], "corpus_id": 46262900, "doc_id": "46262900", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Fuzzy modeling magnetizing curve of a self excited induction generator and effect of mutual inductance", "venue": "2013 International Renewable and Sustainable Energy Conference (IRSEC)", "year": 2013 }, { "abstract": "Inductance has been identified as an emerging troublemaker of interconnects for the next generation high speed digital VLSI design. As a result, accurate and fast inductance extraction is of crucial importance. Formulae based partial inductance extraction method approaches have been widely adopted for inductance extraction due to its simplicity and efficiency. However, there are so many inductance formulae in the literature and there seems luck of detail comparisons of those formulae to check their accuracy and applicability. In this paper, we carefully compare several well known partial self and mutual inductance formulae in details to check their range of applicability and validity. Since some formulae are originally derived for other applications where the parameter dimensions are quite different from the VLSI application, they are not numerically stable and accurate for all the concerned range of VLSI applications. As a result, carefulness must be deployed while applying those formulae.", "author_names": [ "Hyungsuk Kim", "Charlie Chung-Ping Chen" ], "corpus_id": 15412015, "doc_id": "15412015", "n_citations": 16, "n_key_citations": 0, "score": 0, "title": "Be Careful of Self and Mutual Inductance Formulae", "venue": "", "year": 2001 }, { "abstract": "In this paper, a new measurement method of the variations of the self and mutual inductances of a buried permanent magnet synchronous motor is proposed. This method allows the calculation of the inductance variations in the Concordia's reference frame without resorting to Park's assumption of sinusoidal pattern. Afterwards, these parameters are used to develop a new nonlinear torque control strategy. This controller simultaneously achieves accurate torque control (in fact the torque ripples are reduced to zero) and copper losses minimization. To reach this goal, the authors apply input output linearization techniques where the inputs are the stator voltages and the outputs are the provided torque and a judiciously chosen output linked to the copper losses in such a way that, when forced to zero, it leads to the maximum machine efficiency. The performance of the measurement method and of the control strategy is demonstrated by simulations. The results are compared to the ones obtained with a controller based on Park's assumptions.", "author_names": [ "Christophe Delecluse", "Damien Grenier" ], "corpus_id": 126275854, "doc_id": "126275854", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "A measurement method of the exact variations of the self and mutual inductances of a buried permanent magnet synchronous motor and its application to the reduction of torque ripples", "venue": "AMC'98 Coimbra. 1998 5th International Workshop on Advanced Motion Control. Proceedings (Cat. No.98TH8354)", "year": 1998 }, { "abstract": "This paper performs an analysis on the magnetic coupling of phases for a novel transverse flux machine (TFM) by comparison of the values of self and mutual inductance. It is shown that the proposed TFM inherits the merit of magnetic decoupling of phases as in traditional TFM, and thus can readily achieve fault tolerant operation and high precision control.", "author_names": [ "Qian Wang", "Jibin Zou", "Xinghe Fu", "Xintong Jiang" ], "corpus_id": 9831962, "doc_id": "9831962", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Investigation of magnetic coupling of phases in a novel transverse flux machine by consideration of self and mutual inductance", "venue": "Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation", "year": 2010 } ]

[ { "abstract": "This paper describes the fabrication and characterization of a reconfigurable Yagi Uda antenna based on a silicon reflector with a solid state plasma. The silicon reflector, composed of serially connected p i n diodes, forms a highly dense solid state plasma by injecting electrons and holes into the intrinsic region. When this plasma silicon reflector is turned on, the front realized gain of the antenna increases by more than 2 dBi beyond 5.3 GHz. To achieve the large gain increment, the structure of the antenna is carefully designed with the aid of semiconductor device simulation and antenna simulation. By using an aluminum nitride (AlN) substrate with high thermal conductivity, self heating effects from the high forward current in the p i n diode are efficiently suppressed. By comparing the antenna simulation data and the measurement data, we estimated the conductivity of the plasma silicon reflector in the on state to be between 104 and 105 S/m. With these figures, silicon material with its technology is an attractive tunable material for a reconfigurable antenna, which has attracted substantial interest from many areas, such as internet of things (IoT) applications, wireless network security, cognitive radio, and mobile and satellite communications as well as from multiple input multiple output (MIMO) systems.", "author_names": [ "Da-Jin Kim", "Jang-Soon Park", "Cheol Ho Kim", "Jae Hur", "Choong Ki Kim", "Young-Kyun Cho", "Jun-Bong Ko", "Bonghyuk Park", "Dongho Kim", "Yang-Kyu Choi" ], "corpus_id": 3311552, "doc_id": "3311552", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Reconfigurable Yagi Uda antenna based on a silicon reflector with a solid state plasma", "venue": "Scientific Reports", "year": 2017 }, { "abstract": "A plasma Yagi antenna was designed based on the traditional theoretical analysis of Yagi antenna, S11 parameters and patterns were simulated by CST software. According to the simulation, we manufacture plasma Yagi antenna principle prototype and S11 parameters are measured by a vector network analyzer, which is consistent with the simulation results. The results show that the plasma Yagi antenna has good directivity and high gain as the plasma density is high enough. The performance can be compared with the metal antenna.", "author_names": [ "Zhao Hui-chao", "Liu Shao-bin", "Li Yu-quan", "Yang Huan", "Wang Bei-yin" ], "corpus_id": 24269678, "doc_id": "24269678", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Design and research on the plasma Yagi antenna", "venue": "2013 Proceedings of the International Symposium on Antennas Propagation", "year": 2013 }, { "abstract": "A silicon based \"plasma antenna\" has attracted substantial attentions due to the semiconductor's natural ability to reconfigure itself from a metal state to an insulator state, and vice versa. The silicon enables the plasma antenna to operate as a highly practicable and low cost reconfigurable antenna because the external electromagnetic field is coupled with an electron crowded plasma channel. Given these characteristics, it was found that the silicon based plasma channel is capable of becoming a reconfigurable reflector which redirects electromagnetic energy by reflecting an incoming signal back toward its original direction. In this work, the performance of a silicon based reflector mounted on a Yagi Uda antenna is presented. A numerical simulation is carried out to demonstrate the feasibility of the antenna as a plasma channel, prior to its fabrication. The I V characteristics of the fabricated device are consequently shown, and finally the maximum gain along with its beam pattern is demonstrated.", "author_names": [ "Jae Hur", "Choong Ki Kim", "Da-Jin Kim", "Tae-Wook Bang", "Yang-Kyu Choi", "Youngjoo Cho", "Kim Cheol-ho", "Bonghyuk Park", "Park Jang-Soon", "Kim Dong-ho" ], "corpus_id": 115561586, "doc_id": "115561586", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Silicon Based Yagi Uda Antenna Reflector", "venue": "", "year": 2017 }, { "abstract": "Abstract A surface wave driven plasma Yagi Uda monopole array composed of several surface wave driven plasma monopole elements is proposed and studied with finite difference time domain simulation in this work. By varying the excitation power of plasma monopoles, a reconfigurable antenna is obtained for different frequencies. Plasma monopoles are fed by RF power at 500 MHz through an unequal power divider with a fixed power division ratio and a surface wave discharge at gas pressure of 0.4 mb. The results show that while the variations of the excitation power shift the Yagi Uda resonant frequency between 0.6 to 1.6 of the initial center frequency, the array gain and directivity remain approximately unchanged in the new resonant frequency. Since efficiency is critical to communication systems, the total efficiencies of the reconfigurable array were analyzed from the least to the highest excitation power. At the least excitation power the efficiency was found to be 58% compared with the 24% efficiency of the highest excitation power.", "author_names": [ "Fatemeh Sadeghikia", "F Hodjat-Kashani", "Jalil Rashed-Mohassel", "Abbas Ali Lotfi", "J Ghayoomeh-Bozorgi" ], "corpus_id": 122027176, "doc_id": "122027176", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "A Yagi Uda Plasma Monopole Array", "venue": "", "year": 2012 }, { "abstract": "The physics of turbulence is a key to understand the plasma confinement. In reversedfield pinch (RFP) turbulence plays an important role to sustain the plasma configuration. However, experimental study of the turbulence is not sufficient especially around the reversed field surface. Microwave imaging reflectometry (MIR) is a powerful technique to measure the two dimensional (2D) density turbulence localized at the cutoff surface directly. For this purpose, the MIR system in 20 GHz with large aperture imaging optics and a 4 x 4 Yagi Uda antenna array has been developed to measure the turbulence around rcut/a 0.7 0.9 in a large RFP device, TPE RX. The MIR signal Ae is detected by the quadrature detectors, with which the amplitude A and IQ signals (cosine and sine components of the phase ph) of the reflection wave can be obtained. In this system, the spatial resolution is 3.7 cm and the temporal resolution is 1ms. Since this is the first MIR system as a turbulence diagnostics, comparison between the simulation and a laboratory test of MIR system has been carried out. A numerical model based on the Huygens Fresnel equation is used to simulate the MIR signal. Main results in this test and simulation are as follows: (1) the phase ph corresponds to the displacement of the cutoff surface in the radial direction; (2) the amplitude A corresponds to the reflection power, which is modulated by the shape of the cutoff surface; (3) the coherence length of the complex IQ signals is longer than that of the amplitude signals; (4) MIR is valid with the condition 4kdL/D 1 to measure the motion of the cutoff surface. Here L, D, k and d denote distance between cutoff and lens, diameter of the lens, perpendicular wavenumber and radial displacement of the cutoff, respectively. The fluctuations measured in TPE RX mainly distribute in the range of 4kdL/D 0.8 which suggests present MIR system can make a clear image of the cutoff surface in plasma. In the RFP plasma, the generalized ohm's law is written as ej| E| u x B where denotes parallel to the magnetic field (it is poloidal at the reversal surface) In the standard plasma, the poloidal current is driven by the electromotive forces u x B >p, which is produced by the fluctuations in the plasma (dynamo action) In the pulsed poloidal current drive (PPCD) plasma, the additional external field in the poloidal direction is generated and the poloidal current can be directly driven by this external electric field. As a result, the fluctuations may be suppressed with PPCD. In this work, the developed turbulence techniques are as follows: (1) the cross correlation, (2) the wavelet, (3) the maximum entropy method (MEM) (4) the fluctuation", "author_names": [ "Zhongbing Shi" ], "corpus_id": 126109587, "doc_id": "126109587", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Study of turbulence in a reversed field pinch plasma by microwave imaging reflectometry", "venue": "", "year": 2009 }, { "abstract": "A Yagi plasma antenna model was established by HFSS according to the relationship between plasma dielectric constant and electron density. The patterns were simulated by changing plasma parameters and the number of director dipoles. Results show that when the passive vibrators were switched off, the antenna is omnidirectional antenna. The directionality increases with the increase of the number of passive dipole and the main lobe of which narrows down. Then the plasma Yagi antenna model is established by plasma tube, the gain changed by changing the number of passive dipoles, so the plasma Yagi antenna has a very good reconfigurability. Results prove that the feasibility of the plasma Yagi antenna can be used on AIS base station of Ships' Routeing waters. It can promote the communication and capability of maritime supervision in Ships' Routeing waters. http:/www.transnav.eu the International Journal on Marine Navigation and Safety of Sea Transportation Volume 14", "author_names": [ "Yang Sun", "Yuli Chen", "Fancun Kong", "Fei Zhan", "Jiansen Zhao" ], "corpus_id": 221138254, "doc_id": "221138254", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Research on Radiation Characteristics of Plasma Yagi Antenna Based on AIS base station in Ships' Routeing Waters", "venue": "", "year": 2020 }, { "abstract": "In order to reduce the operating cost and improve the benefits of communication system, it is a feasible scheme to reduce the number of antennas used while ensuring the communication quality. Because reconfigurable antenna has the characteristic of automatically changing a certain electrical characteristic parameter, it has become one of the hotspots in antenna research. In the design of this paper, reconfigurable antenna is realized by changing the working state of PIN diodes embedded in external feed matching network. The design of Yagi antenna is introduced below.", "author_names": [ "Lili Zhao", "Pengpeng Yu", "Xinsheng Zhou", "Qicai Dong", "Ziru Wang", "Haiyan Li", "Li-na Su" ], "corpus_id": 213405399, "doc_id": "213405399", "n_citations": 0, "n_key_citations": 0, "score": 2, "title": "Simulation Design of Reconfigurable Multifrequency Yagi Antenna", "venue": "", "year": 2020 }, { "abstract": "Abstract An electronically controlled plasma reflector antenna array is presented in term of Yagi antenna technology and plasma theory in this paper. The array comprised of a plasma symmetrical dipole in the center and 6 plasma column antennas uniformly around the dipole. When only the active plasma dipole and one of passive columns are energized, they perform like conductive metals capable to radiate radio signal like a two element plasma Yagi antenna. Pattern reconfigurability of the antenna array can be achieved by sequentially exciting one of 6 plasma columns, and the plasma antenna array also produces better gain through increasing the number of plasma reflectors. Due to the adoption of equal amplitude and phase feeding technology, it greatly reduces the technical difficulty of the implementation of pattern reconfigurability. On the other hand, if all of plasma columns are off, there is only minor reflection from dielectric tubes, and hence, the plasma antenna array has stealth performance.", "author_names": [ "Bo Yin", "Zu-Fan Zhang" ], "corpus_id": 115516570, "doc_id": "115516570", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "A novel reconfigurable radiating plasma antenna array based on Yagi antenna technology", "venue": "", "year": 2018 }, { "abstract": "In this paper, the design and implementation of a plasma antenna array using Yagi Uda reflectors with beamforming is discussed. The structure consists of the circular array of plasma tubes enclosed a unipolar L band monopole antenna. Beamforming is possible using stimulated plasma tubes. The combination of the above structure with plasma excitation controller provides smart beamforming and uses of the Yagi Uda structure increases gain compared to previous models. An experimental model in the L band is fabricated that shows a good agreement between simulated and measured results.", "author_names": [ "Fatemeh Sadat Mohseni Armaki", "Seyyed Hossein Mohseni Armaki" ], "corpus_id": 132793518, "doc_id": "132793518", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Design and Fabrication of Plasma Yagi Uda Array Antenna With Beamforming", "venue": "IEEE Transactions on Plasma Science", "year": 2019 }, { "abstract": "In this paper, a pattern reconfigurable Yagi Uda antenna based on bistable structural materials is designed. The antenna comprises a director, a driven dipole, a reflector and a substrate. By applying composite laminates as the substrate that holds two stable configurations with opposite curvations, the pattern reconfiguration performance can be realized, where the direction of maximum radiation differs between two states by 114deg. This antenna operates at 2.4 GHz with a relative bandwidth of 10% a gain of 7.49 dB and a front to back ratio of 8.2 dB. This design can be applied to aircraft control systems.", "author_names": [ "Yuwei Zhang", "Zhuang Chen", "Shu Lin", "Jing-xuan Cui", "Jian-lin Jiao", "Hong-jun Zhang", "Alexander Denisov" ], "corpus_id": 210889166, "doc_id": "210889166", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Simulation Design of Pattern Reconfigurable Yagi Uda Antenna Using Bistable Composite Laminates", "venue": "2019 International Symposium on Antennas and Propagation (ISAP)", "year": 2019 } ]

[ { "abstract": "As a fascinating conjugated polymer, graphitic carbon nitride (g C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal free and visible light responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and \"earth abundant\" nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g C3N4 and g C3N4 based nanocomposites, including (1) nanoarchitecture design of bare g C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template free synthesis routes, (2) functionalization of g C3N4 at an atomic level (elemental doping) and molecular level (copolymerization) and (3) modification of g C3N4 with well matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The construction and characteristics of each classification of the heterojunction system will be critically reviewed, namely metal g C3N4, semiconductor g C3N4, isotype g C3N4/g C3N4, graphitic carbon g C3N4, conducting polymer g C3N4, sensitizer g C3N4, and multicomponent heterojunctions. The band structures, electronic properties, optical absorption, and interfacial charge transfer of g C3N4 based heterostructured nanohybrids will also be theoretically discussed based on the first principles density functional theory (DFT) calculations to provide insightful outlooks on the charge carrier dynamics. Apart from that, the advancement of the versatile photoredox applications toward artificial photosynthesis (water splitting and photofixation of CO2) environmental decontamination, and bacteria disinfection will be presented in detail. Last but not least, this comprehensive review will conclude with a summary and some invigorating perspectives on the challenges and future directions at the forefront of this research platform. It is anticipated that this review can stimulate a new research doorway to facilitate the next generation of g C3N4 based photocatalysts with ameliorated performances by harnessing the outstanding structural, electronic, and optical properties for the development of a sustainable future without environmental detriment.", "author_names": [ "Wee-Jun Ong", "Lling-Lling Tan", "Yun Hau Ng", "Siek-Ting Yong", "Siang-Piao Chai" ], "corpus_id": 206536333, "doc_id": "206536333", "n_citations": 3155, "n_key_citations": 8, "score": 1, "title": "Graphitic Carbon Nitride (g C3N4) Based Photocatalysts for Artificial Photosynthesis and Environmental Remediation: Are We a Step Closer To Achieving Sustainability?", "venue": "Chemical reviews", "year": 2016 }, { "abstract": "Abstract Herein, two dimensional (2D) TiO2 mesoporous nanosheets with three to four C3N4 layers grown in situ are employed to design a core shell 2D/2D van der Waals heterojunction (TiO2/C3N4) Edge terminated zero dimensional (0D) Ti3C2 MXene quantum dots (TCQD) are subsequently integrated in the C3N4 surface via electrostatic interactions. The constructed 2D/2D/0D TiO2/C3N4/Ti3C2 composite heterojunction photocatalyst exhibits enhanced CO2 reduction activity compared to TiO2, C3N4, TiO2/C3N4, C3N4/Ti3C2 for CO and CH4 production. A step scheme (S scheme) charge transfer mechanism operates for the prepared samples during CO2 reduction, as authenticated by in situ X ray photoelectron spectroscopy and electron paramagnetic resonance analysis. This study provides a paradigm of a rational structural design for regulating the number and type of heterointerfaces and further insights into the mechanism of multijunction photocatalysts.", "author_names": [ "Fei-Feng He", "Bicheng Zhu", "Bei Cheng", "Jiaguo Yu", "Wingkei Ho", "Wojciech Macyk" ], "corpus_id": 218798460, "doc_id": "218798460", "n_citations": 139, "n_key_citations": 0, "score": 0, "title": "2D/2D/0D TiO2/C3N4/Ti3C2 MXene composite S scheme photocatalyst with enhanced CO2 reduction activity", "venue": "", "year": 2020 }, { "abstract": "Abstract Designing carbonaceous materials modified g C3N4 based photocatalytic system with broadband solar absorption from the visible to near infrared (NIR) region for photocatalytic H2 evolution (PHE) remains a big challenge. Herein, urea formaldehyde resin carbonized nitrogen doped carbon (UFR NC) ribbons modified g C3N4 nanosheets were prepared by a facile thermal treatment method. Experimental results imply that g C3N4/UFR NC composites not only show larger specific surface area (SSA) better crystallinity and outstanding stability but also exhibit faster separation of charge carriers, in which the UFR NC ribbons are more apt to accept electrons. Additionally, g C3N4/UFR NC composites possess superior optical adsorption from visible to NIR light and the band gap can be easily adjusted by changing the content of UFR NC ribbons. Surprisingly, g C3N4/UFR NC0.02 exhibits the highest PHE activity (84.32 umol h 1) which is over 54.75 and 6.51 times higher than that of the g C3N4 obtained by direct calcination of melamine (g C3N4 M) and direct calcination of urea (g C3N4 U) under visible light, and the apparent quantum efficiency (AQE) reaches 6.2% at 420 nm. In addition, the g C3N4/UFR NC0.02 displays an enhanced PHE activity of 26.59 umol h 1 and 0.45 umol h 1 under the blue visible (l 475 nm) and NIR light irradiation (l 800 nm) And the PHE activity of g C3N4/UFR NC0.02 has no obvious change after fourteen runs within 70 h. Our results suggest that constructing carbonaceous materials modified g C3N4 based photocatalytic system will be a promising strategy to PHE.", "author_names": [ "Huinan Che", "Guangbo Che", "Pengjie Zhou", "Chunbo Liu", "Hongjun Dong", "Chunxue Li", "Ning Song", "Chunmei Li" ], "corpus_id": 203937077, "doc_id": "203937077", "n_citations": 105, "n_key_citations": 0, "score": 1, "title": "Nitrogen doped carbon ribbons modified g C3N4 for markedly enhanced photocatalytic H2 production in visible to near infrared region", "venue": "", "year": 2020 }, { "abstract": "Abstract To efficiently facilitate the charge transfer by constructing heterojunction photocatalysts is a promising strategy for improving solar driven hydrogen generation. Herein, a novel 2D/2D nanojunction architecture of Ba5Nb4O15/g C3N4 photocatalysts with powerful interfacial charge transfer are rationally designed. Advanced electron microscopy analysis elucidates the layered hexagonal nanosheets were coupled on the surface of ultrathin g C3N4 forming a 2D/2D nanojunction. More importantly, such characterizations and theoretical calculations together illustrate that a strong interfacial charge transfer existed between the g C3N4 layer and Ba O layer of the Ba5Nb4O15 nanosheets, which fostered the efficient transfer and provided more massive reactive centers for photocatalytic hydrogen evolution. The unique 2D/2D structure in Ba5Nb4O15/g C3N4 heterojunction leads to generate numerous charge transfer nanochannels, and which could accelerate the interfacial charge separation efficiency to a great extent. Ba5Nb4O15/g C3N4 (1:20) sample displayed a remarkable photocatalytic H2 evolution rate (2.67 mmol h 1 g 1) in oxalic acid solution, nearly 2.35 times higher than that of single g C3N4 under visible light and exhibits an outstanding photostability even after four cycles. This work would provide a new insight for the design of 2D/2D heterojunction photocatalyst with efficient interfacial charge transfer and separation for solar to H2 conversion.", "author_names": [ "Kai Wang", "Yuan Li", "Jun Li", "Gaoke Zhang" ], "corpus_id": 165006279, "doc_id": "165006279", "n_citations": 102, "n_key_citations": 0, "score": 1, "title": "Boosting interfacial charge separation of Ba5Nb4O15/g C3N4 photocatalysts by 2D/2D nanojunction towards efficient visible light driven H2 generation", "venue": "", "year": 2020 }, { "abstract": "Abstract By heating g C3N4 powder in the hydrogen atmosphere, nitrogen defects were introduced into the framework of g C3N4 where the nitrogen atoms in g C3N4 were reacted and partially removed with hydrogen. The effects of nitrogen defects on the electronic structure, optical properties, generation of reactive oxygen species and photocatalytic NO oxidation of g C3N4 were investigated by combining experimental characterization and DFT theoretical calculations. The N defect is located at N2C sites and can be tuned by the H2 treating temperature. The obtained N defective g C3N4 products possessed narrower bandgap adjusted by surface N defects and were able to promote the separation of photoexcited charge carries and produce reactive oxygen species more efficiently than pristine g C3N4. The NO+ reaction intermediate was formed on the N defects sites and enabled an accelerated photocatalytic reaction that contributed to enhanced photocatalytic NO removal. The NO removal ratio on N defects g C3N4 obtained at 600 degC (CH H 600) was 2.6 times that of pristine g C3N4 under visible light irradiation. The present work could provide new insights into the understanding of the role of N defects in g C3N4 and application of photocatalytic technology for efficient air purification.", "author_names": [ "Jiazhen Liao", "Wenquan Cui", "Jieyuan Li", "Jianping Sheng", "Hong Wang", "Xing'an Dong", "Peng Chen", "Guangming Jiang", "Zhiming M Wang", "Fan Dong" ], "corpus_id": 199067778, "doc_id": "199067778", "n_citations": 107, "n_key_citations": 0, "score": 0, "title": "Nitrogen defect structure and NO+ intermediate promoted photocatalytic NO removal on H2 treated g C3N4", "venue": "", "year": 2020 }, { "abstract": "A graphite carbon nitride (g C3N4) modified Bi4O5I2 composite was successfully prepared in situ via the thermal treatment of a g C3N4/BiOI precursor at 400degC for 3 hr. The as prepared g C3N4/Bi4O5I2 showed high photocatalytic performance in Methyl Orange (MO) degradation under visible light. The best sample presented a degradation rate of 0.164 min 1, which is 3.2 and 82 times as high as that of Bi4O5I2 and g C3N4, respectively. The g C3N4/Bi4O5I2 was characterized by X ray powder diffractometer (XRD) scanning electron microscopy (SEM) transmission electron microscopy (TEM) Raman, X ray photoelectron spectroscopy (XPS) ultraviolet visible diffuse reflectance spectra (DRS) electrochemical impedance spectroscopy (EIS) and transient photocurrent response in order to explain the enhanced photoactivity. Results indicated that the decoration with a small amount of g C3N4 influenced the specific surface area only slightly. Nevertheless, the capability for absorbing visible light was improved measurably, which was beneficial to the MO degradation. On top of that, a strong interaction between g C3N4 and Bi4O5I2 was detected. This interplay promoted the formation of a favorable heterojunction structure and thereby enhanced the charge separation. Thus, the g C3N4/Bi4O5I2 composite presented greater charge separation efficiency and much better photocatalytic performance than Bi4O5I2. Additionally, g C3N4/Bi4O5I2 also presented high stability. *O2 and holes were verified to be the main reactive species.", "author_names": [ "Zhe-sheng Feng", "Lin Zeng", "Qingle Zhang", "Shifeng Ge", "Xinyue Zhao", "Hongjun Lin", "Yiming He" ], "corpus_id": 197269183, "doc_id": "197269183", "n_citations": 94, "n_key_citations": 0, "score": 0, "title": "In situ preparation of g C3N4/Bi4O5I2 complex and its elevated photoactivity in Methyl Orange degradation under visible light.", "venue": "Journal of environmental sciences", "year": 2020 }, { "abstract": "Abstract Z scheme type photocatalysts with two photochemical systems of graphic C3N4 (g C3N4) and anatase TiO2 (A TiO2) nanocrystals combined with Au nanoparticles (NPs) (Au/A TiO2)@g C3N4] were successfully fabricated. The surface heterojunction between coexposed {001} and {101} facets in A TiO2 nanocrystals improves separation efficiency of photoelectrons and holes. Supported Au NPs gather and transfer the stimulated electrons originated from A TiO2 to g C3N4. Wrapped g C3N4 nanosheets can not only trap the photoelectrons, but also its surface p bond can improve adsorption capabilities for CO2. (Au/A TiO2)@g C3N4 catalysts with enriched surface photoelectrons and CO2 exhibit high photocatalytic activity for visible light driven conversion of CO2, i.e. the formation rates of CH4 and CO over (Au/A TiO2)@C3N4 5 catalyst are 37.4 and 21.7 mmol g 1 h 1, respectively. The selectivity for CO2 reduction is higher than 99% and the selectivity of CH4 product increases from 1.4% to 63.3% The innovation of Z scheme type photocatalysts is expected to provide new inspiration for artificial simulation photosynthesis.", "author_names": [ "Chujun Wang", "Yilong Zhao", "Hui Xu", "Yifei Li", "Yuechang Wei", "Jian Liu", "Zhen Zhao" ], "corpus_id": 208747572, "doc_id": "208747572", "n_citations": 98, "n_key_citations": 0, "score": 0, "title": "Efficient Z scheme photocatalysts of ultrathin g C3N4 wrapped Au/TiO2 nanocrystals for enhanced visible light driven conversion of CO2 with H2O", "venue": "", "year": 2020 }, { "abstract": "With the fast development of industrial and human activity, large amounts of persistent organic pollutants, heavy metal ions and radionuclides are released into the natural environment, which results in environmental pollution. The efficient elimination of the natural environment is crucial for the protection of environment to against the pollutants' toxicity to human beings and living organisms. Graphitic carbon nitride (g C3N4) has drawn multidisciplinary attention especially in environmental pollutants' cleanup due to its special physicochemical properties. In this review, we summarized the recent works about the synthesis of g C3N4, element doping, structure modification of g C3N4 and g C3N4 based materials, and their application in the sorption, photocatalytic degradation and reduction solidification of persistent organic pollutants and heavy metal ions. The interaction mechanisms were discussed from advanced spectroscopic analysis and computational approaches at molecular level. The challenges and future perspectives of g C3N4 based materials' application in environmental pollution management are presented in the end. This review highlights the real applications of g C3N4 based materials as adsorbents or photocatalysts in the adsorption reduction solidification of metal ions or photocatalytic degradation of organic pollutants. The contents are helpful for the undergraduate students to understand the recent works in the elimination of organic/inorganic pollutants in their pollution management.", "author_names": [ "Zhongshan Chen", "Sai Zhang", "Yang Liu", "Njud Saleh Alharbi", "Samar Omar Rabah", "Suhua Wang", "Xiangxue Wang" ], "corpus_id": 218657669, "doc_id": "218657669", "n_citations": 79, "n_key_citations": 0, "score": 1, "title": "Synthesis and fabrication of g C3N4 based materials and their application in elimination of pollutants.", "venue": "The Science of the total environment", "year": 2020 }, { "abstract": "Abstract In this paper, an ultrathin 2D/2D Ti3C2/g C3N4 heterojunction was synthesized by direct calcination the mixture of bulk Ti3C2 and urea, where urea not only acts as the gas template to exfoliate Ti3C2 into nanosheets, but also as the precursor of g C3N4 to craft Ti3C2/g C3N4 heterojunction. CO2 photoreduction activity tests reveal that pure g C3N4 (UCN) exhibits very weak photoactivity. However, when Ti3C2 was coupled with g C3N4, the photocatalytic performance is soaringly enhanced. The optimal sample (10TC) shows the yields of 5.19 and 0.044 mmol h 1 g 1 for CO and CH4, respectively, and the total CO2 conversion is 8.1 times higher than that of UCN. The enhanced CO2 photoreduction activity is mainly attributed to the combined effects of (1) improved CO2 adsorption and activation, and (2) the construction of ultrathin 2D/2D Ti3C2/g C3N4 heterojunction, where the intimate contact stimulates an efficient spatial separation of photo excited charge carriers.", "author_names": [ "Chao Yang", "Qiuyang Tan", "Qin Li", "Jie Zhou", "Jiajie Fan", "Bo Li", "Jie Sun", "Kangle Lv" ], "corpus_id": 212772064, "doc_id": "212772064", "n_citations": 95, "n_key_citations": 0, "score": 0, "title": "2D/2D Ti3C2 MXene/g C3N4 nanosheets heterojunction for high efficient CO2 reduction photocatalyst: Dual effects of urea", "venue": "", "year": 2020 }, { "abstract": "Abstract The photocatalytic overall water splitting is an ideal pathway to generate hydrogen gas for sustainable energy production. Herein, the 2D/2D Co3(PO4)2/g C3N4 heterojunctions were successfully synthesized for overall water splitting from pure water by a simple direct precipitation route under the effect of coulomb electrostatic interaction. The introduction of Co3(PO4)2 nanosheets broadens the light absorption range of Co3(PO4)2/g C3N4 heterojunction, and in addition, the unusual 2D/2D heterostructure can provide more contact areas to promote the interfacial charge transfer between g C3N4 nanosheets and Co3(PO4)2 nanosheets, which considerably enhances the photogenerated charge separation. Among the Co3(PO4)2/g C3N4 heterojunctions, 35% Co3(PO4)2/g C3N4 exhibits the optimal H2 and O2 evolution rates which are 375.6 and 177.4 mmol g 1 h 1, respectively. Moreover, the apparent quantum efficiency of the 35% Co3(PO4)2/g C3N4 reaches up to 1.32% at 420 nm. Furthermore, the 2D/2D Co3(PO4)2/g C3N4 composite possesses the prominent stability and recyclability, testifying a potential application for the conversion of the sustainable energy.", "author_names": [ "Weilong Shi", "Mingyang Li", "Xiliu Huang", "Hongji Ren", "Chao Yan", "Feng Guo" ], "corpus_id": 204121136, "doc_id": "204121136", "n_citations": 79, "n_key_citations": 0, "score": 1, "title": "Facile synthesis of 2D/2D Co3(PO4)2/g C3N4 heterojunction for highly photocatalytic overall water splitting under visible light", "venue": "", "year": 2020 } ]

[ { "abstract": "The invention discloses a programmable tracking circuit of an SA (sense amplifier) of an SRAM (static random access memory) The programmable tracking circuit comprises a word line driving circuit (WLDRIVER) a programmable timing control circuit and a sense amplifier driving circuit (SA Driver) wherein the WLDRIVER is used for driving word line signals WL and DWL; the programmable timing control circuit is controlled by DWL, and is a programmable array DBL (duplicated bit line) discharging circuit mainly comprising NMOSs (N channel metal oxide semiconductors) the SA Driver is used for controlling the on and off of the SA. According to the programmable tracking circuit, the influence of process variations, voltage and temperature on the on off time of the SA is avoided.", "author_names": [ "" ], "corpus_id": 140226822, "doc_id": "140226822", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Programmable tracking circuit of SA (sense amplifier) of SRAM (static random access memory)", "venue": "", "year": 2013 }, { "abstract": "An analysis of timing and input referred offset of sense amplifiers (SA) is presented, and a new SA architecture with capacitive offset correction is proposed. Offset sources are first analyzed in a cross coupled latch based SA design, and the analysis is then extended to the proposed SA. The results show the proposed offset correction technique can reduce the total sensing time by up to 40% while eliminating dynamic offset due to the difference in resolving inverters trip points. A self timed SRAM with a new replica timing structure is designed to generate optimal SA enable timing with respect to the total input referred offset. Calculations for timing delay and offset are compared with simulation results in both a conventional and a proposed SA design. The presented simulation results are based on a 10 Kb CMOS SRAM array in 130 nm BiCMOS SiGe technology operating at a 500 MHz clock and 1.5 V supply.", "author_names": [ "Roman Fragasse", "Ramy Tantawy", "Brian Dupaix", "Trevor Dean", "D diSabato", "Matthew R Belz", "Dale Shane Smith", "Jamin Mccue", "Waleed Khalil" ], "corpus_id": 149487378, "doc_id": "149487378", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Analysis of SRAM Enhancements Through Sense Amplifier Capacitive Offset Correction and Replica Self Timing", "venue": "IEEE Transactions on Circuits and Systems I: Regular Papers", "year": 2019 }, { "abstract": "A novel cascade control replica bitline delay (CCRBD) technique has been proposed to reduce timing process variation of SRAM sense amplifier in this brief. The main idea of this technique is that both replica bitlines (RBLs) are utilized, and one is cascade controlled by the other. Simulation results show that the timing process variation of this technique decreases by 41.83% compared with conventional strategy. Simultaneously, the cycle time is also reduced by 19% at the supply voltage of 800mV in TSMC 65 nm technology. Additionally, the area of the proposed scheme is nearly the same as that with conventional replica bitline technique.", "author_names": [ "Chunyu Peng", "Youwu Tao", "Wenjuan Lu", "Zhengping Li", "Xinchun Ji", "Jinlong Yan", "Junning Chen" ], "corpus_id": 41383549, "doc_id": "41383549", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "A novel cascade control replica bitline delay technique for reducing timing process variation of SRAM sense amplifier", "venue": "IEICE Electron. Express", "year": 2015 }, { "abstract": "", "author_names": [ "Bhupendra Singh Reniwal" ], "corpus_id": 117283785, "doc_id": "117283785", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Variability aware design of SRAM in conventional and non conventional MOS technologies a sense amplifier perspective", "venue": "", "year": 2017 }, { "abstract": "Variability and reliability have become major threats in nano scale era. Both leads to variation in transistor parameters that eventually affect the performance parameters. One of the failure mechanism is Bias Temperature Instability (BTI) which impacts mobility and threshold voltage (Vth) of the transistor. This paper investigates the impact of BTI on SRAM sense amplifier at different process corners along with variability effect in 45nm technology. The results depict that, impact of Positive BTI (PBTI) is less than Negative BTI (NBTI) on sensing delay of sense amplifier. Moreover across all process corners sensing delay increases as supply voltage (Vbd) decreases and temperature increases. A surrogate model has been developed by using support vector machine (SVM) for variability and reliability analysis of sensing delay. Adaptive learning is used in order to develop the model with less number of samples which attributes to less run time. Evaluation of single sample of sensing delay requires 0.077ms and 0.081ms for read 0 and read 1 respectively. Correlation coefficient has been obtained between HSPICE and SVM in order to validate the model. The values of correlation coefficients are 0.9996 and 0.9997 for read 0 and read 1 respectively.", "author_names": [ "Sapna Khandelwal", "Jyoti Meena", "Lokesh Garg", "Dharmendar Boolchandani" ], "corpus_id": 3080954, "doc_id": "3080954", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Variability and reliability aware surrogate model for sensing delay analysis of SRAM sense amplifier", "venue": "2016 20th International Symposium on VLSI Design and Test (VDAT)", "year": 2016 }, { "abstract": "Random variations play a critical role in determining SRAM yield, by affecting both the bitcell and the read sense amplifiers (SA) In this work, a process control monitor for SRAM SA offset is proposed and implemented in 28nm LP CMOS technology. The monitor provides accurate measurement of SA offset from a large sample size and accounts for all proximity effects that may affect the SA offset. The all digital design of the monitor makes it adequate for low voltage testing, high speed data collection, and ease of migration to newer technologies. Detailed measurement results are provided for two of the most commonly used sense amplifiers at different supply and temperature conditions. Statistical yield estimation using the measured sense amplifier offset shows good correlation with measured yield for a 512Kb SRAM. The monitor is a critical part of SRAM silicon yield validation, which is becoming of increasing importance with technology scaling, and the significant increase in random variations.", "author_names": [ "Mohamed H Abu-Rahma", "Ying Chen", "Wing Sy", "Wee Ling Ong", "Leon Yeow Ting", "Sei Seung Yoon", "Michael Han", "Esin Terzioglu" ], "corpus_id": 2846654, "doc_id": "2846654", "n_citations": 32, "n_key_citations": 3, "score": 0, "title": "Characterization of SRAM sense amplifier input offset for yield prediction in 28nm CMOS", "venue": "2011 IEEE Custom Integrated Circuits Conference (CICC)", "year": 2011 }, { "abstract": "Random variations play a critical role in determining SRAM yield because they affect both the bitcell and the read sense amplifiers (SA) In this chapter, a process control monitor for SRAM SA offset is proposed and implemented in 28nm LP CMOS technology. The monitor accurately measures SA offset from a large sample size and accounts for all the layout proximity effects. The all digital design of the monitor makes it appropriate for low voltage testing, high speed data collection, and migration to newer technologies. Detailed measurement results are provided for two of the most commonly used sense amplifiers at different supply voltage and temperature conditions. Statistical yield estimation using the measured sense amplifier offset correlates well with measured yield for a 512Kb SRAM.", "author_names": [ "Mohamed H Abu-Rahma", "Mohab H Anis" ], "corpus_id": 59662735, "doc_id": "59662735", "n_citations": 4, "n_key_citations": 1, "score": 0, "title": "Characterization of SRAM Sense Amplifier Input Offset for Yield Prediction", "venue": "", "year": 2013 }, { "abstract": "", "author_names": [ "Chunyu Peng", "Youwu Tao", "Wenjuan Lu", "Zhengping Li", "Xinchun Ji", "Jinlong Yan", "Junning Chen" ], "corpus_id": 207226599, "doc_id": "207226599", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Erratum: A novel cascade control replica bitline delay technique for reducing timing process variation of SRAM sense amplifier [IEICE Electronics Express Vol 12 (2015) No 5 pp 20150102]", "venue": "IEICE Electron. Express", "year": 2015 }, { "abstract": "A highly sensitive sense amplifier for static random access memory (SRAM) with a very low offset voltage, negligible static current, and low kickback noise is presented in this paper. We propose to use a preamplifier stage instead of positive feedback between the input and the sense amplifier to improve the sensitivity of the sense amplifier. The proposed sense amplifier is designed and simulated using 0.18 mm CMOS technology node. With a supply voltage of 1.4 V and an operating frequency of 1 GHz, the proposed sensing amplifier has a sensing delay of 193.2 ps, which is 85% better than conventional designs. The sense amplifier has an offset voltage of 18 mV.", "author_names": [ "Pallab Pran Dutta", "B ArunMohan", "Saroj Mondal" ], "corpus_id": 221719279, "doc_id": "221719279", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "An 18 mV Offset, 193 ps Sensing Delay, and Low Static Current Sense Amplifier for SRAM", "venue": "2020 24th International Symposium on VLSI Design and Test (VDAT)", "year": 2020 }, { "abstract": "Abstract In modern computer memory role is to sense the low power signals, this paper optimally finds the best solutions to improve the performance of the Sense Amplifier for CMOS SRAM. The circuit is designed and simulated in the Advanced Design System. The simulation result shows that the required output voltage 1.2 V is available after addition of an Inverter at the output having identical PMOS NMOS in the circuit. It is observed that the performance of the sense amplifier has been improved drastically. To have better results now our future work will concern the 22 nm technology.", "author_names": [ "Raja Saravana Kumar Selvakumar", "M Ganesh Lakshmana Kumar", "S Raja Gopal" ], "corpus_id": 201141371, "doc_id": "201141371", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Material analysis of high degree of variability in thin CMOS for SRAM current sense amplifier", "venue": "", "year": 2020 } ]

[ { "abstract": "In this paper, we review the recent progress in the resistive random access memory (ReRAM) technology, one of the most promising emerging nonvolatile memories, in which both electronic and electrochemical effects play important roles in the nonvolatile functionalities. First, we provide a brief historical overview of the research in this field. We also provide a technological overview and the epoch making achievements, followed by an account of the current understanding of both bipolar and unipolar ReRAM operations. Finally, we summarize the challenges facing the ReRAM technology as it moves toward the beyond 2X nm generation of nonvolatile memories and the so called beyond complementary metal oxide semiconductor (CMOS) device.", "author_names": [ "Hiroyuki Akinaga", "Hisashi Shima" ], "corpus_id": 10082831, "doc_id": "10082831", "n_citations": 752, "n_key_citations": 25, "score": 0, "title": "Resistive Random Access Memory (ReRAM) Based on Metal Oxides", "venue": "Proceedings of the IEEE", "year": 2010 }, { "abstract": "This paper reviews recent advances in Charge Trap Flash (CTF) memories. CTFs are predicted to replace the traditional floating gate flash devices beyond the 32 nm node. The paper focuses on work done at IIT Bombay in the areas of both nitride based SONOS devices as well as nanocrystal (NC) based devices. For SONOS devices, results are presented for optimization of the nitride layer to obtain the best characteristics, and the simulation of the program/erase transients. For NC devices, experimental characteristics of single and dual layer cells, as well as simulation results are presented.", "author_names": [ "C Sandhya", "P K Singh", "Swati Kedia Gupta", "Hitasha Chandar Rohra", "M Shivatheja", "Udayan Ganguly", "Ralf Hofmann", "Gautam Mukhopadhyay", "Souvik Mahapatra", "J M Vasi" ], "corpus_id": 30482436, "doc_id": "30482436", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Recent advances in charge trap flash memories", "venue": "2009 2nd International Workshop on Electron Devices and Semiconductor Technology", "year": 2009 }, { "abstract": "Charge trapping is dramatically suppressed in ZnO transparent thin film transistors (TFTs) employing a multilayered gate insulator with HfO2 layer sandwiched by Al2O3 layers. In spite of its high dielectric constant, HfO2 has critical drawbacks including huge charge trap density in interfaces. We suggest and demonstrate an elegant solution to minimize the charge trapping introducing Al2O3 buffer layers. The operation of Al2O3/HfO2/Al2O3 multilayered gate insulator structure in the ZnO transparent TFT is evaluated to ensure the voltage difference in the hysteresis loop as low as 0.2V, and the immunization to the threshold voltage shift induced by repeated sweeps of gate voltage.", "author_names": [ "Seongpil Chang", "Yong-Won Song", "Sanggyun Lee", "Sang Myeon Lee", "Byeong Kwon Ju" ], "corpus_id": 117130840, "doc_id": "117130840", "n_citations": 77, "n_key_citations": 0, "score": 0, "title": "Efficient suppression of charge trapping in ZnO based transparent thin film transistors with novel Al2O3/HfO2/Al2O3 structure", "venue": "", "year": 2008 }, { "abstract": "Abstract The program/erase (P/E) characteristic of tunnel barrier engineered charge trap flash (TBE CTF) memory with MAHOS (Metal/Al 2 O 3 /HfO 2 /SiO 2 /Si) structure and MAHAHOS (Metal/Al 2 O 3 /HfO 2 /Al 2 O 3 /HfO 2 /SiO 2 /Si) structure were investigated. The tunnel barrier structures for nonvolatile memory (NVM) application were designed by using the quantum mechanical tunnel model (QM) and then the CTF memory devices were fabricated by stacking various dielectric materials for tunnel barrier, charge trap layer and blocking layer. As a result, a faster P/E speed and a longer data retention time were obtained from the MAHAHOS memory device. Especially, the program speed was enhanced by 10 4 times from 100 ms to 10 us, and the erase speed was enhanced by 10 2 times from 1 s to 10 ms. Also, the MAHAHOS device showed an improved retention characteristic compared with the MAHOS device. In addition, it is found that a high work function gate electrode (Pt) contributes to a significant reduction of data erasing time and an improved data retention characteristic of MAHAHOS memory device.", "author_names": [ "Se-Man Oh", "Hee-Wook You", "Kwan-Su Kim", "Young-Hie Lee", "Won-Ju Cho" ], "corpus_id": 101626906, "doc_id": "101626906", "n_citations": 11, "n_key_citations": 1, "score": 1, "title": "Electrical properties of HfO2 charge trap flash memory with SiO2/HfO2/Al2O3 engineered tunnel layer", "venue": "", "year": 2010 }, { "abstract": "MHOS (metal HfO2 SiO2 Si) structure capacitors were fabricated to investigate the charge trapping properties of HfO2 layer with various thicknesses for the applications of charge trap flash (CTF) memory devices. Also, the centroid of charge trap in HfO2 layer was extracted by constant current stress method and compared with that of conventional Si3N4 layer. The gate leakage current of MHOS capacitor due to tunneling was significantly reduced by stacking the HfO2 trap layer on thin SiO2 tunnel layer. The MHOS capacitors showed a larger memory window than the MNOS (metal Si3N4 SiO2 Si) capacitors at the same trap layer thickness, because the HfO2 layer has better charge trapping efficiency than the Si3N4 layer. It is found that ultrathin HfO2 trap layer with a thickness of 2 nm stored almost the same charges with Si3N4 layer with a thickness of 7 nm. Consequently, the application of ultrathin HfO2 to charge storage layer can considerably improve the performance and enhance the high density of CTF memory.", "author_names": [ "Hee-Wook You", "Won-Ju Cho" ], "corpus_id": 120922361, "doc_id": "120922361", "n_citations": 100, "n_key_citations": 2, "score": 0, "title": "Charge trapping properties of the HfO2 layer with various thicknesses for charge trap flash memory applications", "venue": "", "year": 2010 }, { "abstract": "A characterization technique capable of measuring the electrical charge injected during programming operations in silicon nitride based charge trapping memories has been developed. The trapping efficiency, defined as the fraction of carriers which gets trapped in the device with respect to the total injected charge, is extracted and is evaluated along the programming transient for a wide set of devices, featuring different material deposition techniques and different thicknesses. The trapping efficiency is found to be almost insensitive to the injection conditions, whereas it depends on the quantity of filled traps, the thickness of the trapping layer and the conduction band offset between the trapping layer and the top oxide. A higher trapping efficiency in general leads to faster programming transients and more effective programming when increasing the gate voltage.", "author_names": [ "Amit Suhane", "Antonio Arreghini", "Geert Van den bosch", "Laurent Breuil", "Antonio Cacciato", "A Rothschild", "Malgorzata Jurczak", "Jan Van Houdt", "Kristin De Meyer" ], "corpus_id": 42276633, "doc_id": "42276633", "n_citations": 9, "n_key_citations": 1, "score": 0, "title": "Experimental evaluation of trapping efficiency in silicon nitride based charge trapping memories", "venue": "2009 Proceedings of the European Solid State Device Research Conference", "year": 2009 }, { "abstract": "A new memory structure using threshold shifting from charge stored in nanocrystals of silicon (5nm in size) is described. The devices utilize direct tunneling and storage of electrons in the nanocrystals. The limited size and capacitance of the nanocrystals limit the numbers of stored electrons. Coulomb blockade effects may be important in these structures but are not necessary for their operation. The threshold shifts of 0.2 0.4 V with read and write times less than 100's of a nanosecond at operating voltages below 2.5 V have been obtained experimentally. The retention times are measured in days and weeks, and the structures have been operated in an excess of 109 cycles without degradation in performance. This nanomemory exhibits characteristics necessary for high density and low power.", "author_names": [ "Sandip Tiwari", "Farhan Rana", "Hussein Ibrahim Hanafi", "Allan Hartstein", "Emmanuel F Crabbe", "Kevin K H Chan" ], "corpus_id": 16600279, "doc_id": "16600279", "n_citations": 1512, "n_key_citations": 9, "score": 0, "title": "A silicon nanocrystals based memory", "venue": "", "year": 1996 }, { "abstract": "Charge trapping memories offer advantages for scaling data flash memories in the sub 50nm groundrule. This paper reviews the progress of the main concepts in charge trapping, NROM and SONOS. Both have undergone significant new developments, like the 4 bits/cell for the NROM and the introduction of new materials for SONOS and new cell structures, e.g. including Fin Fets. Depending on the progress during the next years these concepts will be even more able to compete with the still dominating floating gate techniques", "author_names": [ "Karl-Heinz Kuesters", "Christoph Ludwig", "Thomas Mikolajick", "Nicolas Nagel", "Michael Specht", "V Pissors", "N Schulze", "E Stein", "Josef Willer" ], "corpus_id": 18749995, "doc_id": "18749995", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Future trends in charge trapping memories", "venue": "2006 8th International Conference on Solid State and Integrated Circuit Technology Proceedings", "year": 2006 }, { "abstract": "Operating properties of charge trapping type Flash memory devices with single or stacked structures on trapping layer are investigated in this letter. Improved operation and reliability characteristics can be achieved by adapting the stacked high k films as charge trapping layer due to the modification in the trap density and the energy level of traps, the mechanism of electron/hole transmission, and the suitable band offset. Moreover, with a small bandgap of second film in the stacked trapping layer, operating characteristics of devices are further enhanced.", "author_names": [ "Ping-Hung Tsai", "Kuei-Shu Chang-Liao", "Te-Chiang Liu", "Tien-Ko Wang", "Pei-Jer Tzeng", "Cha-Hsin Lin", "L -S Lee", "Ming-Jinn Tsai" ], "corpus_id": 28806027, "doc_id": "28806027", "n_citations": 35, "n_key_citations": 3, "score": 0, "title": "Charge Trapping Type Flash Memory Device With Stacked High $k$ Charge Trapping Layer", "venue": "IEEE Electron Device Letters", "year": 2009 }, { "abstract": "Atomically thin layered two dimensional materials, including transition metal dichalcogenide (TMDC) and black phosphorus (BP) have been receiving much attention, because of their promising physical properties and potential applications in flexible and transparent electronic devices. Here, for the first time we show nonvolatile charge trap memory devices, based on field effect transistors with large hysteresis, consisting of a few layer black phosphorus channel and a three dimensional (3D) Al2O3/HfO2/Al2O3 charge trap gate stack. An unprecedented memory window exceeding 12 V is observed, due to the extraordinary trapping ability of the high k HfO2. The device shows a high endurance of over 120 cycles and a stable retention of ~30% charge loss after 10 years, even lower than the reported MoS2 flash memory. The high program/erase current ratio, large memory window, stable retention and high on/off current ratio, provide a promising route towards flexible and transparent memory devices utilising atomically thin two dimensional materials. The combination of 2D materials with traditional high k charge trap gate stacks opens up an exciting field of nonvolatile memory devices.", "author_names": [ "Qi Feng", "Faguang Yan", "Wengang Luo", "Kaiyou Wang" ], "corpus_id": 205986329, "doc_id": "205986329", "n_citations": 64, "n_key_citations": 0, "score": 1, "title": "Charge trap memory based on few layer black phosphorus.", "venue": "Nanoscale", "year": 2016 } ]

[ { "abstract": "Two dimensional intrinsic ferromagnetic semiconductors with controllable magnetic phase transition are highly desirable for spintronics. Nevertheless, reports on their successful experimental realization are still rare. Herein, based on first principles calculations, we propose to achieve such a functional material, namely CrSbS3 monolayer by exfoliating from its bulk crystal. Intrinsic CrSbS3 monolayer is a ferromagnetic half semiconductor with a moderate bandgap of 1.90 eV. It features an intriguing magnetic phase transition from ferromagnetic to antiferromagnetic when applying a small compressive strain ~2% making it ideal for fabricating strain controlled magnetic switches or memories. In addition, the predicted strong anisotropic absorption of visible light and small effective masses make the CrSbS3 monolayer promising for optoelectronic applications.", "author_names": [ "Jinlong Yang" ], "corpus_id": 237401207, "doc_id": "237401207", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "CrSbS3 monolayer: a potential phase transition ferromagnetic semiconductor.", "venue": "Nanoscale", "year": 2021 }, { "abstract": "We have used molecular simulation with two intermolecular potential models, TraPPE UA and TraPPE EH, the latter of which accounts for the tetrahedral shape, to study the effects of shape on methane adsorption on graphite. Both models give good descriptions of the vapour liquid equilibria in the bulk phase, but adsorption on graphite is better described by the TraPPE EH model. Molecular configurations in the monolayer, show the variation with temperature of the registry sites for the carbon and hydrogen atoms of the methane molecules. At temperatures below 70 K, the centre of mass (COM) of the molecules is in registry with the centre of the carbon hexagons. For temperatures above 70 K, a commensurate monolayer is initially formed as at low temperatures, then as the loading is increased the first layer remains in registry, but the COM of the methane molecules in the first layer shifts to the top of the graphite carbon atoms with the C H bond pointing to carbon atoms in the second shell of a C hexagon. At temperatures above 93 K, the first adsorbate layer goes through these two commensurate states and then undergoes a transition to an incommensurate solid. Finally, for temperatures greater than 110 K methane behaves like a pseudo spherical molecule.", "author_names": [ "Han Zhang", "Shiliang Johnathan Tan", "Luisa Prasetyo", "Duong D Do", "David A Nicholson" ], "corpus_id": 220670107, "doc_id": "220670107", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A simulation study of the low temperature phase diagram of the methane monolayer on graphite: a test of potential energy functions.", "venue": "Physical chemistry chemical physics PCCP", "year": 2020 }, { "abstract": "Transition metal dichalcogenides (TMDs) exist in various crystal structures with semiconducting, semi metallic, and metallic properties. The dynamic control of these phases is of immediate interest for next generation electronics such as phase change memories. Of the binary Mo and W based TMDs, MoTe2 is attractive for electronic applications because it has the lowest energy difference (40 meV) between the semiconducting (2H) and semi metallic (1T' phases, allowing for MoTe2 phase change by electrostatic doping. Here we report phase change between the 2H and 1T' polymorphs of MoTe2 in thicknesses ranging from the monolayer to bulk like case (73 nm) using an ionic liquid electrolyte at room temperature and in air. We find consistent evidence of a partially reversible 2H 1T' transition using in situ Raman spectroscopy where the phase change occurs in the top most layers of the MoTe2 flake. We find a thickness dependent transition voltage where higher voltages are necessary to drive the phase change for thicker flakes. We also show evidence of electrochemical activity during the gating process by observation of Te metal formation. This finding suggests the formation of Te vacancies which have been reported to lower the energy difference between the 2H and 1T' phase, potentially aiding the phase change process. Our discovery that the phase change can be achieved on the surface layer of bulk like materials reveals that this electrochemical mechanism does not require isolation of a single layer and the effect may be more broadly applicable than previously thought.", "author_names": [ "Dante Zakhidov", "Daniel A Rehn", "Evan J Reed", "Alberto Salleo" ], "corpus_id": 170078804, "doc_id": "170078804", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Reversible Electrochemical Phase Change in Monolayer to Bulk Like MoTe2 by Ionic Liquid Gating.", "venue": "ACS nano", "year": 2020 }, { "abstract": "In this paper, we report a simulation study of the effect of the herringbone orientational phase transition on the isosteric heat of adsorption and the heat capacity of the nitrogen adsorption monolayer on graphite surface. We use the previously proposed regression equations of state for phases with the short and long ranged orientational ordering (Ustinov et al. in J Phys Chem C 122:2897 2908, 2018) The proposed approach allows one to give an exhaustive thermodynamic description of the isobaric phase transition without direct estimation of the chemical potential, using only the pVT data obtained in a canonical Monte Carlo simulation. The herringbone orientational phase transition is indicated by a peak in the temperature dependence of the heat capacity. Its height and shape is close to those observed experimentally. In addition, the heat spike is observed on the isosteric heat curves near the transition region. It decreases with increasing temperature and completely disappears at a temperature close to the melting point in the gas crystal system. A combined analysis of the heat capacity and isosteric heat of adsorption demonstrates that the nitrogen monolayer on graphite surface has similar features inherent in a three dimensional system and, therefore, the translational and rotational degrees of freedom normal to the surface are involved in the mechanism of the long to short ranged orientational transition.", "author_names": [ "Sergey S Akimenko", "Vitaly A Gorbunov", "Eugene A Ustinov" ], "corpus_id": 107833734, "doc_id": "107833734", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Heat capacity and heat of adsorption at orientational phase transition in nitrogen monolayer on graphite", "venue": "Adsorption", "year": 2019 }, { "abstract": "In this work a vapor phase assisted approach for the synthesis of monolayer MoS2 is demonstrated, based on the sulfurization of thin MoO3 x precursor films in an H2S atmosphere. We discuss the co existence of various possible growth mechanisms, involving solid gas and vapor gas reactions. Different sequences were applied in order to control the growth mechanism and to obtain monolayer films. These variations include the sample temperature and a time delay for the injection of H2S into the reaction chamber. The optimized combination allows for tuning the process route towards the potentially more favorable vapor gas reactions, leading to an improved material distribution on the substrate surface. Raman and photoluminescence (PL) spectroscopy confirm the formation of ultrathin MoS2 films on SiO2/Si substrates with a narrow thickness distribution in the monolayer range on length scales of a few millimeters. Best results are achieved in a temperature range of 950 1000 degC showing improved uniformity in terms of Raman and PL line shapes. The obtained films exhibit a PL yield similar to mechanically exfoliated monolayer flakes, demonstrating the high optical quality of the prepared layers.", "author_names": [ "Devendra Pareek", "Marco A Gonzalez", "Jannik Zohrabian", "Mohamed Hassan Sayed", "Volker Steenhoff", "Colleen Lattyak", "Martin Vehse", "Carsten Agert", "Jurgen Parisi", "Sascha Schafer", "Levent Gutay" ], "corpus_id": 104368446, "doc_id": "104368446", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "A vapor phase assisted growth route for large scale uniform deposition of MoS2 monolayer films", "venue": "", "year": 2019 }, { "abstract": "An integrated approach is applied to reveal fine changes in the surface normal structure of 1,2 dimyristoyl sn glycero 3 phospho l serine (DMPS) monolayers at the air lipid water interface occurring in a liquid expanded (LE) liquid condensed (LC) transition. The combination of the Langmuir monolayer technique, X ray reflectometry, and molecular dynamics (MD) modeling provides new insight into the molecular nature of electrostatic phenomena in different stages of lipid compression. A homemade setup with a laboratory X ray source (l 1.54 A) offers a nondestructive way to reveal the structural difference between the LE and LC phases of the lipid. The electron density profile in the direction normal to the interface is recovered from the X ray reflectivity data with the use of both model independent and model based approaches. MD simulations of the DMPS monolayer are performed for several areas per lipid using the all atom force field. Using the conventional theory of capillary waves, a comparison is made b.", "author_names": [ "Yury A Ermakov", "Viktor E Asadchikov", "B S Roschin", "Yu O Volkov", "Daria A Khomich", "Alexey Nesterenko", "A M Tikhonov" ], "corpus_id": 203152825, "doc_id": "203152825", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Comprehensive Study of the Liquid Expanded Liquid Condensed Phase Transition in 1,2 Dimyristoyl sn glycero 3 phospho l serine Monolayers: Surface Pressure, Volta Potential, X ray Reflectivity, and Molecular Dynamics Modeling", "venue": "Langmuir", "year": 2019 }, { "abstract": "An integrated approach is applied to reveal fine changes in the surface normal structure of dimyristoylphosphatidylserine (DMPS) monolayers at the air/lipid/water interface occurring in a liquid expanded (LE) liquid condensed (LC) transition. The combination of the Langmuir monolayer technique, X ray reflectometry and molecular dynamics (MD) modeling provides new insight into the molecular nature of electrostatic phenomena in different stages of lipid compression. A homemade setup with a laboratory X ray source (l=1.54 A) offers a nondestructive way to reveal the structural difference between the LE and LC phases of the lipid. The electron density profile in the direction normal to the interface is recovered from the X ray reflectivity data with the use of both model independent and model based approaches. MD simulations of the DMPS monolayer are performed for several areas per lipid using the all atom force field. Using the conventional theory of capillary waves, a comparison is made between the electron density profiles reconstructed from the X ray data and those calculated directly from MD modeling, which demonstrates remarkable agreement between the experiment and simulations for all selected lipid densities. This confirms the validity of the simulations and allows an analysis of the contributions of the hydrophobic tails and hydrated polar groups to the electron density profile and to the dipole component of the electric field at the interface. According to the MD data, the dependence of the Volta potential on the area per lipid in the monolayer has a different molecular nature below and above the phase transition. In the LE state of the monolayer, the potential is determined mostly by the oriented water molecules in the polar region of the lipid. In the LE LC transition, these molecules are displaced to the bulk, and their effect on the Volta potential becomes insignificant compared with the contribution of the hydrophobic tails. The hydrophobic tails are highly ordered in the state of the liquid crystal so that their dipole moments entirely determine the growth of the potential upon compression up to the monolayer collapse.", "author_names": [ "E A", "A E", "Roschin Boris S", "V O", "K A", "N M", "Aleksey M Tikhonov" ], "corpus_id": 201829722, "doc_id": "201829722", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Comprehensive study of the LE LC phase transition in DMPS monolayers: surface pressure, Volta potential, X ray reflectivity and MD modeling.", "venue": "Langmuir the ACS journal of surfaces and colloids", "year": 2019 }, { "abstract": "Structural phase change materials are of great importance for applications in information storage devices. Thermally driven structural phase transitions are employed in phase change memory to achieve lower programming voltages and potentially lower energy consumption than mainstream nonvolatile memory technologies. However, the waste heat generated by such thermal mechanisms is often not optimized, and could present a limiting factor to widespread use. The potential for electrostatically driven structural phase transitions has recently been predicted and subsequently reported in some two dimensional materials, providing an athermal mechanism to dynamically control properties of these materials in a nonvolatile fashion while achieving potentially lower energy consumption. In this work, we employ DFT based calculations to make theoretical comparisons of the energy required to drive electrostatically induced and thermally induced phase transitions. Determining theoretical limits in monolayer MoTe2 and thin films of Ge2Sb2Te5, we find that the energy consumption per unit volume of the electrostatically driven phase transition in monolayer MoTe2 at room temperature is 9% of the adiabatic lower limit of the thermally driven phase transition in Ge2Sb2Te5. Furthermore, experimentally reported phase change energy consumption of Ge2Sb2Te5 is 100 10,000 times larger than the adiabatic lower limit due to waste heat flow out of the material, leaving the possibility for energy consumption in monolayer MoTe2 based devices to be orders of magnitude smaller than Ge2Sb2Te5 based devices.Phase change materials: less is moreTheoretical calculations reveal that the electrostatically driven phase transition of monolayer MoTe2 is accompanied by little heat waste. Phase change materials have enormous potential for thermal and information storage applications, as they can switch between different phases (and properties) with external stimuli. The amount of heat dissipated during these transitions can however limit the operation and further miniaturization of devices. A team from Stanford University has now modeled heat dissipation during the phase transition in electrostatically driven MoTe2 and thermally driven Ge2Sb2Te5: MoTe2 could consume 100 10,000 times less energy per unit volume than Ge2Sb2Te5, as in the latter case most of the energy becomes heat waste. The small amount of heat that enters and leaves the system in the case of MoTe2 makes it very promising for low energy and low dimension devices.", "author_names": [ "Daniel A Rehn", "Y Li", "Eric Pop", "Evan J Reed" ], "corpus_id": 139686849, "doc_id": "139686849", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "Theoretical potential for low energy consumption phase change memory utilizing electrostatically induced structural phase transitions in 2D materials", "venue": "npj Computational Materials", "year": 2018 }, { "abstract": "Thermally or chemically active colloids generate thermodynamic gradients in the solution in which they are immersed and thereby induce hydrodynamic flows that affect their dynamical evolution. Here we study a mean field model for the many body dynamics of a monolayer of spherically symmetric active particles located at a fluid fluid interface. Due to the spherical symmetry, the particles do not self propel. Instead, the dynamics is driven by the long ranged Marangoni flows, due to the response of the interface to the activity of the particles, which compete with the direct interaction between particles. We demonstrate analytically that, in spite of the intrinsic out of equilibrium character of the system, the monolayer evolves to a \"pseudoequilibrium\" state, in which the Marangoni flows force the coexistence of the thermodynamic phases associated to the direct interaction. In particular, we study the most interesting case of a r 3 soft repulsion that models electrostatic or magnetic interparticle forces. For a sufficiently large average density, two dimensional phase transitions (freezing from liquid to hexatic, and melting from solid to hexatic) should be observable in a radially stratified, \"onion like\" structure within the monolayer. Furthermore, the analysis allows us to conclude that, while the activity may be too weak to allow direct detection of such induced Marangoni flows, it is relevant as a collective effect in the emergence of the experimentally observable spatial structure of phase coexistences noted above. Finally, the relevance of these results for potential experimental realizations is critically discussed.", "author_names": [ "Alvaro Dominguez", "Mihail N Popescu" ], "corpus_id": 52339429, "doc_id": "52339429", "n_citations": 3, "n_key_citations": 1, "score": 0, "title": "Phase coexistence in a monolayer of active particles induced by Marangoni flows.", "venue": "Soft matter", "year": 2018 }, { "abstract": "A theoretical analysis of the characteristics of the hybrid surface plasmon of a monolayer graphene wrapped metamaterial filled cylindrical waveguide is performed. The dispersion relations for different configurations of metamaterials [double positive (DPS) graphene DPS, DPS graphene double negative (DNG) DNG graphene DPS, and DNG graphene DNG] are simulated by solving Maxwell's equations for cylindrical symmetry and implementing impedance boundary conditions at the interface. The electromagnetic response of graphene is modeled using Kubo's formalism. The influence of the geometrical parameters of the waveguide structure, the chemical potential of graphene and the parameters of partnering materials on the dispersion curve, the effective mode index, and the phase velocity is presented. It is observed that the existence of graphene along with metamaterials provides better control and tuning of the propagation of the surface waves. The backward surface waves, forward surface waves, and slow surface waves for the fundamental mode are studied for different waveguide configurations. The results are found to be in accordance with the published literature. These results may have potential applications in tuning surface waves, waveguide technology, modulators, backward wave amplifiers, traveling wave masers, frequency selectors, circular polarizers, switching and phase compensation, and graphene based slow light devices.", "author_names": [ "Maryam Saeed", "Abdul Ghaffar", "Majeed A S Alkanhal", "Ali H Alqahtani", "Yasin Khan", "Sajjad ur Rehman" ], "corpus_id": 225108662, "doc_id": "225108662", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Plasmon modes supported by metamaterial filled monolayer graphene cylindrical waveguides", "venue": "", "year": 2020 } ]

[ { "abstract": "Abstract Rapid developments in semiconductor technology have substantially increased the computational capability of computers. As a result of this and recent developments in theory, machine learning (ML) techniques have become attractive in many new applications. This trend has also inspired researchers working on integrated circuit (IC) design and optimization. ML based design approaches have gained importance to challenge/aid conventional design methods since they can be employed at different design levels, from modeling to test, to learn any nonlinear input output relationship of any analog and radio frequency (RF) device or circuit; thus, providing fast and accurate responses to the task that they have learned. Furthermore, employment of ML techniques in analog/RF electronic design automation (EDA) tools boosts the performance of such tools. In this paper, we summarize the recent research and present a comprehensive review on ML techniques for analog/RF circuit modeling, design, synthesis, layout, and test.", "author_names": [ "Engin Afacan", "Nuno C Lourenco", "Ricardo Martins", "Gunhan Dundar" ], "corpus_id": 229499571, "doc_id": "229499571", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Review: Machine learning techniques in analog/RF integrated circuit design, synthesis, layout, and test", "venue": "Integr.", "year": 2021 }, { "abstract": "Transient stability analysis (TSA) plays an important role in power system analysis to investigate the stability of power system. Traditionally, transient stability analysis methods have been developed using time domain simulation by means of numerical integration method. In this paper, a new approach is proposed to model power systems as an integrated circuit and simulate the power system dynamic behavior by integrated circuit simulator as preliminary exploration for the ambition of using very large scale integrated circuit chip to mimic power system behaviors. The proposed method modeled power grid, generator, governor, and exciter with high fidelity. The power system dynamic simulation accuracy and efficiency of the proposed approach are verified and demonstrated by case study on an IEEE standard system.", "author_names": [ "Renchang Dai", "Peng Wei", "Yijing Liu", "Zhiwei Wang" ], "corpus_id": 235358268, "doc_id": "235358268", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Power System Transient Modeling and Simulation using Integrated Circuit", "venue": "ArXiv", "year": 2021 }, { "abstract": "We present Simphony, a free and open source software toolbox for abstracting and simulating photonic integrated circuits, implemented in Python. The toolbox is both fast and easily extensible; plugins can be written to provide compatibility with existing layout tools, and device libraries can be easily created without a deep knowledge of programming. We include several examples of photonic circuit simulations with novel features and demonstrate a speedup of more than 20x over a leading commercially available software tool.", "author_names": [ "Sequoia Ploeg", "Hyrum Gunther", "Ryan M Camacho" ], "corpus_id": 221640899, "doc_id": "221640899", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Simphony: An Open Source Photonic Integrated Circuit Simulation Framework", "venue": "Computing in Science Engineering", "year": 2021 }, { "abstract": "This paper presents our proposed methods to ICDAR 2021 Robust Reading Challenge Integrated Circuit Text Spotting and Aesthetic Assessment (ICDAR RRCICTEXT 2021) For the text spotting task, we detect the characters on integrated circuit and classify them based on yolov5 detection model. We balance the lowercase and non lowercase by using SynthText, generated data and data sampler. We adopt semi supervised algorithm and distillation to furtherly improve the model's accuracy. For the aesthetic assessment task, we add a classification branch of 3 classes to differentiate the aesthetic classes of each character. Finally, we make model deployment to accelerate inference speed and reduce memory consumption based on NVIDIA Tensorrt. Our methods achieve 59.1 mAP on task 3.1 with 31 FPS and 306M memory (rank 1) 78.7% F2 score on task 3.2 with 30 FPS and 306M memory (rank 1)", "author_names": [ "Qiyao Wang", "Li Zhu", "Yi Niu" ], "corpus_id": 233181548, "doc_id": "233181548", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "1st Place Solution to ICDAR 2021 RRC ICTEXT End to end Text Spotting and Aesthetic Assessment on Integrated Circuit", "venue": "ArXiv", "year": 2021 }, { "abstract": "A miniaturized Ka band bandpass filter (BPF) is presented by using monolithic microwave integrated circuit (MMIC) technology in this brief. Aiming at low cost and high integration, small die area of MMIC BPFs is significantly required for RF front end modules.However, the filtering performance of BPFs is negatively correlated to its miniaturization. To this end, the folded hybrid resonator is investigated in this brief, which is composed of a quasi lumped capacitor and a distributed microstrip line. To realize miniaturization, two metal layers of GaAs process are fully utilized. For low loss, the distributed inductor is designed on the top thick layer, while the quasi lumped capacitor is on the lower metal layer of high sheet resistance. To reduce the unwanted mutual coupling between adjacent quasi lumped capacitors, shielding structures are added into BPFs, resulting in a 5 dB and 12 dB enhancement to the lower and upper stopbands, respectively. Based on the mixed electric magnetic coupling topology, a second order MMIC bandpass filter is designed and fabricated by using GaAs process. Small die area, low loss, high selectivity, and wide stopband are simultaneously obtained, indicating a promising application of the proposed miniaturized MMIC bandpass filters.", "author_names": [ "Guangxu Shen", "Wenquan Che", "Wenjie Feng", "Yongrong Shi", "Yiming Shen" ], "corpus_id": 234135589, "doc_id": "234135589", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A Miniaturized Ka Band Bandpass Filter Using Folded Hybrid Resonators Based on Monolithic Microwave Integrated Circuit Technology", "venue": "IEEE Transactions on Circuits and Systems II: Express Briefs", "year": 2021 }, { "abstract": "In this study, for two cases of monolithic 3 dimensional integrated circuit (M3DIC) consisting of vertically stacked feedback field effect transistors (FBFETs) the variation of electrical characteristics of the FBFET was presented in terms of electrical coupling by using technology computer aided design (TCAD) simulation. In the Case 1, the M3DIC was composed with an N type FBFET in an upper tier (tier2) and a P type FBFET in a lower tier (tier1) and in the Case 2, it was composed with the FBFETs of opposite type of the Case 1 on each tier. To utilize the FBFET as a logic device, the study on optimal structure of FBFET was first performed in terms of reducing a memory window. Based on the N type FBFET, the memory window was investigated with different values of doping concentration and length of channel region divided into two regions. The threshold voltage, capacitance, and transconductance of two cases of M3DIC composed with proposed FBFET were investigated for different thickness of an interlayer dielectric (TILD) In the Case 1, only for reverse sweep, the threshold voltage of FBFET in the tier2 was changed significantly at TILD 15 nm, and the capacitance and transconductance of FBFET in the tier2 changed significantly at TILD 20 nm, as bottom gate voltage applied with 0 and 1 V. In the Case 2, the electrical characteristics of FBFET in the tier2 changed greater than Case 1 with different TILD.", "author_names": [ "Jong Hyeok Oh", "Yun Seop Yu" ], "corpus_id": 232230477, "doc_id": "232230477", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Electrical Coupling for Monolithic 3 D Integrated Circuit Consisting of Feedback Field Effect Transistors.", "venue": "Journal of nanoscience and nanotechnology", "year": 2021 }, { "abstract": "Miniaturized implantable devices play a crucial role in neural interfaces by monitoring and modulating neural activities on the peripheral and central nervous systems. Research efforts toward a compact wireless closed loop system stimulating the nerve automatically according to the user's condition have been maintained. These systems have several advantages over open loop stimulation systems such as reduction in both power consumption and side effects of continuous stimulation. Furthermore, a compact and wireless device consuming low energy alleviates foreign body reactions and risk of frequent surgical operations. Unfortunately, however, the miniaturized closed loop neural interface system induces several hardware design challenges such as neural activity recording with severe stimulation artifact, real time stimulation artifact removal, and energy efficient wireless power delivery. Here, we will review recent approaches toward the miniaturized closed loop neural interface system with integrated circuit (IC) techniques.", "author_names": [ "Jaeouk Cho", "Geunchang Seong", "Yonghee Chang", "Chul-Woong Kim" ], "corpus_id": 235249531, "doc_id": "235249531", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Energy Efficient Integrated Circuit Solutions Toward Miniaturized Closed Loop Neural Interface Systems", "venue": "Frontiers in Neuroscience", "year": 2021 }, { "abstract": "In this work, we present a significant step toward in vivo ophthalmic optical coherence tomography and angiography on a photonic integrated chip. The diffraction gratings used in spectral domain optical coherence tomography can be replaced by photonic integrated circuits comprising an arrayed waveguide grating. Two arrayed waveguide grating designs with 256 channels were tested, which enabled the first chip based optical coherence tomography and angiography in vivo three dimensional human retinal measurements. Design 1 supports a bandwidth of 22 nm, with which a sensitivity of up to 91 dB (830 uW and an axial resolution of 10.7 um was measured. Design 2 supports a bandwidth of 48 nm, with which a sensitivity of 90 dB (480 uW and an axial resolution of 6.5 um was measured. The silicon nitride based integrated optical waveguides were fabricated with a fully CMOS compatible process, which allows their monolithic co integration on top of an optoelectronic silicon chip. As a benchmark for chip based optical coherence tomography, tomograms generated by a commercially available clinical spectral domain optical coherence tomography system were compared to those acquired with on chip gratings. The similarities in the tomograms demonstrate the significant clinical potential for further integration of optical coherence tomography on a chip system. The goal of an optical coherence tomography (OCT) imaging system that is integrated on a photonic chip has taken a step closer to reality. Elisabet Rank and coworkers from Austria have shown that arrayed waveguide gratings (AWGs) integrated optical devices commonly used to separate different wavelength channels in an optical communications system, can be used to replace diffraction gratings in an OCT system. Several designs of silicon nitride AWGs with 256 channels in the near infrared were fabricated and then tested in an OCT system which was able to capture in vivo tomograms and angiography of the human eye's retina, with comparable quality to a conventional system. The next stage of the OCT on a chip research will focus on exploring the use of multimode interference structures, integrated photodiodes, and compact light sources.", "author_names": [ "Elisabet Rank", "Ryan Sentosa", "Danielle J Harper", "Matthias Salas", "Anna Gaugutz", "Dana Seyringer", "Stefan Nevlacsil", "Alejandro Maese-Novo", "Moritz Eggeling", "Paul Muellner", "Rainer Hainberger", "Martin Sagmeister", "Jochen Kraft", "Rainer A Leitgeb", "Wolfgang Drexler" ], "corpus_id": 230719129, "doc_id": "230719129", "n_citations": 5, "n_key_citations": 0, "score": 2, "title": "Toward optical coherence tomography on a chip: in vivo three dimensional human retinal imaging using photonic integrated circuit based arrayed waveguide gratings", "venue": "Light, science applications", "year": 2021 }, { "abstract": "We demonstrate an ultra sensitive waveguide enhanced Raman sensor for low concentration organic compounds dissolved in water. The spectra are obtained using silicon nitride slot waveguides coated with a thin film of hexamethyldisilazane modified mesoporous silica. Enriched locally by 600 fold within the coating, a micromolar level of cyclohexanone is probed. The sensor is also capable of simultaneous quantification of multiple analytes, and the adsorbed analytes can be completely released from the coating. These properties make this on chip Raman sensor promising for diverse applications, especially for the monitoring of non polar organics and biomolecules in aqueous environments.", "author_names": [ "Zuyang Liu", "Haolan Zhao", "Bettina Baumgartner", "Bernhard Lendl", "Andim Stassen", "Andre G Skirtach", "Nicolas Le Thomas", "Roel Baets" ], "corpus_id": 232090166, "doc_id": "232090166", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Ultra sensitive slot waveguide enhanced Raman spectroscopy for aqueous solutions of non polar compounds using a functionalized silicon nitride photonic integrated circuit.", "venue": "Optics letters", "year": 2021 }, { "abstract": "Recycling of used ICs as new replacement parts in maintaining older electronic systems is a serious reliability concern. This paper presents a novel approach to estimate the operational age of CMOS chips by measuring IDDQ, the quiescent current from power supply or the total leakage current in steady state. This current decreases as the circuit ages, largely due to the increase in the magnitude of the PMOS transistor threshold voltage caused by negative bias temperature instability (NBTI) We exploit the fact that the impact of NBTI on an individual transistor depends upon the operational stress based upon the duration of its ON state. Novelty of our technique is a normalized difference, I, computed from current measurements at two input test patterns and is proposed as a self referencing circuit age indicator. The first pattern is chosen such that its IDDQ is controlled by a large number of minimally stressed PMOS transistors; for the other the IDDQ is controlled by approximately equal number of highly stressed PMOS transistors. The difference between these two IDDQ values increases with the circuit age. This approach requires no hardware modification in the circuit and, hence, can be applied to legacy ICs. Simulation results show that we can reliably identify recycled ICs that have been used for as little as six months. Prattay Chowdhury E mail: [email protected] Ujjwal Guin E mail: [email protected] Adit D. Singh E mail: [email protected] Vishwani D. Agrawal E mail: [email protected] 1Department of Electrical and Computer Engineering, University of Texas at Dallas, Richardson, TX 75080, USA 2Department of Electrical and Computer Engineering, Auburn University, Auburn, AL 36849, USA", "author_names": [ "Prattay Chowdhury", "Ujjwal Guin", "Adit D Singh", "Vishwani D Agrawal" ], "corpus_id": 216561526, "doc_id": "216561526", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Estimating Operational Age of an Integrated Circuit", "venue": "J. Electron. Test.", "year": 2021 } ]

[ { "abstract": "Abstract Metalloporphyrinic metal organic framework (PCN 222) is a promising photocatalytic material due to its large surface area and 1D channel, exceptional stability, high visible light capture capability, and semiconductor properties. Herein, we constructed a highly efficient visible light driven type II heterojunction photocatalyst PCN 222 PW12/TiO2 by one step solvothermal method. The 5 wt% PCN 222 PW12/TiO2 showed the superior photocatalytic properties for degrading rhodamine B (RhB) and Ofloxacin, which are 10.69 and 10.48 times higher than pure TiO2 under same conditions. The excellent photocatalytic performance of PCN 222 PW12/TiO2 ternary composite material was attributed to the improved adsorption capacity of organic pollutants, optical absorption in the entire visible light region, and highly efficient separation of photoinduced carriers. Besides, we found that h+ O2 and OH are the main active elements in the photocatalytic degradation process. This will back up the higher photocatalytic activity of PCN 222 PW12/TiO2 compared with pure TiO2. The photocatalytic efficiency of composite maintained a similar level of photoactivity after four times recovery, which showed excellent stability and recyclability of PCN 222 PW12/TiO2. This work provides new insights into the fabrication porphyrin MOF composite materials with high photocatalytic efficiency for environmental remediation.", "author_names": [ "Lanjie Li", "Xinming Yu", "Lei Xu", "Ya-hui Zhao" ], "corpus_id": 213920320, "doc_id": "213920320", "n_citations": 16, "n_key_citations": 0, "score": 1, "title": "Fabrication of a novel type visible light driven heterojunction photocatalyst: Metal porphyrinic metal organic framework coupled with PW12/TiO2", "venue": "", "year": 2020 }, { "abstract": "A visible light mediated direct C H arylation of quinoxalin 2(1H) ones with aryl acyl peroxides has been developed. The reaction proceeds smoothly through a radical process in the absence of photocatalyst, additive and metal catalyst, providing the corresponding products in moderate to good yields. This methodology opens a simple and green access to 3 arylquinoxalin 2(1H) ones.", "author_names": [ "Jun Xu", "Hongdou Zhang", "Jianmin Zhao", "Zhigang Ni", "Pengfei Zhang", "Bing-Feng Shi", "Wan-mei Li" ], "corpus_id": 229491756, "doc_id": "229491756", "n_citations": 14, "n_key_citations": 0, "score": 1, "title": "Photocatalyst metal and additive free, direct C H arylation of quinoxalin 2(1H) ones with aryl acyl peroxides induced by visible light", "venue": "", "year": 2020 }, { "abstract": "An enduring catalyst built from carbon Splitting water into its constituent elements, hydrogen and oxygen, generally requires the assistance of metal catalysts. Liu et al. now show that a metal free hybrid material composed of carbon and nitrogen can promote this reaction all on its own, with the help of some visible light. The photocatalyst combines one material (C3N4) known to split water into hydrogen and peroxide with a second material (CDot) that breaks the peroxide down before it can damage the first. The robust stability of this hybrid bodes well for practical implementation of optimized analogs in solar energy storage schemes. Science, this issue p. 970 A hybrid nanomaterial comprising carbon and nitrogen proves a robust catalyst for light driven water splitting into H2 and O2. The use of solar energy to produce molecular hydrogen and oxygen (H2 and O2) from overall water splitting is a promising means of renewable energy storage. In the past 40 years, various inorganic and organic systems have been developed as photocatalysts for water splitting driven by visible light. These photocatalysts, however, still suffer from low quantum efficiency and/or poor stability. We report the design and fabrication of a metal free carbon nanodot carbon nitride (C3N4) nanocomposite and demonstrate its impressive performance for photocatalytic solar water splitting. We measured quantum efficiencies of 16% for wavelength l 420 20 nanometers, 6.29% for l 580 15 nanometers, and 4.42% for l 600 10 nanometers, and determined an overall solar energy conversion efficiency of 2.0% The catalyst comprises low cost, Earth abundant, environmentally friendly materials and shows excellent stability.", "author_names": [ "Juan Liu", "Yang Liu", "Naiyun Liu", "Yuzhi Han", "Xing Zhang", "Hui Huang", "Yeshayahu Lifshitz", "Shui-Tong Lee", "Jun Zhong", "Zhenhui Kang" ], "corpus_id": 23564579, "doc_id": "23564579", "n_citations": 2513, "n_key_citations": 2, "score": 0, "title": "Metal free efficient photocatalyst for stable visible water splitting via a two electron pathway", "venue": "Science", "year": 2015 }, { "abstract": "The photo driven direct C C/C N bond formation initiated by electron donor acceptor (EDA) complexes for the synthesis of indoles has been accomplished via [3 2] annulations of secondary arylamines with alkynes using IC4F9 as oxidants in the absent of any photocatalysts and metals. This green transformation exhibits the advantages of operational simplicity, good functional tolerances and mild reaction conditions. The in situ generated EDA complexes derived from arylamines with alkynes were characterized by UV vis absorption spectrometry and NMR titration experiments.", "author_names": [ "Wei Guo", "Kailiang Tao", "Zhen Biao Xie", "Liuhuan Cai", "Mingming Zhao", "Wen-Han Tan", "Gongpin Liu", "Weijie Mei", "Ling Deng", "Xiao-lin Fan", "Lvyin Zheng" ], "corpus_id": 202688114, "doc_id": "202688114", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "Photo Driven Photocatalyst /Metal Free Direct C C/C N Bond Formation: Synthesis of Indoles via EDA Complexes.", "venue": "The Journal of organic chemistry", "year": 2019 }, { "abstract": "Cross contamination of foods with pathogenic microorganisms such as bacteria, viruses, and parasites may occur at any point in the farm to fork continuum. Food contact and nonfood contact surfaces are the most frequent source of microbial cross contamination. In the wake of new and emerging food safety challenges, including antibiotic resistant human pathogens, conventional sanitation and disinfection practices may not be sufficient to ensure safe food processing, proper preparation, and also not be environmentally friendly. Nanotechnology enabled novel food safety interventions have a great potential to mitigate the risk of microbial cross contamination in the food chain. Especially engineered nanoparticles (ENPs) are increasingly finding novel applications as antimicrobial agents. Among various ENPs, photocatalyst metal oxides have shown great promise as effective nontargeted disinfectants over a wide range of microorganisms. The present review provides an overview of antimicrobial properties of various photocatalyst metal oxides and their potential applications as surface coatings. Further, this review discusses the most common approaches to developing antimicrobial coatings, methods to characterize, test, and evaluate antimicrobial efficacy as well as the physical stability of the coatings. Finally, regulations and challenges concerning the use of these novel photocatalytic antimicrobial coatings are also discussed.", "author_names": [ "Veerachandra K Yemmireddy", "Yen-Con Hung" ], "corpus_id": 90814688, "doc_id": "90814688", "n_citations": 62, "n_key_citations": 1, "score": 0, "title": "Using Photocatalyst Metal Oxides as Antimicrobial Surface Coatings to Ensure Food Safety Opportunities and Challenges.", "venue": "Comprehensive reviews in food science and food safety", "year": 2017 }, { "abstract": "Abstract Photocatalysis is a promising technology that can convert solar energy into chemical energy. However, developing photocatalyst that could be put into the practical application remains a big challenge worldwide. In the recent years, an emerging type of core shell/core shell like composites, in which the metal or metal containing nanoparticles (M/MC NPs) cores are encapsulated by the metal organic frameworks (MOFs) shells, have attracted increasing attention in photocatalysis. These M/MC NP@MOF nanocomposites are believed to be one of the most effective and convenient ways to achieve property synergies of MOFs and M/MC NPs. Even though this field is currently in its infancy, the promising results obtained have validated the potential use of M/MC NP@MOF nanocomposites in practical applications. In this review, the fundamental mechanisms of photocatalysis were briefly introduced. The synthesis of M/MC NP@MOF nanocomposites and related photocatalytic applications (such as photocatalytic hydrogen generation and Cr(VI) reduction) are summarized and exemplified. Special emphasis is given to the synergistic effects between the MOFs shell and NPs core that result in an enhanced performance in heterogeneous photocatalysis. Finally, the unsolved problems of M/MC NP@MOF nanocatalysts are discussed and the future development prospects are proposed.", "author_names": [ "Yang Liu", "Zhifeng Liu", "Danlian Huang", "Min Cheng", "Guangming Zeng", "Cui Lai", "Chen Zhang", "Chengyun Zhou", "Wenjun Wang", "Danni Jiang", "Han Wang", "Binbin Shao" ], "corpus_id": 107488334, "doc_id": "107488334", "n_citations": 111, "n_key_citations": 0, "score": 0, "title": "Metal or metal containing nanoparticle@MOF nanocomposites as a promising type of photocatalyst", "venue": "Coordination Chemistry Reviews", "year": 2019 }, { "abstract": "Abstract Visible light active, heterogeneous, and organic photocatalysts exhibit a more sustainable and environmentally friendly alternative to classical metal based catalysts. Two dimensional covalent organic frameworks (2D COFs) with permanent porosity, columnar p arrays and excellent stability, that can become an excellent platform for heterogeneous photocatalysis of organic transformations. Here we report a predesigned imine based COF with electron donor and acceptor structure. And new framework possesses large surface area, high crystallinity, outstanding stability and broad absorption range in the visible light region as well as good photoelectric response characteristics. Importantly, it was found to be a highly effective heterogeneous photocatalyst for reductive dehalogenation of phenacyl bromide derivatives and a alkylation of aldehydes under irradiation of visible light. In addition, the COF gave good recyclability and could be reused after a simple separation manipulation. The current present still reveals a great prospect for 2D COFs as metal free, heterogeneous photocatalysts for organic transformations.", "author_names": [ "Ziping Li", "Yongfeng Zhi", "Pengpeng Shao", "Hong Xia", "Guosheng Li", "Xiao Feng", "Xiong Chen", "Zhan Shi", "Xiaoming Liu" ], "corpus_id": 104362989, "doc_id": "104362989", "n_citations": 82, "n_key_citations": 1, "score": 0, "title": "Covalent organic framework as an efficient, metal free, heterogeneous photocatalyst for organic transformations under visible light", "venue": "Applied Catalysis B: Environmental", "year": 2019 }, { "abstract": "Conversion of naturally abundant dinitrogen (N2) to ammonia (NH3) is one of the most attractive and challenging topics in chemistry. Current studies mainly focus on electrocatalytic nitrogen reduction reaction (NRR) using metal based electrocatalysts, while metal free and solar driven photocatalysts have been rarely explored. Here, on basis of the \"s donation p* backdonation\" concept, single B atom supported on holey g CN (B@g CN) can serve as metal free photocatalyst for highly efficient N2 fixation and reduction under visible and even infrared spectra. Our results reveal that N2 can be efficiently activated and reduced to NH3 with extremely low overpotential of 0.15 V and activation barrier of 0.61 eV, lower than most of metal based NRR catalysts, thereby guaranteeing the high energy efficiency and fast kinetics of NRR. The inherent properties of B@g CN, such as centralized spin polarization on the B atom, efficient prohibition of competitive hydrogen evolution reaction (HER) and reduced exciton binding energy, are responsible for the high selectivity and Faradic efficiency for NRR under ambient conditions. Moreover, for the first time, we theoretically disclose that the external potential provided by photogenerated electrons for NRR/HER endowing B@g CN spontaneous NRR and inaccessible HER. This work may provide a promising lead for designing efficient and robust metal free single atom catalysts toward photocatalytic NRR under visible/infrared spectrum.", "author_names": [ "Xingshuai Lv", "Wei Wei", "Fengping Li", "Baibiao Huang", "Ying Dai" ], "corpus_id": 201274885, "doc_id": "201274885", "n_citations": 81, "n_key_citations": 0, "score": 0, "title": "Metal Free B@g CN: Visible/Infrared Light Driven Single Atom Photocatalyst Enables Spontaneous Dinitrogen Reduction to Ammonia.", "venue": "Nano letters", "year": 2019 }, { "abstract": "Summary Solar water disinfection catalyzed by metal free photocatalyst has emerged as a promising approach for clean water production. By using the edge functionalized graphitic carbon nitride (g C3N4) as photocatalytic disinfectants, we find that the pathogen rich water can be rapidly purified in 30 min with a disinfection efficiency of over 99.9999% under visible light irradiation, which meets the requirement for drinking water. The edge functionalized g C3N4 shows a first order disinfection rate that is five times higher than the previously reported best metal free photocatalyst but only consumes 1/10 of the catalyst. The catalytic activity is also comparable to that of the best metal based photocatalyst. Results of the highest occupied molecular orbitals and Mulliken charge distribution reveal that the exposed COOH and C=O groups at the edges of g C3N4 nanosheets not only significantly promote charge separation but also induce the upward bending of the surface band, facilitating the generation of hydrogen peroxide.", "author_names": [ "Zhenyuan Teng", "Nailiang Yang", "Hongying Lv", "Sicong Wang", "Maozhi Hu", "Chengyin Wang", "Dan Wang", "Guoxiu Wang" ], "corpus_id": 104405560, "doc_id": "104405560", "n_citations": 76, "n_key_citations": 0, "score": 0, "title": "Edge Functionalized g C3N4 Nanosheets as a Highly Efficient Metal free Photocatalyst for Safe Drinking Water", "venue": "Chem", "year": 2019 }, { "abstract": "A full spectrum (300 700 nm) responsive porphyrin supramolecular photocatalyst with a theoretical solar spectrum efficiency of 44.4% is successfully constructed. For the first time, hydrogen and oxygen evolution (40.8 and 36.1 umol g 1 h 1 is demonstrated by a porphyrin photocatalyst without the addition of any cocatalysts. The strong oxidizing performance also presents an efficient photodegradation activity that is more than ten times higher than that of g C3 N4 for the photodegradation of phenol. The high photocatalytic reduction and oxidation activity arises from a strong built in electric field due to molecular dipoles of electron trapping groups and the nanocrystalline structure of the supramolecular photocatalyst. The appropriate band structure of the supramolecular photocatalyst adjusted via the highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels of the porphyrin gives rise to thermodynamic driving potential for H2 and O2 evolution under visible light irradiation. Controlling the energy band structure of photocatalysts via the ordered assembly of structure designed organic molecules could provide a novel approach for the design of organic photocatalysts in energy and environmental applications.", "author_names": [ "Zijian Zhang", "Yongfa Zhu", "Xianjie Chen", "Hanjie Zhang", "Jun Wang" ], "corpus_id": 58540086, "doc_id": "58540086", "n_citations": 82, "n_key_citations": 0, "score": 0, "title": "A Full Spectrum Metal Free Porphyrin Supramolecular Photocatalyst for Dual Functions of Highly Efficient Hydrogen and Oxygen Evolution.", "venue": "Advanced materials", "year": 2019 } ]

[ { "abstract": "A two dimensional carbon allotrope, H net, is proposed using first principle calculations. H net incorporates C4 distorted squares, C6 hexagons, and C8 octagons. Unlike previously reported planar graphene and other theoretical carbon sheets, H net is a two atom thick polymorph with identical C6 C4 C6 components cross facing and covalently buckled to feature a handshake like model. The feasibility of H net is evident from its dynamic stability as confirmed by phonon mode analysis and its lower total energy. H net is energetically more favorable than synthesized graphdiyne and theoretical graphyne, BPC, S graphene, polycyclic net, a squarographite, and lithographite. We explored a possible route for the synthesis of H net from graphene nanoribbons. Electronic band structure calculations indicated that H net is a semiconductor with an indirect band gap of 2.11 eV, whereas graphene and many other two dimensional carbon sheets are metallic. We also explored the electronic structure of one dimensional nanoribbons derived from H net. The narrowest H net nanoribbon showed metallic behavior, whereas the other nanoribbons are semiconductors with band gaps that increase as the nanoribbons widen. H net and its tailored nanoribbons are expected to possess more electronic properties than graphene because of their exceptional crystal structure and different energy band gaps.", "author_names": [ "Meng Hu", "Yu Shu", "Lin Cui", "Bo Xu", "Dongli Yu", "Julong He" ], "corpus_id": 37410525, "doc_id": "37410525", "n_citations": 16, "n_key_citations": 0, "score": 1, "title": "Theoretical two atom thick semiconducting carbon sheet.", "venue": "Physical chemistry chemical physics PCCP", "year": 2014 }, { "abstract": "Abstract Hydrogen adsorption on a single Si and SiO2 molecule, doped within C(6,6) and C(10,0) carbon nanotubes (CNTs) is studied using first principles calculations based on density functional theory. Two orientations of the H2 molecule, inside the nanotubes, are compared. Our calculations revealed a rather weak hydrogen binding energy inside both types of pristine CNTs namely, 0.51 eV/H2 and 0.38 eV/H2 for C(6,6) and C(10,0) nanotubes, respectively. When a single Si atom is doped in the interior surface of either type of CNTs, it tends to decouple from the wall and to drift towards the nanotube's axis. A Si atom can bind two hydrogen atoms more strongly 1.4 eV/H2 and 1.13 eV/H2 on Si within metallic and semiconducting CNTs, respectively) than just a pristine CNT would do. A SiO2 molecule binds the hydrogen atoms even stronger, along with formation of water molecule within the metallic CNT. The corresponding binding energy of 1.73 eV/H2 for the C(6,6) is found to be the highest one among the configurations considered. Based on our resuls, we believe that intrinsically Si and SiO2 doped CNTs can be considered as plausible candidates for enhancing the hydrogen adsorption properties.", "author_names": [ "Seyed Vahid Hosseini", "Hadi Arabi", "Ahmad Kompany" ], "corpus_id": 106289983, "doc_id": "106289983", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Silicon atom and silicon oxide molecule, within the metallic and semiconducting carbon nanotubes as promising centers candidates for hydrogen adsorption: A DFT theoretical study", "venue": "", "year": 2018 }, { "abstract": "Abstract Mechanical, electronic and magnetic properties of a single boron atom doped C 6 N 6 sheet B 1 C 6 N 6 and two boron atoms doped C 6 N 6 B 2 C 6 N 6 sheet are studied using first principles calculations based on density functional theory. The in plane stiffness, E for B 2 C 6 N 6 (100.75 N/m) and bulk modulus, G for both B 1 C 6 N 6 (73.61 N/m) and B 2 C 6 N 6 (67.8 N/m) sheets are found to be less than that of pure s triazine C 6 N 6 E 134.41 N/m and G 82.80 N/m) sheet. Interestingly, the substitution of C atom with a B atom in C 6 N 6 sheet induced a total magnetic moment of 1 m B and 2 m B for B 1 C 6 N 6 and B 2 C 6 N 6 cases respectively. This shows that some of the bonding electron in the sheet is freed up as a result of an added hole. This gives rise to the spin polarized 2p orbitals of the nitrogen and neighbouring B or C atoms. After B doping, the semiconducting property is well preserved. These interesting properties make the B 1 C 6 N 6 and B 2 C 6 N 6 sheet as suitable candidates for applications in spin related device.", "author_names": [ "Yusuf Zuntu Abdullahi", "Tiem Leong Yoon", "A A Kassimu" ], "corpus_id": 224931367, "doc_id": "224931367", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Metal free ferromagnetic semiconductor: Mechanical, electronic and magnetic properties of boron doped graphitic carbon nitride (g C6N6) sheet", "venue": "", "year": 2020 }, { "abstract": "We investigate the structural, electronic and magnetic properties of three configurations of buckled heptazine supercell with adsorbed hydrogen, namely, and using DFT approach. The calculated adsorption energy for the three structures is very disparate. The structure is energetically more stable than structures. The less stable structures which contain H atoms adsorbed in vertical direction induced a total magnetic moment of whereas for the case, the adsorbed H atom formed a dangling bond (in the horizontal direction) with N having or like hybridized structure that leaves no unpaired electrons. A different electronic character is found for the three configurations. Specifically, appears to be semiconducting with a narrow band gap whereas the other two configurations, and are half metallic and metallic respectively. In general, our findings present theoretical insights of the most stable buckled heptazine with adsorbed H atom structure for the applications in hydrogen gas storage.", "author_names": [ "Yusuf Zuntu Abdullahi", "Tiem Leong Yoon", "Rania Edrees Adam Mohammad" ], "corpus_id": 104568920, "doc_id": "104568920", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Selective hydrogen adsorption on a buckled carbon nitride sheet: first principles calculation", "venue": "", "year": 2018 }, { "abstract": "The semimetallic bandstructure of graphene and silicene limit their use in functional devices. Mixing silicon and carbon offers a rather unexplored pathway to build semiconducting sheets compatible with current Si based electronics. We present here a complete theoretical study of the phase diagram of two dimensional silicon carbon binaries. To scan the composition range, we employ an ab initio global structural prediction method, complemented by exhaustive enumeration of two dimensional structure prototypes. We find a wealth of two dimensional low energy structures, from standard honeycomb single and double layers, passing by dumbbell geometries, to carbon nanosheets bridged by Si atoms. Many of these phases depart from planarity, either through buckling, or by germinating three dimensional networks with a mixture of sp2 and sp3 bonds. We further characterize the most interesting crystal structures, unveiling a large variety of electronic properties, that could be exploited to develop high performance electronic devices at the nanoscale.", "author_names": [ "Pedro Borlido", "Ahmad W Huran", "Miguel A L Marques", "Silvana Botti" ], "corpus_id": 215615791, "doc_id": "215615791", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Novel two dimensional silicon carbon binaries by crystal structure prediction.", "venue": "Physical chemistry chemical physics PCCP", "year": 2020 }, { "abstract": "Metamaterials and transformation optics have received considerable attention in the recent years, as they have found an immense role in many areas of optical science and engineering by offering schemes to control electromagnetic fields. Another area of science that has been under the spotlight for the last few years relates to exploration of graphene, which is formed of carbon atoms densely packed into a honey comb lattice. This material exhibits unconventional electronic and optical properties, intriguing many research groups across the world including us. But our interest is mostly in studying interaction of electromagnetic waves with graphene and applications that might follow. Our group as well as few others pioneered investigating prospect of graphene for plasmonic devices and in particular plasmonic metamaterial structures and transformation optical devices. In this thesis, relying on theoretical models and numerical simulations, we show that by designing and manipulating spatially inhomogeneous, nonuniform conductivity patterns across a flake of graphene, one can have this material as a one atom thick platform for infrared metamaterials and transformation optical devices. Varying the graphene chemical potential by using static electric field allows for tuning the graphene conductivity in the terahertz and infrared frequencies. Such design flexibility can be exploited to create \"patches\" with differing conductivities within a single flake of graphene. Numerous photonic functions and metamaterial concepts are expected to follow from such platform. This work presents several numerical examples demonstrating these functions. Our findings show that it is possible to design one atom thick variant of several optical elements analogous to those in classic optics. Here we theoretically study one atom thick metamaterials, one atom thick waveguide elements, cavities, mirrors, lenses, Fourier optics and finally a few case studies illustrating transformation optics on a single sheet of graphene in mid infrared wavelengths. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Electrical Systems Engineering First Advisor Nader Engheta This dissertation is available at ScholarlyCommons: http:/repository.upenn.edu/edissertations/715", "author_names": [ "Ashka Vakil" ], "corpus_id": 136432367, "doc_id": "136432367", "n_citations": 66, "n_key_citations": 3, "score": 0, "title": "Transformation optics using graphene: One atom thick optical devices based on graphene", "venue": "", "year": 2012 }, { "abstract": "Atomically thick two dimensional materials have been increasingly attracting research interest not only due to their promising applications in a range of functional devices but also to their theoretical value to unraveling the catalytic electron transfer process within a simplified scenario. In this work, the monoatomic thick dot sized graphitic carbon nitride (g C3N4) has been synthesized and intimately contacted to the basal plane of the graphene sheet to form the monolayer g C3N4 dots@graphene (MTCG) The electrocatalytic activity of the MTCG in the oxygen reduction reaction is found to rival that of the commercial Pt/C catalyst in terms of the catalytic current density and half wave potential. The density functional theory calculations confirm the catalytic improvement of the MTCG originates from a higher efficiency for the reduction of OOH( than that of the g C3N4 alone; therefore, the current work is expected to provide new insights in developing next generation, highly efficient catalysts for the oxygen reduction reaction.", "author_names": [ "Xiaopeng Wang", "Lixia Wang", "Fei Zhao", "Chuangang Hu", "Yang Zhao", "Zhipan Zhang", "Shi-Lu Chen", "Gaoquan Shi", "Liangti Qu" ], "corpus_id": 3213103, "doc_id": "3213103", "n_citations": 66, "n_key_citations": 0, "score": 0, "title": "Monoatomic thick graphitic carbon nitride dots on graphene sheets as an efficient catalyst in the oxygen reduction reaction.", "venue": "Nanoscale", "year": 2015 }, { "abstract": "Abstract Metallic Sn exhibits high theoretical capacity and low operating voltage for Na+ storage, but it suffers from huge volume changes during Na+ insertion/extraction and from big experimental difficulties to achieve high areal capacities with mass loadings larger than 10 mg cm 2. Here we propose a facile and novel synthesis strategy towards hierarchically porous foams of Sn nanodots (3.2 nm) uniformly distributed in a three dimensional sheet like nitrogen doped carbon (SNC) framework derived from a low cost SnO2/polyacrylamide composite hydrogel. The resulting Sn@SNC foams effectively integrate the intriguing merits of the two building blocks, namely both Sn nanodots and SNC framework as active materials providing capacity and the SNC framework as a flexible buffer for the volume change, as an excellent conductor for electrons and as a spacer for the Sn nanodots suppressing aggregation. Moreover, the hierarchically porous structure of the Sn@SNC foam enables fast Na+ diffusion in thick electrodes, finally offering high performance Na+ storage at high mass loadings of up to 20 mg cm 2 with a reversible areal capacity of 1.0 mA h cm 2 at 3 mA cm 2 over 700 cycles.", "author_names": [ "Long Pan", "Haijian Huang", "Mingdong Zhong", "Markus Niederberger" ], "corpus_id": 105202612, "doc_id": "105202612", "n_citations": 24, "n_key_citations": 0, "score": 0, "title": "Hydrogel derived foams of nitrogen doped carbon loaded with Sn nanodots for high mass loading Na ion storage", "venue": "", "year": 2019 }, { "abstract": "Silicon, the most commonly used semiconducting material, is intrinsically 3D. Although the element silicon lies directly beneath carbon in the periodic table, it does not easily form the crystalline bonding present in graphite because the arrangement is energetically unfavorable.1 However, if this bonding were to be realized in crystals made of silicon atoms, the resulting material could prove to be as exciting as the ultimately thin Nobel Prize winning 2D form of graphite: graphene. It has been predicted2 that with only three strong directional bonds for each atom, instead of the four formed in the diamond structure of silicon, silicene (the silicon analogue of graphene) could possess highly mobile charge carriers with exotic properties. Despite being predicted to be unstable in ambient conditions,1 we have succeeded in creating silicene on the surface of zirconium diboride (ZrB2/ a metallic ceramic material.3 Silicene has also been created by a number of researchers on silver surfaces.4 6 To prove the presence of silicene, a comprehensive characterization of the structural, electronic, and chemical properties is essential. However, the properties of these samples differ from those of the (currently hypothetical) freestanding silicene because the silicene is in close contact with the substrate surface. The silicene that we produced rests on thin, singlecrystalline ZrB2 films with silicon wafers as substrates (see Figure 1) Silicene is formed by surface segregation at elevated temperatures, under ultra high vacuum (UHV) conditions.3 In this process, silicon atoms diffuse from the silicon wafer to the diboride surface and segregate to spontaneously form silicene. Although the silicene is oxidized on exposure to air, it can be formed again at the same time as the oxide is removed by an annealing procedure in UHV. In this way, we were able to study silicene in different complementary experimental set ups, using Figure 1. Illustration of a silicene sheet (gray) on a zirconium diboride (ZrB2) substrate. Red: Zirconium atoms. Blue: Boron atoms.", "author_names": [ "Rainer Friedlein", "Antoine Fleurence", "Yukiko Yamada-Takamura", "Taisuke Ozaki" ], "corpus_id": 124313587, "doc_id": "124313587", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Silicene: atom thick silicon with tunable properties", "venue": "", "year": 2013 }, { "abstract": "The present study is in sequel to the previous research (Phys. Chem. Chem. Phys. 16 (2014) p. 19122) where a solution based nucleation and growth approach that involved direct epitaxial nucleation of nanofibres of poly(3 hexylthiophene) (P3HT) on carbon nanotubes (CNTs) for potential use as next generation building blocks for applications including field effect transistors and photovoltaic devices, was described. Also presented was a theoretical analysis of epitaxial mechanism of nucleation and growth of semiconducting conjugated polymers notably, P3HT on CNTs. In the present study, we elucidate the impact of molecular weight of P3HT on structural morphology and photophysical properties. The change in average molecular weight of P3HT from ~14 to ~60 kDa resulted in several structural changes, even though the mechanism of nucleation and growth continued to be epitaxial process. In the case of high molecular weight P3HT, the crystallized fibrils were ~200 400 nm in length and ~2 3 nm thick. In contrast, for the low molecular weight, the fibrils were significantly longer >5 mm) in length and ~800 1000 nm thick, which are envisaged to involve chain folding in relation to shorter fibrils. Furthermore, the graft density of fibrils crystallized on CNTs was remarkably higher for the high molecular weight P3HT such that the connectivity between successive fibrils is anticipated to be through very small tie molecules. On the other hand, the graft density of low molecular weight P3HT crystallized on CNTs was low. Thus, the interconnectivity between successive fibrils is anticipated to involve large tie molecules. The differences in connectivity between successive fibrils (besides the structural morphology) for low and high molecular weight P3HT, would at least, in part, impact the charge carrier mobility.", "author_names": [ "V S A Challa", "Krishna Chaitanya Nune", "Raja Devesh Kumar Misra" ], "corpus_id": 101977205, "doc_id": "101977205", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "The impact of molecular weight on nanoscale supramolecular structure of semiconducting poly(3 hexylthiophene) on carbon nanotubes and photophysical properties", "venue": "", "year": 2016 } ]

[ { "abstract": "Summary Recently, non fullerene n type organic semiconductors have attracted significant attention as acceptors in organic photovoltaics (OPVs) due to their great potential to realize high power conversion efficiencies. The rational design of the central fused ring unit of these acceptor molecules is crucial to maximize device performance. Here, we report a new class of non fullerene acceptor, Y6, that employs a ladder type electron deficient core based central fused ring (dithienothiophen[3.2 b] pyrrolobenzothiadiazole) with a benzothiadiazole (BT) core to fine tune its absorption and electron affinity. OPVs made from Y6 in conventional and inverted architectures each exhibited a high efficiency of 15.7% measured in two separate labs. Inverted device structures were certified at Enli Tech Laboratory demonstrated an efficiency of 14.9% We further observed that the Y6 based devices maintain a high efficiency of 13.6% with an active layer thickness of 300 nm. The electron deficient core based fused ring reported in this work opens a new door in the molecular design of high performance acceptors for OPVs.", "author_names": [ "Jun Yuan", "Yunqiang Zhang", "Liuyang Zhou", "Guichuan Zhang", "Hin-Lap Yip", "Tsz-Ki Lau", "Xinhui Lu", "Can Zhu", "Hongjian Peng", "Paul A Johnson", "Mario Leclerc", "Yong Cao", "Jacek Ulanski", "Yongfang Li", "Yingping Zou" ], "corpus_id": 139354200, "doc_id": "139354200", "n_citations": 1788, "n_key_citations": 1, "score": 1, "title": "Single Junction Organic Solar Cell with over 15% Efficiency Using Fused Ring Acceptor with Electron Deficient Core", "venue": "Joule", "year": 2019 }, { "abstract": "", "author_names": [ "Martin A Green", "Ewan D Dunlop", "Jochen Hohl-Ebinger", "Masahiro Yoshita", "Nikos Kopidakis", "Anita W Y Ho-baillie" ], "corpus_id": 213997228, "doc_id": "213997228", "n_citations": 459, "n_key_citations": 4, "score": 0, "title": "Solar cell efficiency tables (Version 55)", "venue": "", "year": 2019 }, { "abstract": "", "author_names": [ "Martin A Green", "Ewan D Dunlop", "Jochen Hohl-Ebinger", "Masahiro Yoshita", "Nikos Kopidakis", "Xiaojing Hao" ], "corpus_id": 225625121, "doc_id": "225625121", "n_citations": 214, "n_key_citations": 0, "score": 0, "title": "Solar cell efficiency tables (version 56)", "venue": "", "year": 2020 }, { "abstract": "Similar and indeterminate defect detection of solar cell surface with heterogeneous texture and complex background is a challenge of solar cell manufacturing. The traditional manufacturing process relies on human eye detection which requires a large number of workers without a stable and good detection effect. In order to solve the problem, a visual defect detection method based on multi spectral deep convolutional neural network (CNN) is designed in this paper. Firstly, a selected CNN model is established. By adjusting the depth and width of the model, the influence of model depth and kernel size on the recognition result is evaluated. The optimal CNN model structure is selected. Secondly, the light spectrum features of solar cell color image are analyzed. It is found that a variety of defects exhibited different distinguishable characteristics in different spectral bands. Thus, a multi spectral CNN model is constructed to enhance the discrimination ability of the model to distinguish between complex texture background features and defect features. Finally, some experimental results and K fold cross validation show that the multi spectral deep CNN model can effectively detect the solar cell surface defects with higher accuracy and greater adaptability. The accuracy of defect recognition reaches 94.30% Applying such an algorithm can increase the efficiency of solar cell manufacturing and make the manufacturing process smarter.", "author_names": [ "Haiyong Chen", "Yue Pang", "Qidi Hu", "Kun Liu" ], "corpus_id": 56482391, "doc_id": "56482391", "n_citations": 45, "n_key_citations": 2, "score": 0, "title": "Solar cell surface defect inspection based on multispectral convolutional neural network", "venue": "J. Intell. Manuf.", "year": 2020 }, { "abstract": "A green, efficient and stable solar cell based only on water and safe and cheap elements of the periodic table is proposed in this work, finally consolidating (also from a sustainability viewpoint) the concept of \"artificial photosynthesis\" studied for decades by the scientific community. The concept of dye sensitized solar cells is re proposed here with a metal free organic dye, an iodine based electrolyte in a 100% aqueous environment and a new cathode (cationic PEDOT) synthesized for the first time with the aim of inhibiting the repulsion between the anions of redox couples and the PEDOT:PSS matrix commonly used as the counter electrode. This elegant setup leads to a record efficiency of 7.02% the highest value ever obtained for a water based solar cell and, in general, for a photovoltaic device free of both organic solvents and expensive/heavy metals.", "author_names": [ "Federico Bella", "Luca Porcarelli", "Daniele Mantione", "Claudio Gerbaldi", "Claudia Barolo", "Michael Gratzel", "David Mecerreyes" ], "corpus_id": 213419588, "doc_id": "213419588", "n_citations": 48, "n_key_citations": 0, "score": 0, "title": "A water based and metal free dye solar cell exceeding 7% efficiency using a cationic poly(3,4 ethylenedioxythiophene) derivative+", "venue": "Chemical science", "year": 2020 }, { "abstract": "With the recent emergence of a new class of high performance nonfullerene acceptors (NFAs) organic solar cells (OSCs) have entered a new phase of research featuring high power conversion efficienc.", "author_names": [ "Shuixing Li", "Changzhi Li", "Minmin Shi", "Hongzheng Chen" ], "corpus_id": 216504126, "doc_id": "216504126", "n_citations": 151, "n_key_citations": 0, "score": 0, "title": "New Phase for Organic Solar Cell Research: Emergence of Y Series Electron Acceptors and Their Perspectives", "venue": "", "year": 2020 }, { "abstract": "Two dimensional Ruddlesden Popper phase (2DRP) perovskites are known to exhibit improved photostability and environmental stability compared with their three dimensional (3D) counterparts. However, fundamental questions remain over the interaction between the bulky alkylammoniums and the 2DRP perovskite framework. Here, we unambiguously demonstrate that a sulfur sulfur interaction is present for a new bulky alkylammonium, 2 (methylthio)ethylamine hydrochloride (MTEACl) In addition to a weaker van der Waals interaction, the interaction between sulfur atoms in two MTEA molecules enables a (MTEA) 2 (MA) 4 Pb 5 I 16 n 5) perovskite framework with enhanced charge transport and stabilization. The result is 2DRP perovskite solar cells with significantly improved efficiency and stability. Cells with a power conversion efficiency as high as 18.06% (17.8% certified) are achieved, along with moisture tolerance for up to 1,512 h (under 70% humidity conditions) thermal stability for 375 h (at 85 degC) and stability under continuous light stress (85% of the initial efficiency retained over 1,000 h of operation at the maximum power point) Two dimensional perovskite solar cells have been engineered to be robust against moisture, high temperatures and light stress.", "author_names": [ "Hui-Hui Ren", "Shidong Yu", "Lingfeng Chao", "Yingdong Xia", "Yuanhui Sun", "Shouwei Zuo", "Fan Li", "Tingting Niu", "Yingguo Yang", "Huan-xin Ju", "Bixin Li", "Hai Yan Du", "Xingyu Gao", "Jie-yu Zhang", "Jianpu Wang", "Lijun Zhang", "Yonghua Chen", "Wentao Huang" ], "corpus_id": 210166401, "doc_id": "210166401", "n_citations": 134, "n_key_citations": 0, "score": 0, "title": "Efficient and stable Ruddlesden Popper perovskite solar cell with tailored interlayer molecular interaction", "venue": "", "year": 2020 }, { "abstract": "Abstract All polymer solar cells (All PSCs) offer several distinct merits including superior thermal stability and flexibility. Here, we report a novel polymer acceptor PJ1 that exhibits a narrow band gap around 1.4 eV and a high extinction coefficient about 1.39 x 105 cm 1. When PJ1 is blended with donor polymer PBDB T, all PSC with a record power conversion efficiency (PCE) of 14.4% is achieved, which is mainly attributed to the broad absorption, efficient charge separation and collection, and low energy loss. The synergetic effects of molecular weight of PJ1 on the photovoltaic performance are also investigated. It is found that the increase in molecular weight can result in the red shift of absorption along with slight enhancement of extinction coefficient, which therefore benefits photocurrent. In addition, all PSC based on PJ1 demonstrate much better thermal stability than the control device based on small molecule acceptor (TTPBT IC) as evidenced by the insignificant morphology change of PBDB T:PJ1 versus excessive phase separation of PBDB T:TTPBT IC when annealed at 150 degC. Of particular interest is that the all PSCs based on PBDB T:PJ1 can retain high PCEs even when the thickness of photoactive layer is increased over 300 nm (PCE of 12.1% or the device area is enlarged to 1 cm2 (PCE of 13.0%", "author_names": [ "Tao Jia", "Jiabin Zhang", "Wenkai Zhong", "Yuanying Liang", "Kai Zhang", "Sheng Dong", "Lei Ying", "Feng Liu", "Xiaohui Wang", "Fei Huang", "Yong Cao" ], "corpus_id": 216326677, "doc_id": "216326677", "n_citations": 95, "n_key_citations": 0, "score": 0, "title": "14.4% efficiency all polymer solar cell with broad absorption and low energy loss enabled by a novel polymer acceptor", "venue": "", "year": 2020 }, { "abstract": "Organic solar cells are currently experiencing a second golden age thanks to the development of novel non fullerene acceptors (NFAs) Surprisingly, some of these blends exhibit high efficiencies despite a low energy offset at the heterojunction. Herein, free charge generation in the high performance blend of the donor polymer PM6 with the NFA Y6 is thoroughly investigated as a function of internal field, temperature and excitation energy. Results show that photocurrent generation is essentially barrierless with near unity efficiency, regardless of excitation energy. Efficient charge separation is maintained over a wide temperature range, down to 100 K, despite the small driving force for charge generation. Studies on a blend with a low concentration of the NFA, measurements of the energetic disorder, and theoretical modeling suggest that CT state dissociation is assisted by the electrostatic interfacial field which for Y6 is large enough to compensate the Coulomb dissociation barrier.", "author_names": [ "Lorena Perdigon-Toro", "Huotian Zhang", "Anastasia A Markina", "Jun Yuan", "Seyed Mehrdad Hosseini", "Christian M Wolff", "Guangzheng Zuo", "Martin Stolterfoht", "Yingping Zou", "Feng Gao", "Denis Andrienko", "Safa Shoaee", "Dieter Neher" ], "corpus_id": 210881793, "doc_id": "210881793", "n_citations": 91, "n_key_citations": 0, "score": 0, "title": "Barrierless Free Charge Generation in the High Performance PM6:Y6 Bulk Heterojunction Non Fullerene Solar Cell.", "venue": "Advanced materials", "year": 2020 }, { "abstract": "Summary Perovskite/silicon tandem solar cells represent an attractive pathway to upgrade the market leading crystalline silicon technology beyond its theoretical limit. Two terminal architectures result in reduced plant costs compared to four terminal ones. However, it is challenging to monolithically process perovskite solar cells directly onto the micrometer sized texturing on the front surface of record high efficiency amorphous/crystalline silicon heterojunction cells, which limits both high temperature and solution processing of the top cells. To tackle these hurdles, we present a mechanically stacked two terminal perovskite/silicon tandem solar cell, with the sub cells independently fabricated, optimized, and subsequently coupled by contacting the back electrode of the mesoscopic perovskite top cell with the texturized and metalized front contact of the silicon bottom cell. By minimizing optical losses, as achieved by engineering the hole selective layer/rear contact structure, and using a graphene doped mesoporous electron selective layer for the perovskite top cell, the champion tandem device demonstrates a 26.3% efficiency (25.9% stabilized) over an active area of 1.43 cm2.", "author_names": [ "Enrico Lamanna", "Fabio Matteocci", "Emanuele Calabro", "Luca Serenelli", "Enrico Salza", "Luca Martini", "Francesca Menchini", "Massimo Izzi", "Antonio Agresti", "Sara Pescetelli", "Sebastiano Bellani", "Antonio Esau Del Rio Castillo", "Francesco Bonaccorso", "Mario Tucci", "Aldo Di Carlo" ], "corpus_id": 214218881, "doc_id": "214218881", "n_citations": 40, "n_key_citations": 1, "score": 0, "title": "Mechanically Stacked, Two Terminal Graphene Based Perovskite/Silicon Tandem Solar Cell with Efficiency over 26%", "venue": "Joule", "year": 2020 } ]

[ { "abstract": "This book focuses on topics at the forefront of electrochemical research. Splitting water by electrolysis; splitting water by visible light; the recent development of lithium batteries; theoretical approaches to intercalation; and fundamental concepts of electrode kinetics, particularly as applied to semiconductors are discussed. It is recommended for electrochemists, physical chemists, corrosion scientists, and those working in the fields of analytical chemistry, surface and colloid science, materials science, electrical engineering, and chemical engineering.", "author_names": [ "B E Conway" ], "corpus_id": 98168714, "doc_id": "98168714", "n_citations": 5456, "n_key_citations": 5, "score": 1, "title": "Modern Aspects of Electrochemistry", "venue": "", "year": 1971 }, { "abstract": "Thank you for reading modern aspects of electrochemistry. As you may know, people have look hundreds times for their chosen books like this modern aspects of electrochemistry, but end up in malicious downloads. Rather than enjoying a good book with a cup of tea in the afternoon, instead they cope with some infectious virus inside their laptop. modern aspects of electrochemistry is available in our digital library an online access to it is set as public so you can download it instantly. Our book servers spans in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the modern aspects of electrochemistry is universally compatible with any devices to read.", "author_names": [ "Wolfgang Ziegler" ], "corpus_id": 63696027, "doc_id": "63696027", "n_citations": 153, "n_key_citations": 10, "score": 0, "title": "Modern Aspects Of Electrochemistry", "venue": "", "year": 2016 }, { "abstract": "", "author_names": [ "J M Bockris", "B E Conway", "Ronald L Meek" ], "corpus_id": 97118645, "doc_id": "97118645", "n_citations": 108, "n_key_citations": 7, "score": 0, "title": "Modern Aspects of Electrochemistry: No. 6", "venue": "", "year": 1968 }, { "abstract": "", "author_names": [ "Mordechay Schlesinger" ], "corpus_id": 138401344, "doc_id": "138401344", "n_citations": 31, "n_key_citations": 0, "score": 0, "title": "Modern Aspects of Electrochemistry, Number 43", "venue": "", "year": 2009 }, { "abstract": "", "author_names": [ "Roger Parsons" ], "corpus_id": 94137588, "doc_id": "94137588", "n_citations": 40, "n_key_citations": 0, "score": 0, "title": "Modern Aspects of Electrochemistry", "venue": "", "year": 1985 }, { "abstract": "", "author_names": [ "John Martin Hale" ], "corpus_id": 103504749, "doc_id": "103504749", "n_citations": 19, "n_key_citations": 2, "score": 0, "title": "Modern Aspects of Electrochemistry, J.O'M. Bockris, B.E. Conway (Eds. Plenum Press, New York (1972)", "venue": "", "year": 1974 }, { "abstract": "", "author_names": [ "Mordechay Schlesinger" ], "corpus_id": 138350778, "doc_id": "138350778", "n_citations": 6, "n_key_citations": 1, "score": 0, "title": "Modern Aspects of Electrochemistry No. 44", "venue": "", "year": 2009 }, { "abstract": "", "author_names": [ "Mordechay Schlesinger" ], "corpus_id": 212632545, "doc_id": "212632545", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "MODERN ASPECTS OF ELECTROCHEMISTRY", "venue": "", "year": 2013 }, { "abstract": "Download PDF Ebook and Read OnlineModern Aspects Of Electrochemistry No 4%0D. Get Modern Aspects Of Electrochemistry No 4%0D If you desire actually obtain guide modern aspects of electrochemistry no 4%0D to refer now, you should follow this web page constantly. Why? Keep in mind that you require the modern aspects of electrochemistry no 4%0D source that will give you ideal requirement, don't you? 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Life is consistently establishing as well as you require some new publication modern aspects of electrochemistry no 4%0D to be reference consistently.", "author_names": [ "Ralph E White", "Costas Georgios Vayenas", "Maria Gamboa-Aldeco" ], "corpus_id": 138896237, "doc_id": "138896237", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Modern Aspects of Electrochemistry No. 40", "venue": "", "year": 2007 }, { "abstract": "", "author_names": [ "JOHN O'M Bockris", "Milton J Allen" ], "corpus_id": 140120737, "doc_id": "140120737", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Modern Aspects of Electrochemistry, No. 2", "venue": "", "year": 1960 } ]

[ { "abstract": "Solution processed semiconductors are compatible with a range of substrates, which enables their direct integration with organic circuits, microfluidics, optical circuitry and commercial microelectronics. Ultrasensitive photodetectors based on solution process colloidal quantum dots operating in both the visible and infrared have been demonstrated, but these devices have poor response times (on the scale of seconds) to changes in illumination, and rapid response devices based on a photodiode architecture suffer from low sensitivity. Here, we show that the temporal response of these devices is determined by two components electron drift, which is a fast process, and electron diffusion, which is a slow process. By building devices that exclude the diffusion component, we are able to demonstrate a >1,000 fold improvement in the sensitivity bandwidth product of tuneable colloidal quantum dot photodiodes operating in the visible and infrared.", "author_names": [ "Jason Paul Clifford", "Gerasimos Konstantatos", "Keith William Johnston", "Sjoerd Hoogland", "Larissa Levina", "Edward H Sargent" ], "corpus_id": 22848177, "doc_id": "22848177", "n_citations": 390, "n_key_citations": 3, "score": 1, "title": "Fast, sensitive and spectrally tuneable colloidal quantum dot photodetectors.", "venue": "Nature nanotechnology", "year": 2009 }, { "abstract": "Summary Fast and sensitive infrared (IR) photodetection is of interest for depth imaging that is fundamental to machine vision, augmented reality, and autonomous driving. Colloidal quantum dots (CQDs) are appealing candidates for this goal: in contrast with III V semiconductors, they offer facile tuning of IR absorption and enable ease of integration via solution processing. So far, the best short wave IR CQD photodetectors have been limited to 70 ns response time and quantum efficiency of 17% at 1,450 nm. To advance the field using CQDs, large diameter CQDs are needed that combine passivation with efficient charge transport. Here, we report an efficient ligand exchange route that tailors the halide passivants and introduces an added exchange step crucial to efficient passivation, removal of unwanted organics, and charge transport. In devices, the CQD solids give rise to external quantum efficiency greater than 80% at 1,550 nm, a measured detectivity of 8 x 1011 Jones, and a 10 ns response time.", "author_names": [ "Maral Vafaie", "James Z Fan", "Amin Morteza Najarian", "Olivier Ouellette", "Laxmi Kishore Sagar", "Koen Bertens", "Bin Sun", "F Pelayo Garcia de Arquer", "Edward H Sargent" ], "corpus_id": 233772029, "doc_id": "233772029", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Colloidal quantum dot photodetectors with 10 ns response time and 80% quantum efficiency at 1,550 nm", "venue": "", "year": 2021 }, { "abstract": "Colloidal quantum dots (CQDs) are emerging solution processed materials combining low cost, easy deposition on large and flexible substrates, and bandgap tunability. The latter feature, which allows spectral tuning of the absorption profile of the semiconductor, makes these materials particularly attractive for light detection applications. Lead sulfide (PbS) CQDs, in particular, have shown astonishing performance as a light sensitive material operating at visible and infrared (IR) wavelengths. Early studies of PbS CQDs used as a photosensitive resistor (photoconductor) showed an impressive responsivity exceeding 1000 A/W and a detectivity (D* higher then 10^13 Jones. This impressive D* was preserved in the successive development of the first PbS CQD photodiode, showing the possibility to realize fast f_3db 1Mhz and sensitive IR detectors. Currently, the field is moving toward the development of hybrid devices and phototransitors. PbS CQDs have been combined in field effect transistors (FETs) with graphene and MoS2 channels, showing ultra high gain (exceeding 10^8 electrons/photons) and high D* Recently a photo junction FET (photo JFET) has been reported that breaks the inherent dark current/gain/bandwidth compromise affecting photoconductive light detectors. With this presentation we offer a broad overview on CQD photodetection highlighting the past achievements, the benefits, the challenges and the prospects for the future research on this field.", "author_names": [ "Valerio Adinolfi", "Edward H Sargent" ], "corpus_id": 124259192, "doc_id": "124259192", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Colloidal quantum dot photodetectors (Presentation Recording)", "venue": "SPIE NanoScience Engineering", "year": 2015 }, { "abstract": "Abstract Infrared light detection enables diverse technologies ranging from night vision to gas analysis. Emerging technologies such as low cost cameras for self driving cars require highly sensitive, low cost photodetector cameras with spectral sensitivities up to wavelengths of 10 um. For this purpose, colloidal quantum dot (QD) graphene phototransistors offer a viable alternative to traditional technologies owing to inexpensive synthesis and processing of QDs. However, the spectral range of QD/graphene phototransistors is thus far limited to 1.6 um. Here, HgTe QD/graphene phototransistors with spectral sensitivity up to 3 um are presented, with specific detectivities of 6 x 108 Jones at a wavelength of 2.5 um and a temperature of 80 K. Even at kHz light modulation frequencies, specific detectivities exceed 108 Jones making them suitable for fast video imaging. The simple device architecture and QD film patterning in combination with a broad spectral sensitivity manifest an important step toward low cost, multi color infrared cameras.", "author_names": [ "Matthias J Grotevent", "Claudio U Hail", "Sergii Yakunin", "Dominik Bachmann", "Michel Calame", "Dimos Poulikakos", "Maksym V Kovalenko", "Ivan Shorubalko" ], "corpus_id": 232293210, "doc_id": "232293210", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Colloidal HgTe Quantum Dot/Graphene Phototransistor with a Spectral Sensitivity Beyond 3 um", "venue": "Advanced science", "year": 2021 }, { "abstract": "Colloidal quantum dots (CQDs) are promising materials for IR light detection due to 15 their tunable bandgap and solution processing; but to date, the time response of CQD IR 16 photodiodes has been inferior to that provided by Si and InGaAs. We reasoned that the high 17 permittivity of II VI CQDs leads to slow charge extraction due to screening and capacitance; 18 whereas III Vs if their surface chemistry could be mastered offer a strong covalent character for 19 low permittivity and fast operation. In initial studies, we found that existing covalent character led 20 to imbalanced charge transport in InAs, the result of unpassivated surfaces and uncontrolled heavy 21 doping. We report surface management using amphoteric ligand coordination and find that it 22 addresses simultaneously the In and As surface dangling bonds. The new InAs CQD solids combine 23 high mobility (0.04 cm2 V 1 s 1) with a 4x reduction in permittivity compared to PbS CQDs. The 24 resulting photodiodes achieve a response time faster than 300 ps a more than 100x improvement 25 compared to the best previously reported CQD photodiodes combined with an external quantum 26 efficiency (EQE) of 30% at 940 nm. 27 Infrared photodetection underpins applications in medicine and bioimaging, information technology, 28 machine vision, and security1,2. Emerging technologies such as autonomous driving and augmented reality 29 rely on Light Detection and Ranging (LiDAR) based on time of flight (ToF)3. This requires sensitive and 30 ultrafast photodetection of infrared light with sub ns resolution4. Today, this is achieved in the near31 infrared (NIR) using indirect bandgap silicon detectors limited by silicon's low absorption coefficient 32 and, at longer wavelengths, using epitaxially grown semiconductors such as III Vs and Hg1 xCdxTe. 33 Colloidal quantum dots (CQDs) are of interest by their low temperature solution processing, which 34 allows them to be integrated in post processing with a silicon electronics front end7 10. Their bandgap is 35 size tuned over a wide range of wavelengths. PbS, for example, has a widely programmable absorption 36 onset covering the visible and short wavelength infrared (SWIR)11,12; however, its high permittivity, 37 stemming from its ionic character er =180 for bulk PbS13 slows charge extraction both for bulk14 and 38 CQD photodiodes15 due to screening and capacitance effects. 39 Indium arsenide (InAs) CQDs can be tuned in a similar spectral range as PbS CQDs, and offer the 40 prospective advantage of a covalent lattice and hence lower permittivity16,17. This, however, comes with a 41 challenge: the surface in InAs CQDs is charge imbalanced, leading to poor passivation and heavy doping, 42 as surface states pin the Fermi level near the conduction band minimum. Much effort has been paid to 43 improving mobility by decreasing interdot distance via ligand exchanges and surface treatments in CQD 44 solids18,19, but III V CQDs require a new approach in order to neutralize CQD charge surface states and 45 reduce trap density. 46 Trap states in InAs semiconductors originate from surface In and As dangling bonds20. Growing 47 epitaxially matched inorganic shells on CQDs passivates surface defects, but it hinders CQD coupling 48 and carrier transport21,22. Using molecular metal chalcogenide complexes (MCCs, e.g. Sn2S6 and 49 In2Se4) enhances carrier mobility in III V CQD solids, leading to an impressive mobility of 15 cm2V 1s50 1, but introduces undesired in gap states19,23. Etching As sites using strong acids facilitates In site 51 passivation but leads to low mobility (10 3 cm2V 1s 1)18,20,24. 52 Here we present a new surface passivation strategy that addresses charge imbalance and passivation 53 in InAs CQD solids for infrared photodetectors. We introduced InBr3 passivants to replace native insulating 54 oleic acid ligands, thereby providing surface passivation and charge transport simultaneously. We found 55 that InBr3 is amphoteric, dissociating into an X type ligand (Br that passivates In dangling bonds; and 56 into a Z type (InX2) ligand25 that passivates As dangling bonds. We incorporate N,N dimethylformamide 57 (DMF) as a coordinating agent to stabilize otherwise unstable Brand InX2passivants. We assess the co58 passivated InAs surfaces using a suite of spectroscopies and density functional theory (DFT) calculations. 59 The resulting InBr3 InAs CQD solids achieve a mobility value of 0.04 cm2V 1s 1, >10 times higher than in 60 halide exchanged InAs solids18; and a low dielectric constant of 6.3 a near 4x advance compared to PbS 61 CQD solid counterparts. The corresponding photodiode devices achieve a 30% external quantum 62 efficiency (EQE) a responsivity of 0.22 A W 1, and measured detectivity of 1011 cmHz1/2W 1 at the 63 excitonic peak (940 nm) Ultrafast transient photocurrent (TPC) experiments reveal a fall time of 300 ps, 64 equivalent of >1 GHz bandwidth. This is the first demonstration of efficient III V CQD photodiodes and 65 the fastest solution processed infrared photodiode reported, with over a 100 fold improvement compared 66 to the best CQDs photodiodes15,26. 67", "author_names": [ "B Sun", "najarian Am", "Chong Zheng", "Laxmi Kishore Sagar", "M Choi", "Xubiao Li", "Larissa Levina", "Se-Woong Baek", "Song-ee Lee", "Kirmani Ar", "Jehad Abed", "M Liu", "P Li", "Lee J Richter", "Oleksandr Voznyy", "Z Lu", "Arquer FPGd", "Edward H Sargent" ], "corpus_id": 229511424, "doc_id": "229511424", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Sub nanosecond Infrared Photodetection using III V Colloidal Quantum Dots", "venue": "", "year": 2020 }, { "abstract": "The ability to detect near infrared and mid infrared radiation has spawned great interest in colloidal HgTe quantum dots (QDs) In contrast to the studies focused on extending the spectral range of HgTe QD devices, the temporal response, another fi gure of merit for photodetectors, is rarely investigated. In this work, a single layer, aqueous HgTe QD based photoconductor structure with very fast temporal response (up to 1 MHz 3 dB bandwidth) is demonstrated. The device is fabricated using a simple spray coating process and shows excellent stability in ambient conditions. The origin of the remarkably fast time response is investigated by combining light intensity dependent transient photocurrent, temperature dependent photocurrent, and fi eld effect transistor (FET) measurements. The charge carrier mobility, as well as the energy levels and carrier lifetimes associated with the trap states in the QDs, are identifi ed. The results suggest that the temporal response is dominated by a fast bimolecular recombination process under high light intensity and by a trap mediated recombination process at low light intensity. Interestingly, it was found that the gain and time response of aqueous HgTe QD based photoconductors can be tuned by controlling the QD size and surface chemistry, which provides a versatile approach to optimize the photodetectors with selectable sensitivity and operation bandwidth.", "author_names": [ "Mengyu Chen", "Huijie Yu", "Stephen V Kershaw", "Haihua Xu", "Shuchi Gupta", "Frederik Hetsch", "Andrey L Rogach", "Ni Zhao" ], "corpus_id": 137117670, "doc_id": "137117670", "n_citations": 64, "n_key_citations": 2, "score": 0, "title": "Fast, Air Stable Infrared Photodetectors based on Spray Deposited Aqueous HgTe Quantum Dots", "venue": "", "year": 2014 }, { "abstract": "Herein, we report the first solution processed broadband photodetectors to break the past compromise between sensitivity and speed of response. Specifically, we report photodiodes having normalized detectivity (D* 10 Jones and a 3dB bandwidth of 2.9 MHz. This finding represents a 170,000 fold improvement in response speed over the most sensitive colloidal quantum dot (CQD) photodetector reported and a 100,000 fold improvement in sensitivity over the fastest CQD photodetector reported. At the outset of this study, sensitive, solution processed IR photodetectors were severely limited by low response speeds. Much faster response speeds had been demonstrated by solution processed photodetectors operating in the visible, but these devices offered no benefits for extending the spectral sensitivity of silicon. No available solution processed", "author_names": [ "Jason Paul Clifford" ], "corpus_id": 138403297, "doc_id": "138403297", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "COLLOIDAL QUANTUM DOT SCHOTTKY BARRIER PHOTODIODES", "venue": "", "year": 2008 }, { "abstract": "Graphene is an appealing material for optoelectronics and photodetection applications. It has various extraordinary properties, including ultrahigh mobility at room temperature, which enables fast response times. Colloidal quantum dots exhibit unique optical properties of spectral tunability and high absorption coefficients. We combine the favourable electronic properties of graphene with the optical characteristics of colloidal quantum dots to realize a novel hybrid graphene quantum dot photodetector for visible and short wave infrared frequencies. [1] The unique electronic properties of graphene offer a gate tunable carrier density and polarity that enable us to tune the sensitivity and operating speed of the detector. Here, we exploit this to maximize the photoconductive gain or to fully reduce it to zero, which is useful for pixelated imaging applications, while the implementation of nanoscale local gates enables a locally tunable photoresponse. We also demonstrate our novel approach to fully suppress dark currents in graphene based photodetectors and increase operation speed of our devices. At the current state our singleand multipixel photodetectors can operate at 30, 60 and up to 90 frames per second. The resulting technology is extremely promising for visible and, more importantly, short wave infrared (SWIR) imaging applications. Sensing and imaging in SWIR range lies at the heart of safety and security applications in civil and military surveillance, night vision applications, automotive vision systems for driver safety, food and pharmaceutical inspection and environmental monitoring. Operation of a prototype device sensitive to visible and IR light in the auditorium will be demonstrated during the talk.", "author_names": [ "A M Goossens", "Gabriele Navickaite", "Juan Piqueras", "Gerasimos Konstantatos", "L F H", "" ], "corpus_id": 211629422, "doc_id": "211629422", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Hybrid graphene quantum dot phototransistors for IR imaging applications", "venue": "", "year": 2014 }, { "abstract": "Heterostructures can be assembled from liquid phase exfoliated (LPE) layered materials (LMs) [1] via inkjet printing with tens m [1] resolution and controllable thickness [2] to make photodetectors (PDs) [2] However, LPE materials are unfavourable compared to chemical vapor deposited and mechanically exfoliated LMs, due to the presence of traps [1] which results in low responsivities ~mA/W [1,2] Here, we fabricate printable PDs based on graphene and black phosphorus (BP) inks (Fig. 1) showing high responsivity >300A/W) and broadband (0.4 2.8 m) detection (Fig. 2) LPE BP is used due to its broadband optical absorption (400 3500nm) [3] and its tuneable layer dependent direct bandgap [3] Photoexcited holes from BP are injected into graphene, leaving behind uncompensated electrons, resulting in photogating. We achieve a photoconductive gain (ratio of carrier life time measured from the device response time to transit time [4]~107 ,broadband (400 2800nm) and fast ~50ms) response time. The dark current shows a 1/f component, with a noise equivalent power~1.88x10 10W/Hz, and a detectivity~107 Jones. The responsivity is at least three orders of magnitude higher than previously reported ink jet printed BP PDs operating at the same spectral range [5] and the operating wavelength range (up to 2.8 m) is ~0.5 m longer compared to state of the art hybrid LMs colloidal quantum dots PDs [6,7]", "author_names": [ "Alfonso Ruocco", "Giancarlo Soavi", "T A", "", "Ioannis Paradisanos", "Konstantinos Dimos", "E J", "Hannah F Y Watson", "Lucia Lombardi", "Stephen A Hodge", "Andrea C Ferrari", "Ilya Goykhman" ], "corpus_id": 201788728, "doc_id": "201788728", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Graphene 2019 June 25 28 2019 Rome Italy Graphene black phosphorus photodetectors", "venue": "", "year": 2019 }, { "abstract": "Silicon technology is dominant in electronics and optoelectronics. The cut off wavelength of silicon is less than 1.1m\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin} 69pt} \\begin{document}\\upmu$\\end{document}m due to the bandgap, limiting applications of silicon in communication, sensing, and light harvesting. A new strategy for infrared photodetection is presented by integrating silicon and PbSe colloidal quantum dots (CQDs) which combines advantages of silicon devices and PbSe CQDs. In this study, we introduce a silicon based photodetector that is sensitive to infrared light with spectral response from 405 nm to 1550 nm. The device can deliver a high responsivity of 648.7AW 1 and a fast response of 32.3m\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin} 69pt} \\begin{document}\\upmu$\\end{document}s at 1550 nm. Besides, the detectivity and the external quantum efficiency of the device reached 7.48 x 1010 Jones and 6.47 x 104% respectively. The performance of the device originates from the photovoltage generated at the interface between the silicon and the quantum dots. This photovoltage changed the width of the depletion layer to realize detection. These results indicate that the silicon based quantum dot infrared photodetectors prepared by this method have application prospects in the field of optoelectronics.", "author_names": [ "Pengyu Chen", "Zhiming Wu", "Yuanlin Shi", "Chunyu Li", "Jinquan Wang", "Jun Yang", "Xiang Dong", "Jun Gou", "Jun Wang", "Yadong Jiang" ], "corpus_id": 232173286, "doc_id": "232173286", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "High performance silicon based PbSe CQDs infrared photodetector", "venue": "Journal of Materials Science: Materials in Electronics", "year": 2021 } ]

[ { "abstract": "We propose a scheme for reservoir computing using multiple semiconductor lasers with optical feedback arranged in parallel on a photonic integrated circuit, and we investigate the performance of reservoir computing numerically. The virtual nodes are obtained from the temporal waveforms of the outputs of the parallel reservoir lasers. We test the chaotic time series prediction task, memory capacity, and nonlinear channel equalization task to investigate the performance of reservoir computing. We found that our scheme using multiple lasers outperforms that using a single laser with multiple delay times. Large memory capacity can also be obtained for the multiple lasers. Finally, we investigate the effect of parameter mismatch of the multiple lasers on reservoir computing performance.", "author_names": [ "Chihiro Sugano", "Kazutaka Kanno", "Atsushi Uchida" ], "corpus_id": 199683775, "doc_id": "199683775", "n_citations": 24, "n_key_citations": 1, "score": 1, "title": "Reservoir Computing Using Multiple Lasers With Feedback on a Photonic Integrated Circuit", "venue": "IEEE Journal of Selected Topics in Quantum Electronics", "year": 2020 }, { "abstract": "Microwave photonics (MWP) studies the interaction between microwaves and optical waves for the generation, transmission, and processing of microwave signals (i.e. three key domains) taking advantage of the broad bandwidth and low loss offered by modern photonics. Integrated MWP using photonic integrated circuits (PICs) can reach a compact, reliable, and green implementation. Most PICs, however, are recently developed to perform one or more functions restricted inside a single domain. Herein, as highly desired, a multifunctional PIC is proposed to cover the three key domains. The PIC is fabricated on an InP platform by monolithically integrating four laser diodes and two modulators. Using the multifunctional PIC, seven fundamental functions across microwave signal generation, transmission, and processing are demonstrated experimentally. Outdoor field trials for electromagnetic environment surveillance along in service high speed railways are also performed. The success of such a PIC marks a key step forward for practical and massive MWP implementations.", "author_names": [ "Xihua Zou", "Fang Zou", "Zizheng Cao", "Bing Lu", "Xianglei Yan", "Ge Yu", "Xiong Deng", "Bin Luo", "Lianshan Yan", "Wei Pan", "Jianping Yao", "Antonius M J Koonen" ], "corpus_id": 102352484, "doc_id": "102352484", "n_citations": 28, "n_key_citations": 0, "score": 1, "title": "A Multifunctional Photonic Integrated Circuit for Diverse Microwave Signal Generation, Transmission, and Processing", "venue": "Laser Photonics Reviews", "year": 2019 }, { "abstract": "We present a photonic integrated circuit (PIC) transceiver for frequency modulated continuous wave (FMCW) LiDAR applications. The transmitter consists of a widely tunable sampled grating distributed Bragg reflector laser (SGDBR) and a frequency discriminator which combines multimode interference couplers, a tunable asymmetric Mach Zehnder Interferometer (a MZI) and balanced photodiodes. The frequency discriminator converts frequency fluctuations of the laser to amplitude fluctuations of the photodiode currents. This provides an error signal for feedback into the laser cavity for frequency stabilization. Frequency modulation is obtained by a phase shifter in the a MZI which tunes the quadrature point of the filter and the frequency where the error is zero. An on chip receiver couples power from the transmitter to self heterodyne with the time delayed echo of a distant object. The generated beat frequency of the self heterodyne measurement gives the echo signals time of flight to obtain the distance and velocity of the reflecting object. The theory of the components is described, and characterization of the transmitter and receiver is presented.", "author_names": [ "Brandon J Isaac", "Bowen Song", "Sergio Pinna", "Larry A Coldren", "Jonathan Klamkin" ], "corpus_id": 145964698, "doc_id": "145964698", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Indium Phosphide Photonic Integrated Circuit Transceiver for FMCW LiDAR", "venue": "IEEE Journal of Selected Topics in Quantum Electronics", "year": 2019 }, { "abstract": "Photonic reservoir computing is a new paradigm for performing high speed prediction and classification tasks in an efficient manner. The major challenge for the miniaturization of photonic reservoir computing is the need for the use of photonic integrated circuits. Herein, we experimentally demonstrate reservoir computing using a photonic integrated circuit with a semiconductor laser and a short external cavity. We propose a method to increase the number of virtual nodes in delayed feedback using short node intervals and outputs from multiple delay times. We perform time series prediction and nonlinear channel equalization tasks using reservoir computing with the photonic integrated circuit. We show that the photonic integrated circuit with optical feedback outperforms the photonic integrated circuit without optical feedback for prediction tasks. To enhance the memory effect we feed past input signals in the current input data and demonstrate successful performance in an n step ahead prediction task.", "author_names": [ "Kosuke Takano", "Chihiro Sugano", "Masanobu Inubushi", "Kazuyuki Yoshimura", "Satoshi Sunada", "Kazutaka Kanno", "Atsushi Uchida" ], "corpus_id": 53787257, "doc_id": "53787257", "n_citations": 34, "n_key_citations": 2, "score": 1, "title": "Compact reservoir computing with a photonic integrated circuit.", "venue": "Optics express", "year": 2018 }, { "abstract": "The interaction of optical and acoustic waves via stimulated Brillouin scattering (SBS) has recently reached on chip platforms, which has opened new fields of applications ranging from integrated microwave photonics and on chip narrow linewidth lasers, to phonon based optical delay and signal processing schemes. Since SBS is an effect that scales exponentially with interaction length, on chip implementation on a short length scale is challenging, requiring carefully designed waveguides with optimized opto acoustic overlap. In this work, we use the principle of Brillouin optical correlation domain analysis to locally measure the SBS spectrum with high spatial resolution of 800 mm and perform a distributed measurement of the Brillouin spectrum along a spiral waveguide in a photonic integrated circuit. This approach gives access to local opto acoustic properties of the waveguides, including the Brillouin frequency shift and linewidth, essential information for the further development of high quality photonic phononic waveguides for SBS applications.The interaction of optical and acoustic waves via stimulated Brillouin scattering (SBS) has recently reached on chip platforms, which has opened new fields of applications ranging from integrated microwave photonics and on chip narrow linewidth lasers, to phonon based optical delay and signal processing schemes. Since SBS is an effect that scales exponentially with interaction length, on chip implementation on a short length scale is challenging, requiring carefully designed waveguides with optimized opto acoustic overlap. In this work, we use the principle of Brillouin optical correlation domain analysis to locally measure the SBS spectrum with high spatial resolution of 800 mm and perform a distributed measurement of the Brillouin spectrum along a spiral waveguide in a photonic integrated circuit. This approach gives access to local opto acoustic properties of the waveguides, including the Brillouin frequency shift and linewidth, essential information for the further development of high quality photonic.", "author_names": [ "Atiyeh Zarifi", "Birgit Stiller", "Moritz Merklein", "Neuton Li", "Khu Vu", "Duk-Yong Choi", "Pan Ma", "Steve J Madden", "Benjamin J Eggleton" ], "corpus_id": 117301552, "doc_id": "117301552", "n_citations": 17, "n_key_citations": 2, "score": 0, "title": "Highly localized distributed Brillouin scattering response in a photonic integrated circuit", "venue": "", "year": 2018 }, { "abstract": "We report for the first time the successful wavelength stabilization of two hybrid integrated InP/Polymer DBR lasers through optical injection. The two InP/Polymer DBR lasers are integrated into a photonic integrated circuit, providing an ideal source for millimeter and Terahertz wave generation by optical heterodyne technique. These lasers offer the widest tuning range of the carrier wave demonstrated to date up into the Terahertz range, about 20 nm (2.5 THz) on a single photonic integrated circuit. We demonstrate the application of this source to generate a carrier wave at 330 GHz to establish a wireless data transmission link at a data rate up to 18 Gbit/s. Using a coherent detection scheme we increase the sensitivity by more than 10 dB over direct detection.", "author_names": [ "Guillermo Carpintero", "Shintaro Hisatake", "David de Felipe", "Robinson Cruzoe Guzman", "Tadao Nagatsuma", "Norbert Keil" ], "corpus_id": 3497009, "doc_id": "3497009", "n_citations": 23, "n_key_citations": 1, "score": 0, "title": "Wireless Data Transmission at Terahertz Carrier Waves Generated from a Hybrid InP Polymer Dual Tunable DBR Laser Photonic Integrated Circuit", "venue": "Scientific Reports", "year": 2018 }, { "abstract": "For the first time, an integrated electro optical RF modulator based on the quadratic electro optical effect with CMOS compatible sub volt driver voltages is presented. As unique feature, this modulator provides an amplitude tuning of the modulated carrier wave. The silicon based modulator was fabricated using process steps of an established photonic integrated circuit technology and covered by a nonlinear optical polymer in a post process. We demonstrate a device tunability of up to 350 pm/V, surpassing state of the art silicon modulators with an order of magnitude. Moreover, the ring resonator is designed to have an ultra low per bit energy consumption of 87 aJ/bit demonstrating the potential for high performance photonic devices with low energy consumption.", "author_names": [ "Patrick Steglich", "Christian Mai", "Anna Peczek", "Falk Korndorfer", "Claus Villringer", "Birgit Dietzel", "Andreas Mai" ], "corpus_id": 58674726, "doc_id": "58674726", "n_citations": 15, "n_key_citations": 0, "score": 0, "title": "Quadratic electro optical silicon organic hybrid RF modulator in a photonic integrated circuit technology", "venue": "2018 IEEE International Electron Devices Meeting (IEDM)", "year": 2018 }, { "abstract": "This paper summarizes the recent advances of integrated hybrid InP/SOI lasers and transmitters based on edge coupling. First, we review the different integration methods between III V material and silicon. Then, we focus on using an external III V chip coupled via edge coupling to our silicon photonic integrated circuit. The paper reports on the results of wavelength tunable lasers containing one or two ring resonators as well as an integrated reflectivity tunable mirror. We demonstrate that a wide thermal tuning range, exceeding the C band, with a high side mode suppression ratio above 35 dB can be achieved. Design of external silicon cavities enables the realization of a broad range of on chip functionalities as well as advanced hybrid transmitters. Parallel wavelength tunable cavities and compact variable optical attenuator controlled arrayed waveguide gratings on silicon are integrated with a reflective semiconductor optical amplifiers, creating fast wavelength switching lasers. Furthermore, integrated transmitters that combine silicon modulators with tunable hybrid III V/Si lasers are reported. The integrated transmitter for on off keying signal generation exhibits more than 30 nm wavelength tunability and excellent bit error rate performance up to 40 Gb/s. A multichannel integrated transmitter is then reported with combined silicon based arrayed waveguide gratings laser cavity and multiple ring modulators. Finally, an advanced wavelength tunable hybrid III V/Si transmitter with two microring modulators nested in a Mach Zehnder interferometer is demonstrated for quadrature phase shift keying generation where a BPSK signal is generated by each ring.", "author_names": [ "Guilhem de Valicourt", "Chia-Ming Chang", "Michael S Eggleston", "Argishti Melikyan", "Chen Zhu", "Jeffrey Lee", "Jesse E Simsarian", "Sethumadhavan Chandrasekhar", "Jeffrey H Sinsky", "Kwangwoong Kim", "Po Dong", "Anaelle Maho", "Agnes Verdier", "Romain Brenot", "Young-Kai Chen" ], "corpus_id": 3441837, "doc_id": "3441837", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "Photonic Integrated Circuit Based on Hybrid III V/Silicon Integration", "venue": "Journal of Lightwave Technology", "year": 2018 }, { "abstract": "We report on the heterogeneous integration of electrically pumped InP Fabry Perot lasers on a SOI photonic integrated circuit by transfer printing. Transfer printing is a promising micromanipulation technique that allows the heterogeneous integration of optical and electronic components realized on their native substrate onto a target substrate with efficient use of the source material, in a way that can be scaled to parallel manipulation and that allows mixing components from different sources onto the same target. We pre process transfer printable etched facet Fabry Perot lasers on their native InP substrate, transfer print them into a trench defined in an SOI photonic chip and post process the printed lasers on the target substrate. The laser facet is successfully butt coupled to the photonic circuit using a silicon inverse taper based spot size converter. Milliwatt optical output power coupled to the Si waveguide circuit at 100 mA is demonstrated.", "author_names": [ "Joan Juvert", "Tommaso Cassese", "Sarah Uvin", "Andreas de Groote", "Brad Snyder", "Lieve Bogaerts", "Geraldine Jamieson", "Joris Van Campenhout", "Gunther Roelkens", "Dries van Thourhout" ], "corpus_id": 52057481, "doc_id": "52057481", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "Integration of etched facet, electrically pumped, C band Fabry Perot lasers on a silicon photonic integrated circuit by transfer printing.", "venue": "Optics express", "year": 2018 }, { "abstract": "We report a compact, scalable, quantum photonic integrated circuit realised by combining multiple, independent InGaAs/GaAs quantum light emitting diodes (QLEDs) with a silicon oxynitride waveguide circuit. Each waveguide joining the circuit can then be excited by a separate, independently electrically contacted QLED. We show that the emission from neighbouring QLEDs can be independently tuned to degeneracy using the Stark Effect and that the resulting photon streams are indistinguishable. This enables on chip Hong Ou Mandel type interference, as required for many photonic quantum information processing schemes.", "author_names": [ "David J P Ellis", "Anthony J Bennett", "Christian Dangel", "James P Lee", "J P Griffiths", "Thomas A Mitchell", "Taofiq K Paraiso", "Peter D Spencer", "David A Ritchie", "Andrew J Shields" ], "corpus_id": 4946269, "doc_id": "4946269", "n_citations": 26, "n_key_citations": 0, "score": 0, "title": "Independent indistinguishable quantum light sources on a reconfigurable photonic integrated circuit", "venue": "", "year": 2018 } ]

[ { "abstract": "Current research into semiconductor clusters is focused on the properties of quantum dots fragments of semiconductor consisting of hundreds to many thousands of atoms with the bulk bonding geometry and with surface states eliminated by enclosure in a material that has a larger band gap. Quantum dots exhibit strongly size dependent optical and electrical properties. The ability to join the dots into complex assemblies creates many opportunities for scientific discovery.", "author_names": [ "A Paul Alivisatos" ], "corpus_id": 98248597, "doc_id": "98248597", "n_citations": 9082, "n_key_citations": 63, "score": 1, "title": "Semiconductor Clusters, Nanocrystals, and Quantum Dots", "venue": "Science", "year": 1996 }, { "abstract": "Research on fluorescent semiconductor nanocrystals (also known as quantum dots or qdots) has evolved over the past two decades from electronic materials science to biological applications. We review current approaches to the synthesis, solubilization, and functionalization of qdots and their applications to cell and animal biology. Recent examples of their experimental use include the observation of diffusion of individual glycine receptors in living neurons and the identification of lymph nodes in live animals by near infrared emission during surgery. The new generations of qdots have far reaching potential for the study of intracellular processes at the single molecule level, high resolution cellular imaging, long term in vivo observation of cell trafficking, tumor targeting, and diagnostics.", "author_names": [ "Xavier Michalet", "Fabien Pinaud", "Laurent A Bentolila", "James M Tsay", "Soren Doose", "Jingyi Jessica Li", "Gobalakrishnan Sundaresan", "Anna M Wu", "Sanjiv Sam Gambhir", "Shimon Weiss" ], "corpus_id": 17004377, "doc_id": "17004377", "n_citations": 6738, "n_key_citations": 67, "score": 0, "title": "Quantum Dots for Live Cells, in Vivo Imaging, and Diagnostics", "venue": "Science", "year": 2005 }, { "abstract": "We propose an implementation of a universal set of one and two quantum bit gates for quantum computation using the spin states of coupled single electron quantum dots. Desired operations are effected by the gating of the tunneling barrier between neighboring dots. Several measures of the gate quality are computed within a recently derived spin master equation incorporating decoherence caused by a prototypical magnetic environment. Dot array experiments that would provide an initial demonstration of the desired nonequilibrium spin dynamics are proposed.", "author_names": [ "Daniel Loss", "David P DiVincenzo" ], "corpus_id": 13152124, "doc_id": "13152124", "n_citations": 4621, "n_key_citations": 99, "score": 0, "title": "Quantum computation with quantum dots", "venue": "", "year": 1998 }, { "abstract": "We describe the development of multifunctional nanoparticle probes based on semiconductor quantum dots (QDs) for cancer targeting and imaging in living animals. The structural design involves encapsulating luminescent QDs with an ABC triblock copolymer and linking this amphiphilic polymer to tumor targeting ligands and drug delivery functionalities. In vivo targeting studies of human prostate cancer growing in nude mice indicate that the QD probes accumulate at tumors both by the enhanced permeability and retention of tumor sites and by antibody binding to cancer specific cell surface biomarkers. Using both subcutaneous injection of QD tagged cancer cells and systemic injection of multifunctional QD probes, we have achieved sensitive and multicolor fluorescence imaging of cancer cells under in vivo conditions. We have also integrated a whole body macro illumination system with wavelength resolved spectral imaging for efficient background removal and precise delineation of weak spectral signatures. These results raise new possibilities for ultrasensitive and multiplexed imaging of molecular targets in vivo.", "author_names": [ "Xiaohu Gao", "Yuanyuan Cui", "Richard M Levenson", "Leland W K Chung", "Shuming Nie" ], "corpus_id": 41561027, "doc_id": "41561027", "n_citations": 4149, "n_key_citations": 86, "score": 0, "title": "In vivo cancer targeting and imaging with semiconductor quantum dots", "venue": "Nature Biotechnology", "year": 2004 }, { "abstract": "The field of nanotechnology holds great promise for the diagnosis and treatment of human disease. However, the size and charge of most nanoparticles preclude their efficient clearance from the body as intact nanoparticles. Without such clearance or their biodegradation into biologically benign components, toxicity is potentially amplified and radiological imaging is hindered. Using intravenously administered quantum dots in rodents as a model system, we have precisely defined the requirements for renal filtration and urinary excretion of inorganic, metal containing nanoparticles. Zwitterionic or neutral organic coatings prevented adsorption of serum proteins, which otherwise increased hydrodynamic diameter by >15 nm and prevented renal excretion. A final hydrodynamic diameter <5.5 nm resulted in rapid and efficient urinary excretion and elimination of quantum dots from the body. This study provides a foundation for the design and development of biologically targeted nanoparticles for biomedical applications.", "author_names": [ "Hak Soo Choi", "Wenhao Liu", "Preeti Misra", "Eiichi Tanaka", "J Pascal Zimmer", "Binil Itty Ipe", "Moungi G Bawendi", "John V Frangioni" ], "corpus_id": 205273572, "doc_id": "205273572", "n_citations": 3250, "n_key_citations": 84, "score": 0, "title": "Renal clearance of quantum dots", "venue": "Nature Biotechnology", "year": 2007 }, { "abstract": "We report a synthesis of highly luminescent (CdSe)ZnS composite quantum dots with CdSe cores ranging in diameter from 23 to 55 A. The narrow photoluminescence (fwhm 40 nm) from these composite dots spans most of the visible spectrum from blue through red with quantum yields of 30 50% at room temperature. We characterize these materials using a range of optical and structural techniques. Optical absorption and photoluminescence spectroscopies probe the effect of ZnS passivation on the electronic structure of the dots. We use a combination of wavelength dispersive X ray spectroscopy, X ray photoelectron spectroscopy, small and wide angle X ray scattering, and transmission electron microscopy to analyze the composite dots and determine their chemical composition, average size, size distribution, shape, and internal structure. Using a simple effective mass theory, we model the energy shift for the first excited state for (CdSe)ZnS and (CdSe)CdS dots with varying shell thickness. Finally, we characterize the.", "author_names": [ "Bashir O Dabbousi", "Javier Rodriguez-Viejo", "Frederic Victor Mikulec", "J R Heine", "Hedi Mattoussi", "R Ober", "++SS and K F Jensen", "Moungi G Bawendi" ], "corpus_id": 14518717, "doc_id": "14518717", "n_citations": 3052, "n_key_citations": 30, "score": 0, "title": "(CdSe)ZnS Core Shell Quantum Dots Synthesis and Characterization of a Size Series of Highly Luminescent Nanocrystallites", "venue": "", "year": 1997 }, { "abstract": "With their bright, photostable fluorescence, semiconductor quantum dots show promise as alternatives to organic dyes for biological labeling. Questions about their potential cytotoxicity, however, remain unanswered. While cytotoxicity of bulk cadmium selenide (CdSe) is well documented, a number of groups have suggested that CdSe QDs are cytocompatible, at least with some immortalized cell lines. Using primary hepatocytes as a liver model, we found that CdSe core QDs were indeed acutely toxic under certain conditions. Specifically, we found that the cytotoxicity of QDs was modulated by processing parameters during synthesis, exposure to ultraviolet light, and surface coatings. Our data further suggests that cytotoxicity correlates with the liberation of free Cd2+ ions due to deterioration of the CdSe lattice. When appropriately coated, CdSe core QDs can be rendered non toxic and used to track cell migration and reorganization in vitro. Our results inform design criteria for the use of QDs in vitro and especially in vivo where deterioration over time may occur.", "author_names": [ "Austin M Derfus", "Warren C W Chan", "Sangeeta N Bhatia" ], "corpus_id": 13292214, "doc_id": "13292214", "n_citations": 2945, "n_key_citations": 74, "score": 0, "title": "Probing the Cytotoxicity Of Semiconductor Quantum Dots.", "venue": "Nano letters", "year": 2004 }, { "abstract": "Suitable labels are at the core of luminescence and fluorescence imaging and sensing. One of the most exciting, yet also controversial, advances in label technology is the emerging development of quantum dots (QDs) inorganic nanocrystals with unique optical and chemical properties but complicated surface chemistry as in vitro and in vivo fluorophores. Here we compare and evaluate the differences in physicochemical properties of common fluorescent labels, focusing on traditional organic dyes and QDs. Our aim is to provide a better understanding of the advantages and limitations of both classes of chromophores, to facilitate label choice and to address future challenges in the rational design and manipulation of QD labels.", "author_names": [ "Ute Resch-Genger", "Markus Grabolle", "Sara Cavaliere-Jaricot", "Roland Nitschke", "Thomas Nann" ], "corpus_id": 9007994, "doc_id": "9007994", "n_citations": 2937, "n_key_citations": 45, "score": 0, "title": "Quantum dots versus organic dyes as fluorescent labels", "venue": "Nature Methods", "year": 2008 }, { "abstract": "We report that nanoscale carbon particles (carbon dots) upon simple surface passivation are strongly photoluminescent in both solution and the solid state. The luminescence emission of the carbon dots is stable against photobleaching, and there is no blinking effect. These strongly emissive carbon dots may find applications similar to or beyond those of their widely pursued silicon counterparts.", "author_names": [ "Ya-Ping Sun", "Bing Zhou", "Yi Lin", "Wei Wang", "Kurukulasuriya Alexius Shiral Fernando", "Pankaj Pathak", "Mohammed Meziani", "Barbara A Harruff", "X P Wang", "Haifang Wang", "Pengju George Luo", "Hua Yang", "Muhammet Kose", "Baili Chen", "Lucia Monica Veca", "Su-Yuan Xie" ], "corpus_id": 26788653, "doc_id": "26788653", "n_citations": 3014, "n_key_citations": 29, "score": 0, "title": "Quantum sized carbon dots for bright and colorful photoluminescence.", "venue": "Journal of the American Chemical Society", "year": 2006 }, { "abstract": "Fluorescent semiconductor nanocrystals (quantum dots) have the potential to revolutionize biological imaging, but their use has been limited by difficulties in obtaining nanocrystals that are biocompatible. To address this problem, we encapsulated individual nanocrystals in phospholipid block copolymer micelles and demonstrated both in vitro and in vivo imaging. When conjugated to DNA, the nanocrystal micelles acted as in vitro fluorescent probes to hybridize to specific complementary sequences. Moreover, when injected into Xenopus embryos, the nanocrystal micelles were stable, nontoxic <5 x 109 nanocrystals per cell) cell autonomous, and slow to photobleach. Nanocrystal fluorescence could be followed to the tadpole stage, allowing lineage tracing experiments in embryogenesis.", "author_names": [ "Benoit Dubertret", "Paris A Skourides", "David J Norris", "Vincent Noireaux", "Ali H Brivanlou", "Albert Libchaber" ], "corpus_id": 4089168, "doc_id": "4089168", "n_citations": 2639, "n_key_citations": 48, "score": 0, "title": "In Vivo Imaging of Quantum Dots Encapsulated in Phospholipid Micelles", "venue": "Science", "year": 2002 } ]

[ { "abstract": "", "author_names": [ "Angel R O Sousa" ], "corpus_id": 213352350, "doc_id": "213352350", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Tuning the electral conductivity of an n type organic semiconductor by means of solution doping for thermoeletric applications", "venue": "", "year": 2020 }, { "abstract": "In this paper, a general numerical methodology is developed and validated for the simulation of steady as well as transient thermal and electrical behaviors of thermoelectric generator (TEG) based air flow self cooling systems. The present model provides a comprehensive framework to advance the study of self cooling applications by combining fluid flow, heat transfer and electric circuit simulations. The methodology is implemented by equation based coupled modeling capabilities from multidisciplinary fields to capture the dynamic thermos electric interaction in TEG elements, enabling the simulation of overall heating/cooling/power characteristics as well as spatially distributed thermal and flow fields in the entire device. Experiments have been conducted on two types of self cooling arrangements to measure the device temperature, voltage and power produced by TEG modules. It was found that the computational model was able to predict the experimental results within 5% error. A parametric study was carried out using the validated model to study the effect of heat sink geometry and TEG arrangements on device temperature and power produced by the device. It was found that the power for self cooling could be maximized by proper matching of the TEG modules to the fluid mover. Although an increase in fin density results in a rise in fan power consumption, a marked increase in net power and decreases in thermal resistance are observed.", "author_names": [ "Cheng-Xian Lin", "Robel Kiflemariam" ], "corpus_id": 208836621, "doc_id": "208836621", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Numerical Simulation and Validation of Thermoeletric Generator Based Self Cooling System with Airflow", "venue": "Energies", "year": 2019 }, { "abstract": "Abstract The n type and p type thermoelectric property of nanoporous SnSe assembled by hollow cage cluster is studied by First principles calculations and Boltzmann transport theory. The nanoporous SnSe presents low Shear modulus (3.16 GPa) low Shear sound velocity (925 m/s) low average sound velocity (1203 m/s) low Debye temperature (101 K) and large Gruneisen parameter (3.3) which implies that weak Sn Se atomic interactions and strong anharmonicity of the bonding arrangement. Owing to the cubic structure of nanoporous SnSe, the thermoelectric property along different direction is isotropous. For n type, the optimal ZT at 800 K is 2.25, while the highest ZT of p type is 1.81. The strong differences between n type and p type are mainly dominated by the Seebeck coefficient, which is related to the carrier effective mass. This work not only demonstrates the excellent property of nanoporous SnSe, but also provides insights to understand the transport performance of cage structure.", "author_names": [ "Donglin Guo", "Chunhong Li", "Kejian Li", "Bin Shao", "Dengming Chen", "Yilong Ma", "Jianchun Sun", "Xianlong Cao", "Wen Zeng" ], "corpus_id": 225131802, "doc_id": "225131802", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "The thermoeletric performance of nanoporous SnSe assembled by hollow cage cluster", "venue": "", "year": 2021 }, { "abstract": "Panas buang pada air conditioner merupakan energy berkualitas rendah yang terbuang cuma cuma ke lingkungan, kalor yang terbuang tersebut dapat dimanfaatkan untuk memanaskan modul thermoelektik generator (TEG) akan tetapi modul tersebut perlu didinginkan pada sisi lainnya agar tercipta perbedaan temperature pada kedua sisi modul. Pada penelitian ini dilakukan eksperimen dengan memanfaatkan dua media pendingin yaitu air dan refrigerant yang keluar dari evaporator pada sebuah heat exchanger tipe liquid plate yang besrfungsi sebagai heat sink Hasil pengujian menunjukkan kinerja terbaik didapatkan pada media refrigerant dimana open circuit voltage (V oc dan Short circuit current (I sc yang dihasilkan dari 10 modul yang disusun seri adalah 9,31 Volt dan 270.8 mA dengan selisih temperature 21.08 o C, dan pada media pendingin air V oc 7,5 Volt I sc 200,2 mA dengan selisih temperature 17,5 o C Kata Kunci: Air Conditioner Thermoelectric generator media pendingin, air refrigerant", "author_names": [ "Mustafa Mustafa", "Muhammad Hasan Basri", "Reyhan Kiay Demak" ], "corpus_id": 232581459, "doc_id": "232581459", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "VARIASI MEDIA PENDINGIN PADA THERMOELETRIC GENERATOR YANG MEMANFAATKAN PANAS BUANG AIR CONDITIONER", "venue": "", "year": 2018 }, { "abstract": "iii LIST OF FIGURES vii LIST OF TABLES viii ACKNOWLEDGMENTS ix CHAPTER 1: INTRODUCTION .1 CHAPTER 2: BACKGROUND AND LITERATURE REVIEW .3 2.1 Literature Review .3 2.2 History .4 2.2.1 Thermocouple History .4 2.2.2 TEG History .5 2.2.3 Peltier History .6 2.3 Applications .6 2.3.1 Thermocouple/TEG .6 2.3.2 Peltier .8 2.4 Thermoelectric Generator vs Peltier .10 2.4.1 Cooling .10 2.4.2 Power Generation..10 2.4.3 Thermal Breakdown..10 2.4.4 Cost .11 2.4.5 Power Generation Efficiency .11 2.5 Thermoelectric Generator vs. Photovoltaic .11", "author_names": [ "Jamison A Olsten" ], "corpus_id": 56209273, "doc_id": "56209273", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Small scale thermoeletric generator for off grid power", "venue": "", "year": 2017 }, { "abstract": "Thermoelectric converters for power generation aim at reducing CO\\(_2\\ emission via the conversion of a part of the low grade waste heat generated by engines, industrial furnaces, gas pipes, etc. to electricity. The recovery of waste heat from the exhaust of an automotive engine, in particular, is an attractive, albeit not very efficient way for reduction of fuel consumption. Thermoelectric converters with high overall efficiency convert heat directly into electricity without moving parts and, thus, not only decrease our reliance on fossil fuels but also actively counteract global warming. State of the art converters are simply too inefficient to be economic, partly due to expensive elementary constituents (Te, Ge, etc. On this background, Heusler compounds with C1\\(_b\\ structure stand out on account of their relatively low cost components and have been extensively studied as potential thermoelectric materials for high temperature power generation up to 1000 K during the last years.", "author_names": [ "Julia Krez", "Benjamin Balke" ], "corpus_id": 139068271, "doc_id": "139068271", "n_citations": 2, "n_key_citations": 0, "score": 1, "title": "Thermoeletric Heusler Compounds", "venue": "", "year": 2016 }, { "abstract": "This paper presents a methodology to estimate thermoelectric module (TEM) internal parameters based on particle swarm optimization (PSO) algorithm. To obtain the correct TEM representation, it is necessary a proper model identification procedure to represent the TEM operation, both in DC and other relevant frequencies. Classical methods for linear parameter estimation are not suitable for the nonlinear TEM characteristics of the proposed model. We devise a model with twenty one parameters, which represent parts of the two TEMs employed, including top, lower and middle layers and heat sinks. The TEM is excited using an electrical current signal with power spectral density of a white noise, and the temperature response is adopted as output for the PSO algorithm to make the estimation. For numerical stability and proper estimation, the white noise excitation is filtered before, to obtain a dynamically persistent signal with high and low frequencies components. Simulation results show the effectiveness of the PSO in TEM parameters estimation.", "author_names": [ "G DanielR Ojeda", "Luiz Alberto Luz de Almeida", "Omar A C Vilcanqui" ], "corpus_id": 9773683, "doc_id": "9773683", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Parameter identification of thermoeletric modules using particle swarm optimization", "venue": "2015 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) Proceedings", "year": 2015 }, { "abstract": "In this paper, a fuzzy controller using thermoelectric for temperature environmental tester is developed. The new structure of fuzzy controller based temperature environmental tester is proposed and implemented to maintain a stable temperature and improve temperature change speed. In order to evaluate the efficiency, an experiment is setup to compare PID controller with our proposed controller. The experimental results, we proved that our proposed fuzzy controller has better performance than PID controller.", "author_names": [ "Gi-Hyun Hwang" ], "corpus_id": 64313105, "doc_id": "64313105", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Development of Fuzzy Controller for Temperature Environment Tester Using Thermoeletric Module", "venue": "", "year": 2015 }, { "abstract": "", "author_names": [ "Tsunehiro Takeuchi" ], "corpus_id": 136087660, "doc_id": "136087660", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Thermoeletric properties of Fe 2 VAl based thin films", "venue": "", "year": 2015 }, { "abstract": "Global warming and developments of alternative energy technologies have become important issues nowadays. Subsequently, the concept of energy harvesting is rising because of its ability of transferring waste energy into usable energy. Thermoelectric devices play a role in this field since there is tremendous waste heat existing in our lives, such as heat from engines, generators, stoves, computers, etc. Thermoelectric devices can extract the waste heat and turn them into electricity. Moreover, the reverse thermoelectric phenomenon has the function of cooling which can be applied to refrigerator or heat dissipation for electronic devices. However, the energy conversion efficiency is still low comparing to other energy technologies. The efficiency is judged by thermoelectric figure of merit (ZT) defined by Seebeck coefficient, electrical conductivity and thermal conductivity. In order to improve ZT, thin film materials are good candidates because of their structural effects on altering ZT. Ca3Co4O9 thin films grown by reactive radio frequency magnetron sputtering followed by post annealing process is studied in this thesis. Structural properties of the films with the evolution of elemental ratio (Ca/Co) of calcium and cobalt have been investigated. For the investigations, three samples having elemental ratio 0.82, 0.72, and 0.66 for sample CCO1, CCO2 and COO3, respectively, have been prepared. Structural properties of the films have been investigated by X ray diffraction (XRD) th 2th and pole figure analyses. Surface morphology of the films has been investigated by scanning electron microscopic (SEM) analyses. The highly oriented and phase pure epitaxial Ca3Co4O9 thin films were obtained in the end. Mixing of ScN and CrN to obtain ScxCr1 xN solid solution thin films by DC magnetron sputtering is the other task in this thesis. Growth of ScN and CrN thin films were studied first in order to get the best mixed growth conditions. The phase shifts between ScN (111) and CrN (111) peaks were observed in mixed growth films by XRD th 2th measurements, indicating the formation of ScxCr1 xN. Surface morphology of the films were investigated by SEM. The (111) oriented ScxCr1 xN thin films with decent surface smoothness grown by DC magnetron sputtering at 600 degC in pure nitrogen with bias were developed.", "author_names": [ "K Lin" ], "corpus_id": 137455999, "doc_id": "137455999", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Thin films for thermoeletric applications", "venue": "", "year": 2014 } ]

[ { "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 present an indoor free space optical communication system to augment traditional short range radio frequency wireless links. In this system, we integrated a high frequency, high current laser driver with an 850 nm wavelength, 500 mW vertical cavity surface emitting laser (VCSEL) array to transmit high speed optical signals with a large spatial coverage. The large current bandwidth capability of the laser driver is enabled by a distributed current driver design utilizing three enhanced mode pseudomorphic high electron mobility transistors. At the optical receiver end, a high sensitivity avalanche photodiode is used to achieve high speed optical signal detection without any light concentrating optical device and is tolerant to angular deviation up to 27deg. The communication link described in this article forms an optical femtocell with an area of 100 cm2 at a distance of three meters from the transmitter. A bit error rate of less than 10 4 is achieved throughout the optical femtocell in a normal in door environment. On off keying and four level pulse amplitude modulation schemes are both implemented with 1.25 Gb/s and 2 Gb/s data rate respectively, using the hardware described in this article. Additionally, the overall performance of this free space optical link is evaluated in terms of viewing angle, distance range, and bit error rate.", "author_names": [ "Spencer Liverman", "Hayden Bialek", "Arun S Natarajan", "Alan X Wang" ], "corpus_id": 210836905, "doc_id": "210836905", "n_citations": 10, "n_key_citations": 1, "score": 1, "title": "VCSEL Array Based Gigabit Free Space Optical Femtocell Communication", "venue": "Journal of Lightwave Technology", "year": 2020 }, { "abstract": "Novel 940 nm (quasi )coherent VCSEL array (3x3) is demonstrated. It exhibits high power (62.4 mW) single spot output with narrow divergence angle ~5deg) over the full range of bias currents, and wide 3 dB E 0 bandwidth (10 GHz)", "author_names": [ "Zuhaib Khan", "Jie-Chen Shin", "Yung-Hao Chang", "Jin-Wei Shi" ], "corpus_id": 221716083, "doc_id": "221716083", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "High Brightness and High Speed Coherent VCSEL Array", "venue": "2020 Conference on Lasers and Electro Optics (CLEO)", "year": 2020 }, { "abstract": "We observe experimentally collective lasing of a topological mode in a vertical cavity surface emitting laser (VCSEL) array. The array is comprised of pillar shaped VCSELs in a crystalline model geometry and is optically pumped.", "author_names": [ "Alex Dikopoltsev", "Tristan H Harder", "Eran Lustig", "Oleg A Egorov", "Johannes Beierlein", "Monika Emmerling", "Christian Schneider", "Sven Hofling", "Mordechai Segev", "Sebastian Klembt" ], "corpus_id": 221717233, "doc_id": "221717233", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Topological Insulator VCSEL Array", "venue": "2020 Conference on Lasers and Electro Optics (CLEO)", "year": 2020 }, { "abstract": "Implant defined coherent vertical cavity surface emitting laser (VCSEL) arrays with an integrated phase shifter that can convert the out of phase mode into the in phase mode were demonstrated. The measured angular full width at half maximum (FWHM) from a <inline formula> <tex math notation=\"LaTeX\"{9} \\times {9} /tex math>/inline formula> coherent VCSEL array in the far field lobes is only 0.82deg. The intensity of the central lobe is about 2.9 times than that of surrounding sidelobes, showing excellent beam quality. The FWHM of the spectrum of a <inline formula> <tex math notation=\"LaTeX\"{9} \\times {9} /tex math>/inline formula> array is only 0.02 nm, showing a single mode operation. It provides a potential method to fabricate larger in phase coherent VCSEL arrays. A remaining challenge is enhancing output power via solving the heat problem.", "author_names": [ "Meng Xun", "Yun Sun", "Xiaowei Jiang", "Runze Zhang", "Jing-tao Zhou" ], "corpus_id": 219511947, "doc_id": "219511947", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Stable in Phase Mode Operation in Coherent VCSEL Array With an Integrated Phase Shifter", "venue": "IEEE Transactions on Electron Devices", "year": 2020 }, { "abstract": "We present the design and test results of a 4 channel 10 Gbps/ch Vertical Cavity Surface Emitting Laser array driver, the cpVLAD. With on chip charge pumps to extend the biasing headroom for the VCSELs needed for low temperature operation and mitigation of the radiation effects. The cpVLAD was fabricated in a 65 nm CMOS technology. The test results show that the cpVLAD is capable of driving VCSELs with forward bias voltages as high as 2.8 V from a 2.5 V power supply. The power consumption of the cpVLAD is 94 mW/ch.", "author_names": [ "X Huang", "Datao Gong", "Q Sun", "Chong-shun Chen", "Di Guo", "Suen Ray Hou", "G Huang", "Szymon Kulis", "C Liu", "T Liu", "Paulo Moreira", "A S'anchez Rodr'iguez", "H L Sun", "Jan Troska", "L Xiao", "Longkun Zhang", "W Zhang", "J Ye" ], "corpus_id": 219125351, "doc_id": "219125351", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "A 4 Channel 10 Gbps/ch CMOS VCSEL Array Driver with on chip Charge Pumps", "venue": "", "year": 2020 }, { "abstract": "Beam steering devices have wide applications in both military and civil fields. The ultimate goal for such devices is to reduce their size, weight, and power consumption. However, the laser source in these devices is spatially separate from the phase shifter, resulting in large size, complex packaging, and low coupling efficiency. To solve these problems, a novel electrically controlled beam steering chip based on coherently coupled vertical cavity surface emitting laser (VCSEL) array directly integrated with liquid crystal optical phased array (LCOPA) is proposed in this paper. Implant defined in phase coherently coupled VCSEL arrays (CCVAs) with uniform near field are designed and fabricated first to act as the coherent laser source for the chip. Then, taking advantage of the CCVA planar structure, the LCOPA is integrated directly on the CCVA by conventional process. The coherent light generated by the in phase CCVA is uniformly and normally incident into the LCOPA and is electrically steered by the LCOPA. One dimensional beam steering is achieved by two proof of concept integrated chips. The chips based on a 4 x 4 square CCVA and a 16 element hexagonal CCVA offer a field of view of 2.21deg and 6.06deg, respectively. Independent control of the CCVA and LCOPA guarantees a relatively high wavelength stability and power stability. Theoretical calculations are also performed, which are consistent with the experiments.", "author_names": [ "Guanzhong Pan", "Chen Xu", "Yiyang Xie", "Yibo Dong", "Qiuhua Wang", "Jun Deng", "Jie Sun", "Hongda Chen" ], "corpus_id": 155795761, "doc_id": "155795761", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Ultra compact electrically controlled beam steering chip based on coherently coupled VCSEL array directly integrated with optical phased array.", "venue": "Optics express", "year": 2019 }, { "abstract": "This paper presents a fiber Bragg grating (FBG) interrogator based on vertical surface cavity emitting lasers (VCSEL) A Fabry Perot filter technique is developed to directly calibrate the dynamic wavelength behavior of VCSELs at both low and high sweep rates. A broad bandwidth light source is constructed by multiplexing five VCSELs together to increase the number of FBGs that can be tracked. Scanning of the VCSEL array is accomplished by a high speed electronic switch circuit. The developed interrogator achieves a sweep bandwidth of 10 nm at a scanning rate of 4 kHz. Low velocity impact testing of a composite plate with a surface mounted FBG sensor shows that the wavelength detection error was 2.7% when compared with the FBG strain obtained by a high speed swept laser.", "author_names": [ "Guodong Guo", "Mark Pankow", "Kara Peters" ], "corpus_id": 199087894, "doc_id": "199087894", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "High Speed Interrogation Approach for FBG Sensors Using a VCSEL Array Swept Source", "venue": "IEEE Sensors Journal", "year": 2019 }, { "abstract": "The operating conditions and structural design that are necessary to realize 2dimensional (2D) phased locked VCSEL array using Talbot effect (Talbot VCSEL) were studied by numerical analysis of mutual injection locking by using the laser rate equation. Analysis of a few elements confirms the tendency of mutual injection locking and shows that the locking range can be expanded by increasing the number of elements which have close wavelength. Furthermore, Talbot VCSEL of a 2D array was analyzed to clarify the optimal array configuration that are necessary for locking operation. As the results, the aperture diameter of >5 m and the array size of 9x9 with 30 m of array pitch is appropriate minimum configuration of the 2D VCSEL array.", "author_names": [ "Taichi Shichijo", "Tomoyuki Miyamoto" ], "corpus_id": 198445859, "doc_id": "198445859", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Rate equation based numerical analysis of mutual injection for phase locked 2D VCSEL array using Talbot effect", "venue": "Japanese Journal of Applied Physics", "year": 2019 }, { "abstract": "Metal grids are used to solve the current spreading problem in coherently coupled implant defined vertical cavity surface emitting laser (VCSEL) arrays. In phase mode operation with a near diffraction limited beam is achieved in hexagonal 19 element arrays. The measured beamwidth of the arrays is as low as 1.3deg, which is only about 1.08 times of the diffraction limit. The arrays can maintain a relatively high proportion of 29.2% average power in the central lobe from threshold to maximum output power. The narrow beamwidth and high power proportion benefit from the uniform near field optical intensity owing to the metal grids. This technique provides an alternative method to realize large area in phase coherently coupled VCSEL array with high beam quality.", "author_names": [ "Guanzhong Pan", "Yiyang Xie", "Chen Xu", "Qiuhua Wang", "Yibo Dong", "Jun Deng", "Hongda Chen", "Jie Sun" ], "corpus_id": 203654578, "doc_id": "203654578", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "In Phased Implant Defined Hexagonal VCSEL Array With Near Diffraction Limited Beam", "venue": "IEEE Photonics Technology Letters", "year": 2019 } ]

[ { "abstract": "Research on high voltage (HV) silicon carbide (SiC) power semiconductor devices has attracted much attention in recent years. This paper overviews the development and status of HV SiC devices. Meanwhile, benefits of HV SiC devices are presented. The technologies and challenges for HV SiC device application in converter design are discussed. The state of the art applications of HV SiC devices are also reviewed.", "author_names": [ "Shiqi Ji", "Zheyu Zhang", "Fred Wang" ], "corpus_id": 115276142, "doc_id": "115276142", "n_citations": 63, "n_key_citations": 4, "score": 1, "title": "Overview of high voltage sic power semiconductor devices: development and application", "venue": "", "year": 2017 }, { "abstract": "In order to improve the efficiency, reliability and maintainability of the aircraft, the aerospace world has found in progressive electrification that reduces or removes the hydraulic, mechanical and pneumatic power systems. Power devices are widely applied in power system, while conventional Si power devices have reached the theoretical limitation. Admittedly, many advantages, such as high breakdown electric field strength, high saturated electron drift velocity and high thermal conductivity can be seen from SiC semiconductor material, and SiC power electronic devices made of which can have the ability to adapt to high voltage, high power, high frequency, high temperature and other harsh environment. This paper presents an overview of SiC power electronic devices used for the secondary power source in aerospace, through the comparison of power electronic devices between SiC and Si, the advantages of SiC devices and the development are analyzed, on the basis of which, emphatically discussed the application status of SiC devices in secondary power source, including aeronautical static inverter, transformer rectifier unit, DC DC converter, and motor drive. In the end, the existing problems in the application of SiC power electronic devices are discussed, as well as the impacts on aviation technology.", "author_names": [ "Qian Xun", "Boyang Xun", "Zuxin Li", "Wang Peiliang", "Zhiduan Cai" ], "corpus_id": 114944090, "doc_id": "114944090", "n_citations": 25, "n_key_citations": 0, "score": 0, "title": "Application of SiC power electronic devices in secondary power source for aircraft", "venue": "", "year": 2017 }, { "abstract": "The current status of silicon carbide (SiC) device development in various voltage ranges is reviewed. Especially for next generation high to ultra high voltage devices, developments in SiC super junction Metal Oxide Semiconductor Field Effect Transistors (MOSFET, here denoted as SJ MOS) and SiC Insulated Gate Bipolar Transistors (IGBTs) are introduced. We expect that these next generation devices are going to trigger a paradigm shift in power electronics components, enabling very low conduction and switching losses.", "author_names": [ "Yoshiyuki Yonezawa" ], "corpus_id": 53083150, "doc_id": "53083150", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Recent Progress in High to Ultra High Voltage SiC Power Devices: Development and Application", "venue": "2018 International Power Electronics Conference (IPEC Niigata 2018 ECCE Asia)", "year": 2018 }, { "abstract": "With the development of electric propulsion and payload technology, Silicon Carbide which is a typical semiconductor device with wide bandgap will play a greater role in spacecraft power system in the future. It has the advantages as high breakdown voltage, high electron drift velocity, high thermal conductivity, high voltage, high frequency and high anti radiation. This paper mainly introduces the new research progress of SiC based power diodes, JFETs and MOSFETs, as well as discusses the application prospects of SiC power semiconductor devices in spacecraft power systems.", "author_names": [ "Xing Jie", "Kang Qing", "Zhang Xuan", "Li Feng" ], "corpus_id": 45319770, "doc_id": "45319770", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Application Prospect of SiC Power Semiconductor Devices in Spacecraft Power Systems", "venue": "2017 13th IEEE International Conference on Electronic Measurement Instruments (ICEMI)", "year": 2017 }, { "abstract": "Extensive research in wide bandgap material technology such as silicon carbide (SiC) has led to the development of medium voltage (MV) power semiconductor devices with blocking voltages of 3.3 to 15 kV. When these devices are used in various applications, they are exposed to a high peak voltage stress and a very high $dv/dt$ (50 100 V/ns) These impose stringent requirements on the gate driving stage for these devices in terms of featuring a high isolation voltage capability along with a high $dv/dt$ ruggedness, which makes it necessary to have an ultralow coupling capacitance between primary and secondary sides of the gate drivers. One of the key issues in achieving this MV insulation pertains to the necessary clearance and creepage requirements, as defined in IEC 61800 5 1 standards. While the successful operation of these gate drivers is demonstrated in MV converter applications such as solid state transformers, and MV grid connected inverters, substantial research needs to be carried out to improve the gate drivers' performance and provide a plug and play solution. This article aims to comprehensively review these gate drivers and consolidate various required design features concerning their galvanic isolation stage, based on normal and short circuit operation of MV high power converter systems. Different device short circuit protection schemes for these gate drivers are explored in detail. Additional applications and functionalities of the gate drivers, including gate drivers used in the series connection of MV devices and intelligent gate drivers, are also provided in brief. Based on prior research, this review aims to provide design choices and guidelines for the gate drivers, accelerating the growth and deployment of MV SiC devices for field applications.", "author_names": [ "Anup Anurag", "Sayan Acharya", "Nithin Kolli", "Subhashish Bhattacharya" ], "corpus_id": 229197470, "doc_id": "229197470", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Gate Drivers for Medium Voltage SiC Devices", "venue": "IEEE Journal of Emerging and Selected Topics in Industrial Electronics", "year": 2021 }, { "abstract": "Silicon based Power Semiconductor Devices are extensively used in power electronic applications for the last few decades. Recent developments in power electronics require devices with high power rating, switching frequency and operating temperature but silicon based devices do not facilitate these requirements. Wide band gap semiconductor devices like Silicon Carbide and Gallium Nitride are gaining popularity in overcoming the limitations of silicon based devices. The superior material properties of WBG semiconductor: band gap, electric field, thermal conductivity and electron mobility enables them to handle the requirements. This paper reviews the material properties of Silicon Carbide in comparison to Silicon. It also provides an overview of available SiC based power semiconductor devices and converter topologies.", "author_names": [ "Raksha Adappa", "K Suryanarayana", "H Swathi Hatwar", "M Ravikiran Rao" ], "corpus_id": 211208758, "doc_id": "211208758", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Review of SiC based Power Semiconductor Devices and their Applications", "venue": "2019 2nd International Conference on Intelligent Computing, Instrumentation and Control Technologies (ICICICT)", "year": 2019 }, { "abstract": "MV solid state transformers enabled by SiC semiconductor devices is a promising replacement to conventional low frequency transformers. However, when MV SiC devices are used in converter applications, they are exposed to a high peak stress (5 kV to 10 kV) and a very high dv dt (10 kV/uS to 100 kV/uS) Operating these semiconductor devices at these high peak stresses require careful designing from the packaging point of view, as well as designing the auxiliary systems such as the gate drivers and busbars, to handle the peak stress conditions. Recently, an extra high voltage (XHV) power module has been developed by Wolfspeed to package the 10 kV SiC MOSFETs for continuous and reliable operation. This paper aims at testing these modules in continuous operation for qualifying their operation in a MV solid state transformer. Reliable operation of these modules require the development of reliable auxiliary parts including gate drivers, bus bars and inductors. Design and development of the auxiliary system is also carried out. Successful tests demonstrating operation at MV levels are also shown. These tests serve as a qualification method for using these devices in a MV solid state transformer. It is envisaged that successful operation of these devices would accelerate the growth and deployment of MV SiC devices for field operation.", "author_names": [ "Anup Anurag", "Sayan Acharya", "Subhashish Bhattacharya" ], "corpus_id": 201065642, "doc_id": "201065642", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Evaluation of Extra High Voltage (XHV) Power Module for Gen3 10 kV SiC MOSFETs in a Mobile Utility Support Equipment based Solid State Transformer (MUSE SST)", "venue": "2019 10th International Conference on Power Electronics and ECCE Asia (ICPE 2019 ECCE Asia)", "year": 2019 }, { "abstract": "Power devices based on wide bandgap material such as silicon carbide (SiC) can operate at higher switching speeds, higher voltages, and higher temperatures compared to those based on silicon material. This article highlights some opportunities brought by SiC devices in existing and emerging applications in terms of efficiency and power density improvement. While the opportunities are clear, there are also design challenges that must be met in order to realize their full potential. For example, the fast switching speeds and high dv/dt of SiC devices can cause increased electromagnetic interference, current overshoot, cross talk effect, and have a negative impact on loads such as motors. This article presents several potential solutions to tackle the application challenges and to fully exploit the superior characteristics of SiC devices and converters while attenuating their negative side effects. This article provides an overview of recent SiC device research and development activities based on academic literature, work carried out by the authors and collaborators as well as input from industry. It aims to provide benchmark results and a timely and useful reference to accelerate the adoption and deployment of SiC devices and converters.", "author_names": [ "Xibo Yuan", "Ian Laird", "Sam Walder" ], "corpus_id": 226646648, "doc_id": "226646648", "n_citations": 7, "n_key_citations": 1, "score": 0, "title": "Opportunities, Challenges, and Potential Solutions in the Application of Fast Switching SiC Power Devices and Converters", "venue": "IEEE Transactions on Power Electronics", "year": 2021 }, { "abstract": "Multiphase systems provides benefits compared to three phase systems, such as improved torque per ampere, high power density, better fault tolerance, lower current per phase (due to power splitting among a higher number of phases) and lower torque ripple, among others. Depending on the application, the system must meet determined requirements, such as the presence of harmonic content, power losses, and common mode voltage (CMV) generation. This paper presents a comparative analysis of space vector modulation (SVM) techniques applied to a five phase voltage source inverter with SiC switches to provide an overview of their performance. The performance of five phase 2L SVPWM (space vector pulse width modulation) 2L+2M SVPWM, 4L SVPWM techniques, and their discontinuous versions, are analyzed by focusing on harmonic content, power losses, and CMV generation using SiC semiconductor devices. Matlab/Simulink and PLECS simulations are performed to achieve the above mentioned goal. The use of different techniques allows (1) reducing the harmonic distortion when 2L+2M SVPWM and 4L SVPWM are applied, and (2) the switching sequence of the modulation techniques can influence the switching losses. Therefore, the use of SiC switches reduces the switching losses. (3) However, CMV dv/dt increases. Therefore, it is possible to minimize the effects of the CMV dv/dt and amplitude by choosing the adequate technique.", "author_names": [ "Fernando Acosta-Cambranis", "Jordi Zaragoza", "Luis Romeral", "N Berbel" ], "corpus_id": 230598957, "doc_id": "230598957", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Comparative Analysis of SVM Techniques for a Five Phase VSI Based on SiC Devices", "venue": "", "year": 2020 }, { "abstract": "This paper deals with I V characteristics of SiC SBD and rectifying capabilities of four SiC SBD using a new package under the temperature up to 300degC. As regards of the I V characteristics, as the temperature increases, the threshold voltage decreases and the reverse current increases dramatically. This increase of the reverse current of the diodes under study leads to the limitation of the rectifying characteristics of the proposed packaging. This study demonstrates the ability of the later to be used in a harsh environment ones the components problems will have been solved.", "author_names": [ "Keisuke Koyanagi", "Akinari Yamane", "Masahiro Kozako", "Ichiro Omura", "Masayuki Hikita", "Zarel Valdez-Nava", "Sorin Dinculescu", "Thierry Lebey" ], "corpus_id": 42459033, "doc_id": "42459033", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Development of a new package for next generation power semiconductor devices: Toward high temperature and high voltage applications", "venue": "2013 IEEE 10th International Conference on Power Electronics and Drive Systems (PEDS)", "year": 2013 } ]

[ { "abstract": "Perovskite Photovoltaics For many types of low cost solar cells, including those using dye sensitized titania, performance is limited by low open circuit voltages. Lee et al. (p. 643, published online 4 October; see the Perspective by Norris and Aydil) have developed a solid state cell in which structured films of titania or alumina nanoparticles are solution coated with a lead halide perovskite layer that acts as the absorber and n type photoactive layer. These particles are coated with a spirobifluorene organic hole conductor in a solar cell with transparent oxide and metal contacts. For the alumina particles, power conversion efficiencies of up to 10.9% were obtained. Mesostructured alumina acts as an insulating scaffold for the assembly of very thin films of n and p type semiconductors. The energy costs associated with separating tightly bound excitons (photoinduced electron hole pairs) and extracting free charges from highly disordered low mobility networks represent fundamental losses for many low cost photovoltaic technologies. We report a low cost, solution processable solar cell, based on a highly crystalline perovskite absorber with intense visible to near infrared absorptivity, that has a power conversion efficiency of 10.9% in a single junction device under simulated full sunlight. This \"meso superstructured solar cell\" exhibits exceptionally few fundamental energy losses; it can generate open circuit photovoltages of more than 1.1 volts, despite the relatively narrow absorber band gap of 1.55 electron volts. The functionality arises from the use of mesoporous alumina as an inert scaffold that structures the absorber and forces electrons to reside in and be transported through the perovskite.", "author_names": [ "Michael M Lee", "Joel Teuscher", "Tsutomu Miyasaka", "Takurou N Murakami", "Henry J Snaith" ], "corpus_id": 37971858, "doc_id": "37971858", "n_citations": 7384, "n_key_citations": 55, "score": 1, "title": "Efficient Hybrid Solar Cells Based on Meso Superstructured Organometal Halide Perovskites", "venue": "Science", "year": 2012 }, { "abstract": "Recently, inorganic and hybrid light absorbers such as quantum dots and organometal halide perovskites have been studied and applied in fabricating thin film photovoltaic devices because of their low cost and potential for high efficiency. Further boosting the performance of solution processed thin film solar cells without detrimentally increasing the complexity of the device architecture is critically important for commercialization. Here, we demonstrate photocurrent and efficiency enhancement in meso superstructured organometal halide perovskite solar cells incorporating core shell Au@SiO2 nanoparticles (NPs) delivering a device efficiency of up to 11.4% We attribute the origin of enhanced photocurrent to a previously unobserved and unexpected mechanism of reduced exciton binding energy with the incorporation of the metal nanoparticles, rather than enhanced light absorption. Our findings represent a new aspect and lever for the application of metal nanoparticles in photovoltaics and could lead to facile tuning of exciton binding energies in perovskite semiconductors.", "author_names": [ "Wei Zhang", "Michael Saliba", "Samuel D Stranks", "Yao Sun", "Xian Shi", "Ulrich B Wiesner", "Henry J Snaith" ], "corpus_id": 37918428, "doc_id": "37918428", "n_citations": 435, "n_key_citations": 3, "score": 0, "title": "Enhancement of perovskite based solar cells employing core shell metal nanoparticles.", "venue": "Nano letters", "year": 2013 }, { "abstract": "To date, numerous approaches have been developed for fabricating high quality organometal halide perovskite thin films, however, perovskite films obtained by such methods reveal a brown or dark brown color, which might restrain their light absorption ability. Here we report a route to synthesize dark blue mirror like perovskite dense films via a two step spin coating process assisted by treatment of nonpolar solvent scouring. Photovoltaic cells based on such dark blue films demonstrate a high short circuit current density (Jsc) of ~23 mA cm 2 and a power conversion efficiency (PCE) of 16.1% Our method would provide a new candidate method for the fabrication of perovskite solar cells with high performance.", "author_names": [ "Jianhang Qiu", "Wang Gaoxiang", "Wenjing Xu", "Jin Qun", "Lusheng Liu", "Bing-Ping Yang", "Tai Kaiping", "Anyuan Cao", "Xin Jiang" ], "corpus_id": 56339157, "doc_id": "56339157", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Dark blue mirror like perovskite dense films for efficient organic inorganic hybrid solar cells", "venue": "", "year": 2016 }, { "abstract": "For efficient hybrid solar cells based on organometal halide perovskites, the real origin of the I V hysteresis became a big issue and has been discussed widely. In this study, simulated I V curves.", "author_names": [ "Ludmila Cojocaru", "Satoshi Uchida", "P V V Jayaweera", "Shoji Kaneko", "Jotaro Nakazaki", "Takaya Kubo", "Hiroshi Segawa" ], "corpus_id": 98707369, "doc_id": "98707369", "n_citations": 78, "n_key_citations": 0, "score": 0, "title": "Origin of the Hysteresis in I V Curves for Planar Structure Perovskite Solar Cells Rationalized with a Surface Boundary induced Capacitance Model", "venue": "", "year": 2015 }, { "abstract": "Organometal halide perovskites are promising solar cell materials for next generation photovoltaic applications. The long carrier lifetime and diffusion length of these materials make them very attractive for use in light absorbers and carrier transporters. While these aspects of organometal halide perovskites have attracted the most attention, the consequences of the Rashba effect, driven by strong spin orbit coupling, on the photovoltaic properties of these materials are largely unexplored. In this work, taking the electronic structure of methylammonium lead iodide as an example, we propose an intrinsic mechanism for enhanced carrier lifetime in 3D Rashba materials. Based on first principles calculations and a Rashba spin orbit model, we demonstrate that the recombination rate is reduced due to the spin forbidden transition. These results are important for understanding the fundamental physics of organometal halide perovskites and for optimizing and designing the materials with better performance. The proposed mechanism including spin degrees of freedom offers a new paradigm of using 3D Rashba materials for photovoltaic applications. The organometal halide perovskites (OMHPs) have attracted significant attention due to the rapid increase in their photovoltaic power conversion efficiency. In the past 2 years, the reported efficiency of OMHP based solar cells has almost doubled from 9.7%1 to over 20%,2 4 making OHMPs very promising for low cost and high efficiency photovoltaics. Methylammonium lead iodide, CH3NH3PbI3 (MAPbI3) and other closely related hybrid perovskites such as Cl doped and Br doped MAPbI3 (MAPbI3 xClx and MAPbI3 xBrx) (NH2)2CHPbI3 (formamidinium lead iodide, FAPbI3) and Sn doped MAPbI3 (MAPbxSn1 xI3) all display band gaps (1.1 to 2.1 eV) in the visible light region, favorable for photovoltaic applications.5 13 The class of materials also possesses strong light absorption, fast charge generation and high carrier mobility.14,15 In particular, exceptionally long carrier lifetime and diffusion length have been observed in MAPbI3 and MAPbI3 xClx, making them better solar cell candidates than other semiconductors with similar band gaps and absorption coefficients.16 18 Intense research has been directed toward understanding and further enhancing the long carrier lifetime and diffusion length in OMHPs. Previous studies reported a relatively low defect 2 concentration in MAPbI3, which reduces the scattering centers for nonradiative charge carrier recombination. Recently, it has been suggested that the spatial carrier segregation caused by disorder induced localization24 or domains acting as internal p n junctions25 27 may reduce the recombination rate. Though many of the OMHPs are 3D Rashba materials driven by strong spin orbit coupling (SOC) and bulk ferroelectricity,28 31 the effects of spin and orbital degrees of freedom on photovoltaic applications are largely unexplored beyond band gap engineering.29 In this work, we focus on an intrinsic mechanism for the enhancement of long carrier lifetime due to the Rashba splitting. Using first principles calculations and effective models, we find that the Rashba splitting arising from SOC under inversion symmetry breaking can result in spin allowed and spin forbidden recombination channels. The spin forbidden recombination path has a significantly slower transition rate due to the mismatch of spin and momentum. The spin allowed recombination path, though kinetically favorable, can be suppressed under appropriate spin texture due to the low population of free carriers. Taking the electronic structures of MAPbI3 under various distortions as examples, we show that the proposed mechanism is possible under room temperature, and is potentially responsible for the long carrier lifetime in OMHPs. This spindependent recombination mechanism highlights the possibility of using 3D Rashba materials for efficient photovoltaic applications. Fig. 1 illustrates the mechanism for enhancing the carrier lifetime in a generic 3D Rashba material. The strong spin orbit coupling effect from heavy elements (e.g. Pb, Sn, I and Br) and the polar distortion (e.g. aligned molecular dipoles in OMHPs) give rise to the Rashba effect, which lifts the two fold degeneracy of bands near the band gap. Near the band gap, the spin degeneracies of the conduction and valence bands are lifted, giving rise to \"inner\" and \"outer\" bands with opposite spin textures, characterizing spin rotation direction as \"clockwise\" (kh 1) and \"counterclockwise\" (kh +1) (Fig. 1) The photo excitation process creates free electrons and holes, which can quickly relax to band extrema in the presence of inelastic phonon scattering. When the spin textures of conduction band minimum (CBM) and valence band maximum (VBM) are opposite, the radiative recombination of Ckh= 1 Vkh=+1 is a spin forbidden transition due", "author_names": [ "Fan Zheng", "Liang Z Tan", "Shi Liu", "Andrew M Rappe" ], "corpus_id": 119239379, "doc_id": "119239379", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Rashba Spin Orbit Coupling Enhanced Carrier Lifetime in Organometal Halide Perovskites", "venue": "", "year": 2015 }, { "abstract": "Hybrid solar cells based on organometal halide perovskite absorbers have recently emerged as promising class for cost and energy efficient photovoltaics. So far, unraveling the morphology of the different materials within the nanostructured absorber layer has not been accomplished. Here, we present the first visualization of the mesoporous absorber layer in a perovskite solar cell from analytical transmission electron microscopy studies. Material contrast is achieved by electron spectroscopic imaging. We found that infiltration of the hole transport material into the scaffold is low and inhomogeneous. Furthermore, our data suggest that the device performance is strongly affected by the morphology of the TiO2 scaffold with a fine grained structure being disadvantageous.", "author_names": [ "Diana Nanova", "Anne Katrin Kast", "Martin Pfannmoller", "Christian Muller", "Lisa Veith", "Irene Wacker", "Michaela Agari", "Wilfried Hermes", "Peter Erk", "Wolfgang Kowalsky", "Rasmus R Schroder", "Robert Lovrincic" ], "corpus_id": 5163852, "doc_id": "5163852", "n_citations": 53, "n_key_citations": 0, "score": 0, "title": "Unraveling the nanoscale morphologies of mesoporous perovskite solar cells and their correlation to device performance.", "venue": "Nano letters", "year": 2014 }, { "abstract": "Hybrid perovskites have recently seen an unprecedented improvement in the power conversion efficiency in photovoltaics devices, and therefore are very promising materials for developing efficient and low cost single junction solar cells [1 3] However, a critical issue is the limited understanding of the correlation between the degree of crystallinity and the emergent perovskite/hole (or electron) transport layer on device performance as well as photo stability. Los Alamos National laboratory (LANL) developed an efficient growth procedure for 3D halide perovskites in inverted perovskite cell architecture using PEDOT PSS as a p type hole transporting material (HTM) [4] The initial collaboration between FOTON/ISCR and LANL led to the observation of a reversible self healing mechanism under light soaking [5] and showed that the aging of the precursor solution plays a role in the nucleation of the perovskite crystallites [6] In this study, we show that growth of methylammonium lead perovskites (MAPbI3) on nickel oxide (NiO) HTM, results in the formation of ordered and crystalline thin films with enhanced crystallinity, leading to characteristic XRD Bragg peak width reminiscent of exclusively observed in the tetragonal phase in single crystals. Photo physical and interface sensitive measurements reveal a reduced trap density at the MAPbI3 perovskite/NiO interface in comparison with perovskites grown on PEDOT: PSS. Photovoltaic cells exhibit a high open circuit voltage (1.12 V) indicating a nearideal energy band alignment. Moreover, we observe photo stability of photovoltaic devices up to 10 Suns, which is a direct result of the enhanced crystallinity of perovskite thin films on NiO. These results elucidate the critical role of the quality of the perovskite/HTL interface in rendering highperformance and photo stable optoelectronic devices [7] [1] Lee, M. M. Teuscher, J. Miyasaka, T. Murakami, T. N. Snaith, H. J. \"Efficient Hybrid Solar Cells Based on Meso Superstructured Organometal Halide Perovskites\" Science 338, 643 (2012) [2] Burschka, J. et al. \"Sequential deposition as a route to high performance perovskitesensitized solar cells\" Nature 499, 316 319 (2013) [3] Jeon, N. J. et al. \"Solvent engineering for high performance inorganic organic hybrid perovskite solar cells\" Nat. Mater. 13, 897 903 (2014) [4] Nie, W. et al, \"High efficiency solution processed perovskite solar cells with millimeterscale grains\" Science 347, 522 (2015) [5] Nie, W. et al, \"Light activated photocurrent degradation and self healing in perovskite solar cells\" Nat. Comm. 7, 11574 (2016) [6] Tsai, H. et al,\" Effect of Precursor Solution Aging on the Crystallinity and Photovoltaic Performance of Perovskite Solar Cells\" Adv. Ener. Mat. 7, 1602159 (2017) [7] Nie, W. et al, Adv. Mater. (In press)", "author_names": [ "Olivier Durand", "Wanyi Nie", "Hsinhan Tsai", "Reza Asadpour", "Jean-Christophe Blancon", "Fangze Liu", "Constantinos C Stoumpos", "Joseph W Strzalka", "Jared J Crochet", "Pulickel M Ajayan", "Boubacar Traore", "Mikael Kepenekian", "Claudine Katan", "Sergei Tretiak", "Mercouri G Kanatzidis", "Muhammad A Alam", "Jacky Even", "Aditya D Mohite" ], "corpus_id": 105191302, "doc_id": "105191302", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Critical role of Interface and perovskite lattice in high efficiency and photostable solar cells", "venue": "", "year": 2017 }, { "abstract": "Due to their outstanding optical properties and superior charge carrier mobilities, organometal halide perovskites have been widely investigated in photodetection and solar cell areas. In perovskites photodetection devices, their high optical absorption and excellent quantum efficiency contribute to the responsivity, even the specific detectivity. In this work, we developed a lateral phototransistor based on mesoscopic graphene/perovskite heterojunctions. Graphene nanowall shows a porous structure, and the spaces between graphene nanowall are much appropriated for perovskite crystalline to mount in. Hot carriers are excited in perovskite, which is followed by the holes' transfer to the graphene layer through the interfacial efficiently. Therefore, graphene plays the role of holes' collecting material and carriers' transporting channel. This charge transfer process is also verified by the luminescence spectra. We used the hybrid film to build phototransistor, which performed a high responsivity and specific detectivity of 2.0 x 103 A/W and 7.2 x 1010 Jones, respectively. To understand the photoconductive mechanism, the perovskite's passivation and the graphene photogating effect are proposed to contribute to the device's performance. This study provides new routes for the application of perovskite film in photodetection.", "author_names": [ "Dahua Zhou", "Leyong Yu", "Peng-Li Zhu", "Hongquan Zhao", "Shuanglong Feng", "Jun Shen" ], "corpus_id": 232383548, "doc_id": "232383548", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Lateral Structured Phototransistor Based on Mesoscopic Graphene/Perovskite Heterojunctions", "venue": "Nanomaterials", "year": 2021 }, { "abstract": "While the field of perovskite based optoelectronics has mostly been dominated by photovoltaics, light emitting diodes and transistors, semiconducting properties peculiar to perovskites make them interesting candidates for innovative and disruptive applications in light signal detection. Perovskites combine effective light absorption in the broadband range with good photo generation yield and high charge carrier mobility, which combination provides promising potential for exploiting sensitive and fast photodetectors that are targeted for image sensing, optical communication, environmental monitoring, or chemical/biological detection. Currently, organic inorganic hybrid and all inorganic halide perovskites with controlled morphologies of polycrystalline thin films, nano particles/wires/sheets, and bulk single crystals have shown key figure of merit features in terms of their responsivity, detectivity, noise equivalent power, linear dynamic range, and response speed. The sensing region has been covered from ultraviolet visible near infrared (UV Vis NIR) to gamma photons, based on two or three terminal device architectures. Diverse photoactive materials and devices with superior optoelectronic performances have stimulated attention from researchers in multidisciplinary areas. We offer a comprehensive overview of the recent progress of perovskite based photodetectors, focusing on versatile compositions, structures, and morphologies of constituent materials, and diverse device architectures toward the superior performance metrics. Combining the advantages of both organic semiconductors (facile solution processability) and inorganic semiconductors (high charge carrier mobility) perovskites are expected to replace commercial silicon for future photodetection applications. The optical and electronic properties of noble metallic nanoparticles can be exploited to enhance the performance of inorganic/organic photodetectors. We integrated a uniformly distributed layer of Au nanorods (AuNRs) into vertically structured perovskite photoconductive photodetectors and report, as a result, perovskite AuNR hybrid photodetectors that exhibit significant photocurrent enhancements. Ultimately it achieves a responsivity of ~320 A/W at a low driving voltage of 1 V. This is an improvement of 60% compared to the responsivity of pristine devices ~200 A/W) The high responsivity and low driving voltage place this device among the highest performing perovskite based thin film photoconductive photodetectors reported. We characterized the stability and linearity of the photoresponse following repeated light/dark cycles. The hybrid device also shows a fast response (with the decay time of ~95 ns) compared to pristine devices ~230 ns) The improvements in photodetection performance are attributed to plasmon enhanced optical absorption, as well as advances in charge extraction and transport. Metal halide perovskites have rapidly advanced thin film photovoltaic performance; as a result, the materials' ob served instabilities urgently require a solution. Using density functional theory (DFT) we show that a low energy of formation, exacerbated in the presence of humidity, explains the propensity of perovskites to decompose back into their precursors. We find, also using DFT, that intercalation of phenylethylammonium between perovskite layers in troduces quantitatively appreciable van der Waals interactions; and these drive an increased formation energy and should therefore improve material stability. Here we report the reduced dimensionality (quasi 2D) perovskite films that exhibit improved stability while retaining the high performance of conventional three dimensional perovskites. Continuous tuning of the dimensionality, as assessed using photophysical studies, is achieved by the choice of stoi chiometry in materials synthesis. We achieve the first certified hysteresis free solar power conversion in a planar per ovskite solar cell, obtaining a 15.3% certified PCE, and observe greatly improved performance longevity. The same protocol was applied to develop highly stable and efficient photodectors in diverse device configurations. Organometal halide perovskites exhibit large bulk crystal domain sizes, rare traps, excellent mobilities, and carriers that are free at room temperature properties that support their excellent performance in charge separating devices. In devices that rely on the forward injection of electrons and holes, such as light emitting diodes (LEDs) excellent mobilities contribute to the efficient capture of nonequilibrium charge carriers to rare nonradiative centres. Moreover, the lack of bound excitons weakens the competition of desired radiative over undesired nonradiative recombination. Here we also report a perovskite mixed material, one comprised of a series of differently quantum size tuned grains, that funnels photoexcitations to the lowest bandgap light emitter in the mixture. The materials function as charge carrier concentrators, ensuring that radiative recombination successfully outcompetes trapping and hence nonradiative recombination. We use the new material to build devices that exhibit an external quantum efficiency (EQE) of 8.8% and a radiance of 80 Wsr 1m 2. These represent the brightest and most efficient solution processed near infrared LEDs to date. Here we show that, by concentrating photoexcited states into a small subpopulation of radiative domains, one can achieve a high quantum yield even at low excitation intensities. We tailor the composition of quasi 2D perovskites to direct the energy transfer into the lowest bandgap minority phase, and to do so faster than it is lost to non radiative centres. The new material exhibits 60% photoluminescence quantum yield at excitation intensities as low as 1.8 mW/cm2, yielding a ratio of quantum yield to excitation intensity of 0.3 cm2/mW; this represents a two orders of magnitude decrease in the excitation power required to reach high efficiency compared to the best prior reports. Using this strategy, we report LEDs with EQEs of 7.4% and a high luminescence of 8400 cd/m2.", "author_names": [ "Dong Ha Kim", "Huan Mei Wang", "Ju Won Lim", "Li Na Quan", "Ilgeum Lee", "Edward H Sargent" ], "corpus_id": 139769290, "doc_id": "139769290", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Optoelectronic hybrid perovskite materials and devices (Conference Presentation)", "venue": "", "year": 2018 }, { "abstract": "A sensitized solar cell introduced by O'Regan and Gratzel in 1991 was one of the milestones in third generation hybrid solar cells because of the novelty of its architecture, ease of its fabrication, cost effectiveness and good efficiency. Despite persistent efforts made by various groups around the world for over 20 years, the efficiency of DSSCs had not crossed 13% Very recently however, a major path breaking advance has been realized in the domain of solid state sensitized solar cells with the introduction of organometal halide perovskites as efficient alternatives to liquid electrolyte based DSSCs. These new systems have already shown efficiency values of about 15 16% and hold great promise for even higher efficiency (20% at lower cost. Interestingly, the optoelectronic properties of organometal halide perovskites can be tuned by varying the organic cation sizes, metal ions, or the halide anions. Several research groups have shown that complete replacement of I with other halide ions such as Br or Cl leads to increase in the energy gap and therefore lower photocurrents and efficiency. However the presence of mixed halides in the perovskite structure such as CH3NH3PbI2Cl can lead to higher photovoltaic performance because of the increase in the carrier diffusion length (B1 mm) without an appreciable increase in the band gap. Chung et al. showed that doping inorganic perovskite CsSnI3 with 5% fluorine could dramatically improve the photocurrent density by nearly 40% However, to the best of our knowledge, there are no reports of mixed halide organometal perovskite systems with I and F ions applied in solar cells. Importantly, Mosconi et al. have shown that the mixed halide perovskite system consists of two different structures whose stability decreases from I to F along the column VIIA in the periodic table. Therefore it is difficult to stabilize I and F based mixed halide perovskite systems. Herein, we report an interesting strategy to incorporate fluoride ions in the perovskite structure via partial substitution of I by BF4 Importantly, I and BF4 both have nearly the same ionic radius, which makes the incorporation of BF4 feasible in the structure. We further show that I and BF4 based mixed halide perovskite possesses an order of magnitude higher low frequency conductivity than I based perovskite without an appreciable change in the absorption onset. In order to incorporate BF4 within the perovskite structure, the organic salt CH3NH3BF4 was prepared using methylamine and tetrafluoroboric acid solutions. The hybrid perovskite films were prepared using chemical vapor deposition of organic salt CH3NH3BF4 on preheated PbI2 films whereas the powder of hybrid perovskite was prepared using the solid state route with a mixture of organic salt and PbI2. The detailed experimental procedure is given in the ESI. The phase of the synthesized perovskite was confirmed using X ray diffraction measurements. Fig. 1(a) shows the XRD pattern of synthesized CH3NH3PbI(3 x)(BF4)x perovskite film on glass. The crystal structure of CH3NH3PbI(3 x)(BF4)x perovskite is found to be identical to the conventional CH3NH3PbI3 tetragonal perovskite structure as indicated by the appearance of peaks at 14.01, 28.31, 31.81 and 43.21 for the (110) (220) (310) and (330) planes, respectively. The presence of sharp peaks in the X ray diffraction pattern indicates the highly crystalline nature of the perovskite film. In order to confirm the presence of BF4 groups in the perovskite structure, we carried out the ATR FTIR study of the CH3NH3PbI(3 x)(BF4)x films on glass. Fig. 1(b) shows the characteristic stretching vibration peaks of BF4 at 1135 cm 967 cm 524 cm 1084 cm 952 cm 1 (for symmetric stretching) and 1053 cm 1 (B F stretching) which are otherwise absent in the CH3NH3PbI3 perovskite. a Centre of Excellence in Solar Energy, National Chemical Laboratory (CSIR NCL) Dr. Homi Bhabha Road, Pune, India b Academy of Scientific and Innovative Research (AcSIR) Network Institute of Solar Energy (CSIR NISE) New Delhi, India. E mail: [email protected], [email protected] Electronic supplementary information (ESI) available: Experimental details and Fig. S1 S4. See DOI: 10.1039/c4cc04537h Received 15th June 2014, Accepted 4th July 2014", "author_names": [ "Satyawan Nagane", "Umesh Pandharinath Bansode", "Onkar S Game", "Shraddha Y Chhatre", "" ], "corpus_id": 115151000, "doc_id": "115151000", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "CH 3 NH 3 PbI 3 x BF 4 x molecular ion substituted hybrid perovskite", "venue": "", "year": 2014 } ]

[ { "abstract": "ABSTRACT China's integration into the information and communications technology global value chain has taken place as global technology corporations outsourced and offshored an increasing range of functions, including manufacturing, assembly, and to some extent, innovation to more competitive regions within China. Initially disappointed with low levels of technology transfer from foreign companies, China has sought to achieve greater levels of technology autonomy through more aggressive efforts in recent years to push for indigenous innovation by leveraging market access. China has achieved some limited success in establishing domestic brands but continues to lack significant core technology in critical areas such as semiconductors.", "author_names": [ "Seamus Grimes", "Chun Lei Yang" ], "corpus_id": 55239152, "doc_id": "55239152", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "From foreign technology dependence towards greater innovation autonomy: China's integration into the information and communications technology (ICT) global value chain (GVC)", "venue": "", "year": 2018 }, { "abstract": "This paper presents a hypothesis stating that at the initial stage of growth by a latecomer, increased participation in the global value chain (GVC) is necessary to learn foreign knowledge and production skills, that functional upgrading at middle income stage requires effort to seek separation and independence from existing foreign dominated GVCs, and that latecomer firms and economies might have to seek reintegration back into the GVC after establishing their own local value chains. This paper aims to verify this \"in out in again\" hypothesis by looking into firm cases of upgrading in Korea and Brazil. Trends in the share of foreign value added in gross exports (FVA) in successful catching up economies of Korea and Taiwan, including China recently, are consistent with this pattern. Regression results also confirm a negative correlation between the degree of local creation and diffusion of knowledge and FVA values, such that gaining increased local knowledge is a basis for increasing (reducing) domestic value added (foreign value added) Given that this variable of local creation and diffusion of knowledge is a key innovation system variable, this finding implies that building local innovation systems is the key in making a possible upgrade while being integrated into the GVC.Cet article presente une hypothese selon laquelle, au stade initial de la croissance d'une entreprise entree tardivement sur un marche, une participation accrue a la chaine de valeur mondiale (CVM) est necessaire pour acquerir les connaissances et les competences de production etrangeres. Selon cette hypothese, pour une entreprise a revenu intermediaire, passer au niveau superieur de facon fonctionnelle necessite des efforts pour devenir independant et se distinguer des CVM existantes dominees par des etrangers. Enfin, l'hypothese suggere que les entreprises et economies entrees tardivement pourraient avoir a se reintegrer dans la CVM apres avoir etabli leur propre chaine de valeur locale. Cet article verifie cette hypothese en examinant des cas d'entreprises passant au niveau superieur en Coree et au Bresil. Les tendances de la VAE (part de la valeur ajoutee etrangere dans les exportations brutes) dans les economies emergentes a succes sont compatibles avec ce modele. Les resultats de regression confirment une correlation negative entre la creation locale de connaissances et les valeurs de la VAE, de telle sorte que l'augmentation des connaissances locales est la base pour augmenter la valeur ajoutee nationale (reduire valeur ajoutee etrangere) Cette constatation implique que la construction de systemes locaux d'innovation est la cle de la mise a niveau via la CVM.", "author_names": [ "Keun Lee", "Marina H S Szapiro", "Zhuqing Mao" ], "corpus_id": 158736538, "doc_id": "158736538", "n_citations": 73, "n_key_citations": 5, "score": 1, "title": "From Global Value Chains (GVC) to Innovation Systems for Local Value Chains and Knowledge Creation", "venue": "", "year": 2017 }, { "abstract": "Unfortunately the wrong surname of the guest editor Sampath was inserted during the typesetting process. The correct name is Gehl Sampath.", "author_names": [ "Keun Lee", "Marina H S Szapiro", "Zhuqing Mao" ], "corpus_id": 158173480, "doc_id": "158173480", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Correction to: From Global Value Chains (GVC) to Innovation Systems for Local Value Chains and Knowledge Creation", "venue": "", "year": 2018 }, { "abstract": "This paper has forwarded the N shaped curve hypothesis that while at the initial stage of growth more GVC is desirable for learning from outside, functional upgrading requires some effort or stage of seeking separation and independence from the existing foreign dominated GVC, and that the latecomer firms and economies might have to seek again for an opening to integrate back into the GVC after building up their own local value chains. This paper has tried to verify this 'N shaped, InOut In again' hypothesis first by looking into cases of 'upgrading and independence' in Korea and Brazil, and second by checking the national level data of the share of foreign value added (FVA) It is shown that the trends of FVA in successful catching up economies, like Korea, Taiwan, and recently China, is consistent with this N shaped or In Out In again pattern. The paper has also presented some regression results that confirms some correlations between the degree of local creation and diffusion of knowledge and the values of FVA. This can be regarded as an important contribution because it illustrates the linkage between the innovation system variables (knowledge localization) to the GVC variable of the FVA. This finding implies that building local innovation systems is the key to make upgrading and local value creation possible while being integrated in the GVC.", "author_names": [], "corpus_id": 220246137, "doc_id": "220246137", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "From Global Value Chains (GVC) to Innovation Systems for Local Value Chains", "venue": "", "year": 2017 }, { "abstract": "This paper puts forth a hypothesis that while at the initial stage of growth by a latecomer, more participation at the global value chains (GVC) is desired to learn foreign knowledge and production skills, functional upgrading requires effort to seek separation and independence from existing foreigndominated GVC, and that latecomer firms and economies might have to re seek an integration back into GVC after building up their own local value chains. This paper attempted to verify this \"In OutIn Again\" hypothesis by looking into cases of \"upgrading and independence\" in Korea and Brazil, and by checking the national level data of the share of foreign value added (FVA) Trends of FVA in successful catching up economies, including China in recent years, are consistent with this In Out In Again pattern. Regression results also confirm correlations between the degree of local creation and diffusion of knowledge and FVA values. This finding can be viewed as an important contribution because the relationship illustrates the linkage between innovation system variables (knowledge localization) to the GVC variable of the FVA. This finding further implies that building local innovation systems is the key in making possible upgrading and local value creation while integrating in the GVC.", "author_names": [ "Keun Lee", "Marina H S Szapiro", "Zhuqing Mao" ], "corpus_id": 212410255, "doc_id": "212410255", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "From Global Value Chains (GVC) to Innovation Systems for Local Value Chains and Knowledge", "venue": "", "year": 2017 }, { "abstract": "Received Septmber 20, 2018 Revised from October 23, 2019 Accepted November 30, 2019 Available online March 15, 2019 The concept of global value chains (GVC) is elaborated by the scientists and applied by practices in the fields of management, economics and politics. Contemporary due to the globalization of the creation, production and consumption process the boundaries between national, regional and international innovation systems becoming fuzzy. This phenomenon is not extensively explored consequently it encouraged to investigate GVC at sectoral level highlighting the high technology sectors' peculiarities of the downstream GVC processes The article is addressed to underline the relevance of GVC approach and empirically observe the trends of high technology sectors' fragmentation and shifts of downstream value added in Baltic region countries. The high technology sectors are distinct due to high rate of investments to R&D, therefore the decomposition of the high technology sector's value added to local and foreign consumption is appropriate. The empirical research is accomplished by comparative investigation of high technology sectors in the Baltic Region countries and based on longitudinal World Input Output Data (WIOD) available for the period from 2000 till 2014. The descriptive and predictive statistical methods were applied exploring proposed indicators for the investigation the dynamics of high technology sectors' downstream value added distribution within GVC. It enabled to compare the high technology sectors in Baltic region countries and to develop predictive models for distinct high technology sectors. The findings could be applied to examine the international business environment trends at sectoral level. JEL classification: F19; M16 DOI: 10.14254/1800 5845/2020.16 1.7", "author_names": [ "Audrone Kvedariene", "Borisas Melnikas", "Egle Kazlauskiene", "Daiva Andriusaitiene" ], "corpus_id": 216162539, "doc_id": "216162539", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "High Technology Sectors' Participation in Downstream GVC: Case of Baltic Region", "venue": "", "year": 2020 }, { "abstract": "Since the U.S.firstly proposed strategic plan of advanced manufacturing industry in 1990s,Germany,Japan and other developed countries also successively put forward its own advanced technology development plan and advanced manufacturing development strategy.At present,promoting industrial independent innovation capacity,transform and upgrade traditional manufacturing with advanced technology,accelerate the development of advanced manufacturing,are the necessary condition to realize the upgrading of the industrial structure in China.Advanced manufacturing industry should possess not only advanced manufacturing technology,advanced management technology and advanced manufacturing mode,also have a perfect innovation network and strong ability to innovate.In the condition of global FDI rapid flow and manufacturing value chain unceasingly crossed borders,formation of innovative network and promotion of innovation capability need effective insertion of innovation network in GVC.This kind of insertion depends upon the interaction between governance modes of innovation network and GVC,and modes of knowledge transfer determined by governance.Synergy between modes of governance and knowledge transfer stimulates dynamic revolution from disorder interlink between modules,promotion of ordering degree,to integration among modules,further finishes upgrade of GVC as a dynamic inserted system.", "author_names": [ "Zhang Bao-sheng" ], "corpus_id": 168015786, "doc_id": "168015786", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Innovation Network Governance,Dynamic Embeddedness and GVC Upgrade Take Advanced Manufacturing Industry for an Example", "venue": "", "year": 2011 }, { "abstract": "The implementation of the effective embedding in GVC,is one of the key issues of industrial development,upgrading innovation capability and international competitiveness in developing countries.At present,the core of value added in the value chain of auto industry is still controlled by developed countries,and the fracture between the third and second value chains of China's auto industry hinders its effective embedding in GVC,while the construction of co creation subsystems and formation of dynamically embedded co creation system characterized by the three level embedding governance upgrading both benefit,embedding China's auto industry in GVC and its innovation capability upgraded.", "author_names": [ "Zhang Bao-sheng" ], "corpus_id": 167236673, "doc_id": "167236673", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Co creation and GVC Embedding:Study on the Innovation Network Governance of China's Auto Industry", "venue": "", "year": 2010 }, { "abstract": "i DECLARATION OF PLAGIARISM ii ACKNOWLEDGEMENT iii LIST OF FIGURES vi LIST OF TABLES vii LIST OF ACRONYMS viii CHAPTER 1: INTRODUCTION 9 1.1 Research Context. 9 1.2 Objectives of the Research 10 1.3 Methodology 11 1.4 Organization of the Research 17 CHAPTER 2: LITERATURE REVIEW ON INNOVATION SYSTEM AND THE GLOBAL VALUE CHAIN (GVC) 18 2.1 Innovation and Innovation System 18 2.2 National Innovation System 19 2.3 National System of Innovation Approach 20 2.4 Internationalization of Innovation System 24 2.5 Theory of Global Value Chains 25 2.6 Value Chain Analysis 31 CHAPTER 3: NSI ANALYSIS 35 3.1 Cluster analysis 36 3.2 Access to Financial resources 42 3.3 Linkage with Vocational training programs. 43 CHAPTER 4: GVC ANALYSIS 46 4.1 The International coffee market 46 4.2 Overview of Trung Nguyen Corporation 57", "author_names": [ "Thi Tuong", "Vi Tran", "Daniel Stefan Hain", "Roman Jurowetzki", "Trung Nguyen", "Trung Nguyen's" ], "corpus_id": 210886683, "doc_id": "210886683", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "MASTER THESIS: ENHANCING THE PARTICIPATION OF TRUNG NGUYEN COFFEE IN THE GLOBAL VALUE CHAIN (GVC) Student:", "venue": "", "year": 2018 }, { "abstract": "How to solve the contradiction between economic growth and ecological environmental protection is a practical problem that should be solved urgently at present. The development of green technology in the manufacturing industry must rely on technology innovation. However, the process of implementing green innovation in the manufacturing industry is full of high uncertainty and risk. First, the green innovation risks were divided into global green R&D risk, global green manufacturing risk, global green marketing risk, and global green service risk from the perspective of the process. Then, this study established a management criteria system of green innovation risk identification in the manufacturing industry under the global value chain (GVC) Furthermore, three methods were applied to identify the green innovation risk of the manufacturing industry under the GVC. Finally, this paper put forward the countermeasures to the green innovation risk of the manufacturing industry under the GVC. The empirical research results of this paper are as follows: From the perspective of the green innovation process, four risks are classified in this study, namely, global green R&D risk, global green manufacturing risk, global green marketing risk, and global green service risk. Among the four stages of green innovation risk, green marketing risk is the highest, followed by green service risk, and green R&D risk and green manufacturing risk are the least. Global green service risk and green R&D risk can be reduced mainly through risk diversification and risk reduction. Global green manufacturing risk and green marketing risk can be reduced mainly through risk diversification and secondary through risk reduction.", "author_names": [ "Yingying Sun", "Kexin Bi", "Shi Yin" ], "corpus_id": 213231585, "doc_id": "213231585", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Measuring and Integrating Risk Management into Green Innovation Practices for Green Manufacturing under the Global Value Chain", "venue": "", "year": 2020 } ]

[ { "abstract": "We review the performance and discuss the potential of GaNbased field effect transistors for high power, high temperature operation. Recent Monte Carlo simulations predict that GaNbased transistors operating at high voltages may outperform GaAs based transistors even at room temperature. Our GaN/AlGaN doped channel HFETs (DC HFETs) demonstrated highest kequency operation among all wide band gap semiconductor'\" devices because of excellent transport properties of two dimensional electron gas at the AlGaNIGaN heterointerface and a large sheet carrier concentration in the The I V and C V measurements and the theory of GaN AlNGaN SIS structures demonstrated a small leakage current across the AlN/GaN interface and a large conduction band discontinuity. Recently, Fan et al. lo demonstrated very low resistance ohmic contacts to n GaN (specific resistivity of 8.9x10 ohm cm2 for 1017 ~m material. Our studies demonstrated that the contact resistance rapidly decreases with an increase of the sheet electron concentration in these heterostructures. \" The transient Monte Carlo simulations showed that, in spite of a higher effective mass in GaN compared to GaAs (0.22 m, compared to 0.067 m, electrons in GaN based FETs are expected to exhibit strong overshoot effects but at much higher fields than in GaAs. These calculations predict that, at high enough voltages, GaN based FETs may actually outperform GaAs based devices even at room temperature. Hence, all building blocks exist for realizing superior GaNbased field effect transistors for high frequency, high power operation.", "author_names": [ "M A Khan", "Q Chen", "Jialing Yang", "M Zubair Anwar", "M P Blasingame", "Michael S Shur", "Jinwook Burm", "Lester F Eastman" ], "corpus_id": 110636176, "doc_id": "110636176", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "RECENT ADVANCES IN 111 V NITRIDE ELECTRON DEVICES", "venue": "", "year": 1996 }, { "abstract": "Schottky and Ohmic contacts based electronics play an important role in highly sensitive detection of biomolecules and neural electric impulses, respectively. The reversible conversion between these two contacts appears especially important for multifunctional sensing by just one biosensor. Here, Schottky barrier height (SBH) is successfully tuned by triboelectric nanogenerator (TENG) and the same device is made to achieve reversible conversion between Schottky contact and Ohmic contact. In the same Schottky to Ohmic reversible (SOR) biosensor, highly sensitive detections of biomolecule (i.e. neurotransmitter) and neural electric signal are achieved at different contact states. The SOR biosensor reveals the feasibility of using one device to realize multifunctional detection. This work proposes a simple and significant method to achieve reversible tuning between the Schottky contact and Ohmic contact on one device by TENG, which exhibits great potential in developing multifunctional and high sensitivity biosensors, rectifiers, and other functional electronic devices.", "author_names": [ "Hu Li", "Yaming Zhang" ], "corpus_id": 214335907, "doc_id": "214335907", "n_citations": 32, "n_key_citations": 0, "score": 1, "title": "Reversible Conversion between Schottky and Ohmic Contacts for Highly Sensitive, Multifunctional Biosensors", "venue": "", "year": 2019 }, { "abstract": "Incorporation of two dimensional (2D) materials in electronic devices inevitably involves contact with metals, and the nature of this contact (Ohmic and/or Schottky) can dramatically affect the electronic properties of the assembly. Controlling these properties to reliably form low resistance Ohmic contact remains a great challenge due to the strong Fermi level pinning (FLP) effect at the interface. Herein, we employ density functional theory calculations to show that van der Waals stacking can significantly modulate Schottky barrier heights in the contact formed between multilayer InSe and 2D metals by suppressing the FLP effect. Importantly, the increase of InSe layer number induces a transition from Schottky to Ohmic contact, which is attributed to the decrease of the conduction band minimum and rise of the valence band maximum of InSe. Based on the computed tunneling and Schottky barriers, Cd3C2 is the most compatible electrode for 2D InSe among the materials studied. This work illustrates a straightforward method for developing more effective InSe based 2D electronic nanodevices.", "author_names": [ "Tao Shen", "Jichang Ren", "Xinyi Liu", "Shuang Li", "Wei Liu" ], "corpus_id": 59307051, "doc_id": "59307051", "n_citations": 62, "n_key_citations": 0, "score": 0, "title": "van der Waals Stacking Induced Transition from Schottky to Ohmic Contacts: 2D Metals on Multilayer InSe.", "venue": "Journal of the American Chemical Society", "year": 2019 }, { "abstract": "Here we investigated interfacial reactions and interdiffusion of titanium/gold ohmic contacts with a tin doped single crystal b Ga2O3 (010) substrate. After annealing at 470 degC for 1 min in N2 to form an ohmic contact, we studied the interface via scanning transmission electron microscopy and transmission electron microscopy with energy dispersive X ray spectroscopy as well as electron energy loss spectroscopy. At the interface, annealing causes Ti to diffuse and oxidize, reducing Ga2O3 at the interface. This forms a defective b Ga2O3 layer of 3 5 nm that has a relatively high Ti concentration. Above this is a 3 5 nm layer of Ti TiOx that is partially lattice matched to the b Ga2O3 substrate. The thermodynamic favorability of these redox reactions was explained by calculating Gibbs free energies of the reactions. In addition, the anneal causes interdiffusion of Ti and Au, until Au is in contact with the thin Ti TiOx layer. A layer of Ti rich nanocrystals, around 5 nm in diameter, is formed within the Au Ti intermixed matrix, about 3 nm above the Ti TiOx layer. Based on these observations, the ohmic properties are tentatively attributed to the interdiffusion of Ti and Au and the resulting thin Ti TiOx layer, which helps band alignment. In addition, lattice matching of the defective Ga2O3 and Ti TiOx layers to b Ga2O3 facilitates the transport of carriers. A physical understanding of Ti/Au metallization can provide insights into future materials selection for thermally stable contacts in b Ga2O3 power devices.", "author_names": [ "Ming-Hsun Lee", "Rebecca L Peterson" ], "corpus_id": 104406534, "doc_id": "104406534", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "Interfacial reactions of titanium/gold ohmic contacts with Sn doped b Ga2O3", "venue": "APL Materials", "year": 2019 }, { "abstract": "We report silicon delta doped <inline formula> <tex math notation=\"LaTeX\"\\beta /tex math>/inline formula> Ga₂O₃ metal semiconductor field effect transistors (MESFETs) with source drain ohmic contacts formed by patterned regrowth of n type Ga₂O₃ We show that regrown n type contacts can enable a lateral low resistance contact to the two dimensional electron gas channel, with contact resistance lower than <inline formula> <tex math notation=\"LaTeX\"$1.5~\\Omega /tex math>/inline formula> mm. The fabricated MESFET has a peak drain current <inline formula> <tex math notation=\"LaTeX\"{I} _{D,\\text{MAX} /tex math>/inline formula> of 140 mA/mm, transconductance <inline formula> <tex math notation=\"LaTeX\"{g} _{m} /tex math>/inline formula> of 34 mS/mm, and 3 terminal off state breakdown voltage of 170 V. The proposed device structure could provide a promising path towards vertically scaled <inline formula> <tex math notation=\"LaTeX\"\\beta /tex math>/inline formula> Ga₂O₃ field effect transistors.", "author_names": [ "Zhanbo Xia", "Chandan Joishi", "Sriram Krishnamoorthy", "Sanyam Bajaj", "Yuewei Zhang", "Mark R Brenner", "Saurabh Lodha", "Siddharth Rajan" ], "corpus_id": 8941089, "doc_id": "8941089", "n_citations": 61, "n_key_citations": 2, "score": 0, "title": "Delta Doped \\beta$ Ga2O3 Field Effect Transistors With Regrown Ohmic Contacts", "venue": "IEEE Electron Device Letters", "year": 2018 }, { "abstract": "We report high performance WSe2 phototransistors with two dimensional (2D) contacts formed between degenerately p doped WSe2 and undoped WSe2 channel. A photoresponsivity of ~600 mA/W with a high external quantum efficiency up to 100% and a fast response time (both rise and decay times) shorter than 8 ms have been achieved concurrently. More importantly, our WSe2 phototransistor exhibits a high specific detectivity ~1013 Jones) in vacuum, comparable or higher than commercial Si and InGaAs based photodetectors. Further studies have shown that the high photoresponsivity and short response time of our WSe2 phototransistor are mainly attributed to the lack of Schottky barriers between degenerately p doped WSe2 source/drain contacts and undoped WSe2 channel, which can reduce the RC time constant and carrier transit time of a photodetector. Our experimental results provide an accessible strategy to achieve high performance WSe2 phototransistor architectures by improving their electrical transport and photocurrent generation simultaneously, opening up new avenues for engineering future 2D optoelectronic devices.", "author_names": [ "Tianjiao Wang", "Kraig Andrews", "Arthur Bowman", "Tu Hong", "Michael R Koehler", "Jiaqiang Yan", "David G Mandrus", "Zhixian Zhou", "Yaqiong Xu" ], "corpus_id": 4657209, "doc_id": "4657209", "n_citations": 67, "n_key_citations": 1, "score": 0, "title": "High Performance WSe2 Phototransistors with 2D/2D Ohmic Contacts.", "venue": "Nano letters", "year": 2018 }, { "abstract": "AlGaN/GaN high electron mobility transistors on semi insulating bulk ammonothermal GaN have been investigated. By application of regrown ohmic contacts, the problem with obtaining low resistance ohmic contacts to low dislocation high electron mobility transistor (HEMT) structures was solved. The maximum output current was about 1 A/mm and contact resistances was in the range of 0.3 0.6 O*mm. Good microwave performance was obtained due to the absence of parasitic elements such as high access resistance.", "author_names": [ "Wojciech Wojtasiak", "Marcin Goralczyk", "Daniel Gryglewski", "Marcin Zajac", "Robert Kucharski", "Pawel Prystawko", "Anna Piotrowska", "Marek Ekielski", "Eliana Kaminska", "Andrzej Taube", "Marek Wzorek" ], "corpus_id": 54448566, "doc_id": "54448566", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "AlGaN/GaN High Electron Mobility Transistors on Semi Insulating Ammono GaN Substrates with Regrown Ohmic Contacts", "venue": "Micromachines", "year": 2018 }, { "abstract": "While thermodynamic detailed balance limits the maximum power conversion efficiency of a solar cell, the quality of its contacts can further limit the actual efficiency. The criteria for good contacts to organic semiconductors, however, are not well understood. Here, by tuning the work function of poly(3,4 ethylenedioxythiophene) hole collection layers in fine steps across the Fermi level pinning threshold of the model photoactive layer, poly(3 hexylthiophene):phenyl C61 butyrate methyl ester, in organic solar cells, we obtain direct evidence for a non ohmic to ohmic transition at the hole contact that lies 0.3 eV beyond its Fermi level pinning transition. This second transition corresponds to reduction of the photocurrent extraction resistance below the bulk resistance of the cell. Current detailed balance analysis reveals that this extraction resistance is the counterpart of injection resistance, and the measured characteristics are manifestations of charge carrier hopping across the interface. Achieving ohmic transition at both contacts is key to maximizing fill factor without compromising open circuit voltage nor short circuit current of the solar cell.The importance of ohmic contacts for organic solar cells has been recognized, but how the transition to ohmic behavior occurs is unknown. Tan et al. show that this transition happens separately beyond Fermi level pinning, when the interfacial contact resistivity becomes sufficiently low.", "author_names": [ "Jun-Kai Tan", "Rui-Qi Png", "Chao Zhao", "Peter K H Ho" ], "corpus_id": 52010874, "doc_id": "52010874", "n_citations": 29, "n_key_citations": 0, "score": 0, "title": "Ohmic transition at contacts key to maximizing fill factor and performance of organic solar cells", "venue": "Nature Communications", "year": 2018 }, { "abstract": "We report on the electrical and microstructural characterization of Au free Ti/Al/Ti/TiN contacts for AlGaN/GaN heterostructures. Ultra low Au free ohmic contact has been obtained with contact resistance and specific contact resistivity as low as <inline formula> <tex math notation=\"LaTeX\"$0.21~\\Omega \\cdot \\text{mm} /tex math>/inline formula> and <inline formula> <tex math notation=\"LaTeX\"{1.16}\\times {10} 6} \\Omega \\cdot \\text{cm}{2} /tex math>/inline formula> respectively. The ohmic alloy temperature is reduced as low as 550 degC by pre ohmic recess of the AlGaN barrier and optimization of the thickness of bottom Ti layer. We found that interfacial layer formation of AlN between the ohmic metal and AlGaN surface is crucial to realize a low contact resistance with reduced low annealing temperature by a combination of electrical <inline formula> <tex math notation=\"LaTeX\"{I} /tex math>/inline formula> <inline formula> <tex math notation=\"LaTeX\"{V} /tex math>/inline formula> characterization and high resolution transmission electron microscopy analysis. Furthermore, we suggest a hypothesis that the bottom Ti layer plays a catalytic role for the Al N reaction with optimized thickness.", "author_names": [ "Jinhan Zhang", "Xuanwu Kang", "Xinhua Wang", "Sen Huang", "C Chen", "Ke Wei", "Yingkui Zheng", "Qi Zhou", "Wanjun Chen", "Bo Zhang", "Xinyu Liu" ], "corpus_id": 46898340, "doc_id": "46898340", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Ultralow Contact Resistance Au Free Ohmic Contacts With Low Annealing Temperature on AlGaN/GaN Heterostructures", "venue": "IEEE Electron Device Letters", "year": 2018 }, { "abstract": "Most semiconductor devices require low resistance ohmic contact to p type doped regions. In this work, we present a semi salicide process that forms low resistance contacts ~10 4 O cm2) to epitaxially grown p type >5x1018 cm 3) 4H SiC at temperatures as low as 600 degC using rapid thermal processing (RTP) The first step is to self align the nickel silicide (Ni2Si) at 600 degC. The second step is to deposit aluminium on top of the silicide, pattern it and then perform a second annealing step in the range 500 degC to 700 degC.", "author_names": [ "Mattias Ekstrom", "Shuoben Hou", "Hossein Elahipanah", "Arash Salemi", "Mikael Ostling", "Carl-Mikael Zetterling" ], "corpus_id": 139365785, "doc_id": "139365785", "n_citations": 11, "n_key_citations": 1, "score": 0, "title": "Low Temperature Ni Al Ohmic Contacts to p Type 4H SiC Using Semi Salicide Processing", "venue": "", "year": 2018 } ]

[ { "abstract": "Topological protection for lasers Ideas based on topology, initially developed in mathematics to describe the properties of geometric space under deformations, are now finding application in materials, electronics, and optics. The main driver is topological protection, a property that provides stability to a system even in the presence of defects. Harari et al. outline a theoretical proposal that carries such ideas over to geometrically designed laser cavities. The lasing mode is confined to the topological edge state of the cavity structure. Bandres et al. implemented those ideas to fabricate a topological insulator laser with an array of ring resonators. The results demonstrate a powerful platform for developing new laser systems. Science, this issue p. eaar4003, p. eaar4005 Lasing is observed in an edge mode of a designed optical topological insulator. INTRODUCTION Topological insulators emerged in condensed matter physics and constitute a new phase of matter, with insulating bulk and robust edge conductance that is immune to imperfections and disorder. To date, topological protection is known to be a ubiquitous phenomenon, occurring in many physical settings, ranging from photonics and cold atoms to acoustic, mechanical, and elastic systems. So far, however, most of these studies were carried out in entirely passive, linear, and conservative settings. RATIONALE We propose topological insulator lasers: lasers whose lasing mode exhibits topologically protected transport without magnetic fields. Extending topological physics to lasers is far from natural. In fact, lasers are built on foundations that are seemingly inconsistent with the essence of topological insulators: They require gain (and thus are non Hermitian) they are nonlinear entities because the gain must be saturable, and they are open systems because they emit light. These properties, common to all lasers, cast major doubts on the possibility of harnessing topological features to make a topological insulator laser. Despite this common mindset, we show that the use of topological properties leads to highly efficient lasers, robust to defects and disorder, with single mode lasing even at conditions high above the laser threshold. RESULTS We demonstrate that topological insulator lasers are theoretically possible and experimentally feasible. We consider two configurations involving planar arrays of coupled active resonators. The first is based on the Haldane model, archetypical for topological systems. The second model, geared toward experiment, constitutes an aperiodic array architecture creating an artificial magnetic field. We show that by introducing saturable gain and loss, it is possible to make these systems lase in a topological edge state. In this way, the lasing mode exhibits topologically protected transport; the light propagates unidirectionally along the edges of the cavity, immune to scattering and disorder, unaffected by the shape of the edges. Moreover, we show that the underlying topological properties not only make the system robust to fabrication and operational disorder and defects, they also lead to a highly efficient single mode lasing that remains single mode even at gain values high above the laser threshold. The figure describes the geometry and features of a topological insulator laser based on the Haldane model while adding saturable gain, loss, and an output port. The cavity is a planar honeycomb lattice of coupled microring resonators, pumped at the perimeter with a lossy interior. We show that under these conditions, lasing occurs at the topological edge mode, which has unidirectional flux and is extended around the perimeter with almost uniform intensity. The topological cavities exhibit higher efficiency than the trivial cavity, even under strong disorder. For the topological laser with a small gap, the topological protection holds as long as the disorder level is smaller than the gap size. DISCUSSION The concept of the topological insulator laser alters current understanding of the interplay between disorder and lasing, and opens exciting possibilities at the interface of topological physics and laser science, such as topologically protected transport in systems with gain. We show here that the laser system based on the archetypal Haldane model exhibits topologically protected transport, with features similar to those of its passive counterpart. This behavior means that this system is likely to have topological invariants, despite the nonhermiticity. Technologically, the topological insulator laser offers an avenue to make many semiconductor lasers operate as one single mode high power laser. The topological insulator laser constructed from an aperiodic array of resonators was realized experimentally in an all dielectric platform, as described in the accompanying experimental paper by Bandres et al. Topological insulator laser based on the Haldane model and its efficiency. (A) Planar honeycomb lattice of coupled microring resonators pumped at the perimeter. The topological lasing mode has unidirectional flux with almost uniform intensity, which builds up as the mode circulates and drops when passing the output coupler. (B) Slope efficiency (in arbitrary units) versus disorder strength for three cases differing only in the Haldane phase (of the next to nearest neighbor coupling) a topological laser with the maximum gap (blue; Haldane phase of p/2) one with a small topological gap (red; Haldane phase of p/8) and a topologically trivial laser with no gap (black; Haldane phase of 0) Topological insulators are phases of matter characterized by topological edge states that propagate in a unidirectional manner that is robust to imperfections and disorder. These attributes make topological insulator systems ideal candidates for enabling applications in quantum computation and spintronics. We propose a concept that exploits topological effects in a unique way: the topological insulator laser. These are lasers whose lasing mode exhibits topologically protected transport without magnetic fields. The underlying topological properties lead to a highly efficient laser, robust to defects and disorder, with single mode lasing even at very high gain values. The topological insulator laser alters current understanding of the interplay between disorder and lasing, and at the same time opens exciting possibilities in topological physics, such as topologically protected transport in systems with gain. On the technological side, the topological insulator laser provides a route to arrays of semiconductor lasers that operate as one single mode high power laser coupled efficiently into an output port.", "author_names": [ "Gal Harari", "Miguel A Bandres", "Yaakov Lumer", "Mikael C Rechtsman", "Yidong Chong", "Mercedeh Khajavikhan", "Demetrios N Christodoulides", "Mordechai Segev" ], "corpus_id": 206665715, "doc_id": "206665715", "n_citations": 380, "n_key_citations": 5, "score": 1, "title": "Topological insulator laser: Theory", "venue": "Science", "year": 2018 }, { "abstract": "In the following, the first results on ultraviolet laser desorption (UVLD) of bioorganic compounds in the mass range above 10000 daltons are reported. Strong molecular ion signals were registered by use of an organic matrix with strong absorption at the wavelength used for controlled energy deposition and soft desorption (7)", "author_names": [ "Michael Karas", "F Hillenkamp" ], "corpus_id": 10873255, "doc_id": "10873255", "n_citations": 4900, "n_key_citations": 176, "score": 0, "title": "Laser desorption ionization of proteins with molecular masses exceeding 10,000 daltons.", "venue": "Analytical chemistry", "year": 1988 }, { "abstract": "Random Processes and Random Fields Optical Turbulence in the Atmosphere Free Space Propagation of Gaussian Beam Waves Classical Theory of Optical Wave Propagation Line of Sight Propagation Weak Fluctuation Theory, Part 1 Line of Sight Propagation Weak Fluctuation Theory, Part 2 Propagation Through Random Phase Screens Laser Satellite Communication Systems Propagation Through Complex Paraxial ABCD Optical Systems Doublepassage Problems Laser Radar Systems Line of Sight Propagation Strong Fluctuation Theory Appendices Special Functions Integral Table Tables of Beam Statistics Mathematica Programmes.", "author_names": [ "Larry C Andrews", "Ronald L Phillips" ], "corpus_id": 117361600, "doc_id": "117361600", "n_citations": 3179, "n_key_citations": 515, "score": 0, "title": "Laser Beam Propagation Through Random Media", "venue": "", "year": 1998 }, { "abstract": "Laser light with a Laguerre Gaussian amplitude distribution is found to have a well defined orbital angular momentum. An astigmatic optical system may be used to transform a high order Laguerre Gaussian mode into a high order Hermite Gaussian mode reversibly. An experiment is proposed to measure the mechanical torque induced by the transfer of orbital angular momentum associated with such a transformation.", "author_names": [ "" ], "corpus_id": 1292384, "doc_id": "1292384", "n_citations": 5714, "n_key_citations": 123, "score": 0, "title": "Orbital angular momentum of light and the transformation of Laguerre Gaussian laser modes.", "venue": "Physical review. A, Atomic, molecular, and optical physics", "year": 1992 }, { "abstract": "Infrared Route to Graphene Electrodes Electrochemical capacitors can deliver large amounts of power quickly, but have limited energy storage because only the surface regions of electrodes can store charge. Graphene represents an alternative to activated carbon electrodes because of their high conductivity and surface area, but graphene sheets tend to reassociate and lose surface area. El Kady et al. (p. 1326; see the Perspective by Miller) show that graphite oxide sheets can be converted by infrared laser irradiation into porous graphene sheets that are flexible, robust, and highly conductive. Infrared laser reduction of graphene oxide creates a strong porous electrode with both high surface area and high conductivity. Although electrochemical capacitors (ECs) also known as supercapacitors or ultracapacitors, charge and discharge faster than batteries, they are still limited by low energy densities and slow rate capabilities. We used a standard LightScribe DVD optical drive to do the direct laser reduction of graphite oxide films to graphene. The produced films are mechanically robust, show high electrical conductivity (1738 siemens per meter) and specific surface area (1520 square meters per gram) and can thus be used directly as EC electrodes without the need for binders or current collectors, as is the case for conventional ECs. Devices made with these electrodes exhibit ultrahigh energy density values in different electrolytes while maintaining the high power density and excellent cycle stability of ECs. Moreover, these ECs maintain excellent electrochemical attributes under high mechanical stress and thus hold promise for high power, flexible electronics.", "author_names": [ "Maher F El-Kady", "Veronica Strong", "Sergey Dubin", "Richard B Kaner" ], "corpus_id": 18958488, "doc_id": "18958488", "n_citations": 3055, "n_key_citations": 22, "score": 0, "title": "Laser Scribing of High Performance and Flexible Graphene Based Electrochemical Capacitors", "venue": "Science", "year": 2012 }, { "abstract": "Molecular excitation by the simultaneous absorption of two photons provides intrinsic three dimensional resolution in laser scanning fluorescence microscopy. The excitation of fluorophores having single photon absorption in the ultraviolet with a stream of strongly focused subpicosecond pulses of red laser light has made possible fluorescence images of living cells and other microscopic objects. The fluorescence emission increased quadratically with the excitation intensity so that fluorescence and photo bleaching were confined to the vicinity of the focal plane as expected for cooperative two photon excitation. This technique also provides unprecedented capabilities for three dimensional, spatially resolved photochemistry, particularly photolytic release of caged effector molecules.", "author_names": [ "Winfried Denk", "James H Strickler", "Watt W Webb" ], "corpus_id": 18431535, "doc_id": "18431535", "n_citations": 6830, "n_key_citations": 109, "score": 0, "title": "Two photon laser scanning fluorescence microscopy.", "venue": "Science", "year": 1990 }, { "abstract": "Solid State Laser Engineering is written from an industrialperspective and discusses in detail the characteristics, design, construction and practical problems of solid statelasers. Emphasis is placed on engineering and practicalconsiderations, with a phenomenological treatment usingmodelsbeing preferred to abstract mathematical derivations.This new edition has been updated and revised to includeimportant developments, concepts and technologies that haveemerged since the publication of the first edition.", "author_names": [ "Walter Koechner" ], "corpus_id": 111013814, "doc_id": "111013814", "n_citations": 3347, "n_key_citations": 194, "score": 0, "title": "Solid State Laser Engineering", "venue": "", "year": 1976 }, { "abstract": "Abstract This study demonstrates the significant effect of the recoil pressure and Marangoni convection in laser powder bed fusion (L PBF) of 316L stainless steel. A three dimensional high fidelity powder scale model reveals how the strong dynamical melt flow generates pore defects, material spattering (sparking) and denudation zones. The melt track is divided into three sections: a topological depression, a transition and a tail region, each being the location of specific physical effects. The inclusion of laser ray tracing energy deposition in the powder scale model improves over traditional volumetric energy deposition. It enables partial particle melting, which impacts pore defects in the denudation zone. Different pore formation mechanisms are observed at the edge of a scan track, at the melt pool bottom (during collapse of the pool depression) and at the end of the melt track (during laser power ramp down) Remedies to these undesirable pores are discussed. The results are validated against the experiments and the sensitivity to laser absorptivity is discussed.", "author_names": [ "Saad A Khairallah", "Andrew T Anderson", "Alexander M Rubenchik", "Wayne E King" ], "corpus_id": 85539499, "doc_id": "85539499", "n_citations": 645, "n_key_citations": 21, "score": 0, "title": "Laser powder bed fusion additive manufacturing: Physics of complex melt flow and formation mechanisms of pores, spatter, and denudation zones", "venue": "", "year": 2016 }, { "abstract": "The Linac Coherent Light Source free electron laser has now achieved coherent X ray generation down to a wavelength of 1.2 A and at a brightness that is nearly ten orders of magnitude higher than conventional synchrotrons. Researchers detail the first operation and beam characteristics of the system, which give hope for imaging at atomic spatial and temporal scales.", "author_names": [ "Paul J Emma", "Ron Akre", "John R Arthur", "R M Bionta", "Christoph Bostedt", "John D Bozek", "Axel Brachmann", "Philip H Bucksbaum", "Ryan N Coffee", "Franz Josef Decker", "Y Ding", "David Harry Dowell", "Steve Edstrom", "A S Fisher", "Josef C Frisch", "Sasha Gilevich", "Jerome B Hastings", "Gregory Ross Hays", "Ph Hering", "Zhirong Huang", "Richard H Iverson", "Henrik Loos", "Marc Messerschmidt", "A A Miahnahri", "Stefan Moeller", "Heinz Dieter Nuhn", "G Pile", "Daniel Ratner", "Jeffrey A Rzepiela", "D C Schultz", "Peter M Stefan", "H Tompkins", "J J Turner", "James J Welch", "William E White", "Juhao Wu", "Gerald Yocky", "John N Galayda" ], "corpus_id": 31414508, "doc_id": "31414508", "n_citations": 2166, "n_key_citations": 102, "score": 0, "title": "First lasing and operation of an angstrom wavelength free electron laser", "venue": "", "year": 2010 }, { "abstract": "Processing of materials by ultrashort laser pulses has evolved significantly over the last decade and is starting to reveal its scientific, technological and industrial potential. In ultrafast laser manufacturing, optical energy of tightly focused femtosecond or picosecond laser pulses can be delivered to precisely defined positions in the bulk of materials via two /multi photon excitation on a timescale much faster than thermal energy exchange between photoexcited electrons and lattice ions. Control of photo ionization and thermal processes with the highest precision, inducing local photomodification in sub 100 nm sized regions has been achieved. State of the art ultrashort laser processing techniques exploit high 0.1 1 mm spatial resolution and almost unrestricted three dimensional structuring capability. Adjustable pulse duration, spatiotemporal chirp, phase front tilt and polarization allow control of photomodification via uniquely wide parameter space. Mature opto electrical/mechanical technologies have enabled laser processing speeds approaching meters per second, leading to a fast lab to fab transfer. The key aspects and latest achievements are reviewed with an emphasis on the fundamental relation between spatial resolution and total fabrication throughput. Emerging biomedical applications implementing micrometer feature precision over centimeter scale scaffolds and photonic wire bonding in telecommunications are highlighted.", "author_names": [ "Mangirdas Malinauskas", "Albertas Zukauskas", "Satoshi Hasegawa", "Yoshio Hayasaki", "Vygantas Mizeikis", "Ricardas Buividas", "Saulius Juodkazis" ], "corpus_id": 52132580, "doc_id": "52132580", "n_citations": 535, "n_key_citations": 2, "score": 0, "title": "Ultrafast laser processing of materials: from science to industry", "venue": "Light, science applications", "year": 2016 } ]

[ { "abstract": "Fabrication of efficient, effective, and low cost solar cell is still a challenging task using metal oxide semiconductors; in this work, g MnO2/a Bi2O3 heterojunction was deposited on amorphous silicon substrate (a Si) as a solar cell using vacuum thermal evaporation technique. XRD analysis of g MnO2/a Bi2O3 showed a polycrystalline structure; SEM micrographs revealed that g MnO2 has quasi spherical nanoparticles with a grain size average of 86.86 nm, while a Bi2O3 has cauliflower like microstructure with a grain size average of 250.71 nm; the optical bandgap were found to be 3.792 and 1.888 eV for g MnO2 and a Bi2O3 respectively; I V characteristic curve measurement was performed to evaluate the photovoltaic efficiency of MgF2/g MnO2/a Bi2O3/a Si solar cell and found to be 3.28%", "author_names": [ "Aus A Najim", "Malek A H Muhi", "Kadhim R Gbashi", "Ammar T Salih" ], "corpus_id": 125770033, "doc_id": "125770033", "n_citations": 11, "n_key_citations": 0, "score": 1, "title": "Synthesis of Efficient and Effective g MnO2/a Bi2O3/a Si Solar Cell by Vacuum Thermal Evaporation Technique", "venue": "Plasmonics", "year": 2017 }, { "abstract": "Efficiency of Silicon commercial solar cells covered with germanate glasses doped with Eu3+ ions, with and without gold nanoparticles, was measured. Enhancement of the efficiency was observed in the presence of gold nanoparticles when compared to germanate glasses without gold nanoparticle. The results were attributed to the plasmonic enhancement around Eu3+ ions due to the presence of gold nanoparticles and the energy transfer from excited nanoparticles to the Eu3+ ions.", "author_names": [ "J A M Garcia", "Luciana R P Kassab", "Roberto Koji Onmori", "Bismarck Costa Lima", "L A Gomez-Malagon", "Anderson S L Gomes" ], "corpus_id": 22625140, "doc_id": "22625140", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Influence of gold nanoparticles on Eu3+ doped GeO2 Bi2O3 glasses covered Silicon solar cell", "venue": "2016 31st Symposium on Microelectronics Technology and Devices (SBMicro)", "year": 2016 }, { "abstract": "Pb based hybrid perovskite solar cells, despite their advantages, face challenges in commercialization. In recent years, Bi based chalcohalides are being considered as potential alternative candidates, however, their current device efficiency remains unsatisfactory. Herein, a two step solution method is developed and applied to the fabrication of BiSI films. The method consists of the formation of Bi2S3 (step I) and its conversion to BiSI (step II) The Bi2S3 was fabricated by a thiol amine solution process and the BiSI conversion was achieved by chemical reaction between the as formed Bi2S3 and BiI3. It was found that the formation of BiSI was highly dependent on the Bi:S molar ratio of the Bi2O3 thiourea solution and the number of times of step I. The as fabricated BiSI film had an optical band gap of 1.61 eV and exhibited nanorod morphology. In addition, the electronic structure is explored and discussed for solar cells applications.", "author_names": [ "Yong Chan Choi", "Eunjeong Hwang" ], "corpus_id": 208235378, "doc_id": "208235378", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Controlled Growth of BiSI Nanorod Based Films through a Two Step Solution Process for Solar Cell Applications", "venue": "Nanomaterials", "year": 2019 }, { "abstract": "In this study, eco friendly Pb free Bi2O3 B2O3 ZnO glass frits were chosen as an inorganic additive for the Al paste used in Si solar cells. The effects of the molar ratio of Bi2O3 to B2O3 in the glass composition on the electrical resistance of the Al electrode and on the cell performance were investigated. The results showed that as the molar ratio of Bi2O3 to B2O3 increased, the glass transition temperature and softening temperature decreased because of the reduced glass viscosity. In Al screen printed Si solar cells, as the molar ratio of Bi2O3 to B2O3 increased, the sheet electrical resistance of the Al electrode decreased and the cell efficiency increased. The uniformity and thickness of the back surface field was significantly influenced by the glass composition.", "author_names": [ "Bit-Na Kim", "Hyeong Jun Kim", "Hyo Sik Chang", "Hyun Seon Hong", "Sung-Soo Ryu", "Heon Lee" ], "corpus_id": 123404316, "doc_id": "123404316", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Effect of the Molar Ratio of B2O3 to Bi2O3 in Al Paste with Bi2O3 B2O3 ZnO Glass on Screen Printed Contact Formation and Si Solar Cell Performance", "venue": "", "year": 2013 }, { "abstract": "The coupling of a solar cell with a super capacitor is gaining interest owing to its superior photo to electrical conversion efficiency and its in situ energy storage ability for green and sustainable energy development. In this work, the electrochemical performances of the fabricated super capacitor and perovskite solar cell were individually measured for the fabrication of a photo super capacitor. A Bi2O3/MnO2 based symmetrical and asymmetrical super capacitor were fabricated. The symmetrical super capacitor could charge up to 1.0 V, which gave a specific capacitance of 136.4 F/g at a scan rate of 2 mV/s. The power and energy densities of the bismuth based symmetrical super capacitor were 51.8 W/kg and 7.1 Wh/kg, respectively and were improved to 25.6 Wh/kg and 115.3 W/kg when a Bi2O3/MnO2 positive electrode was integrated to a polypyrrole/reduced graphene oxide (PyR) negative electrode. It thus proven the feasibility of an asymmetrical super capacitor to promote the performance of a super capacitor. The dissatisfying stability performance of the Bi2O3/MnO2//PyR asymmetrical super capacitor (60% capacitance retained) prompted for screening of other pseudocapacitive materials. An asymmetrical super capacitor comprising a positive cobalt oxide/zinc oxide/reduced graphene oxide electrode (RZCo) and a negative polypyrrole/reduced graphene oxide electrode was then fabricated. A wide operational potential range for the RZCo//PyR asymmetrical super capacitor resulted in a high specific capacitance of 470.8 F/g, as opposed to the Bi2O3/MnO2 symmetrical super capacitor of 136.4 F/g and 144.1 F/g for the bismuth based asymmetrical super capacitor, at a scan rate of 2mV/s, additionally exhibited 1.6 fold higher in energy and power densities, which fulfilling the criteria as the energy storage device for the photo super capacitor.Perovskite solar cells were fabricated from a series of cesium based halide mixtures perovskite harvesting materials, denoted as CsPbBr3 xIx, where x 0 0.3. An optimum iodide concentration of CsPbBr2.9I0.1 perovskite solar cell with an efficiency of 3.9% was fabricated. The solar cell achieved an open circuit voltage of more than 1.0 V and a fill factor of 64% by employing Spiro OMeTAD as a hole transporting material with enhanced stability. The performances of the CsPbBr2.9I0.1 solar cell with P3HT/MoO3 hole transporting material was also investigated. The deeper HOMO and shallower LUMO level of the hole and electron transporting materials, respectively has achieved high Voc of 1.23 V, but with lower power conversion efficiency of 2.51% due to reduction in the Jsc, implies an additional charge loss processes at the interface of perovskite/HTM. In high humidity of more than 80 percent, the perovskite solar cell comprising CsPbBr2.9I0.1 achieved an efficiency of 0.46% The perovskite solar cell retains 70% of its original efficiency after a week storage in dark and 33% efficiency retained under UV and air exposure at a high relative humidity of more than 80% for 24 hours. The integration of the perovskite solar cell and the asymmetrical super capacitor enabled simultaneous photoconversion and charge storage within the photo super capacitor. The photovoltage and photocurrent measurements were successfully performed, evidencing that the photo super capacitor was responsive to light illumination. Referred to the photovoltage measurement, zero voltage was presented at the first 50 s without the shine of light. Subsequently, the photovoltage was abruptly shooted up to ~80 mV and continue increasing to 90 mV for 100 s in the presence of light, and was then decreases drastically when light was switched off. To further proof the energy conversion and storage of the photo super capacitor, the photocharged integrated device was galvanostatically discharged in dark at the current of 0.1 mA. As the integrated device reaches the cut off potential of 0.07 V, the discharging process took place in dark with the connection of only super capacitor's electrodes, thus shows the workability of the photo super capacitor. To enable practical application, improvizations such as optimizing thickness of each active layer and encapsulation of the photo super capacitor are needed to prevent electrolyte loss.", "author_names": [ "Chi Huey Ng" ], "corpus_id": 204302020, "doc_id": "204302020", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Fabrication of super capacitor and perovskite sensitized solar cell for the assembly of photo super capacitor", "venue": "", "year": 2018 }, { "abstract": "The present invention discloses a paste composition for preparing a solar cell electrode, a solar cell electrode, and a solar cell wherein the paste composition comprises conductive powder, an organic carrier and glass powder. The glass powder contains 0.1 to 20 wt% of PbO, 30 to 60 wt% of Bi2O3, 1.0 to 15 wt% of TeO2 and 8 to 30 wt% of WO3, and the mass ratio of TeO2 to WO3 is 0.5: 1 to 1.75: 1. The solar cell electrode prepared through the use of the paste composition of the present invention has excellent adhesive strength and minimizes the series resistance (Rs) thereby providing high conversion efficiency.", "author_names": [ "" ], "corpus_id": 140984305, "doc_id": "140984305", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Paste composition for preparing solar cell electrode, solar cell electrode and solar cell", "venue": "", "year": 2016 }, { "abstract": "The invention relates to a back field aluminum paste for a crystalline silicon solar cell. The raw material of the back field aluminum paste for the crystalline silicon solar cell comprises, by weight, 74 parts of aluminum powder, 20 25 parts of organic binder, 1 4 parts of lead free glass power and 0.1 2 parts of additive. The raw material of the organic binder comprises, by weight, 40 70 parts of terpineol, 5 10 parts of butyl carbitol, 5 10 parts of butyl carbitol acetate, 3 10 parts of ethyl cellulose, 5 15 parts of dibutyl phthalate and 1 part of sorbitan stearate. The raw material of thelead free glass power comprises, by weight, 30 60 parts of Bi2O3, 5 15 parts of B2O3, 3 parts of BiF3, 10 20 parts of SiO2, 5 10 parts of ZnO, 1 5 parts of TiO2, 10 20 parts of Al2O3 and 1 3 parts ofP2O5. The additive is spherical copper power with the purity of more than 99% and the fineness of 20000 mesh. The aluminum powder, the organic binder, the lead free glass powder and the additives aremixed uniformly and rolled with a three roll mill to obtain a fineness of less than or equal to 10 micrometer and a viscosity of 30 60Pa.s. The back field aluminum paste for the crystalline silicon solar cell has high photoelectric conversion efficiency, high adhesion, little adhesion conversion efficiencyattenuation after high temperature aging and good boiling resistance.", "author_names": [ "" ], "corpus_id": 146665120, "doc_id": "146665120", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Back field aluminum paste for crystalline silicon solar cell", "venue": "", "year": 2016 }, { "abstract": "Developing a lead free glass frit binder in aluminum electrode paste is one of important subjects for further development of Si solar cell. However, lead free aluminum electrode usually shows weaker mechanical and electric properties. The effects of B2O3content in Bi2O3 SiO2 B2O3 ZnO based glass frit on the mechanical and electric properties of solar cell were investigated. It is found that B2O3is the main factor causing the electrode instability and ashing.Reducing or removing the content of B2O3can improve the electrode stability and membrane strength but lead to higher contact resistance between Si and Al electrode and lower photovoltage of Si solar cell. A new Bi2O3 SiO2 Fe2O3 ZnO lead free glass system, in which B2O3was replaced by Fe2O3, was designed and prepared. Results show that the Al electrode using this new glass frit shows good water resistance, good electrical performance and surface and membrane strength.", "author_names": [ "Zhang Hon" ], "corpus_id": 137759746, "doc_id": "137759746", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Effect of B_2O_3 content in lead free glass frit on the stability of aluminum electrode of Si solar cell", "venue": "", "year": 2013 }, { "abstract": "Conductive paste of the present invention contains at least a conductive powder, glass frit and an organic vehicle, said glass frit comprising Te, Ba, Bi, and further comprising selecting from Li, Na and K, at least one. The molar amount of Te in terms of TeO2 in terms of 55 85mol% containing a molar amount of Ba in terms of BaO is 0.1 35mol% Bi in terms of molar amount in terms of Bi2O3 0.1 25mol comprising an amount of at least one mole and selected from the Li, Na and K, in terms of oxides is 0.1 15mol% The conductive paste is formed using the light receiving surface electrode (3) Thereby achieving electrically conductive paste electrodes adapted to make contact resistance between the electrode (3) and the semiconductor substrate (1) a lower solar cell formed by using the electrically conductive paste to achieve high energy conversion efficiency, excellent battery characteristics of the solar cell.", "author_names": [ "" ], "corpus_id": 141159228, "doc_id": "141159228", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A conductive paste and a solar cell", "venue": "", "year": 2013 }, { "abstract": "The present invention relates to an electrode paste for solar cell, an electrode which is manufactured thereby and a solar cell comprising the same and more specifically, to an electrode paste for solar cell, an electrode which is manufactured thereby and a solar cell comprising the same which comprise: a conductive powder, a glass frit and an organic vehicle; wherein the glass frit comprises PbO, Bi2O3 and TeO2. The glass frit comprises: 5 55 weight% of Bi2O3, 10 40 weight% of TeO2 and residual quantity of PbO. [Reference numerals] (AA) Light", "author_names": [ "" ], "corpus_id": 141487518, "doc_id": "141487518", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Electrode paste for solar cell, electrode prepared from the same and solar cell comprising the same", "venue": "", "year": 2012 } ]

[ { "abstract": "Based on first principles density functional theory calculations, we systemically study the properties of two dimensional buckled single layer bismuth (b bismuthene) The structure, stability, and electronic properties are mainly discussed by PBE SOC method and the hybrid functional HSE06 method is used to further revise the band gap. The optimized b bismuthene is determined to be dynamically and thermally stable with an indirect band gap. In particular, there is a peculiar Rashba spin splitting emerging in the valence band maximum (VBM) states. Interestingly, the Rashba energy could be effectively modulated by in layer biaxial strain. By applying in layer biaxial strain, one can find that b bismuthene has indirect direct band gap and semiconductor semimetal transitions. Moreover, we also study the electronic structure of bilayer b bismuthene that is sensitively dependent on the interlayer distance. We demonstrate that the electric field (E field) leads to a breaking of the Rashba type splitting near the VBM of single b bismuthene. More importantly, there is a synergistic effect when both strain and electric field are applied at the same time. The E field induced band splitting character could be modified by the strain strength. Thus, this study indicates that b bismuthene may be a potential material in both electronic and spintronic devices.", "author_names": [ "Ming-yang Liu", "Yang Huang", "Qingyuan Chen", "Ze-yu Li", "Chao Cao", "Yao He" ], "corpus_id": 59446092, "doc_id": "59446092", "n_citations": 38, "n_key_citations": 1, "score": 0, "title": "Strain and electric field tunable electronic structure of buckled bismuthene", "venue": "", "year": 2017 }, { "abstract": "Soon after the synthesis of two dimensional (2D) ultrathin black phosphorus and fabrication of field effect transistors thereof, theoretical studies have predicted that other group VA elements (or pnictogens) N, As, Sb, and Bi can also form stable, single layer (SL) structures. These were nitrogene in a buckled honeycomb structure, arsenene, antimonene, and bismuthene in a buckled honeycomb, as well as washboard and square octagon structures with unusual mechanical, electronic, and optical properties. Subsequently, theoretical studies are followed by experimental efforts that aim at synthesizing these novel 2D materials. Currently, research on 2D pnictogens has been a rapidly growing field revealing exciting properties, which offers diverse applications in flexible electronics, spintronics, thermoelectrics, and sensors. This review presents an evaluation of the previous experimental and theoretical studies until 2019, in order to provide input for further research attempts in this field. To this end, we first reviewed 2D, SL structures of group VA elements predicted by theoretical studies with an emphasis placed on their dynamical and thermal stabilities, which are crucial for their use in a device. The mechanical, electronic, magnetic, and optical properties of the stable structures and their nanoribbons are analyzed by examining the effect of external factors, such as strain, electric field, and substrates. The effect of vacancy defects and functionalization by chemical doping through adatom adsorption on the fundamental properties of pnictogens has been a critical subject. Interlayer interactions in bilayer and multilayer structures, their stability, and tuning their physical properties by vertical stacking geometries are also discussed. Finally, our review is concluded by highlighting new research directions and future perspectives on the challenges in this emerging field.", "author_names": [ "Fatih Ersan", "D Kecik", "V Ongun Ozcelik", "Yelda Kadioglu", "Olcay Uzengi Akturk", "Engin Durgun", "Ethem Akturk", "Salim Ciraci" ], "corpus_id": 150288788, "doc_id": "150288788", "n_citations": 68, "n_key_citations": 0, "score": 1, "title": "Two dimensional pnictogens: A review of recent progresses and future research directions", "venue": "Applied Physics Reviews", "year": 2019 }, { "abstract": "The perfect switching between crystal phases with different electronic structure in III V nanowires allows for the design of superstructures with quantum wells only a single atomic layer wide. However, it has only been indirectly inferred how the electronic structure will vary down to the smallest possible crystal segments. We use low temperature scanning tunneling microscopy and spectroscopy to directly probe the electronic structure of Zinc blende (Zb) segments in Wurtzite (Wz) InAs nanowires with atomic scale precision. We find that the major features in the band structure change abruptly down to a single atomic layer level. Distinct Zb electronic structure signatures are observed on both the conduction and valence band sides for the smallest possible Zb segment: a single InAs bilayer. We find evidence of confined states in the region of both single and double bilayer Zb segments indicative of the formation of crystal segment quantum wells due to the smaller band gap of Zb as compared to Wz. In contrast to the internal electronic structure of the nanowire, surface states located in the band gap were found to be only weakly influenced by the presence of the smallest Zb segments. Our findings directly demonstrate the feasibility of crystal phase switching for the ultimate limit of atomistic band structure engineering of quantum confined structures. Further, it indicates that band gap values obtained for the bulk are reasonable to use even for the smallest crystal segments. However, we also find that the suppression of surface and interface states could be necessary in the use of this effect for engineering of future electronic devices.", "author_names": [ "Johan V Knutsson", "Sebastian Lehmann", "Martin Hjort", "Edvin Lundgren", "Kimberly A Dick", "Rainer Timm", "Anders Mikkelsen" ], "corpus_id": 206715541, "doc_id": "206715541", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Electronic Structure Changes Due to Crystal Phase Switching at the Atomic Scale Limit.", "venue": "ACS nano", "year": 2017 }, { "abstract": "The bilayer formation properties of single component acyl chains of varying length and extent of unsaturation are compared using Langmuir monolayer flow. Four series of structural motifs in the flowing film were considered: linked oleyl chains; chains with a single cis double bond over a range of total chain lengths; chains of the same length with 1 5 cis double bonds; molecules which flow that do not have the standard cis double bond in the chain. Slower flow rates were observed for Langmuir films with increased numbers of linked oleyl chains due to the enhanced interlayer coupling between the flowing and stationary films. Slower flow rates were also observed with increased acyl chain length due to the increased intralayer coupling between the flowing molecules. More rapid flow rates were observed as the number of double bonds within the film forming material was increased, due to both the decreased inter and intralayer coupling. While no single structural feature is common to molecules that undergo mo.", "author_names": [ "Adam B Steel", "++ and Brady J Cheek", "Cary James Miller" ], "corpus_id": 93513014, "doc_id": "93513014", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Langmuir Monolayer Flow across Hydrophobic Surfaces. 3. Influence of Acyl Chain Structure on Supported Bilayer Formation Rates", "venue": "", "year": 2001 }, { "abstract": "Neutron reflectivity has been used to study the structure of deposited phospholipid bilayers in the gel phase and the modifications induced by the presence of a 16 amino acid peptide, the third helix of the Antennapedia homeodomain, p Antp43 58. The phospholipids were dipalmitoyl phosphatidylcholine (DPPC) and mixtures of DPPC with 10% mol/mol of the negatively charged dipalmitoyl phosphatidylserine (DPPS) They were deposited on silicon single crystals by using the Langmuir Schaeffer technique. By pushing the resolution of neutron reflectivity measurements, the bilayer structure was determined at 1 A precision. The thickness of the thin water layer between the substrate and the phospholipids was found to be 5 1 A, that of the headgroups 9 1 A and that of the chains 36 1 A. The deposited bilayer had the same roughness, 5 1 A, as the substrate itself. After peptide insertion, the thickness and roughness of DPPC bilayers did not change while the peptide appeared uniformly distributed in the interfac.", "author_names": [ "Giovanna Fragneto", "Francois Graner", "Thierry Charitat", "++ and P Dubos", "E Bellet-Amalric" ], "corpus_id": 56308110, "doc_id": "56308110", "n_citations": 64, "n_key_citations": 3, "score": 0, "title": "Interaction of the Third Helix of Antennapedia Homeodomain with a Deposited Phospholipid Bilayer: A Neutron Reflectivity Structural Study", "venue": "", "year": 2000 }, { "abstract": "Virtually all structures in living cells are defined by lipid bilayers. Many molecular components can diffuse along these 2 dimensional structures, sampling all or part of the membrane, and this diffusion is central to their function. Supported lipid bilayers capture this membrane fluidity and have been used to study a wide range of membrane associated biomolecules.1 4 Recently, several techniques have been developed to microfabricate barriers on glass substrates to direct lipid bilayer selfassembly, facilitating the patterning of multiple, isolated membrane regions, or corrals, on a single substrate.5 12 The resultant corrals are typically of identical composition; however, a handful of strategies, including spatially directed photochemical transformations11 and membrane stamping,8,13 can be used to produce bilayer arrays with specific composition variations in different corrals. These composition arrays are desirable for investigating numerous biological systems, including how lipid and/or protein composition affects binding of membrane associated receptors with their ligands or each other, cellular processes such as intracellular protein modification and trafficking, and cell activation. In this communication, we introduce a robust approach that, for a wide variety of situations, greatly simplifies the production of large scale parallel bilayer arrays with defined variations in composition. The method, outlined in Figure 1, is based on exposing a prepatterned surface to a gradient of vesicles of various compositions created by flow and taking advantage of irreversible binding of vesicles to a substrate, subsequent fusion into a bilayer, and lipid mixing within each corralled region. For demonstration purposes, we fabricated a simple, millimeter scale, converging channel out of poly(dimethylsiloxane) (PDMS, Sylgard 184; Dow Corning) elastomer (Figure 1A) One wall of the channel consisted of a glass coverslip containing microcontact printed9,10,14 16 grid lines of fibronectin;17 however, any of a variety of materials can be used to create these barriers.5,8,10,12 The elastomer channel was filled with water, and then two solutions of vesicles were manually pumped through the channel as illustrated in Figure 1B. For visualization purposes, each solution contained vesicles supplemented with a small amount of a different fluorescently labeled lipid;18 conceptually, this technique is compatible with any biomolecule that can be incorporated into lipid bilayers by vesicle fusion. Downstream of the convergence, the two solutions partially mix by diffusion,19 exposing the micropatterned array to a controllable, spatially defined gradient of the two types of vesicles. The vesicles are irreversibly captured on the micropatterned coverslip, subsequently rupturing and fusing into a continuous supported lipid bilayer.3,4,21 The local composition of the bilayer reflects the distribution of vesicles exposed to the surface. Because the bilayer is a 2 dimensional fluid, any nonuniformity in membrane composition will be erased by lateral diffusion.10,11 The presence of barriers, however, limits this mixing to defined Address correspondence to this author. Phone: (650) 723 4482. Fax: (650) 723 4817. E mail: [email protected]. (1) Dori, Y. Bianco Peled, H. Satija, S. K. Fields, G. B. McCarthy, J. B. Tirrell, M. J. Biomed. Mater. Res. 2000, 50, 75 81. (2) Grakoui, A. Bromley, S. K. Sumen, C. Davis, M. M. Shaw, A. S. Allen, P. M. Dustin, M. L. Science 1999, 285, 221 7. (3) McConnell, H. M. Watts, T. H. Weis, R. M. Brian, A. A. Biochim. Biophys. Acta 1986, 864, 95 106. (4) Sackmann, E. Science 1996, 271, 43 8. (5) Cremer, P. S. Yang, T. L. J. Am. Chem. Soc. 1999, 121, 8130 1. (6) Groves, J. T. Ulman, N. Boxer, S. G. Science 1997, 275, 651 3. (7) Cremer, P. S. Groves, J. T. Kung, L. A. Boxer, S. G. Langmuir 1999, 15, 3893 6. (8) Hovis, J. S. Boxer, S. G. Langmuir 2000, 16, 894 7. (9) Kam, L. Boxer, S. G. J. Biomed. Mater. Res. Accepted for publication. (10) Kung, L. A. Kam, L. Hovis, J. S. Boxer, S. G. Langmuir 2000, 16, 6773 6. (11) Kung, L. A. Groves, J. T. Ulman, N. Boxer, S. G. AdV. Mater. 2000, 12, 731 4. (12) van Oudenaarden, A. Boxer, S. G. Science 1999, 285, 1046 8. (13) Hovis, J. S. Boxer, S. G. In preparation. (14) Kumar, A. Whitesides, G. M. Appl. Phys. Lett. 1993, 63, 4. (15) Bernard, A. Delamarche, E. Schmid, H. Michel, B. Bosshard, H. R. Biebuyck, H. Langmuir 1998, 14, 2225 9. (16) James, C. D. Davis, R. Meyer, M. Turner, A. Turner, S. Withers, G. Kam, L. Banker, G. Craighead, H. Isaacson, M. Turner, J. Shain, W. IEEE Trans. Biomed. Eng. 2000, 47, 17 21. (17) The use of proteins as barrier materials can confer additional biological activity to patterned lipid bilayer surfaces; we have used fibronectin barriers to promote adhesion of anchorage dependent cells onto lipid bilayer substrates, directing the interaction of these cells with the membrane patches.9 Here, fibronectin was labeled with Cascade Blue (Molecular Probes) to facilitate visualization of the micropatterned barriers. (18) Small unilamellar vesicles (SUVs) were prepared from dilauroylphosphatidylcholine (DLPC. Avanti) supplemented with either 1 mol of TexasRed DHPE (TR DHPE. Molecular Probes) 2 mol of NBD DHPE (Avanti) or 0.5 mol of DiD (Molecular Probes) Lipids were reconstituted in water (5 mg lipids/mL) then extruded10 through 50 nm pore membranes (Avanti) These stock solutions were diluted 1:3 (v/v) in aqueous buffer (pH 7.0) prior to use. Images of fluorescently labeled lipids and proteins were collected using appropriate filter sets, and are presented in false color as indicated in the figure legends. Figure 1. (A) Schematic illustration of the converging flow configuration used to produce limited mixing of two types of vesicles in solution. Two layers of poly(dimethylsiloxane) elastomer were cut using a template, oxidized in an air plasma, and layered to produce three walls of the converging channel (the channel downstream of the convergence measured 1 x 5 x 10 mm3) A glass coverslip patterned with an array of corrals17 comprised the fourth wall of the channel. (B) Schematic diagram illustrating controlled mixing and surface capture onto a substrate subjected to the flow shown in panel A. The local composition of a supported lipid bilayer formed by vesicle fusion reflects the makeup and spatial distribution of vesicles (denoted here as red and green dots) that are flowed past a pre patterned surface. This compositional profile is spatially averaged as the components within each corral diffuse and mix. 12901 J. Am. Chem. Soc. 2000, 122, 12901 12902", "author_names": [ "Lance Kam and", "Steven G Boxer" ], "corpus_id": 94075434, "doc_id": "94075434", "n_citations": 73, "n_key_citations": 1, "score": 0, "title": "Formation of Supported Lipid Bilayer Composition Arrays by Controlled Mixing and Surface Capture", "venue": "", "year": 2000 }, { "abstract": "In this paper, we focus on the synthesis and structure of the new bis(1,3,4 oxadiazole) system 2,5 bis[2 (4 tert butylphenyl) 1,3,4 oxadiazol 5 yl]pyridine (PDPyDP) We have fabricated light emitting diodes (LEDs) using poly[2 methoxy 5 (2 ethylhexoxy) 1,4 phenylene vinylene] (MEH PPV) as the emissive material, with and without a thermally evaporated electron injection/hole blocking layer of either PDPyDP or its vinylene analogue (E) 1,2 bis[2 (4 tert butylphenyl) 1,3,4 oxadiazol 5 yl]ethene (PDVDP) or its phenylene analogue 1,4 bis[2 (4 tert butylphenyl) 1,3,4 oxadiazol 5 yl]benzene (PDPDP) PDPDP is the para isomer of OXD 7, which is a widely used molecular electron transporting material. Electroluminescence spectra indicate that light is emitted only from the MEH PPV layer. Using aluminum as the cathode, the bilayer LED with PDPyDP is considerably more efficient than the corresponding single layer device or devices with PDVDP or PDPDP as the electron injection layer.", "author_names": [ "Changsheng Wang", "Gun Young Jung", "Yulin Hua", "Christopher Pearson", "Martin R Bryce", "Michael C Petty", "Andrei S Batsanov", "Andres E Goeta", "Judith A K Howard" ], "corpus_id": 94180561, "doc_id": "94180561", "n_citations": 121, "n_key_citations": 0, "score": 0, "title": "An Efficient Pyridine and Oxadiazole Containing Hole Blocking Material for Organic Light Emitting Diodes: Synthesis, Crystal Structure, and Device Performance", "venue": "", "year": 2001 }, { "abstract": "Combining infrared reflection adsorption spectroscopy and ab initio quantum chemical methods we study adsorption of water on the \"bilayer terminated\" surface of ice film grown on a Ru(001) substrate. The adsorption was performed at 38 K with gradual increase of the coverage from 0.14 to 0.42 ML. Only three observed infrared bands, which are associated with the free OH groups, could be used for analysis of the structure: the OH stretching bands at 3720, 3695, and 3665 cm 1. The calculated frequencies permit the assignment of these bands to the OH stretching vibrations of the single water molecules stabilized at the terminal OH groups (3720 cm 1) the terminal OH groups of the bilayer surface (3695 cm 1) and the terminal OH groups acting as a proton acceptor toward adsorbed water species (3665 cm 1) Our calculations show that at the submonolayer coverage of water the lateral H bonding interaction between the adsorbed molecules should lead to the aggregation of these molecules into small clusters. The str.", "author_names": [ "and Alexander Pelmenschikov", "Hirohito Ogasawara" ], "corpus_id": 94860625, "doc_id": "94860625", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Small Clusters of Water Adsorbed on the Bilayer Terminated Ice Surface: Infrared Reflection Adsorption Spectra and Quantum Chemical Calculations", "venue": "", "year": 2002 }, { "abstract": "Near field scanning optical microscopy (NSOM) and scanning force microscopy have been employed to spatially resolve the complex morphologies, spectroscopy, and charge transfer induced fluorescence quenching efficiencies of a (perylene phenethylimide)(titanyl phthalocyanine) bilayer (PPEI/TiOPc) The PPEI/TiOPc bilayer is a typical example of a n like/p like molecular semiconductor heterojunction, which is a common component in photocells, LEDs, and other devices. NSOM polarized fluorescence and transmission dataand separate bulk X ray diffraction and spectroscopic measurementson PPEI/TiOPc bilayers and PPEI and TiOPc single layers has lead to a nanoscopic and mesoscopic picture of how vacuum deposition and subsequent solvent vapor annealing controls the local structure of these films. The layers and bilayers are highly organized, containing localized crystalline regions which are preferentially oriented relative to the substrate and PPEI/TiOPc interface. In highly annealed bilayers, only a small fraction.", "author_names": [ "David Michael Adams", "Josef Kerimo", "Eric J Olson", "Arie Zaban", "and Brian A Gregg", "Paul F Barbara" ], "corpus_id": 96257106, "doc_id": "96257106", "n_citations": 39, "n_key_citations": 0, "score": 0, "title": "Spatially Resolving Nanoscopic Structure and Excitonic Charge Transfer Quenching in Molecular Semiconductor Heterojunctions", "venue": "", "year": 1997 }, { "abstract": "Single crystals of NaHP2 (sodium hydrogen dipalmitate) have been prepared from mixtures of NaP (sodium palmitate) and HP (palmitic acid) in ethanol. The phase compound crystallizes in the P21/a space group, with a 9.906 A, b 7.163 A, c 45.580 A, b 92.78deg, and 4 molecules per unit cell. The arrangement of the headgroups is unique among known soap and fatty acid structures by accommodating both hydrogen bonding and electrostatic interactions. Carboxylate and acid like pairs couple perpendicular to the bilayer to accommodate a \"short\" hydrogen bond, and the sodium is shared among laterally adjacent carboxylate anions to create a pseudo six member ring, which adds to the crystal stability. Molecular dynamic (MD) simulations establish a set of interaction parameters to describe the structure and energetics of acid carboxylate bonds, which accounts for the solid state miscibility of HP and NaP. Infrared data, collected by ATR FTIR on very pure, powdered NaH2P3, Na2H3P5, and NaHP2 acid soap standards rev.", "author_names": [ "Matthew Lawrence Lynch", "Fred C Wireko", "++SS and Mounir Tarek", "Michael L Klein" ], "corpus_id": 95562234, "doc_id": "95562234", "n_citations": 32, "n_key_citations": 0, "score": 0, "title": "Intermolecular Interactions and the Structure of Fatty Acid Soap Crystals", "venue": "", "year": 2001 } ]

[ { "abstract": "2.3. Evaluation of Photocatalytic Water Splitting 6507 2.3.1. Photocatalytic Activity 6507 2.3.2. Photocatalytic Stability 6507 3. UV Active Photocatalysts for Water Splitting 6507 3.1. d0 Metal Oxide Photocatalyts 6507 3.1.1. Ti Zr Based Oxides 6507 3.1.2. Nb Ta Based Oxides 6514 3.1.3. W Mo Based Oxides 6517 3.1.4. Other d0 Metal Oxides 6518 3.2. d10 Metal Oxide Photocatalyts 6518 3.3. f0 Metal Oxide Photocatalysts 6518 3.4. Nonoxide Photocatalysts 6518 4. Approaches to Modifying the Electronic Band Structure for Visible Light Harvesting 6519", "author_names": [ "Xiaobo Chen", "Shaohua Shen", "Liejin Guo", "Samuel S Mao" ], "corpus_id": 37077834, "doc_id": "37077834", "n_citations": 5534, "n_key_citations": 23, "score": 1, "title": "Semiconductor based photocatalytic hydrogen generation.", "venue": "Chemical reviews", "year": 2010 }, { "abstract": "Photocatalytic and photoelectrochemical water splitting under irradiation by sunlight has received much attention for production of renewable hydrogen from water on a large scale. Many challenges still remain in improving energy conversion efficiency, such as utilizing longer wavelength photons for hydrogen production, enhancing the reaction efficiency at any given wavelength, and increasing the lifetime of the semiconductor materials. This introductory review covers the fundamental aspects of photocatalytic and photoelectrochemical water splitting. Controlling the semiconducting properties of photocatalysts and photoelectrode materials is the primary concern in developing materials for solar water splitting, because they determine how much photoexcitation occurs in a semiconductor under solar illumination and how many photoexcited carriers reach the surface where water splitting takes place. Given a specific semiconductor material, surface modifications are important not only to activate the semiconductor for water splitting but also to facilitate charge separation and to upgrade the stability of the material under photoexcitation. In addition, reducing resistance loss and forming p n junction have a significant impact on the efficiency of photoelectrochemical water splitting. Correct evaluation of the photocatalytic and photoelectrochemical activity for water splitting is becoming more important in enabling an accurate comparison of a number of studies based on different systems. In the latter part, recent advances in the water splitting reaction under visible light will be presented with a focus on non oxide semiconductor materials to give an overview of the various problems and solutions.", "author_names": [ "Takashi Hisatomi", "Jun Kubota", "Kazunari Domen" ], "corpus_id": 11321291, "doc_id": "11321291", "n_citations": 2491, "n_key_citations": 14, "score": 0, "title": "Recent advances in semiconductors for photocatalytic and photoelectrochemical water splitting.", "venue": "Chemical Society reviews", "year": 2014 }, { "abstract": "Abstract Herein, ZnO/CdS hierarchical composite was prepared through a hydrothermal and chemical bath deposition (CBD) process. Its photocatalytic H2 production performance was tested. Mass ratio of CdS acted a pivotal part in light absorption and photocatalytic properties. Noticeably, promoted photocatalytic H2 production activity of 4134 mmol g 1 h 1 was achieved by the sample with optimal CdS content. Significantly, the photoluminescence (PL) detection of hydroxyl radicals, as well as the in situ XPS measurements was selected to verify the direct Z scheme charge migration mechanism. This mechanism endowed the composite with strong capability for hydrogen evolution and elucidated the improved photocatalytic performance. The improvement of photocatalytic activity was due to hierarchical structure, extended visible light response and direct Z scheme mechanism. This work will give an innovative vision in constructing direct Z scheme photocatalytic system with great photocatalytic H2 production activity.", "author_names": [ "Sheng Wang", "Bicheng Zhu", "Mingjin Liu", "Liu Yang Zhang", "Jiaguo Yu", "Minghua Zhou" ], "corpus_id": 106123991, "doc_id": "106123991", "n_citations": 353, "n_key_citations": 1, "score": 0, "title": "Direct Z scheme ZnO/CdS hierarchical photocatalyst for enhanced photocatalytic H2 production activity", "venue": "Applied Catalysis B: Environmental", "year": 2019 }, { "abstract": "Abstract The photocatalytic performance of BiVO4 is restricted via the fast recombination of photogenerated carriers and low visible light absorption. Fabricating of CuS/BiVO4 (0 4 0) binary heterogeneous photocatalysts by in suit growing of CuS on the surface of BiVO4 can enhance the absorption range of visible light and the separation of photogenerated carriers. Simultaneously, CuS/BiVO4 heterogeneous can provide large surface area and more active sites. The photocatalytic activity of CuS/BiVO4 composites for Ciprofloxacin (CIP) removal was examined under visible light irradiation. The optimal mass ratio of CuS to BiVO4 was determined to be 7% and the first order kinetic constant of CIP degradation over 7% CuS/BiVO4 (0.02151 min 1) was 2.59 and 16.54 times of pristine BiVO4 and CuS, respectively. The improved photodegradation efficiency is attributed to the effective separation of photogenerated carriers via formation of p n heterojunction. The high photostability of as prepared CuS/BiVO4 heterojunction photocatalysts was explored by four successive cycling experiments. The detailed mechanism for improved photocatalytic performance was discussed and the possible degradation pathway of CIP was measured by Liquid Chromatography Mass/Mass Spectrometry. The trapping experiments and electron spin resonance (ESR) spin trapping tests confirm that holes are main active species in photocatalytic degradation of CIP.", "author_names": [ "Cui Lai", "Mingming Zhang", "Bisheng Li", "Danlian Huang", "Guangming Zeng", "Lei Qin", "Xigui Liu", "Huan Yi", "Min Cheng", "Ling Li", "Zhang Chen", "Liang Chen" ], "corpus_id": 106394871, "doc_id": "106394871", "n_citations": 217, "n_key_citations": 0, "score": 0, "title": "Fabrication of CuS/BiVO4 (0 4 0) binary heterojunction photocatalysts with enhanced photocatalytic activity for Ciprofloxacin degradation and mechanism insight", "venue": "Chemical Engineering Journal", "year": 2019 }, { "abstract": "Abstract Water splitting for hydrogen production under light irradiation is an ideal system to provide renewable energy sources and to reduce global warming effects. Even though significant efforts have been devoted to fabricate advanced nanocomposite materials, the main challenge persists, which is lower efficiency and selectivity towards H2 evolution under solar energy. In this review, recent developments in photo catalysts, fabrication of novel heterojunction constructions and factors influencing the photocatalytic process for dynamic H2 production have been discussed. In the mainstream, recent developments in TiO2 and g C3N4 based photo catalysts and their potential for H2 production are extensively studied. The improvements have been classified as strategies to improve different factors of photocatalytic water splitting such as Z scheme systems and influence of operating parameters such as band gap, morphology, temperature, light intensity, oxygen vacancies, pH, and sacrificial reagents. Moreover, thermodynamics for selective photocatalytic H2 production are critically discussed. The advances in photo reactors and their role to provide more light distribution and surface area contact between catalyst and light were systematically described. By applying the optimum operating parameters and new engineering approach on photoreactor, the efficiency of semiconductor photocatalysts for H2 production can be enhanced. The future research and perspectives for photocatalytic water splitting were also suggested.", "author_names": [ "Nur Fajrina", "Muhammad Tahir" ], "corpus_id": 106296401, "doc_id": "106296401", "n_citations": 236, "n_key_citations": 0, "score": 0, "title": "A critical review in strategies to improve photocatalytic water splitting towards hydrogen production", "venue": "", "year": 2019 }, { "abstract": "In recent years, semiconductor photocatalytic process has shown a great potential as a low cost, environmental friendly and sustainable treatment technology to align with the \"zero\" waste scheme in the water/wastewater industry. The ability of this advanced oxidation technology has been widely demonstrated to remove persistent organic compounds and microorganisms in water. At present, the main technical barriers that impede its commercialisation remained on the post recovery of the catalyst particles after water treatment. This paper reviews the recent R&D progresses of engineered photocatalysts, photoreactor systems, and the process optimizations and modellings of the photooxidation processes for water treatment. A number of potential and commercial photocatalytic reactor configurations are discussed, in particular the photocatalytic membrane reactors. The effects of key photoreactor operation parameters and water quality on the photo process performances in terms of the mineralization and disinfection are assessed. For the first time, we describe how to utilize a multi variables optimization approach to determine the optimum operation parameters so as to enhance process performance and photooxidation efficiency. Both photomineralization and photo disinfection kinetics and their modellings associated with the photocatalytic water treatment process are detailed. A brief discussion on the life cycle assessment for retrofitting the photocatalytic technology as an alternative waste treatment process is presented. This paper will deliver a scientific and technical overview and useful information to scientists and engineers who work in this field.", "author_names": [ "Meng Nan Chong", "Bo Jin", "Christopher W K Chow", "Christopher P Saint" ], "corpus_id": 11490118, "doc_id": "11490118", "n_citations": 3562, "n_key_citations": 105, "score": 0, "title": "Recent developments in photocatalytic water treatment technology: a review.", "venue": "Water research", "year": 2010 }, { "abstract": "Abstract The development of efficient photocatalysts for the production of hydrogen peroxide (H2O2) is a promising strategy to realize solar to chemical energy conversion. Graphitic carbon nitride (g C3N4) presents giant potential for photocatalytic H2O2 production, but the sluggish charge separation depresses its photocatalytic performance. Herein, an interfacial Schottky junction composed of Ti3C2 nanosheets and porous g C3N4 nanosheets (TC/pCN) is constructed by a facile electrostatic self assembly route to significantly boost the spatial charge separation to promote the activation of molecular oxygen for H2O2 production. As the optimal sample, TC/pCN 2 possesses the highest H2O2 production rate (2.20 mmol L 1 min 1) under visible light irradiation (l 420 nm) which is about 2.1 times than that of the porous g C3N4. The results of superoxide radical detection and rotating disk electrode measurement suggest that the two step single electron reduction of oxygen is the predominant reaction step during this photocatalytic H2O2 production process. The enhanced photocatalytic performance is ascribed to the formation of Schottky junction and subsequent built in electric field at their interface, which accelerate the spatial charge separation and restrain the charge recombination. This work provides an in depth understanding of the mechanism of photocatalytic H2O2 production, and gives ideas for the design of highly active materials for photocatalytic H2O2 production.", "author_names": [ "Yongxiang Yang", "Zhuotong Zeng", "Guangming Zeng", "Danlian Huang", "Rong Xiao", "Chen Zhang", "Chengyun Zhou", "Weiping Xiong", "Wenjun Wang", "Min Cheng", "Wen-jing Xue", "Hai Guo", "Xiang Tang", "Donghui He" ], "corpus_id": 199080120, "doc_id": "199080120", "n_citations": 182, "n_key_citations": 0, "score": 0, "title": "Ti3C2 Mxene/porous g C3N4 interfacial Schottky junction for boosting spatial charge separation in photocatalytic H2O2 production", "venue": "", "year": 2019 }, { "abstract": "Semiconductor photocatalysis has received much attention as a potential solution to the worldwide energy shortage and for counteracting environmental degradation. This article reviews state of the art research activities in the field, focusing on the scientific and technological possibilities offered by photocatalytic materials. We begin with a survey of efforts to explore suitable materials and to optimize their energy band configurations for specific applications. We then examine the design and fabrication of advanced photocatalytic materials in the framework of nanotechnology. Many of the most recent advances in photocatalysis have been realized by selective control of the morphology of nanomaterials or by utilizing the collective properties of nano assembly systems. Finally, we discuss the current theoretical understanding of key aspects of photocatalytic materials. This review also highlights crucial issues that should be addressed in future research activities.", "author_names": [ "Hua Tong", "Shuxin Ouyang", "Yingpu Bi", "Naoto Umezawa", "Mitsutake Oshikiri", "Jinhua Ye" ], "corpus_id": 205242063, "doc_id": "205242063", "n_citations": 2502, "n_key_citations": 1, "score": 0, "title": "Nano photocatalytic materials: possibilities and challenges.", "venue": "Advanced materials", "year": 2012 }, { "abstract": "Abstract The construction of heterostructures is regarded as an excellent strategy to achieve efficient charge separation and improved photocatalytic activity. Herein, a series of Bi2MoO6/ZnO hierarchical heterostructured photocatalysts were synthesized by a solvothermal method. The morphology of Bi2MoO6 grown on the surface of ZnO nanorods could be controlled by adjusting the experimental conditions. The synthesized samples were characterized by various analytical techniques and their photocatalytic performance was evaluated by photocatalytic reduction of Cr(VI) under visible light irradiation. Compared with those of pure Bi2MoO6 and ZnO, the Bi2MoO6/ZnO composites showed higher photocatalytic activity towards the reduction of Cr(VI) The enhanced photocatalytic activity was mainly attributed to the formation of a heterojunction between Bi2MoO6 and ZnO, which effectively facilitated the separation and transfer of electrons and holes. In addition, the Bi2MoO6/ZnO photocatalysts maintained good stability after three cycles of Cr(VI) photoreduction. A possible photocatalytic mechanism of the as synthesized composites was proposed.", "author_names": [ "Guping Zhang", "Dongyun Chen", "Najun Li", "Qingfeng Xu", "Hua Li", "Jinghui He", "Jianmei Lu" ], "corpus_id": 108719897, "doc_id": "108719897", "n_citations": 142, "n_key_citations": 1, "score": 0, "title": "Fabrication of Bi2MoO6/ZnO hierarchical heterostructures with enhanced visible light photocatalytic activity", "venue": "Applied Catalysis B: Environmental", "year": 2019 }, { "abstract": "Ever increasing fossil fuel combustion along with massive CO2 emissions has aroused a global energy crisis and climate change. Photocatalytic CO2 reduction represents a promising strategy for clean, cost effective, and environmentally friendly conversion of CO2 into hydrocarbon fuels by utilizing solar energy. This strategy combines the reductive half reaction of CO2 conversion with an oxidative half reaction, e.g. H2 O oxidation, to create a carbon neutral cycle, presenting a viable solution to global energy and environmental problems. There are three pivotal processes in photocatalytic CO2 conversion: (i) solar light absorption, (ii) charge separation/migration, and (iii) catalytic CO2 reduction and H2 O oxidation. While significant progress is made in optimizing the first two processes, much less research is conducted toward enhancing the efficiency of the third step, which requires the presence of cocatalysts. In general, cocatalysts play four important roles: (i) boosting charge separation/transfer, (ii) improving the activity and selectivity of CO2 reduction, (iii) enhancing the stability of photocatalysts, and (iv) suppressing side or back reactions. Herein, for the first time, all the developed CO2 reduction cocatalysts for semiconductor based photocatalytic CO2 conversion are summarized, and their functions and mechanisms are discussed. Finally, perspectives in this emerging area are provided.", "author_names": [ "Jingrun Ran", "Mietek Jaroniec", "Shizhang Qiao" ], "corpus_id": 205283910, "doc_id": "205283910", "n_citations": 413, "n_key_citations": 0, "score": 0, "title": "Cocatalysts in Semiconductor based Photocatalytic CO2 Reduction: Achievements, Challenges, and Opportunities.", "venue": "Advanced materials", "year": 2018 } ]

[ { "abstract": "Photoconductive films of the lead salt family are composed of a system of crystallites separated by intercrystalline barriers. The crystallites are lead salts while the intercrystalline barriers are an oxide of lead or of the lead salt. Space charge regions are present at the surface of the crystallites. The lifetime of hole electron pairs is determined in part by surface states while the resistivity is strongly affected by intercrystalline barriers.", "author_names": [ "Richard L Petritz" ], "corpus_id": 123129653, "doc_id": "123129653", "n_citations": 583, "n_key_citations": 2, "score": 1, "title": "Theory of Photoconductivity in Semiconductor Films", "venue": "", "year": 1956 }, { "abstract": "Traditionally, strain effect was mainly considered in the materials with periodic lattice structure, and was thought to be very weak in amorphous semiconductors. Here, we investigate the effects of strain in films of cobalt doped amorphous carbon (Co C) grown on 0.7PbMg1/3Nb2/3O3 0.3PbTiO3 (PMN PT) substrates. The electric transport properties of the Co C films were effectively modulated by the piezoelectric substrates. Moreover, we observed, for the first time, strain induced photoconductivity in such an amorphous semiconductor. Without strain, no photoconductivity was observed. When subjected to strain, the Co C films exhibited significant photoconductivity under illumination by a 532 nm monochromatic light. A strain modified photoconductivity theory was developed to elucidate the possible mechanism of this remarkable phenomenon. The good agreement between the theoretical and experimental results indicates that strain induced photoconductivity may derive from modulation of the band structure via the strain effect.", "author_names": [ "Y C Jiang", "J Gao" ], "corpus_id": 16843345, "doc_id": "16843345", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Strain induced photoconductivity in thin films of Co doped amorphous carbon", "venue": "Scientific reports", "year": 2014 }, { "abstract": "Zn In Se thin films were fabricated on the ultrasonically cleaned glass substrates masked with clover shaped geometry by thermal evaporation of its elemental sources. Temperature dependent conductivity characteristics of the films were investigated under dark and illuminated conditions. The semiconductor type of the films was found as n type by thermal probe test. According to the van der Pauw technique, the dark electrical conductivity analyses showed that the variations of conductivity of unannealed and annealed at [Formula: see text]C samples are in exponential dependence of temperature. These conductivity profiles were found to be dominated by the thermionic emission at high temperature region whereas their behaviors at low temperatures were modeled by hopping theory. On the contrary, as a result of the further annealing temperatures, the surface of the samples showed semi metallic characteristics with deviating from expected Arrhenius behavior. In addition, the temperature dependent photoconductivity of the films was analyzed under different illumination intensities and the results were explained by the supra linear characteristic based on the two center recombination model.", "author_names": [ "Hasan Huseyin Gullu", "Mehmet Parlak" ], "corpus_id": 104374657, "doc_id": "104374657", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "INVESTIGATION OF CONDUCTIVITY CHARACTERISTICS OF Zn In Se THIN FILMS", "venue": "Surface Review and Letters", "year": 2019 }, { "abstract": "A method for improving the discrimination of semiconductor thin film gas sensors, which utilises the amplitude and phase of the photocurrent response to a modulated light source, is proposed. The photoconductivity of microcrystalline silicon films is examined before and after exposure to the vapour of an iodine solution in ethanol. Preliminary results are presented which suggest that the density and/or capture properties of localised states may be reversibly modified. For cadmium selenide however, a small but systematic temperature dependent phase lead is observed in this material at low frequencies, even under vacuum annealed conditions. This is in contrast to present theory, which predicts that for an arbitrary localised state distribution the photocurrent response must lag the applied excitation.", "author_names": [ "Steve Reynolds", "Zdravka I Aneva", "Z Levi", "Diana Nesheva", "Charlie Main", "Vladimir A Smirnov" ], "corpus_id": 99885600, "doc_id": "99885600", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Potential gas sensor applications of semiconductor thin films based on changes in photoresponse", "venue": "", "year": 2007 }, { "abstract": "Abstract This article addresses band edge electronic structure of transition metal/rare earth (TM/RE) non crystalline and nano crystalline elemental and complex oxide high k dielectrics for advanced semiconductor devices. Experimental approaches include X ray absorption spectroscopy (XAS) from TM, RE and oxygen core states, photoconductivity (PC) and visible/vacuum ultra violet (UV) spectroscopic ellipsometry (SE) combined with ab initio theory is applied to small clusters. These measurements are complemented by Fourier transform infra red absorption (FTIR) X ray photoelectron spectroscopy (XPS) high resolution transmission electron microscopy (HRTEM) and X ray diffraction (XRD) Two issues are highlighted: Jahn Teller term splittings that remove d state degeneracies of states at the bottom of the conduction band, and chemical phase separation and crystallinity in Zr and Hf silicates and ternary (Zr(Hf)O2)x(Si3N4)y(SiO2)1 x y alloys. Engineering solutions for optimization of both classes of high k dielectric films, including limits imposed on the continued and ultimate scaling of the equivalent oxide thickness (EOT) are addressed.", "author_names": [ "Gerald Lucovsky" ], "corpus_id": 96588453, "doc_id": "96588453", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Band edge electronic structure of transition metal/rare earth oxide dielectrics", "venue": "", "year": 2006 }, { "abstract": "In a recent paper the photoconductivity of lead sulphide films was discussed in terms of a barrier mechanism Large single crystals of lead telluride have now been grown and, with these, single barrier photocells can be prepared The simplest barrier is formed at a metal semiconductor contact. Such barriers, as exhibited in rectifiers, have been mainly studied It is found that the photosensitivity and time constant of such cells is determined by the total current at the contact point, as expected from barrier theory. The variation in barrier height with temperature and time has also been determined", "author_names": [ "Alan Frank Gibson" ], "corpus_id": 95638618, "doc_id": "95638618", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Single Contact Lead Telluride Photocells", "venue": "", "year": 1952 }, { "abstract": "The optical properties of natural and synthetic melanin have been characterized for a number of laser wavelengths in the visible region. Natural melanin was prepared from hydrolyzed melanosomes isolated from normal, bovine retinal pigment epithelium. The inverse adding doubling method based on the diffusion approximation and radiative transport theory was employed to determine the absorption, scattering, and scattering anisotropy coefficients of melanin from the measurements of diffuse transmission, diffuse reflection and collimated transmission using double integrating spheres. The results obtained by the use of the inverse adding doubling method were compared to the Monte Carlo simulation technique. Characterization of melanin is now being extended to include electrical photoconductivity of melanin thin films on a semiconductor substrate.", "author_names": [ "Randolph D Glickman", "Dhiraj K Sardar", "Felipe S Salinas", "M C Hobbs" ], "corpus_id": 62227455, "doc_id": "62227455", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Optical and electrical characterization of natural and synthetic melanin", "venue": "Proceedings of the Second Joint 24th Annual Conference and the Annual Fall Meeting of the Biomedical Engineering Society] [Engineering in Medicine and Biology", "year": 2002 }, { "abstract": "The optical properties of natural and synthetic melanin have been characterized for anumber of laser wavelengths in the visible region. Natural melanin was prepared from hydrolyzed melanosomes isolated from normal, bovine retinal pigment epithelium. The inverse adding doubling method based on the diffusion approximation and radiative transport theory was employed to determine the absorption, scattering, and scattering anisotropy coefficients of melanin from the measurements of diffuse transmission, diffuse reflection and collimated transmission using double integrating spheres. The results obtained by the use of the inverse adding doubling method were compared to the Monte Carlo simulation technique. Characterization of melanin is now being extended to include electrical photoconductivity of melanin thin films on a semiconductor substrate. Keywords Lasers, Melanin, Optical Properties, Radiative Transport, Electrical, Photoconductivity", "author_names": [ "Universityof Texas" ], "corpus_id": 138036053, "doc_id": "138036053", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "OPTICAL AND ELECTRICAL CHARACTERIZATION OF NATURAL AND SYNTHETIC MELANIN", "venue": "", "year": 2002 }, { "abstract": "Amorphous carbon films with an intermediate content of sp3 atoms are finding applications as resistive switches in devices for bio sensing and for neuromorphic pattern recognition. To understand resistive switching and photoconductivity in amorphous semiconductors dominated by hopping conduction, we present a theory that unifies the optical and electronic properties. The theory considers all of the states to be localized to various extents instead of being extended electronic states. The electronic density of states (eDOS) is modeled with Gaussian functions, symmetric in energy around the Fermi energy. A \"hopping mobility\" between localized states that is explicitly both energy and temperature dependent is introduced. We describe an example application to amorphous carbon films prepared by using high power impulse magnetron sputtering that have a range of sp3 hybridization fractions of the carbon atoms. The electronic bandgaps of the films are observed to correlate with their optical bandgaps. The eDOS is benchmarked against optical property measurements made by ellipsometry. The theory explains the temperature dependence of the resistivity and predicts that the films should show a temperature dependent hopping photoconductivity. Measurements confirm the presence of the photoconductivity and reveal its spectral dependence. A link is made between persistent hopping photoconductivity and resistive switching.", "author_names": [ "Zijun C Zhao", "Thomas J Raeber", "Billy James Murdoch", "Jim G Partridge", "Dougal G McCulloch", "David R Mckenzie" ], "corpus_id": 229414555, "doc_id": "229414555", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Unifying the optical and electrical properties of amorphous carbon: application to hopping photoconductivity and memristance", "venue": "", "year": 2020 }, { "abstract": "The composition of amorphous oxide semiconductors, which are well known for their optical transparency, can be tailored to enhance their absorption and induce photoconductivity for irradiation with green, and shorter wavelength light. In principle, amorphous oxide semiconductor based thin film photoconductors could hence be applied as photosensors. However, their photoconductivity persists for hours after illumination has been removed, which severely degrades the response time and the frame rate of oxide based sensor arrays. We have solved the problem of persistent photoconductivity (PPC) by developing a gated amorphous oxide semiconductor photo thin film transistor (photo TFT) that can provide direct control over the position of the Fermi level in the active layer. Applying a short duration (10 ns) voltage pulse to these devices induces electron accumulation and accelerates their recombination with ionized oxygen vacancy sites, which are thought to cause PPC. We have integrated these photo TFTs in a transparent active matrix photosensor array that can be operated at high frame rates and that has potential applications in contact free interactive displays.", "author_names": [ "Sanghun Jeon", "Seung-Eon Ahn", "I-hun Song", "Chang Jung Kim", "U-In Chung", "Eunha Lee", "In-kyeong Yoo", "Arokia Nathan", "Sungsik Lee", "John Robertson", "Kinam Kim" ], "corpus_id": 5088593, "doc_id": "5088593", "n_citations": 312, "n_key_citations": 3, "score": 0, "title": "Gated three terminal device architecture to eliminate persistent photoconductivity in oxide semiconductor photosensor arrays.", "venue": "Nature materials", "year": 2012 } ]

[ { "abstract": "Atomically thin group VIB transition metal dichalcogenides (TMDs) have recently emerged as a new class of two dimensional (2D) semiconductors with extraordinary properties including the direct band gap in the visible frequency range, the pronounced spin orbit coupling, the ultra strong Coulomb interaction, and the rich physics associated with the valley degree of freedom. These 2D TMDs exhibit great potential for device applications and have attracted vast interest for the exploration of new physics. 2D TMDs have complex electronic structures which underlie their physical properties. Here we review the bulk electronic structures of these new 2D materials as well as the theoretical models developed at different levels, along which we sort out the understanding of the origins of a variety of properties observed or predicted.", "author_names": [ "Gui-Bin Liu", "Di Xiao", "Yugui Yao", "Xiaodong Xu", "Wang Yao" ], "corpus_id": 36481319, "doc_id": "36481319", "n_citations": 346, "n_key_citations": 3, "score": 1, "title": "Electronic structures and theoretical modelling of two dimensional group VIB transition metal dichalcogenides.", "venue": "Chemical Society reviews", "year": 2015 }, { "abstract": "", "author_names": [ "Gui-Bin Liu", "Di Xiao", "Yugui Yao", "Xiaodong Xu", "Wang Yao" ], "corpus_id": 197137971, "doc_id": "197137971", "n_citations": 32, "n_key_citations": 2, "score": 0, "title": "Electronic Structures and Theoretical Modelling of Two Dimensional Group VIB Transition Metal Dichalcogenides", "venue": "", "year": 2015 }, { "abstract": "The electronic properties of phosphorus delta doped structures in silicon, and germanium, are studied using a variety of theoretical approaches. The importance of such phosphorus systems cannot be understated. They can be structurally confined in one, two", "author_names": [ "J A C Smith" ], "corpus_id": 99855809, "doc_id": "99855809", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Modelling the electronic properties of zero one and two dimensional phosphorus systems in semiconductors", "venue": "", "year": 2016 }, { "abstract": "Abstract Charged impurities influence functional properties of two dimensional materials and a detailed theoretical understanding of charged defects is required to enable a rational design of defect engineered nanomaterials for applications in ultrathin devices. To achieve this goal, we have developed multiscale approaches that combine atomistic first principles theories, such as density functional theory, with coarse grained continuum models, such as effective mass models. This allows us to model large supercells which are required to accurately describe the slow decay of the screened defect potential and the defect induced changes in the electronic properties of the two dimensional host material. I will describe the results of our multiscale calculations for charged defects in doped graphene and in transition metal dichalcogenide monolayers which have revealed novel mechanisms for controlling and tuning the electronic structure of two dimensional materials.", "author_names": [ "Johannes Lischner" ], "corpus_id": 140047963, "doc_id": "140047963", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Multiscale modelling of charged impurities in two dimensional materials", "venue": "Computational Materials Science", "year": 2019 }, { "abstract": "Thiophene/benzene fused p conjugated systems are normally employed as the core units of two and three dimensionally expanded small molecule hole transporting materials (HTMs) to improve their electronic and charge transport properties, whereas comparison studies between two dimensional and three dimensional core conformations are less reported. To further find useful clues for the design of highly efficient small molecule HTMs and to find new core units, in this work, four HTM molecules are designed by employing triphenylene, benzotrithiophene, triptycene, and thiophenetriptycene as the core units, and simulated with density functional theory combined with the Marcus hopping model. Our results show that all the considered HTMs display appropriate molecular energy levels, less optical absorption in the visible light region and large Stokes shifts, and high hole mobilities (9.80 x 10 2 cm2 V 1 s 1) Compared with the two dimensional core structures, the three dimensional cores exhibit evident superiorities with the same chemical components. Meanwhile, we also find that the quasi degenerate HOMO energy levels will be helpful to enlarge the transfer integrals between adjacent molecules, and further to promote the hole transport in HTMs. By considering the various elements simultaneously, these investigated HTMs (S 1 S 4) with thiophene and benzene fused cores can be expected as potential promising candidates to help create more efficient solar cells.", "author_names": [ "Zhu-Zhu Sun", "Shuai Feng", "Chuantao Gu", "Nian Cheng", "Jiangfeng Liu" ], "corpus_id": 195758723, "doc_id": "195758723", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Probing effects of molecular conformation on the electronic and charge transport properties in two and three dimensional small molecule hole transporting materials: a theoretical investigation.", "venue": "Physical chemistry chemical physics PCCP", "year": 2019 }, { "abstract": "Combining the bond order length strength (BOLS) and atomic bonding and electronic model (BB model) with density functional theory (DFT) calculations, we studied the atomic bonding and electronic binding energy behavior of Bi atoms adsorbed on the Li(110) surface. We found that the Bi atoms adsorbed on the Li(110) surface form two dimensional (2D) geometric structures, including letter hexagon galaxy crown field and cobweb shaped structures. Thus, we obtained the following quantitative information: (i) the field shaped structure can be considered the bulk structure; (ii) the field shaped structure of Bi atom formation has a 5d energy level of 22.727 eV, and in the letter shape structure, this energy is shifted to values greater than 0.342 eV; and (iii) the Bi/Li(110) heterojunction transfers charge from the inner Li atomic layer to the outermost Bi atomic layer. In addition, we analyzed the bonding and electronic dynamics involved in the formation of the Bi/Li(110) heterojunctions using residual density of states. This work provides a theoretical reference for the fine tuning of binding energies and chemical bonding at the interfaces of 2D metallic materials.", "author_names": [ "Maolin Bo", "Liangjin Ge", "Jibiao Li", "Lei Li", "Chuang Yao", "Zhongkai Huang" ], "corpus_id": 231856777, "doc_id": "231856777", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Atomic Bonding and Electronic Binding Energy of Two Dimensional Bi/Li(110) Heterojunctions via BOLS BB Model", "venue": "ACS omega", "year": 2021 }, { "abstract": "This review provides a perspective on recent developments and their implications for our understanding of novel quantum phenomena in the physics of two dimensional organic solids. We concentrate on the phase transitions and collective response in the charge sector, the importance of coupling of electronic and lattice degrees of freedom and stress an intriguing role of disorder. After a brief introduction to low dimensional organic solids and their crystallographic structures, we focus on the dimensionality and interactions and emergent quantum phenomena. Important topics of current research in organic matter with sizeable electronic correlations are Mott metal insulator phase transitions, charge order and ferroelectricity. Highly frustrated two dimensional systems are established model compounds for studying the quantum spin liquid state and the competition with magnetic long range order. There are also unique examples of quantum disordered state of magnetic and electric dipoles. Representative experimental results are complemented by current theoretical approaches.", "author_names": [ "Martin Dressel", "Silvia Tomi'c" ], "corpus_id": 226975825, "doc_id": "226975825", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Molecular quantum materials: electronic phases and charge dynamics in two dimensional organic solids", "venue": "", "year": 2020 }, { "abstract": "Two dimensional (2D) palladium diselenide (PdSe2 has strong interlayer coupling and a puckered pentagonal structure, leading to remarkable layer dependent electronic structures and highly anisotropic in plane optical and electronic properties. However, the lack of high quality, 2D PdSe2 crystals grown by bottom up approaches limits the study of their exotic properties and practical applications. In this work, chemical vapor deposition growth of highly crystalline few layer =2 layers) PdSe2 crystals on various substrates is reported. The high quality of the PdSe2 crystals is confirmed by low frequency Raman spectroscopy, scanning transmission electron microscopy, and electrical characterization. In addition, strong in plane optical anisotropy is demonstrated via polarized Raman spectroscopy and second harmonic generation maps of the PdSe2 flakes. A theoretical model based on kinetic Wulff construction theory and density functional theory calculations is developed and described the observed evolution of \"square like\" shaped PdSe2 crystals into rhombus due to the higher nucleation barriers for stable attachment on the (1,1) and (1, 1) edges, which results in their slower growth rates. Few layer PdSe2 field effect transistors reveal tunable ambipolar charge carrier conduction with an electron mobility up to 294 cm2 V 1 s 1 which is comparable to that of exfoliated PdSe2 indicating the promise of this anisotropic 2D material for electronics.", "author_names": [ "Yiyi Gu", "Hui Cai", "Jichen Dong", "Yiling Yu", "Anna N Hoffman", "Chenze Liu", "Akinola D Oyedele", "Yu-Chuan Lin", "Zhuozhi Ge", "Alexander A Puretzky", "Gerd Duscher", "Matthew F Chisholm", "Philip D Rack", "Christopher M Rouleau", "Zheng Gai", "Xiangmin Meng", "Feng Ding", "David B Geohegan", "Kai Xiao" ], "corpus_id": 220519224, "doc_id": "220519224", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Two Dimensional Palladium Diselenide with Strong In Plane Optical Anisotropy and High Mobility Grown by Chemical Vapor Deposition.", "venue": "Advanced materials", "year": 2020 }, { "abstract": "Gold nanomaterials, including one dimensional (1D) gold nanorods (AuNRs) and nanowires (AuNWs) and two dimensional (2D) gold nanoprisms with a large surface area and stability, have attracted widespread research interest. A large number of experimental and theoretical studies have shown that the properties of low dimensional gold nanomaterials depend on their anisotropic shape. In this work, we theoretically conceived a new type of gold nanomaterial, namely, thiolate (SR) monolayer passivated quasi 1D and quasi 2D gold nanocrystals and infinite superstructures, which were formed by the fusion of seed clusters Au28(SR)20, Au36(SR)24, Au44(SR)28 and Au52(SR)32 or the layer by layer growth of gold atoms along the [100] and/or [010] directions. By means of DFT and TD DFT calculations, the structure and properties of these model gold nanocrystals and superstructures are studied in depth. It is found that the passivation of the monolayer of thiolate leads to significantly improved near infrared absorption properties in comparison with the ligand free gold nanocrystals. Upon passivating the thiolate monolayer, the ultrathin 1D gold nanowire and 2D gold nanosheet demonstrate a metal to semiconductor transition. The novel electronic structures, optical absorption and semiconductor to metal transition found in these thiolate protected low dimensional gold nanocrystals suggest that the passivation of the SR ligand is a promising way to tailor the properties of gold nanomaterials.", "author_names": [ "Liang Yang", "Pu Wang", "Zhenhua Yang", "Yong Pei" ], "corpus_id": 211261064, "doc_id": "211261064", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Effect of thiolate ligand passivation on the electronic structure and optical absorption properties of ultrathin one and two dimensional gold nanocrystals.", "venue": "Nanoscale", "year": 2020 }, { "abstract": "Abstract The third order nonlinear optical response of protein molecules to a sequence of infrared (IR) pulses reflects abundant information on the conformational dynamics of these macromolecules. In this chapter, we review the theoretical methods for simulating the protein two dimensional infrared spectroscopy based on molecular dynamic simulations. The chapter starts by constructing the effective fluctuating Frenkel exciton (FE) Hamiltonian based on the classical molecular dynamics simulation and density functional theory electrostatic map. The parameters required are generated from the electronic structure calculations. As a generalization of this Stark model, vibrational solvatochromism is further discussed. Nonlinear response function calculation protocols, such as the sum over states model, cumulant expansion of Gaussian fluctuation, and numerical propagation equations such as the stochastic Liouville equation and numerical integration of the Schrodinger equation are then described in detail. We also demonstrate that the simulation result can be improved by introducing the statistical mechanics techniques such as the integrated tempering sampling method and the Markov state models, which achieve a more comprehensive sampling of the thermodynamics and kinetics.", "author_names": [ "Zhijun Pan", "Wei Zhuang" ], "corpus_id": 219873759, "doc_id": "219873759", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Theoretical simulation of protein two dimensional infrared spectroscopy", "venue": "", "year": 2020 } ]

[ { "abstract": "Investigates the patterns of technological evolution and their impact on environmental conditions. Seven hypotheses are offered in order to demonstrate that technology is a central force in shaping the environments within which organizations operate. These hypotheses are: (1) technological change within a product class will be characterized by long periods of incremental change punctuated by discontinuities; (1a) technological discontinuities are either competence enhancing (build on existing skills and know how) or competence destroying (require fundamentally new skills and competences) (2) the locus of innovation will differ for competence destroying and competence enhancing technological changes. Competence destroying discontinuities will be initiated by new entrants, while competence enhancing discontinuities will be initiated by existing firms; (3) competitive uncertainty will be higher after a technological discontinuity than before discontinuity; (4) environmental munificence (i.e. resource availability and support for growth) will be higher after a technological discontinuity than before the discontinuity; (5) competence enhancing discontinuities will be associated with decreased entry to exit ratios and decreased interfirm sales variability (thus strengthening product leaders and increasing barriers to entry) These patterns will be reversed for competence destroying discontinuities; (6) successive competence enhancing discontinuities will be associated with smaller increases in uncertainty and munificence; and (7) those organizations that initiate major technological innovations will have higher growth rates than other firms in the product class. Data were collected from U.S. firms in three product classes, domestic scheduled passenger airline transport, Portland cement manufacture, and minicomputer manufacture, from the year of the niche market's inception through 1980. Results indicate that after the three niche openings, there were six competence enhancing technological discontinuities and two competence destroying discontinuities in total. Each of these discontinuities had a far greater impact on a key measure of cost or performance than more incremental technological events. In addition, except for the period following the introduction of semiconductor memory in minicomputers, the ability of experienced industry observers to predict demand following technological disruptions was far worse than prior to the disruption. Demand growth following the discontinuity was significantly higher than it was immediately prior to the discontinuity, which had an enormous impact on product class demand. Also, the ratio of entries to exits was higher in each of the five years before a competence enhancing discontinuity than during the five subsequent years, though none of the differences is statistically significant. Though market variability in sales growth was expected, it was found that some firms' sales grew explosively while other firms experienced sales declines. It is also suggested that as technology matures, successive competence enhancing discontinuities increase both uncertainty and munificence, but not as much as those discontinuities that preceded them in establishing the product class. Finally, early adopters of technology were found to experience more growth than other firms. Using three different product types, with a wide range of years from inception, it is shown that technology does evolve through long periods of incremental change punctuated by relatively rare innovations that radically improve the state of the art. Although these incidences of change are rare, they stand out clearly and have significantly altered competitive environments. (SFL)", "author_names": [ "Michael L Tushman", "Philip Anderson" ], "corpus_id": 15075668, "doc_id": "15075668", "n_citations": 5728, "n_key_citations": 288, "score": 1, "title": "Technological Discontinuities and Organizational Environments", "venue": "", "year": 1986 }, { "abstract": "Economists and organization theorists have asked which factors are linked to the rate at which firms exit an industry. Yet little research has linked exit rates to changes over time in the key dimensions which characterize an industry's environment. This study examines linkages between exit rates and changing levels of uncertainty, munificence and complexity in an industry. A longitudinal study of the American cement (1888 1980) and minicomputer (1958 82) industries reveals that uncertainty is the key environmental dimension associated with organizational mortality. Controlling for ecological and macroeconomic conditions, exit rates are associated with uncertainty, but not complexity or munificence. The greater the uncertainty, the higher the exit rates. Two kinds of uncertainty create hazardous environmental conditions: unpredictable changes in demand and eras of ferment bounded by technological discontinuities and dominant designs. Our results indicate that while organizations can deal with different levels of economic munificence and complexity, uncertainty is a significantly more lethal characteristic of organizational environments. The results support Schumpeterian perspectives linking industry turnover to \"waves of creative destruction\" but suggest more broadly that an organization's ability to cope with uncertainty is a key determinant of its life chances. Copyright 2001 by Oxford University Press.", "author_names": [ "Philip Anderson", "Michael L Tushman" ], "corpus_id": 154051384, "doc_id": "154051384", "n_citations": 245, "n_key_citations": 13, "score": 0, "title": "Organizational Environments and Industry Exit: the Effects of Uncertainty, Munificence and Complexity", "venue": "", "year": 2001 }, { "abstract": "The word \"virtual\" describes work that spans one or more discontinuities. The term has been applied to work where people are in discontinuous physical work locations, where work is done in discontinuous time frames, where people have discontinuous organizational affiliations (Watson Manheim, Crowston Chudoba (2002)", "author_names": [ "Jennifer Coady", "Larry Stapleton", "Brian Foley" ], "corpus_id": 53450402, "doc_id": "53450402", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "'Teamwork' A Combined Methodological and Technological Solution for E Working Environments", "venue": "", "year": 2002 }, { "abstract": "Contents: Acknowledgements Introduction Michael J. Leiblein and Arvids A. Ziedonis PART I TYPES OF INNOVATION 1. Michael L. Tushman and Philip Anderson (1986) 'Technological Discontinuities and Organizational Environments' 2. Rebecca M. Henderson and Kim B. Clark (1990) 'Architectural Innovation: The Reconfiguration of Existing Product Technologies and the Failure of Established Firms' 3. Clayton M. Christensen and Joseph L. Bower (1996) 'Customer Power, Strategic Investment, and the Failure of Leading Firms' PART II CAPTURING VALUE FROM INNOVATION 4. David J. Teece (1986) 'Profiting from Technological Innovation: Implications for Integration, Collaboration, Licensing, and Public Policy' 5. Richard C. Levin, Alvin K. Klevorick, Richard R. Nelson and Sidney G. Winter (1987) 'Appropriating the Returns from Industrial Research and Development' 6. Sidney G. Winter (2000) 'Appropriating the Gains from Innovation' 7. Joshua S. Gans and Scott Stern (2003) 'The Product Market and the Market for IdeasA\" Commercialization Strategies for Technology Entrepreneurs' 8. Ashish Arora and Marco Ceccagnoli (2006) 'Patent Protection, Complementary Assets, and Firms' Incentives for Technology Licensing' 9. Mary Tripsas (1997) 'Unraveling the Process of Creative Destruction: Complementary Assets and Incumbent Survival in the Typesetter Industry' PART III DELIVERING INNOVATIVE VALUE THROUGH RESOURCE ALLOCATION AND ORGANIZATION ACTIVITY 10. Wesley M. Cohen and Daniel A. Levinthal (1990) 'Absorptive Capacity: A New Perspective on Learning and Innovation' 11. Lee Fleming and Olav Sorenson (2004) 'Science as a Map in Technological Search' 12. Jack A. Nickerson and Todd R. Zenger (2004) 'A Knowledge based Theory of the Firm The Problem Solving Perspective' 13. Iain M. Cockburn, Rebecca M. Henderson and Scott Stern (2000) 'Untangling the Origins of Competitive Advantage' PART IV DELIVERING INNOVATIVE VALUE THROUGH INTER ORGANIZATIONAL DRIVERS 14. Gary P. Pisano (1990) 'The R&D Boundaries of the Firm: An Empirical Analysis' 15. Walter W. Powell, Kenneth W. Koput and Laurel Smith Doerr (1996) 'Interorganizational Collaboration and the Locus of Innovation: Networks of Learning in Biotechnology' 16. David C. Mowery, Joanne E. Oxley and Brian S. Silverman (1996) 'Strategic Alliances and Interfirm Knowledge Transfer' 17. Michael J. Leiblein, Jeffrey J. Reuer and Frederic Dalsace (2002) 'Do Make or Buy Decisions Matter? The Influence of Organizational Governance on Technological Performance' 18. Joanne E. Oxley and Rachelle C. Sampson (2004) 'The Scope and Governance of International R&D Alliances' 19. Gautam Ahuja and Riitta Katilla (2001) 'Technological Acquisitions and the Innovation Performance of Acquiring Firms: A Longitudinal Study' PART V REAL OPTIONS 20. Rita Gunther McGrath (1997) 'A Real Options Logic for Initiating Technology Positioning Investments' 21. Bruce Kogut and Nalin Kulatilaka (2001) 'Capabilities as Real Options' 22. Timothy B. Folta and Jonathan P. O'Brien (2004) 'Entry in the Presence of Dueling Options' 23. Michael J. Leiblein and Arvids A. Ziedonis (2007) 'Deferral and Growth Options Under Sequential Innovation' 24. Arvids A. Ziedonis (2007) 'Real Options in Technology Licensing' 25. Ron Adner and Daniel A. Levinthal (2004) 'What Is Not A Real Option: Considering Boundaries for the Application of Real Options to Business Strategy'", "author_names": [ "Michael J Leiblein", "Arvids A Ziedonis" ], "corpus_id": 107881531, "doc_id": "107881531", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Technology strategy and innovation management", "venue": "", "year": 2011 }, { "abstract": "The business world is shifting from formal, defined roles. Major business discontinuities such as deregulation, globalization, technological convergence, and the rapid evolution of the Internet have blurred the roles that companies play in their dealings with other businesses. The distinguishing feature of the new marketplace is that consumers become a new source of competence for the corporation. This competence can be seen in industries such as software, which have moved from testing products in usability laboratories, to testing them in customer environments. To effectively harness the competence of the consumer, managers must: engage their customers in an active, explicit, and ongoing dialogue; mobilize communities of customers; manage customer diversity; and cocreate personalized experiences with customers. The real challenge for senior managers will be to provide a stable center while embracing change. The only way to do this is to develop a strong set of organizational values. Readying the organization for customer competence in the new economy will require a major overhaul of the traditional governance systems and organizational structures of the company. The biggest challenge for companies will be to develop the infrastructures needed to support a multichannel distribution network. AN: 2628909 ISSN: 0017 8012 Full Text Word Count: 6022 Database: Health Business FullTEXT CO OPTING CUSTOMER COMPETENCE In the new economy, companies must incorporate customer experience into their business models in ways hitherto untapped. Here are the challenges in doing that. BUSINESS COMPETITION used to be a lot like traditional theater: On stage, the actors had r clearly defined roles, and the customers paid for their tickets, sat back, and watched passively. In business, companies, distributors, and suppliers understood and adhered to their well defined roles in a corporate relationship. Now the scene has changed, and business competition seems more like the experimental theater of the 1960s and 1970s; everyone and anyone can be part of the action. The shift away from formal, defined roles is already occurring in business to business relationships. Major business discontinuities such as deregulation, globalization, technological convergence, and the rapid evolution of the Internet have blurred the roles that companies play in their dealings with other businesses. Consider the relationship between Ford and its main suppliers. Far from being passive providers of materials and parts, Ford's suppliers have become close collaborators in the development of new vehicles. At the same time, however, they compete for value by negotiating the prices for the parts and the materials they supply. Some suppliers are starting to compete directly. For example, Markham, Ontario based auto parts giant Magna International has the ambition and the potentialto assemble automobiles itself. The story's the same for distributors. For example, Wal Mart does more than just distribute Procter Gamble's goods. It shares daily sales information and works with P&G in product warehousing and replenishment to ensure that consumers can always find the goods they want at low prices. In some product categories, however, Wal Mart competes head to head with P&G. For instance, Wal Mart last year rolled out its own brand of detergent, Sam's American Choice, which competes nationally with P&G's popular Tide brand. The changing dynamics of business has been the focus of managerial debate the past few years. Practitioners and scholars talk about companies \"competing as a family.\" They talk about alliances, networks, and collaboration among companies. But managers and researchers have largely ignored the consumer, the agent that is most dramatically transforming the industrial system as we know it. (See the exhibit \"The Evolution and Transformation of Customers.\" Thanks largely to the Internet, consumers have been increasingly engaging themselves in an active and explicit dialogue with manufacturers of products and services. What's more, that dialogue is no longer being controlled by corporations. Individual consumers can address and learn about businesses either on their own or through the collective knowledge of other customers. Consumers can now initiate the dialogue; they have moved out of the audience and onto the stage. Customers are fundamentally changing the dynamics of the marketplace. The market has become a forum in which consumers play an", "author_names": [ "Coimbatore Krishnarao Prahalad", "" ], "corpus_id": 16049155, "doc_id": "16049155", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "file:/F:\\BORRADORES BV 2007\\BV 2004 VERSION CUBANA. LA LEGITIM", "venue": "", "year": 2007 }, { "abstract": "Discontinuous change in the environment often renders old beliefs obsolete or even misleading. Prior research often argues that organizations can benefit from deliberately unlearning their old beliefs to enable the learning of new beliefs. Although intuitively appealing, this claim has rarely been investigated systematically. Using an n armed bandit model, we examine the implications of different unlearning strategies for an organization's ability to adapt to different types of environmental discontinuities. We find that the implications of unlearning depend upon the interplay of the depth and breadth of unlearning, the type of discontinuity, and the timing of unlearning, and results often run counter to common intuition. These results have important implications for the literature on unlearning, theories of learning and the literature on organizational change following discontinuities.", "author_names": [ "Dirk Martignoni" ], "corpus_id": 151101677, "doc_id": "151101677", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "When Old Truths Become New Falsehoods: Unlearning in the Light of Technological Discontinuities", "venue": "", "year": 2019 }, { "abstract": "We work to unbundle the relationship between organizational identity and organizational adaptation to discontinuous technologies. While organizational identity has been envisaged as an impediment to the adoption of technological discontinuities by the majority of scholars, other research has recently portrayed organizational identity as a driver for change. We provide an explorative basis to reconcile these contradictions by dissecting elements of organizational identity that exacerbate organizational inertia and constitu ents of organizational identity that enable organizations to respond earlier and more flexibly to environmental changes. Using field data on the response patterns of German publishing houses to the emergence of digitization and internet enabled business models, we identify four distinct types of organizational identity, which we metaphorically label as Mercenaries, Knights, Villeins, and Samu rai. These four identity types vary with regard to two dimensions of identity: focus, which ranges from highly intra to highly extra domain focused, and locus of legitimacy, which ranges from highly self related to highly environment related. Furthermore, we propose that each of the four types of organizational identity entails a characteristic pattern of adaptation that is idiosyncratic regard ing the response timing, the activeness versus passiveness of the response, and the type of active response strategies. Our re search adds to the emerging stream of research on cognitive emotional determinants of organizational adaptation, particularly by providing a framework that explains how variation in the identity of organizations causes variations in those organizations' adoption of technological discontinuities. We also enhance knowledge on family businesses by showing that family influenced businesses are more likely to develop an intra domain focus, which ultimately engenders a passive or defensive response behavior.", "author_names": [ "Nadine Kammerlander", "Andreas Konig", "Albrecht Enders" ], "corpus_id": 157920045, "doc_id": "157920045", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "How organizational identity affects incumbents' adaptation to discontinuous technological changes An empirical study in the German book publishing industry", "venue": "", "year": 2012 }, { "abstract": "Product innovation strategies of emerging market companies are increasingly challenging conventional wisdom. Drawing on a qualitative case study of Mahindra Reva, the only electric vehicle producer in India, this paper explores how a bricolage strategy enabled a resource constrained emerging market firm to deliver affordable, innovative, and high tech products with minimal capital investments. The findings of this study illustrate how multiple forms of bricolage can be implemented and managed at organizational and interorganizational levels. They show how different bricolage activities relate to different stages of the new product development process, and further, highlight the complementarities between bricolage and engineering activities. This paper argues that bricolage, which is typically regarded as a behavioral trait or skill that allows entrepreneurs and innovators to operate in challenging environments, can also be a carefully planned and executed strategy conducive to innovation. Thus, it suggests that a cost effective bricolage strategy can underpin emerging market companies' development of discontinuity creating and market disrupting technology products.", "author_names": [ "M N Ravishankar" ], "corpus_id": 21911088, "doc_id": "21911088", "n_citations": 26, "n_key_citations": 0, "score": 0, "title": "A Bricolage Perspective on Technological Innovation in Emerging Markets", "venue": "IEEE Transactions on Engineering Management", "year": 2016 }, { "abstract": "Extant research investigates how organizations react to a changing environment, characterized by technological discontinuities or demand transformations. Existing theoretical approaches and empiric.", "author_names": [ "Ns Zimmermann", "Laura J Black" ], "corpus_id": 145920497, "doc_id": "145920497", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Modes and Mechanisms of Organizational Change", "venue": "", "year": 2013 }, { "abstract": "This research paper describes an integrated framework based on both the 'Technology Organization Environment (TOE) framework' and 'Diffusion of Innovation (DoI) theory' The study explores the noteworthy factors and sub factors which are pertinent for the adoption of cloud computing in the Ethiopian Higher Education (EHE) sector. The technology literature herein was based on technology adoption frameworks and theories which were studied in order to identify a set of factors and sub factors relevant to cloud computing adoption. It resulted in conceptualizing an integrated TOE DoI framework for cloud computing adoption in higher education at the university in Ethiopia and in developing its reliable measures. Accordingly, a quantitative study was done with a questionnaire survey comprising 500 respondents in connection with 4 factors (technological, organizational, environmental and socio cultural) Consequently, the cloud computing adoption in Ethiopia was established using factors and concepts adopted from the study. It confirmed that the TOE DoI approach to higher education in Ethiopia is authenticated. Thus, the four factors' reliability statistics validated with a Cronbach's alpha a 0.739, 0.712, 0.761, 0.841, and Cronbach's alpha 'a' based on standard items a 0.740, 0.713, 0.762 and 0.842 for technology, organizational, environmental, and socio cultural factors. This indicates that scaling the four aspects therein suggests profound evidence to determine a cloud computing adoption in EHE with TOE DoI integration.", "author_names": [ "Kamal Kant Hiran", "Anders Henten" ], "corpus_id": 203124058, "doc_id": "203124058", "n_citations": 6, "n_key_citations": 1, "score": 0, "title": "An integrated TOE DoI framework for cloud computing adoption in the higher education sector: case study of Sub Saharan Africa, Ethiopia", "venue": "Int. J. Syst. Assur. Eng. Manag.", "year": 2020 } ]

[ { "abstract": "Abstract A new solid solution of (1 x) Bi0.5Na0.5TiO3 x BaCo0.5Nb0.5O3 (BNT BCN; x 0, 0.05, 0.10, 0.15, 0.20) were fabricated via the solid state route. All the samples reflect single perovskite structure and normal ferroelectric behavior. The lowest band gap ~0.92 eV of Bi0.5Na0.5TiO3 doped with BaCo0.5Nb0.5O3 is achieved. Under simulated standard sunlight, the short circuit photocurrent (Jsc) of ~34.15 uA/cm2 and open circuit photovoltage (Voc) of ~10.24 V in the 0.90BNT 0.10BCN ceramic after the polarization of 60 kV/cm are obtained, which is much higher than that of the most perovskite oxide ceramics. The power conversion efficiency of the 0.90BNT 0.10BCN is about 0.17% The current system shows considerable advantages in the field of high stability photovoltaic devices.", "author_names": [ "Ming-qiang Zhong", "Changlai Yuan", "Xiao Liu", "Baohua Zhu", "Liufang Meng", "Changrong Zhou", "Fei Liu", "Jiwen Xu", "Jiang Wang", "Guanghui Rao" ], "corpus_id": 234190650, "doc_id": "234190650", "n_citations": 2, "n_key_citations": 0, "score": 1, "title": "High photocurrent densities in Bi0.5Na0.5TiO3 ferroelectric semiconductors", "venue": "", "year": 2021 }, { "abstract": "This report describes the sintering and ferroelectric characteristic of 0.76 Bi0.5Na0.5TiO3 (BNT) 0.26SrTiO3 (ST) with CuO addition, synthesized by using a solid state reaction. The XRD, microstructure, and density results reveal that Cu element reduces the sintering temperature from 1150 to 1000 degC. In dielectric study, CuO addition induces the increase of relaxation behavior for 26ST ceramic in the high temperature regime. In the low temperature regime 150 degC) the Cu doping to 26ST accelerates the degree in freezing of dipole, presumably due to the interaction between A site vacancy and nanodomain boundaries. The electromechanical properties of 26ST ceramics with CuO doping show a significant decay in frequency dependence of polarization and strain, which might be related to the formation of A site cation vacancy.", "author_names": [ "Mohsin Saleem", "In-sung Kim", "Min-soo Kim", "Bo-Kun Koo", "Soon-jong Jeong" ], "corpus_id": 139134383, "doc_id": "139134383", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Large signal electrical property of CuO doped of a Bi0.5Na0.5TiO3 SrTiO3", "venue": "Journal of Electroceramics", "year": 2017 }, { "abstract": "Abstract The use of Bi0.5Na0.5TiO3 (BNT) based materials is largely limited by their inherent thermal depolarization where the piezoelectric properties decreases remarkably. It is intractable to simultaneously realize high piezoelectric properties and reliable thermal stability over the required operating range in BNT based systems. Here, we demonstrated an alternative design method to commonly applied chemical doping or substituting to tailor the functional properties, by judiciously forming 0 3 type composites of ferroelectric 0.83(Bi0.5Na0.5)TiO3 0.17(Bi0.5K0.5)TiO3 with semiconductor ZnO inclusions (BNT BKT:ZnO) to balance the aforementioned paradox. In BNT BKT:0.1ZnO composite, we achieved distinguished comprehensive performance: high thermal stability of piezoelectric coefficient d33 (maintaining 73% of the initial value at 120 degC) good fatigue characteristic (deterioration of 8% up to 105 cycles in the field induced strain) and relatively large room temperature d33 of 109 pC/N. The mechanism for the enhanced fatigue behavior was mainly ascribed to the lower defect density arising from the lower oxygen vacancy concentration in composites as compared to pure BNT BKT. Most interestingly, hardening of piezoelectric properties usually produced by doping with lower valence elements, was realized in composites, as characterized by nearly two fold increase in mechanical quality factor (Qm) in comparison to BNT BKT. Our research not only offers a feasible paradigm for tailoring functional properties of BNT based materials though composite engineering, but also inspires further works to benefit a wide range of functionalities in other ferroelectric materials.", "author_names": [ "Wangfeng Bai", "Leijie Wang", "Peng Zheng", "Fei Wen", "Lili Li", "Zhen-guo Ji", "Jiwei Zhai" ], "corpus_id": 139573119, "doc_id": "139573119", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Enhanced thermal stability, hardening of piezoelectric property, and mediated electromechanical response in (Bi0.5Na0.5)TiO3 based piezoceramics via composite approach", "venue": "", "year": 2018 }, { "abstract": "Abstract A lead free solid solution of two ferroelectrics, bismuth sodium titanate and barium titanate, of a composition 0.96(Bi0.5Na0.5TiO3) 0.04(BaTiO3) (termed as BNT BT 4) was prepared by a standard low cost ceramic technology. The phase analysis of the solid solution, carried out using X ray diffraction pattern, shows a major tetragonal phase and a minor impurity phase at room temperature. The surface morphology of the prepared system showed the formation of the high density sample. The phonon mode statistics, width location and intensity of the peaks were analyzed by Raman spectroscopy. The temperature frequency dependence of dielectric parameters (permittivity and tangent loss) and AC conductivity were analyzed. The apparent activation energy of BNT BT 4 was evaluated with help of AC conductivity data. The effect of grain on the capacitive and resistive properties has been studied using an impedance spectroscopy technique. The decrease in the value of grain resistance on rising temperature shows the semiconductor or negative temperature coefficient behavior of the material. Based on an analysis of complex modulus spectrum, the conduction mechanism in the material has been suggested. As BNT BT 4 shows a remarkable temperature independent relative dielectric properties and low tangent loss, it is a potential candidate for devices.", "author_names": [ "Sugato Hajra", "Sushrisangita Sahoo", "Rutuparna Das", "R N P Choudhary" ], "corpus_id": 139371697, "doc_id": "139371697", "n_citations": 67, "n_key_citations": 0, "score": 0, "title": "Structural, dielectric and impedance characteristics of (Bi0.5Na0.5)TiO3 BaTiO3 electronic system", "venue": "", "year": 2018 }, { "abstract": "Owing to polarization driven efficient charge carrier separation, ferroelectric semiconductors with narrow band gaps ~1.3 eV) can constitute an ideal active layer for photovoltaics, as demonstrated in recent studies on lead halide perovskite solar cells. In this study, antiperovskite oxides with a composition of Ba4Pn2O (Pn=As or Sb) are proposed as promising candidates for high performance ferroelectric photovoltaics. Using the density functional theory (DFT) calculations, it is revealed that Ba4Pn2O exhibits moderate macroscopic polarization enough for charge carrier separation. Moreover, they are predicted to have direct band gaps close to the optimal Shockley Queisser value. By investigating optical absorption coefficients and resulting short circuit currents, it is demonstrated that a very thin layer of Ba4Pn2O can yield large photocurrents. The effective masses of charge carriers in Ba4Pn2O are found to be fairly small 0.2me) implying facile extraction of photocarriers. The favorable simulation results along with the confirmed synthesizability of the materials strongly suggest that Ba4Pn2O will be an active layer suitable for photovoltaics.", "author_names": [ "Youngho Kang", "Seungwu Han" ], "corpus_id": 221540197, "doc_id": "221540197", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Antiperovskite oxides as promising candidates for high performance ferroelectric photovoltaics: First principles investigation on Ba4As2O and Ba4Sb2O.", "venue": "ACS applied materials interfaces", "year": 2020 }, { "abstract": "Exploiting spontaneous polarization of ferroelectric materials to achieve high charge separation efficiency is an intriguing but challenging research topic in solar energy conversion. This work shows that loading high work function RuO2 cocatalyst on BiFeO3 (BFO) nanoparticles enhances the intrinsic ferroelectric polarization by efficient screening of charges to RuO2 via RuO2 /BFO heterojunction. This leads to enhancement of the surface photovoltage of RuO2 /BFO single nanoparticles nearly 3 times, the driving force for charge separation and transfer in photocatalytic reactions. Consequently, efficient photocatalytic water oxidation is achieved with quantum efficiency as high as 5.36 at 560 nm, the highest activity reported so far for ferroelectric materials. This work demonstrates that, unlike low photocurrent density in film based ferroelectric devices, high photocatalytic activity could be achieved by regulating the ferroelectric spontaneous polarization using appropriate cocatalyst to enhance driving force for efficient separation and transfer of photogenerated charges in particulate ferroelectric semiconductor materials.", "author_names": [ "Jafar H Shah", "Biaohong Huang", "Ahmed Mahmoud Idris", "Yong Liu", "Anum Shahid Malik", "Weijin Hu", "Zhidong Zhang", "Hongxian Han", "Can Li" ], "corpus_id": 222318789, "doc_id": "222318789", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Regulation of Ferroelectric Polarization to Achieve Efficient Charge Separation and Transfer in Particulate RuO2 /BiFeO3 for High Photocatalytic Water Oxidation Activity.", "venue": "Small", "year": 2020 }, { "abstract": "Ferroelectric materials, equipping a striking bulk photovoltaic effect (BPVE) have shown great potential for the next generation photovoltaic non volatile memories. However, further applications of conventional ferroelectric materials are hindered by their poor performance. The family of hybrid perovskite ferroelectrics combining fascinating polarization and striking semiconducting properties presents significant possibilities. Herein, through a functional unit transmutation strategy, a fatigue free layered hybrid perovskite ferroelectric (C 6 H 5 CH 2 NH 3 2 CsPb 2 Br 7 BCPB has been developed, which demonstrates stable spontaneous polarization P s of 6.5 mC/cm 2 and high Curie temperature up to 425 K. Meanwhile, BCPB shows splendid BPVE properties with noticeable zero bias photocurrent density (5 mA/cm 2 and high on/off switching ratio of current (over 3x10 5 these merits even overmatch the most known ferroelectric semiconductor BiFeO 3 Particularly, the unique structure with self regulated net electrical charged layers gives rise to the fatigue free feature of P s and BPVE (no significant fatigue after 10 8 polarity switching cycles) promoting the potential applications of BCPB in photovoltaic non volatile memories. As a pioneering work, it offers an efficient approach for exploring fatigue free semiconducting ferroelectrics as well as excavates their further applications in next generation electronic devices.", "author_names": [ "Yunpeng Yao", "Yunyan Peng", "Lina Li", "Xinyuan Zhang", "Xitao Liu", "Maochun Hong", "Junhua Luo" ], "corpus_id": 227191148, "doc_id": "227191148", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Exploring a Fatigue Free Layered Hybrid Perovskite Ferroelectric for Photovoltaic Non Volatile Memories.", "venue": "Angewandte Chemie", "year": 2020 }, { "abstract": "Two dimensional ferroelectrics is attractive for synaptic device applications because of its low power consumption and amenability to high density device integration. Here, we demonstrate that Tin monosulfide (SnS) films less than 6 nm thick shows optimum performance as semiconductor channel in in plane ferroelectric analogue synaptic device, whereas thicker films have much poorer ferroelectric response due to screening effects by a higher concentration of charge carriers. The SnS ferroelectric device exhibits synaptic behaviors with highly stable room temperature operation, high linearity in potentiation/depression, long retention, and low cycle to cycle/device to device variations. The simulated device based on ferroelectric SnS achieves 92.1 of pattern recognition accuracy in artificial neural network simulation. By switching the ferroelectric domains partially, multi level conductance states and conductance ratio can be obtained, achieving high pattern recognition accuracy.", "author_names": [ "Ki Chang Kwon", "Yishu Zhang", "Lianzhou Wang", "Wei Yu", "Xiaojie Wang", "In-Hyeok Park", "Hwa Seob Choi", "Teng Ma", "Ziyu Zhu", "Bingbing Tian", "Chenliang Su", "Kian Ping Loh" ], "corpus_id": 219317064, "doc_id": "219317064", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "In Plane Ferroelectric Tin Monosulfide and Its Application in Ferroelectric Analog Synaptic Device.", "venue": "ACS nano", "year": 2020 }, { "abstract": "The hybrid organic inorganic perovskites have been considered as promising candidates for high performance photodetectors. However, how to fabricate self powered broadband perovskite photodetectors with tunable photoresponse is still challenging. Herein, we design, for the first time, a ferroelectric semiconductor SrTiO3 (STO) and perovskite film hybrid structure based photodetector. After applying appropriate poled bias, the hybrid photodetector exhibits higher responsivity and faster response speed as compared to an unpoled device and a device without an STO ferroelectric interlayer. By optimizing the STO interlayer density, the positively poled photocurrent and response speed are enhanced to 0.956 mA and 0.1 s at zero bias, respectively. The corresponding responsivity is as high as 0.73A/W at a wavelength of 550 nm, which is much higher than that of the device without an STO interlayer. The improved performance is attributed to the fact that positively polarized STO layers can provide a built in potent.", "author_names": [ "Fengren Cao", "Wei Tian", "Meng Wang", "Liang Li" ], "corpus_id": 126428882, "doc_id": "126428882", "n_citations": 16, "n_key_citations": 0, "score": 0, "title": "Polarized Ferroelectric Field Enhanced Self Powered Perovskite Photodetector", "venue": "", "year": 2018 }, { "abstract": "Coupling ferroelectric materials with semiconductor materials can improve the performance of photovoltaic cells. The BaTiO3/TiO2(n) (B/T(n) photoanode of dye sensitized solar cells (DSSCs) is composed of a BaTiO3 core, a high performance and frequently used ferroelectric material, and TiO2 nanoparticles, a common semiconductor material. A hysteresis loop, 105 mC cm 2 remnant polarization and 7 kV cm 1 coercive field of the photoanode demonstrate its ferroelectricity. The short circuit current density (Jsc) of the dye sensitized photoanode after polarization (B/T(n)PD) is superior to that of unpolarized (B/T(n)D) by about 2 mA cm 2, regardless of the direction of polarization. The DSSC based on the B/T(4)PD photoanode exhibits a power conversion efficiency (PCE) of 7.29% and a Jsc of 14.44 mA cm 2. Reflectance spectroscopy, Fourier transform infrared spectroscopy (FTIR) and intensity modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS) are carried out to investigate the light absorption, charge injection and separation processes in B/T(n) Spontaneous polarization changes the adsorption state of the dye, which increases the light absorption efficiency, electron injection efficiency, incident light to photocurrent efficiency (IPCE) and Jsc. The discovery reported in this paper provides a method for modulating the interaction of adsorbed molecules with solids by means of electric field changes. This study deepens the understanding of the mechanism of charge transport and photovoltage generation in photovoltaic cells.", "author_names": [ "Dongmei Xie", "Yuan Lin", "Nianqing Fu", "Pin Ma", "Xiaowen Zhou" ], "corpus_id": 104745398, "doc_id": "104745398", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Changes of the dye adsorption state induced by ferroelectric polarization to improve photoelectric performance", "venue": "", "year": 2018 } ]

[ { "abstract": "Unrestricted Travel in Solar Cells In the past 2 years, organolead halide perovskites have emerged as a promising class of light harvesting media in experimental solar cells, but the physical basis for their efficiency has been unclear (see the Perspective by Hodes) Two studies now show, using a variety of time resolved absorption and emission spectroscopic techniques, that these materials manifest relatively long diffusion paths for charge carriers energized by light absorption. Xing et al. (p. 344) independently assessed (negative) electron and (positive) hole diffusion lengths and found them well matched to one another to the ~100 nanometer optical absorption depth. Stranks et al. (p. 341) uncovered a 10 fold greater diffusion length in a chloride doped material, which correlates with the material's particularly efficient overall performance. Both studies highlight effective carrier diffusion as a fruitful parameter for further optimization. Spectroscopy pinpoints facile carrier diffusion as a key factor in the efficiency of perovskite solar cells. [Also see Perspective by Hodes] Low temperature solution processed photovoltaics suffer from low efficiencies because of poor exciton or electron hole diffusion lengths (typically about 10 nanometers) Recent reports of highly efficient CH3NH3PbI3 based solar cells in a broad range of configurations raise a compelling case for understanding the fundamental photophysical mechanisms in these materials. By applying femtosecond transient optical spectroscopy to bilayers that interface this perovskite with either selective electron or selective hole extraction materials, we have uncovered concrete evidence of balanced long range electron hole diffusion lengths of at least 100 nanometers in solution processed CH3NH3PbI3. The high photoconversion efficiencies of these systems stem from the comparable optical absorption length and charge carrier diffusion lengths, transcending the traditional constraints of solution processed semiconductors.", "author_names": [ "Guichuan Xing", "Nripan Mathews", "Shuangyong Sun", "Swee Sien Lim", "Yeng Ming Lam", "Michael Gratzel", "Subodh Gautam Mhaisalkar", "Tze Chien Sum" ], "corpus_id": 852858, "doc_id": "852858", "n_citations": 4699, "n_key_citations": 24, "score": 0, "title": "Long Range Balanced Electron and Hole Transport Lengths in Organic Inorganic CH3NH3PbI3", "venue": "Science", "year": 2013 }, { "abstract": "Optimal transport (OT) theory can be informally described using the words of the French mathematician Gaspard Monge (1746 1818) A worker with a shovel in hand has to move a large pile of sand lying on a construction site. The goal of the worker is to erect with all that sand a target pile with a prescribed shape (for example, that of a giant sand castle) Naturally, the worker wishes to minimize her total effort, quantified for instance as the total distance or time spent carrying shovelfuls of sand. Mathematicians interested in OT cast that problem as that of comparing two probability distributions, two different piles of sand of the same volume. They consider all of the many possible ways to morph, transport or reshape the first pile into the second, and associate a \"global\" cost to every such transport, using the \"local\" consideration of how much it costs to move a grain of sand from one place to another. Recent years have witnessed the spread of OT in several fields, thanks to the emergence of approximate solvers that can scale to sizes and dimensions that are relevant to data sciences. Thanks to this newfound scalability, OT is being increasingly used to unlock various problems in imaging sciences (such as color or texture processing) computer vision and graphics (for shape manipulation) or machine learning (for regression, classification and density fitting) This short book reviews OT with a bias toward numerical methods and their applications in data sciences, and sheds lights on the theoretical properties of OT that make it particularly useful for some of these applications.", "author_names": [ "Gabriel Peyre", "Marco Cuturi" ], "corpus_id": 73725148, "doc_id": "73725148", "n_citations": 741, "n_key_citations": 79, "score": 1, "title": "Computational Optimal Transport", "venue": "Found. Trends Mach. Learn.", "year": 2019 }, { "abstract": "Signaling through the Ror2 receptor tyrosine kinase promotes invadopodia formation for tumor invasion. Here, we identify intraflagellar transport 20 (IFT20) as a new target of this signaling in tumors that lack primary cilia, and find that IFT20 mediates the ability of Ror2 signaling to induce the invasiveness of these tumors. We also find that IFT20 regulates the nucleation of Golgi derived microtubules by affecting the GM130 AKAP450 complex, which promotes Golgi ribbon formation in achieving polarized secretion for cell migration and invasion. Furthermore, IFT20 promotes the efficiency of transport through the Golgi complex. These findings shed new insights into how Ror2 signaling promotes tumor invasiveness, and also advance the understanding of how Golgi structure and transport can be regulated.", "author_names": [ "Michiru Nishita", "Seung-Yeol Park", "Tadashi Nishio", "Koki Kamizaki", "Zhichao Wang", "Kota Tamada", "Toru Takumi", "Ryuju Hashimoto", "Hiroki Otani", "Gregory J Pazour", "Victor W Hsu", "Yasuhiro Minami" ], "corpus_id": 2760407, "doc_id": "2760407", "n_citations": 5992, "n_key_citations": 2, "score": 0, "title": "Ror2 signaling regulates Golgi structure and transport through IFT20 for tumor invasiveness", "venue": "Scientific Reports", "year": 2016 }, { "abstract": "This document specifies version 1.3 of the Transport Layer Security (TLS) protocol. TLS allows client/server applications to communicate over the Internet in a way that is designed to prevent eavesdropping, tampering, and message forgery. This document updates RFCs 4492, 5705, and 6066 and it obsoletes RFCs 5077, 5246, and 6961. This document also specifies new requirements for TLS 1.2 implementations.", "author_names": [ "Eric Rescorla" ], "corpus_id": 956749, "doc_id": "956749", "n_citations": 878, "n_key_citations": 132, "score": 0, "title": "The Transport Layer Security (TLS) Protocol Version 1.3", "venue": "RFC", "year": 2018 }, { "abstract": "AbstractThe Hybrid Single Particle Lagrangian Integrated Trajectory model (HYSPLIT) developed by NOAA's Air Resources Laboratory, is one of the most widely used models for atmospheric trajectory and dispersion calculations. We present the model's historical evolution over the last 30 years from simple hand drawn back trajectories to very sophisticated computations of transport, mixing, chemical transformation, and deposition of pollutants and hazardous materials. We highlight recent applications of the HYSPLIT modeling system, including the simulation of atmospheric tracer release experiments, radionuclides, smoke originated from wild fires, volcanic ash, mercury, and wind blown dust.", "author_names": [ "Ariel F Stein", "Roland R Draxler", "Glenn Rolph", "Barbara Stunder", "Mark D Cohen", "Fong Ngan" ], "corpus_id": 116926013, "doc_id": "116926013", "n_citations": 2638, "n_key_citations": 165, "score": 0, "title": "NOAA's HYSPLIT Atmospheric Transport and Dispersion Modeling System", "venue": "", "year": 2015 }, { "abstract": "This memorandum describes RTP, the real time transport protocol. RTP provides end to end network transport functions suitable for applications transmitting real time data, such as audio, video or simulation data, over multicast or unicast network services. RTP does not address resource reservation and does not guarantee quality of service for real time services. The data transport is augmented by a control protocol (RTCP) to allow monitoring of the data delivery in a manner scalable to large multicast networks, and to provide minimal control and identification functionality. RTP and RTCP are designed to be independent of the underlying transport and network layers. The protocol supports the use of RTP level translators and mixers.", "author_names": [ "Henning Schulzrinne", "Stephen L Casner", "Ron Frederick", "Van Jacobson" ], "corpus_id": 35417665, "doc_id": "35417665", "n_citations": 7004, "n_key_citations": 695, "score": 0, "title": "RTP: A Transport Protocol for Real Time Applications", "venue": "RFC", "year": 1996 }, { "abstract": "PHREEQC version 2 is a computer program written in the C programming language that is designed to perform a wide variety of low temperature aqueous geochemical calculations. PHREEQC is based on an ion association aqueous model and has capabilities for (1) speciation and saturation index calculations; (2) batch reaction and onedimensional (1D) transport calculations involving reversible reactions, which include aqueous, mineral, gas, solidsolution, surface complexation, and ion exchange equilibria, and irreversible reactions, which include specified mole transfers of reactants, kinetically controlled reactions, mixing of solutions, and temperature changes; and (3) inverse modeling, which finds sets of mineral and gas mole transfers that account for differences in composition between waters, within specified compositional uncertainty limits. New features in PHREEQC version 2 relative to version 1 include capabilities to simulate dispersion (or diffusion) and stagnant zones in 1D transport calculations, to model kinetic reactions with user defined rate expressions, to model the formation or dissolution of ideal, multicomponent or nonideal, binary solid solutions, to model fixed volume gas phases in addition to fixed pressure gas phases, to allow the number of surface or exchange sites to vary with the dissolution or precipitation of minerals or kinetic reactants, to include isotope mole balances in inverse modeling calculations, to automatically use multiple sets of convergence parameters, to print user defined quantities to the primary output file and (or) to a file suitable for importation into a spreadsheet, and to define solution compositions in a format more compatible with spreadsheet programs. This report presents the equations that are the basis for chemical equilibrium, kinetic, transport, and inverse modeling calculations in PHREEQC; describes the input for the program; and presents examples that demonstrate most of the program's capabilities.", "author_names": [ "David L Parkhurst", "C A J Appelo" ], "corpus_id": 128792120, "doc_id": "128792120", "n_citations": 6958, "n_key_citations": 717, "score": 0, "title": "User's guide to PHREEQC (Version 2) a computer program for speciation, batch reaction, one dimensional transport, and inverse geochemical calculations", "venue": "", "year": 1999 }, { "abstract": "Couplings and changes of variables. Three examples of coupling techniques. The founding fathers of optimal transport. Qualitative description of optimal transport. Basic properties. Cyclical monotonicity and Kantorovich duality. The Wasserstein distances. Displacement interpolation. The Monge Mather shortening principle. Solution of the Monge problem I: global approach. Solution of the Monge problem II: Local approach. The Jacobian equation. Smoothness. Qualitative picture. Optimal transport and Riemannian geometry. Ricci curvature. Otto calculus. Displacement convexity I. Displacement convexity II. Volume control. Density control and local regularity. Infinitesimal displacement convexity. Isoperimetric type inequalities. Concentration inequalities. Gradient flows I. Gradient flows II: Qualitative properties. Gradient flows III: Functional inequalities. Synthetic treatment of Ricci curvature. Analytic and synthetic points of view. Convergence of metric measure spaces. Stability of optimal transport. Weak Ricci curvature bounds I: Definition and Stability. Weak Ricci curvature bounds II: Geometric and analytic properties.", "author_names": [ "Cedric Villani" ], "corpus_id": 118347220, "doc_id": "118347220", "n_citations": 4147, "n_key_citations": 497, "score": 0, "title": "Optimal Transport: Old and New", "venue": "", "year": 2008 }, { "abstract": "Measurements of the quantum yields of chlorophyll fluorescence and CO2 assimilation for a number of plant species exposed to changing light intensity and atmospheric CO2 concentrations and during induction of photosynthesis are used to examine the relationship between fluorescence quenching parameters and the quantum yield of non cyclic electron transport. Over a wide range of physiological conditions the quantum yield of non cyclic electron transport was found to be directly proportional to the product of the photochemical fluorescence quenching (qQ) and the efficiency of excitation capture by open Photosystem II (PS II) reaction centres (Fv/Fm) A simple fluorescence parameter, DphF/phFm, which is defined by the difference in fluorescence yield at maximal phFm, and steady state phFs, divided by phFm, can be used routinely to estimate changes in the quantum yield of non cyclic electron transport. It is demonstrated that both the concentration of open PS II reaction centres and the efficiency of excitation capture by these centres will determine the quantum yield of non cyclic electron transport in vivo and that deactivation of excitation within PS II complexes by non photochemical processes must influence the quantum yield of non cyclic electron transport.", "author_names": [ "Bernard Genty", "J-M Briantais", "Neil R Baker" ], "corpus_id": 94431733, "doc_id": "94431733", "n_citations": 7222, "n_key_citations": 682, "score": 0, "title": "The relationship between the quantum yield of photosynthetic electron transport and quenching of chlorophyll fluorescence", "venue": "", "year": 1989 }, { "abstract": "This manual is a practical guide for the use of our general purpose Monte Carlo code MCNP. The first chapter is a primer for the novice user. The second chapter describes the mathematics, data, physics, and Monte Carlo simulation found in MCNP. This discussion is not meant to be exhaustive details of the particular techniques and of the Monte Carlo method itself will have to be found elsewhere. The third chapter shows the user how to prepare input for the code. The fourth chapter contains several examples, and the fifth chapter explains the output. The appendices show how to use MCNP on various computer systems and also give details about some of the code internals.", "author_names": [ "Judith F Briesmeister" ], "corpus_id": 123810257, "doc_id": "123810257", "n_citations": 6495, "n_key_citations": 365, "score": 0, "title": "MCNP A General Monte Carlo N Particle Transport Code", "venue": "", "year": 1993 } ]

[ { "abstract": "Abstract In this work, BCN TiO2(A+R) heterojunctions were constructed via a simple one step calcination method as efficient photocatalysts for H2 evolution. Simultaneously, an anatase/rutile phase junction was also obtained due to the crystalline phase transformation that occurred during high temperature calcination. The unique heterojunction and phase junction lead to the formation of an intimate interface and large contact area between two semiconductors and extended the visible light absorption range. Therefore, BCN TiO2(A+R) heterojunctions with a mixed anatase and rutile phase exhibit enhanced photocarrier separation efficiency, realizing an eleven fold increase in the electron lifetime compared to that of pure TiO2 and yielding a remarkable visible light driven H2 evolution rate nearly 7.5 and 12.2 times higher than that of TiO2(A+R) and pure BCN, respectively. This work provides a new strategy for designing efficient water splitting photocatalysts with highly efficient charge separation and transfer.", "author_names": [ "Xiaolei Xing", "Huihui Zhu", "Min Zhang", "Limin Xiao", "Qiuye Li", "Jianjun Yang" ], "corpus_id": 145823615, "doc_id": "145823615", "n_citations": 11, "n_key_citations": 0, "score": 1, "title": "Effect of heterojunctions and phase junctions on visible light photocatalytic hydrogen evolution in BCN TiO2 photocatalysts", "venue": "Chemical Physics Letters", "year": 2019 }, { "abstract": "All solid state Z scheme BCN TiO2 binary heterostructures with a surface oxygen vacancy layer as the contact interface are fabricated by NaBH4 reduction and ball milling. The effect of the surface oxygen vacancy layer of BCN TiO2 binary heterostructures on the charge carrier transfer and photocatalytic hydrogen evolution was thoroughly investigated. UV vis diffuse reflection spectra results reveal that the surface oxygen vacancy can extend the light absorption from the UV to the visible light region for BCN TiO2 binary heterostructures. The steady state/time resolved photoluminescence spectra exhibit an increased charge carrier lifetime, improved charge carrier separation efficiency and strengthened direct Z scheme charge transfer process for BCN TiO2 x heterostructures. As expected, the BCN TiO2 x heterostructures exhibited a higher visible light photocatalytic efficiency, about 7 and 11 times higher than that of the pure TiO2 and BCN samples. Namely, the photocatalytic activity of hydrogen evolution can be greatly promoted by constructing the surface oxygen vacancy layer. This work provides a new pathway to construct an efficient contact layer for the direct Z scheme system to improve the charge carrier separation and transfer and thereby improve the photocatalytic activity.", "author_names": [ "Xiaolei Xing", "Huihui Zhu", "Min Zhang", "Lili Hou", "Qiuye Li", "Jianjun Yang" ], "corpus_id": 102660284, "doc_id": "102660284", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Interfacial oxygen vacancy layer of a Z scheme BCN TiO2 heterostructure accelerating charge carrier transfer for visible light photocatalytic H2 evolution", "venue": "", "year": 2018 }, { "abstract": "Abstract BCN TiO 2 nanocomposites are obtained by a simple calcination method using a hexagonal boron carbon nitride (BCN) semiconductor and nanotubular titanic acid (NTA) as precursors. The BCN TiO 2 nanocomposites are characterized systematically by XRD, TEM, XPS, DRS, ESR, BET, I t and PL techniques. Compared with the novel TiO 2 or single BCN sample, the BCN TiO 2 nanocomposites prepared by a calcination method show the highest photocatalytic activity for hydrogen production under visible light irradiation. The photocatalytic activity of BCN TiO 2 nanocomposites is optimized by changing the amount of BCN. Characterization results confirm that a large amount of single electron oxygen vacancies can be formed when NTA was calcined at the higher temperature, which is beneficial to the enhancement of visible light absorption and the transfer of photogenerated carriers due to the formation of ohmic contact at the interface between BCN and novel TiO 2 Therefore, the visible light photocatalytic activity for H 2 production of BCN TiO 2 nanocomposites has been improved significantly by the formation of BCN TiO 2 Z scheme photocatalyst, which results in efficient space separation of photo induced charge carriers.", "author_names": [ "Xiaolei Xing", "Min Zhang", "Lili Hou", "Limin Xiao", "Qiuye Li", "Jianjun Yang" ], "corpus_id": 103722679, "doc_id": "103722679", "n_citations": 23, "n_key_citations": 0, "score": 0, "title": "Z scheme BCN TiO2 nanocomposites with oxygen vacancy for high efficiency visible light driven hydrogen production", "venue": "", "year": 2017 }, { "abstract": "BCN TiO2 was prepared by doping Ti(OH)4 with graphite like structure BCN in an annealing process at 400[degC] for 2[h] The catalyst samples were characterized by X ray diffraction (XRD) X ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) Graphite like structure BCN was detected by XRD. The results showed that with graphite like structure BCN doped in, the crystal size became smaller than pure TiO2. Also B, C, N were detected in crystal lattice of TiO2, in which Boron was in the form of Bx+ Carbon substituted some of the lattice oxygen atoms as Ti C, and Nitrogen was in the form of Ti N and Ti O N.", "author_names": [ "L Zhang", "Ling Li", "Zonggang Mou", "Xifeng Li" ], "corpus_id": 95397341, "doc_id": "95397341", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Preparation and Characterization of BCN TiO2 Nanoparticles", "venue": "", "year": 2011 }, { "abstract": "Ti3+ self doped TiO2/BCN heterojunction (Ti3+ TiO2/BCN) was constructed via a hydrothermal method with using NaBH4 as reducing agent. The BCN nanosheets function as a good support to block the agglomeration of Ti3+ TiO2 nanoparticles, which decreased the recombination of photogenerated charge carriers. The Ti3+ TiO2/BCN sample exhibited enhanced electronic conductivity and absorption in visible light region because of the introduction of Ti3+ and oxygen vacancies (Ov) The as prepared Ti3+ TiO2/BCN sample showed enhanced photoelectrochemical (PEC) performance as confirmed by analyses of LSV, EIS, Bode plots and M S. Under the visible light irradiation, the optimally Ti3+ self doped TiO2/BCN heterojunction sample yield a photocurrent density of 0.69 mA/cm2 at 1.23 V versus RHE, which is over three times as high as BCN and TiO2/BCN at the same conditions.", "author_names": [ "Zheng Liang", "Junqi Li", "Nan Ye Lei", "Liu Guo", "Qianqian Song" ], "corpus_id": 139272029, "doc_id": "139272029", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Construction of Ti3+ self doped TiO2/BCN heterojunction with enhanced photoelectrochemical performance for water splitting", "venue": "Journal of Materials Science: Materials in Electronics", "year": 2018 }, { "abstract": "Titanium dioxide has attracted much attention in the past decades. When it was doped by some elements, such as C, N, P, S and B, the conductibility will be obviously changed. In this work, the BCN doped TiO2 with nanostructured fllm was fabricated by co deposit method. The structure was studied by X ray difiraction measurement. The microstructure was observed by XPS. The investigation of ac impedance spectra for BCN doped TiO2 thin fllm was performed. The grain resistance, resistance of grain boundary, and the capacitance in the thin fllm were determined from impedance technique. 1. INTRODUCTION Recently, much progress has been achieved in the fleld of visible light active TiO2 by incorporation of various dopants into its lattice. Especially the doping of nonmetal, such as nitrogen, uorine, chlorine, sulfur, boron and carbon (1{5) Some studies have been reported that doping of nonmetal showed dramatic improvement over undoped TiO2 in its optical absorption and photocatalytic activity under visible light. Asahi et al. theoretically calculated the band structure of the N doped TiO2 and concluded that the visible light sensitivity was due to the narrowing of the band gap by mixing the N2p and O2p states (2,6,7) An additional contribution to the impedance arises from the larger scale microstructural elements, such as grain boundaries and remote electrical contacts. From the analysis of impedance data, relaxation processes at the tip surface junction, grain boundaries, and electrodes can be difierentiated according to characteristic time constants (8,9) Combination of this analysis with spatially resolved impedance imaging yields frequency, bias, and position dependent information on microscopic transport properties. In this paper, the BCN doped TiO2 with nanostructured fllm was fabricated by co deposit method.The structure was studied by X ray difiraction measurement. The microstructure was observed by XPS. The investigation of ac impedance spectra for BCN doped TiO2 thin fllm was performed. The resistance and impedance value in deferent frequency for the thin fllm were determined from impedance technique. 2. SECTION 1 2.1. Experimental Procedure The preparation of TiOBCN includes the use of the precursors Ti(OH)4 and BCN, and subsequent calcination. Detailed procedures are described below. The Ti(OH)4 was prepared by precipitation as described below. The 0.005mol TiCl4 solution was cooled down i10 C below in ice water. Then, 28mL of H2O2 solution (30% was dropped under constant stirring to obtain a transparent, complex compound. Next, a strong NH3 H2O aqueous solution (25% was added dropwise into the transparent yellow precursors resulting in a pH of 10. The transparent yellow precursors were heated to 50 C under constant stirring to a obtain yellow precipitate, which was then flltered, thoroughly washed with distilled water and dried overnight at 70 C. Finally, the prepared Ti(OH)4 was calcined at 400 C for 4h to yield TiO2. Graphite BCN powder was synthesized by high temperature anneals. The resulting Ti(OH)4 and BCN were mixed thoroughly at a mass ratio 10 1. This mixture was then calcined at 400 for 4h for the synthesis of TiOBCN, then added some binder to the TiOBCN power formed fllm. 2.2. Results and Discussion The crystalline phases of the prepared samples were measured by X ray difiraction (XRD) using a Rigaku D/Max III. V X ray difirac tometer with Cu Kfi radiation (1.5406 \" at 40kV and 40mA and a secondary graphite monochromator. Measurements were recorded in steps of 0.025 with a count time of 2s in the 2u range of 20 {70 Fig. 1 shows XRD patterns of the synthesized", "author_names": [ "Ling Zhang", "Yongfan Zhang", "Liangguo Yan", "Fangxin He" ], "corpus_id": 138546509, "doc_id": "138546509", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Investigation of the Electrical Properties of BCN codoped TiO2 Thin Film Using Impedance Spectroscopy", "venue": "", "year": 2011 }, { "abstract": "Abstract With the development of clean and renewable energy, hydrogen produced via photoelectrochemical (PEC) water splitting has attracted considerable attention. However, to develop the photoanodes with stable and excellent PEC ability is still a big challenge. In our work, TiO 2 nanorods decorated with boron doped g C 3 N 4 (BCN/TiO 2 is fabricated via thermal polymerization method to improve the PEC performance. The BCN/TiO 2 displays 4 fold increase of the photocurrent density (1.01 mA cm 2 at 1.23 V vs. RHE under irradiation (100 mW cm 2 AM 1.5 G) And the onset potential of BCN/TiO 2 exhibits a negative shift with 100 mV. Attributed to the broad light absorption of BCN and hetero junction forming between BCN and TiO 2 the IPCE value is increased to 87.8% in 380 nm, and the charge separation and transfer efficiency are both increased. Doping metal free inorganic material with heteroatoms is a simple and efficient strategy to increase the light absorption within visible light and charge transfer efficiency in PEC and photocatalytic applications.", "author_names": [ "Kong Weiqian", "Xiaofang Zhang", "Binbin Chang", "Yannan Zhou", "Shouren Zhang", "He Guangli", "Bao-cheng Yang", "Junjie Li" ], "corpus_id": 102743342, "doc_id": "102743342", "n_citations": 28, "n_key_citations": 0, "score": 0, "title": "Fabrication of B doped g C3N4/TiO2 heterojunction for efficient photoelectrochemical water oxidation", "venue": "", "year": 2018 }, { "abstract": "Abstract The establishment of ultrasensitive, highly selective and cost effective photoelectrochemical (PEC) biosensing platforms is essential for biological assays. In this work, a novel visible light driven PEC platform was developed for ultrasensitive detection of bisphenol A (BPA) based on TiO2 nanoparticles embedded in borocarbonitrides nanosheets (TiO2/BCN) which were fabricated through one step thermal treatment approach. The introduction of BCN not only extends photoresponding of TiO2 to visible light area, but also effectively suppresses the recombination of photoinduced electron hole pairs, and then presented enhanced PEC performances. The PEC sensing platform is constructed via a stepwise modification method with the aids of BPA aptamer, and characterized by PEC and electrochemical impedance spectroscopy (EIS) In the presence of BPA, the photocurrent can be greatly enhanced because BPA can inhibit the recombination of photogenerated electron hole pairs and accelerate the interfacial charge transfer process. The results demonstrated that the photocurrent is highly linear over BPA concentrations ranging from 0.1 fM to 5 nM with a low detection limit of 0.03 fM (S/N 3) Moreover, the as fabricated PEC sensor exhibited high selectivity and low cost, which could be successfully applied for the fast, sensitive, and selective determination of BPA in real water samples.", "author_names": [ "Ding Jiang", "Xiaojiao Du", "Lei Zhou", "Henan Li", "Kun Wang" ], "corpus_id": 103389030, "doc_id": "103389030", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "TiO2 nanoparticles embedded in borocarbonitrides nanosheets for sensitive and selective photoelectrochemical aptasensing of bisphenol A", "venue": "", "year": 2018 }, { "abstract": "Abstract It can be said that energy depletion and environmental pollution on a global scale are the most serious and urgent issues facing mankind in recent times. It is, thus, vital to design novel energy production and conversion systems that utilize natural energy and allow sustainable development without environmental destruction or pollution. In line with these objectives, the decomposition of H2O into H2 and O2, as well as the related reactions using visible light responsive photocatalysts under sunlight irradiation, has been intensively investigated as one of the most promising environmentally benign energy production systems to address these issues. In the past half century, research on various photocatalytic systems using metal oxides has been carried out. However, to achieve higher efficiency in the production of H2, more innovative breakthroughs in the development of photocatalytic materials are strongly desired. To address such issues, graphitic carbon nitride (g C3N4) and hexagonal boron carbon nitride (BCN) nano materials have been investigated as promising visible light responsive photocatalytic materials. In this chapter, we have highlighted the development of such g C3N4 and hexagonal BCN photocatalytic nano materials, focusing on their design, construction and optimization, as well as their applications to environmentally benign solar energy conversion systems, for the decomposition of H2O, reduction and fixation of CO2, and organic redox reactions. Such visible light responsive photocatalytic materials are considered to be the most important research for the development of safe and clean energy production technologies for the 21st century and beyond.", "author_names": [ "Bo Wang", "Masakazu Anpo", "Xinchen Wang" ], "corpus_id": 139384871, "doc_id": "139384871", "n_citations": 6, "n_key_citations": 0, "score": 1, "title": "Visible Light Responsive Photocatalysts From TiO2 to Carbon Nitrides and Boron Carbon Nitride", "venue": "", "year": 2018 }, { "abstract": "Abstract BCN TiO2 was prepared by doping TiO2 with graphite like structure BCN, and characterised by X ray diffraction (XRD) X ray photoelectron spectroscopy (XPS) scanning electron microscope (SEM) and visible light photocatalysis visible light degradation of MB. The results demonstrated that BCN TiO2 has weaker anatase crystal characteristic peaks, and the crystal size become smaller. XPS result showed that B, C, N have been dopped in crystal lattice of TiO2. Boron was in the form of Bx+ Carbon substituted some of the lattice oxygen atoms as Ti C, and Nitrogen was in the form of Ti N and Ti O N. According to the result of visible light photocatalysis, with BCN dopped in, the catalysts photocatalytic efficiency is greatly improved.", "author_names": [ "Ling Zhang", "Ling Li", "Mou Zonggang", "Xifeng Li" ], "corpus_id": 98474658, "doc_id": "98474658", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Study on microstructure and catalytic performance of B, C, N co dopped TiO2", "venue": "", "year": 2012 } ]

[ { "abstract": "The semiconductor industry has been able to improve the performance of electronic systems for more than four decades by making ever smaller devices. However, this approach will soon encounter both scientific and technical limits, which is why the industry is exploring a number of alternative device technologies. Here we review the progress that has been made with carbon nanotubes and, more recently, graphene layers and nanoribbons. Field effect transistors based on semiconductor nanotubes and graphene nanoribbons have already been demonstrated, and metallic nanotubes could be used as high performance interconnects. Moreover, owing to the excellent optical properties of nanotubes it could be possible to make both electronic and optoelectronic devices from the same material.", "author_names": [ "Phaedon Avouris", "Zhihong Chen", "Vasili Perebeinos" ], "corpus_id": 205442641, "doc_id": "205442641", "n_citations": 1814, "n_key_citations": 6, "score": 1, "title": "Carbon based electronics.", "venue": "Nature nanotechnology", "year": 2007 }, { "abstract": "", "author_names": [ "Philipp Maisch", "Luca Lucera", "Christoph J Brabec", "Hans-J Egelhaaf" ], "corpus_id": 115751056, "doc_id": "115751056", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Flexible Carbon based Electronics: Flexible Solar Cells", "venue": "", "year": 2018 }, { "abstract": "We report for the first time an innovative visible light photolabile poly(ionic liquid) (VP PIL) The as prepared VP PIL features low Tg (47 degC) good thermal stability (Td 284 degC) and solubility in ranges of polar solvents. Upon blue light irradiation ~452 nm) C O bonds of picolinuim units are photocleaved, and the charges of PILs are simultaneously converted from positive to negative. Taking full advantages of these excellent properties of VP PIL, a visible light degradable film for the first time is fabricated. Moreover, to demonstrate its applications in electronics, we prepared high quality VP PIL containing conductive ink for flexible interconnects and graphene electrodes for supercapacitors.", "author_names": [ "Tongtong Zhou", "Yuan G Lei", "Hanzhi Zhang", "Ping Zhang", "Casey Yan", "Zijian Zheng", "Yongming Chen", "You Yu" ], "corpus_id": 20994486, "doc_id": "20994486", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Visible Light Photolabile, Charge Convertible Poly(ionic liquid) for Light degradable Films and Carbon Based Electronics.", "venue": "ACS applied materials interfaces", "year": 2016 }, { "abstract": "High quality yttrium oxide (Y(2)O(3) is investigated as an ideal high kappa gate dielectric for carbon based electronics through a simple and cheap process. Utilizing the excellent wetting behavior of yttrium on sp(2) carbon framework, ultrathin (about few nm) and uniform Y(2)O(3) layers have been directly grown on the surfaces of carbon nanotube (CNT) and graphene without using noncovalent functionalization layers or introducing large structural distortion and damage. A top gate CNT field effect transistor (FET) adopting 5 nm Y(2)O(3) layer as its top gate dielectric shows excellent device characteristics, including an ideal subthreshold swing of 60 mV/decade (up to the theoretical limit of an ideal FET at room temperature) The high electrical quality Y(2)O(3) dielectric layer has also been integrated into a graphene FET as its top gate dielectric with a capacitance of up to 1200 nF/cm(2) showing an improvement on the gate efficiency and on state transconductance of over 100 times when compared with that of its back gate counterpart.", "author_names": [ "Zhenxing Wang", "Huilong Xu", "Zhiyong Zhang", "Sheng Wang", "Li Ding", "Qingsheng Zeng", "Leijing Yang", "Tian Pei", "Xuelei Liang", "Min Gao", "Lian-Mao Peng" ], "corpus_id": 5386157, "doc_id": "5386157", "n_citations": 114, "n_key_citations": 2, "score": 0, "title": "Growth and performance of yttrium oxide as an ideal high kappa gate dielectric for carbon based electronics.", "venue": "Nano letters", "year": 2010 }, { "abstract": "Carbon based nanomaterials such as carbon nanotubes (CNTs) and graphene, which possess superior electrical, thermal and mechanical properties, have been proposed as alternative materials for future electronics. The proposed applications span from the device level, replacing silicon based transistors, with single walled carbon nanotubes (SWCNTs) or graphene, to packaging level using multi walled carbon nanotubes (MWCNTs) for interconnects. To further exploit the potential of carbon based electronics in electronic packaging, a novel 3D carbon based electronic system is targeted in this thesis. In order to achieve the goal of a 3D carbon based electronic system, this thesis addresses some of the technical issues including material synthesis, process compatibility and system integration. First of all, the chemical vapor deposition (CVD) synthesis of horizontally aligned SWCNTs (HA SWCNTs) vertically aligned MWCNTs (VA MWCNTs) and bilayer graphene were investigated for material preparation. For the HA SWCNTs on the ST cut quartz substrate, it has been found that adding a top heater is critical for synthesis of high quality HA SWCNTs in a cold wall reactor. The catalyst engineering of MWCNTs in a hexagonal pattern was performed to achieve high aspect ratio MWCNT bundles for through silicon via (TSV) interconnects. In addition, a nucleation activity model has been proposed as an explanation for the fast and controllable synthesis of bilayer graphene on a copper foil in the cold wall CVD. The transfer of CNTs and graphene was conducted to circumvent material synthesis incompatibilities with current semiconductor and packaging processes. The PET frame was utilized to ease the HA SWCNTs transfer during the transportation. In particular, tape assisted transfer of MWCNT bundles for TSVs has been proposed and experimentally demonstrated to increase the yield and efficiency. After the transfer of VA MWCNT bundle into the via, different polymers were used for filling the gap between the VA MWCNT bundle and the side walls of the via, and their performance was investigated and compared. In addition, a double densification process has been developed to overcome the tilting issue of the high aspect ratio VA MWCNTs bundles for the TSV interconnect. For bubbling transfer of graphene, a consolidation polydimethylsiloxane (PDMS) layer was added on top of polymathic methacrylate (PMMA) layer in order to avoid the cracks caused by bubbles. In order to solve the high resistivity issue of pure VA MWCNTs filled TSV interconnects, a novel CNT Cu nanocomposite has been developed. This composite material consisted of high aspect ratios, VA MWCNTs deposited and coated by Cu, and exhibited the same order of magnitude resistivity as Cu, but with a similar thermal expansion performance to silicon. In parallel, attempts were made to stack pure VA MWCNT filled TSVs and CNT Cu nanocomposite filled TSV. In the end, a via last based process for 3D integration was proposed and demonstrated. Electrical characterization was carried out at each step of the 3D integration process.", "author_names": [ "Wei Mu" ], "corpus_id": 139040800, "doc_id": "139040800", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "3D Integration of Carbon Based Electronics", "venue": "", "year": 2016 }, { "abstract": "Abstract Carbon based nanomaterials like nanotubes and graphene have emerged as future generation electronic materials for device applications because of their interesting properties such as high mobility and ability to carry high current densities compared to conventional semiconductor materials like silicon. Therefore, there is a need to develop techniques to integrate robust gate dielectrics with high quality interfaces for these materials in order to attain maximum performance. To date, a variety of methods including physical vapor deposition, atomic layer deposition (ALD) physical assembly among others have been employed in order to integrate dielectrics for carbon nanotube and graphene based field effect transistors. Owing to the difficulty in wetting pristine surfaces of nanotubes and graphene, most of the ALD methods require a seeding technique involving non covalent functionalization of their surfaces in order to nucleate dielectric growth while maintaining their intrinsic properties. A comprehensive review regarding the various dielectric integration schemes for emerging devices and their limitations with respect to ALD based methods along with a future outlook is provided.", "author_names": [ "Srikar Jandhyala" ], "corpus_id": 135635883, "doc_id": "135635883", "n_citations": 16, "n_key_citations": 1, "score": 0, "title": "Atomic layer deposition of dielectrics for carbon based electronics", "venue": "", "year": 2013 }, { "abstract": "", "author_names": [ "Ashok Srivastava", "Jose M Marulanda", "Yao Xu", "Ashwani K Sharma" ], "corpus_id": 114533540, "doc_id": "114533540", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Carbon Based Electronics: Transistors and Interconnects at the Nanoscale", "venue": "", "year": 2015 }, { "abstract": "Graphene forms an important two dimensional (2D) material class that displays both a high electronic conductivity and optical transparency when doped. Yet, the microscopic origin of the doping mechanism in single sheet or bulk intercalated systems remains unclear. Using large scale ab initio simulations, we show the graphene surface acts as a catalytic reducing/oxidizing agent, driving the chemical disproportionation of adsorbed dopant layers into charge transfer complexes which inject majority carriers into the 2D carbon lattice. As pertinent examples, we focus on the molecular SbCl(5) and HNO(3) intercalates, and the solid compound AlCl(3) Identifying the microscopic mechanism for the catalytic action of graphene is important, given the availability of large area graphene sheets, to spur research into new redox reactions for use in science and technology.", "author_names": [ "Razvan A Nistor", "Dennis M Newns", "Glenn J Martyna" ], "corpus_id": 22082998, "doc_id": "22082998", "n_citations": 67, "n_key_citations": 1, "score": 0, "title": "The role of chemistry in graphene doping for carbon based electronics.", "venue": "ACS nano", "year": 2011 }, { "abstract": "Carbon based nanomaterials such as carbon nanotubes (CNTs) and graphene, which possess superior electrical, thermal and mechanical properties, have been proposed as alternative materials for future electronics. The proposed applications span from the device level, replacing silicon based transistors, with single walled carbon nanotubes (SWCNTs) or graphene, to packaging level using multi walled carbon nanotubes (MWCNTs) for interconnects. To further exploit the potential of carbon based electronics in electronic packaging, a novel 3D all carbon based electronic system is targeted in this thesis. In order to achieve the goal of a 3D carbon based electronic system, this thesis addresses some of the technical issues including material synthesis, process compatibility and system integration. First of all, the synthesis of horizontally aligned SWCNTs (HA SWCNTs) vertically aligned MWCNTs (VA MWCNTs) and graphene were investigated for material preparation. Especially, growth of HA SWCNTs on a ST cut quartz substrate was the first time demonstrated in ac low pressure cold wall CVD with acetylene as a carbon precursor. In addition, the catalyst engineering of MWCNTs in a hexagonal pattern was performed to achieve high aspect ratio MWCNT bundles for through silicon via (TSV) interconnects. The transfer of CNTs and graphene was conducted to circumvent material synthesis incompatibilities with current semiconductor and packaging processes. In particular, tape assisted transfer of MWCNT bundles for TSVs has been proposed and experimentally demonstrated to increase the yield and efficiency. After the transfer of VA MWCNT bundle into the via, different polymers were used for filling the gap between the VA MWCNT bundle and the side walls of the via, and their performance was investigated and compared. In parallel, attempts were made to stack VA MWCNT filled TSVs, with and without using isotropic conductive adhesive. Electrical characterization was carried out at each step of the fabrication process.", "author_names": [ "Wei Mu" ], "corpus_id": 139843552, "doc_id": "139843552", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Towards 3D Integration of Carbon Based Electronics", "venue": "", "year": 2015 }, { "abstract": "Within the next decade, scientists and engineers who have been making silicon based electronic devices smaller and smaller will finally bump into fundamental limitations on the size of such devices. Some labs, though, are trying to smash through those limitations by developing new types of nanoscale electronics based on organic molecules or carbon nanotubes. Two advances in this quest were reported last week: A research team at Yale University and Rice University, Houston, has shown that an assemblage of wirelike organic molecules can function reversibly as a switch to turn current on and off Science 286 1550 (1999) And a team based at Delft University of Technology, the Netherlands, has shown experimentally that kinked nanotubes also can function as electronic devices Nature 402 273 (1999) To make the first advance, graduate student Adam M. Rawlett, working in chemistry professor James M. Tour's lab at Rice, synthesized a conjugated benzenethiol. Graduate student Jia Chen, working at Yale", "author_names": [ "Ron Dagani" ], "corpus_id": 111922825, "doc_id": "111922825", "n_citations": 278, "n_key_citations": 7, "score": 0, "title": "CARBON BASED ELECTRONICS", "venue": "", "year": 1999 } ]

[ { "abstract": "Two organolead halide perovskite nanocrystals, CH(3)NH(3)PbBr(3) and CH(3)NH(3)PbI(3) were found to efficiently sensitize TiO(2) for visible light conversion in photoelectrochemical cells. When self assembled on mesoporous TiO(2) films, the nanocrystalline perovskites exhibit strong band gap absorptions as semiconductors. The CH(3)NH(3)PbI(3) based photocell with spectral sensitivity of up to 800 nm yielded a solar energy conversion efficiency of 3.8% The CH(3)NH(3)PbBr(3) based cell showed a high photovoltage of 0.96 V with an external quantum conversion efficiency of 65%", "author_names": [ "Akihiro Kojima", "Kenjiro Teshima", "Yasuo Shirai", "Tsutomu Miyasaka" ], "corpus_id": 207136521, "doc_id": "207136521", "n_citations": 11745, "n_key_citations": 82, "score": 1, "title": "Organometal halide perovskites as visible light sensitizers for photovoltaic cells.", "venue": "Journal of the American Chemical Society", "year": 2009 }, { "abstract": "Nanocrystalline lead bromide perovskite was synthesized by rapid self organization on a mesoporous aluminum oxide film. With UV excitation, the film exhibited an intense green emission with a narro.", "author_names": [ "Akihiro Kojima", "Masashi Ikegami", "Kenjiro Teshima", "Tsutomu Miyasaka" ], "corpus_id": 94551461, "doc_id": "94551461", "n_citations": 269, "n_key_citations": 0, "score": 0, "title": "Highly Luminescent Lead Bromide Perovskite Nanoparticles Synthesized with Porous Alumina Media", "venue": "", "year": 2012 }, { "abstract": "Abstract Objectives: To elucidate the epidemiological characteristics of patients with rheumatoid arthritis (RA) in Japan using data from the Comprehensive Survey of Living Conditions, a nationwide questionnaire survey conducted in 2016. Methods: In total, 222,365 men and 245,251 women aged =16 years were included in the study. RA patients were defined as those who reported 'currently receiving treatment for RA at hospitals, clinics, or a facility for Japanese traditional massage, acupuncture, moxibustion, or judo orthopedics. The number of RA patients was estimated from the age specific prevalence and total Japanese population in 2016. Further, the prevalence of individuals experiencing difficulties in activities of daily living due to health problems and those with mental distress as evaluated by K6 Scale was examined. Results: The estimated number and prevalence of RA in Japan with 95% confidence interval was 822 (768 880) thousand and 0.75% (0.70 0.80% The population peaked in the late 60s, and the prevalence continued increasing until the early 80s, regardless of sex. Compared with non RA participants, RA patients were more likely to experience difficulties in activities and to be distressed. Conclusion: High prevalence of RA in older age and mental and physical burden among RA patients were confirmed.", "author_names": [ "Masayo Kojima", "Takeo Nakayama", "Kiichiro Tsutani", "Ataru Igarashi", "Toshihisa Kojima", "Sadao Suzuki", "Nobuyuki Miyasaka", "Hisashi Yamanaka" ], "corpus_id": 204773221, "doc_id": "204773221", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Epidemiological characteristics of rheumatoid arthritis in Japan: Prevalence estimates using a nationwide population based questionnaire survey", "venue": "Modern rheumatology", "year": 2019 }, { "abstract": "PURPOSE The beam model in radiation treatment planning systems (RTPSs) plays a crucial role in determining the accuracy of calculated dose distributions. The purpose of this study was to ascertain differences in beam models and their dosimetric influences when a golden beam dataset (GBD) and multi institution measured beam datasets (MBDs) are used for beam modeling in RTPSs. METHODS The MBDs collected from 15 institutions, and the MBDs' beam models, were compared with a GBD, and the GBD's beam model, for Varian TrueBeam linear accelerator. The calculated dose distributions of the MBDs' beam models were compared with those of the GBD's beam model for simple geometries in a water phantom. Calculated dose distributions were similarly evaluated in volumetric modulated arc therapy (VMAT) plans for TG 119 C shape and TG 244 head and neck, at several dose constraints of the planning target volumes (PTVs) and organs at risk. RESULTS The agreements of the MBDs with the GBD were almost all within 1% The calculated dose distributions for simple geometries in a water phantom also closely corresponded between the beam models of GBD and MBDs. Nevertheless, there were considerable differences between the beam models. The maximum differences between the mean energy of the energy spectra of GBD and MBDs were 0.12 MeV 10.5% in AcurosXB (AXB, Eclipse) and 0.11 MeV (7.7% in collapsed cone convolution (CCC, RayStation) The differences in the VMAT calculated dose distributions varied for each dose region, plan, X ray energy, and dose calculation algorithm. The ranges of the differences in the dose constraints were 5.6% to 3.0% for AXB and 24.1% to 2.8% for CCC. In several VMAT plans, the calculated dose distributions of GBD's beam model tended to be lower in high dose regions and higher in low dose regions than those of the MBDs' beam models. CONCLUSIONS We found that small differences in beam data have large impacts on the beam models, and on calculated dose distributions in clinical VMAT plan, even if beam data correspond within 1% GBD's beam model was not a representative beam model. The beam models of GBD and MBDs and their calculated dose distributions under clinical conditions were significantly different. These differences are most likely due to the extensive variation in the beam models, reflecting the characteristics of beam data. The energy spectrum and radial energy in the beam model varied in a wide range, even if the differences in the beam data were less than 1% To minimize the uncertainty of the calculated dose distributions in clinical plans, it was best to use the institutional MBD for beam modeling, or the beam model that ensures the accuracy of calculated dose distributions.", "author_names": [ "Kensuke Tani", "Akihisa Wakita", "Naoki Tohyama", "Yukio Fujita", "Satoshi Kito", "Ryo Miyasaka", "Norifumi Mizuno", "Ryuzo Uehara", "Toru Takakura", "Shunsuke Miyake", "Kazuya Shinoda", "Yoshitaka Oka", "Yasunori Saito", "H Kojima", "Naoki Hayashi" ], "corpus_id": 221887861, "doc_id": "221887861", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Evaluation of differences and dosimetric influences of beam models using golden and multi institutional measured beam datasets in radiation treatment planning systems.", "venue": "Medical physics", "year": 2020 }, { "abstract": "Abstract Objectives To evaluate the efficacy and safety of tacrolimus in adult patients with rheumatoid arthritis (RA) by using the GRADE approach. Methods We searched PubMed, Japana Centra Revuo Medicina Web (Ichu shi web) and the Cochrane Database of Systematic Reviews. Articles fulfilling the predefined inclusion criteria were appraised and used for meta analysis. The primary outcomes were American College of Rheumatology 20 (ACR20) and serum creatinine elevation. Other outcomes included ACR50, ACR70, changes in C reactive protein, modified Health Assessment Questionnaire Disability Index, gastrointestinal disorders, metabolic and nutritional disorders, and infections and infestations. Results We identified five randomized controlled studies, four of which compared tacrolimus to placebo and were included in the meta analysis. The risk ratio of ACR20 achievement was 1.71 (95% confidence interval [CI] 1.20 2.42) for 1 2 mg/day and 2.30 (95% CI 1.79 2.96) for 3 mg/day. The risk ratio of creatinine elevation was 1.95 (95% CI 1.18 3.23) for 1 2 mg/day and 3.81 (95% CI 2.43 5.99) for 3 mg/day. Conclusion Tacrolimus is effective with acceptable safety in the management of RA.", "author_names": [ "Yuko Kaneko", "Yutaka Kawahito", "Masayo Kojima", "Takeo Nakayama", "Shintaro Hirata", "Mitsumasa Kishimoto", "Hirahito Endo", "Yohei Seto", "Hiromu Ito", "Keiichiro Nishida", "Isao Matsushita", "Toshihisa Kojima", "Naoyuki Kamatani", "Kiichiro Tsutani", "Ataru Igarashi", "Mieko Hasegawa", "Nobuyuki Miyasaka", "Hisashi Yamanaka" ], "corpus_id": 210841682, "doc_id": "210841682", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Efficacy and safety of tacrolimus in patients with rheumatoid arthritis A systematic review and meta analysis", "venue": "Modern rheumatology", "year": 2020 }, { "abstract": "Carrier lifetime in low carrier concentration 4H SiC epitaxial layers grown on the C face was enhanced by using carbon implantation and post annealing. The measured carrier lifetime increased with the thickness of the epitaxial layer and was 11.4 us for the 150 um thick epitaxial layer. The internal carrier lifetime was estimated as 21 us from the dependence of the measured carrier lifetime on the epitaxial layer thickness. This value is almost comparable to the reported values of the internal carrier lifetime for the layers grown on the Si face.", "author_names": [ "Mitsuhiro Kushibe", "Johji Nishio", "Ryosuke Iijima", "Akira Miyasaka", "Hirokuni Asamizu", "Hidenori Kitai", "R Kosugi", "Shinsuke Harada", "Kazutoshi Kojima" ], "corpus_id": 139252651, "doc_id": "139252651", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Carrier Lifetimes in 4H SiC Epitaxial Layers on the C Face Enhanced by Carbon Implantation", "venue": "", "year": 2018 }, { "abstract": "To achieve low on state and switching losses simultaneously in SiC bipolar devices, the depth distribution of the carrier lifetime within the voltage blocking layer and the techniques used for observing the carrier lifetime distribution are important considerations. We developed a measurement system of the time resolved free carrier absorption with intersectional lights (IL TRFCA) for the nondestructive measurements of the depth distribution of the carrier lifetime in 4H SiC thick epilayers. To confirm the reliability of the measurement results, we also performed TRFCA measurements to the cross section of the samples. As a result, although the lifetimes are underestimated owing to an inevitable diffusion of the carriers from the measurement region, the system was able to observe a carrier lifetime distribution up to a depth of 250 mm. Our IL TRFCA system demonstrated a depth resolution of ~10 mm, which is the best resolution among previously reported nondestructive measurement techniques. We consider the proposed system to be useful for the development of SiC bipolar devices.", "author_names": [ "Takashi Hirayama", "Keisuke Nagaya", "Akira Miyasaka", "Kazutoshi Kojima", "Tomohisa Kato", "Hajime Okumura", "Masashi Kato" ], "corpus_id": 229931499, "doc_id": "229931499", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Nondestructive measurements of depth distribution of carrier lifetimes in 4H SiC thick epitaxial layers using time resolved free carrier absorption with intersectional lights.", "venue": "The Review of scientific instruments", "year": 2020 }, { "abstract": "The carrier lifetime is an important parameter for high voltage SiC bipolar devices because its distribution in drift layers affects the device performance. Observation techniques for carrier lifetime, along with the development of carrier lifetime control processes, are important to control carrier lifetime distribution. In this study, we developed a microscopic time resolved free carrier absorption system that has a variable spot size of excitation light and two different probe light wavelengths (405 and 637 nm) By selecting a relatively small spot size of excitation light and the probe light of shorter wavelength (405 nm) the distribution of carrier lifetime was observed with a high spatial resolution of ~3 mm. Additionally, by using a relatively large spot size of excitation light and the probe light that leads to stronger free carrier absorption (637 nm) an accurate measurement of carrier lifetime was obtained. The developed system enables the design and development of bipolar SiC devices with carrier lifetime distribution control.", "author_names": [ "Keisuke Nagaya", "Takashi Hirayama", "Takeshi Tawara", "K Murata", "Hidekazu Tsuchida", "Akira Miyasaka", "Hajime Okumura" ], "corpus_id": 225327054, "doc_id": "225327054", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Observation of carrier lifetime distribution in 4H SiC thick epilayers using microscopic time resolved free carrier absorption system", "venue": "", "year": 2020 }, { "abstract": "We fabricated 4H SiC N i P (N intrinsic P) diodes using newly developed low resistivity p type substrates with higher acceptor concentrations than conventional substrate. N i P diodes with 10 mm thick n drift layers were fabricated on both a low resistivity p type substrate and a conventional one to investigate the difference in substrate resistance and bipolar degradation with a heavily doped p type buffer layer. The differential on resistance of N i P diode, using low resistivity p type substrates was decreased to one third compared to the conventional case, and the difference was similar to the p type substrates resistivity. No stacking faults expansion was observed up to 1100 A cm 2. N i P diodes with 233 mm thick n drift layers were fabricated to demonstrate forward characteristics instead of an ultra high voltage n channel IGBTs. The forward characteristics of the N i P diodes with 233 mm thick n drift layers at 200 degC showed low on voltage 6.9 V and low differential on resistance 32.2 mO cm2.", "author_names": [ "Akihiro Koyama", "Mitsuru Sometani", "Kensuke Takenaka", "Koji Nakayama", "Akira Miyasaka", "Kazutoshi Kojima", "Kazuma Eto", "Tomohisa Kato", "Junji Senzaki", "Yoshiyuki Yonezawa", "Hajime Okumura" ], "corpus_id": 213773441, "doc_id": "213773441", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Low V F 4H SiC N i P diodes using newly developed low resistivity p type substrates", "venue": "", "year": 2020 }, { "abstract": "Purpose Strip meniscometry quantitatively measures the volume of tears in the tear meniscus and has been reported to diagnose dry eyes in clinical settings conveniently, easily, and rapidly. In this study, we used a modified strip meniscometry to assess the applicability of measuring the tear volume in mice in experimental settings. Methods Dry eye was induced in 11 9 week old C57BL/6J wild type male mice (11 right eyes) by exposing them to an air fan inside a small compartment for 5 hours for 2 consecutive days. Tear function tests, including the SMTube for mice (SMTM) for tear volume evaluation, break up time, fluorescein staining score, and lissamine green staining score, were performed. The correlation between SMTM and other tear function parameters was assessed. Results The mean SMTM value was 3.89 0.603 mm before and 3.09 0.625 mm after dry environment exposure (P 0.0078* The Spearman's correlation by rank test showed a strong positive correlation between SMTM and tear film break up time and a strong linear negative correlation with fluorescein and lissamine green values. Conclusions The SMTM was capable of rapidly measuring the minimum tear volume in mice and correlated well with tear function parameters and appears to be a promising new modality in the evaluation of dry eyes in mice.", "author_names": [ "Megumi Shinzawa", "Murat Dogru", "Keiichi Miyasaka", "Takashi Kojima", "Kazuo Tsubota" ], "corpus_id": 155101142, "doc_id": "155101142", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "The Application of Strip Meniscometry to the Evaluation of Tear Volume in Mice.", "venue": "Investigative ophthalmology visual science", "year": 2019 } ]

[ { "abstract": "Abstract With the rapid development of modern semiconductor industry, power free or self powered devices become an indispensable part in the electronic components and optoelectronic products. Epitaxial connected TMDs lateral heterojunctions with the maximum built in potential at the hetero interface offer fast separation of the photo generated electron hole (e h) pairs without an external bias, which make them promising for self powered devices. However, so far, the photovoltaic performance of such structures are rarely studied. Here, we report the photovoltaic light sensors based on individual monolayer MoS2 WS2 in plane heterostructures that were created through a one step synthesis strategy. The in situ second harmonic generation (SHG) characterizations of this monolayer in plane heterostructures directly demonstrate their underlying symmetry and high orientation. The photovoltaic photodetectors designed on individual MoS2 WS2 in plane samples that operate in a self powered mode (zero bias) exhibits a spectral responsivity (Rl) of 4.36 mA/W and detectivity (D* of 4.36 x 1013 Jones under 28.64 mW/cm2 532 nm. The primary characteristics of the lateral heterostructure devices are attributed to the built in potential at the interface. The initial self powered light sensor in a monolayer heterostructures combined with the scalable growth can be further applied in other 2D heterostructures.", "author_names": [ "Wanhui Wu", "Qi Zhang", "Xing Zhou", "Linfeng Li", "Jianwei Su", "Fakun Wang", "Tianyou Zhai" ], "corpus_id": 103891773, "doc_id": "103891773", "n_citations": 90, "n_key_citations": 0, "score": 1, "title": "Self powered photovoltaic photodetector established on lateral monolayer MoS2 WS2 heterostructures", "venue": "", "year": 2018 }, { "abstract": "Monolayer heterojunctions such as MoS2/WS2 are attractive for solar energy conversion applications because the interfacial electric field spatially separates charge carriers in less than 100 femtoseconds. Photoelectrochemical cells represent an intriguing platform to collect the spatially separated carriers. However, the recombination, transport, and interfacial charge transfer processes that take place following the ultrafast charge separation step have not been investigated. Here we demonstrate novel charge recombination and transport pathways in monolayer MoS2/WS2 photoelectrochemical cells by spatially resolving the net collection of carriers (i.e. the photocurrent) at the single nanosheet level. We discovered an excitation wavelength dependent recombination pathway that depends on the heterojunction stacking configuration and the carrier generation profile in the heterostructure. Photocurrent mapping measurements revealed that charge transport occurs parallel to the layers over micrometre scale distances even though the indium tin oxide electrode and liquid electrolyte provide efficient charge extraction pathways via intimate electron and hole selective contacts. Our results reveal how composition heterogeneity influences the performance of bulk heterojunction electrodes made from randomly oriented nanosheets and provide critical insight into the design of efficient heterojunction photoelectrodes for solar energy conversion applications.", "author_names": [ "Li Wang", "M Tahir", "Hongli Chen", "Justin B Sambur" ], "corpus_id": 208169780, "doc_id": "208169780", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Probing charge carrier transport and recombination pathways in monolayer MoS2/WS2 heterojunction photoelectrodes.", "venue": "Nano letters", "year": 2019 }, { "abstract": "2D monolayer molybdenum disulphide (MoS2) has been the focus of intense research due to its direct bandgap compared with the indirect bandgap of its bulk counterpart; however its photoluminescence (PL) intensity is limited due to its low absorption efficiency. Herein, we use gallium hemispherical nanoparticles (Ga NPs) deposited by thermal evaporation on top of chemical vapour deposited MoS2 monolayers in order to enhance its luminescence. The influence of the NP radius and the laser wavelength is reported in PL and Raman experiments. In addition, the physics behind the PL enhancement factor is investigated. The results indicate that the prominent enhancement is caused by the localized surface plasmon resonance of the Ga NPs induced by a charge transfer phenomenon. This work sheds light on the use of alternative metals, besides silver and gold, for the improvement of MoS2 luminescence.", "author_names": [ "Sergio Catalan-Gomez", "Sourav Garg", "Andres Redondo-Cubero", "Nuria Gordillo", "Alicia de Andres", "Flavio Nucciarelli", "Seonsing Kim", "Patrick Kung", "Jose Luis Pau" ], "corpus_id": 139224782, "doc_id": "139224782", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Photoluminescence enhancement of monolayer MoS2 using plasmonic gallium nanoparticles", "venue": "", "year": 2019 }, { "abstract": "Here we take a first step toward tackling the challenge of incomplete optical absorption in monolayers of transition metal dichalcogenides for conversion of photon energy, including solar, into other forms of energy. We present a monolayer MoS2 based photoelectrode architecture that exploits nanophotonic light management strategies to enhance absorption within the monolayer of MoS2, while simultaneously integrating an efficient charge carrier separation mechanism facilitated by a MoS2/NiOx heterojunction. Specifically, we demonstrate two extremely thin photoelectrode architectures for solar fuel generation: (i) a planar optical cavity architecture, MoS2/NiOx/Al, that improves optical impedance matching and (ii) an architecture employing plasmonic silver nanoparticles (Ag NPs) MoS2/Ag NPs/NiOx/Al, that further improves light absorption within the monolayer. We used a combination of numerical simulations, analytical models, and experimental optical characterizations to gain insights into the contributions", "author_names": [ "Shah Mohammad Bahauddin", "Hossein Robatjazi", "Isabell Thomann" ], "corpus_id": 124803609, "doc_id": "124803609", "n_citations": 79, "n_key_citations": 0, "score": 0, "title": "Broadband Absorption Engineering to Enhance Light Absorption in Monolayer MoS2", "venue": "", "year": 2016 }, { "abstract": "Novel physical phenomena can emerge in low dimensional nanomaterials. Bulk MoS(2) a prototypical metal dichalcogenide, is an indirect bandgap semiconductor with negligible photoluminescence. When the MoS(2) crystal is thinned to monolayer, however, a strong photoluminescence emerges, indicating an indirect to direct bandgap transition in this d electron system. This observation shows that quantum confinement in layered d electron materials like MoS(2) provides new opportunities for engineering the electronic structure of matter at the nanoscale.", "author_names": [ "Andrea Splendiani", "Liang Sun", "Yuanbo Zhang", "Tianshu Li", "Jonghwan Kim", "Chi Yung Chim", "Giulia Galli", "Feng Wang" ], "corpus_id": 1353329, "doc_id": "1353329", "n_citations": 5858, "n_key_citations": 71, "score": 0, "title": "Emerging photoluminescence in monolayer MoS2.", "venue": "Nano letters", "year": 2010 }, { "abstract": "Layer by layer stacking or lateral interfacing of atomic monolayers has opened up unprecedented opportunities to engineer two dimensional heteromaterials. Fabrication of such artificial heterostructures with atomically clean and sharp interfaces, however, is challenging. Here, we report a one step growth strategy for the creation of high quality vertically stacked as well as in plane interconnected heterostructures of WS2/MoS2 via control of the growth temperature. Vertically stacked bilayers with WS2 epitaxially grown on top of the MoS2 monolayer are formed with preferred stacking order at high temperature. A strong interlayer excitonic transition is observed due to the type II band alignment and to the clean interface of these bilayers. Vapour growth at low temperature, on the other hand, leads to lateral epitaxy of WS2 on MoS2 edges, creating seamless and atomically sharp in plane heterostructures that generate strong localized photoluminescence enhancement and intrinsic p n junctions. The fabrication of heterostructures from monolayers, using simple and scalable growth, paves the way for the creation of unprecedented two dimensional materials with exciting properties.", "author_names": [ "Yongji Gong", "Junhao Lin", "Xingli Wang", "Gang Shi", "Sidong Lei", "Zhong Lin", "Xiaolong Zou", "Gonglan Ye", "Robert Vajtai", "Boris I Yakobson", "Humberto Terrones", "Mauricio Terrones", "Bengkang Tay", "Jun Lou", "Sokrates T Pantelides", "Zheng Liu", "Wu Zhou", "Pulickel M Ajayan" ], "corpus_id": 205410476, "doc_id": "205410476", "n_citations": 1421, "n_key_citations": 13, "score": 0, "title": "Vertical and in plane heterostructures from WS2/MoS2 monolayers.", "venue": "Nature materials", "year": 2014 }, { "abstract": "The growth and exfoliation of two dimensional (2D) materials have led to the creation of edges and novel interfacial states at the juncture between crystals with different composition or phases. These hybrid heterostructures (HSs) can be built as vertical van der Waals stacks, resulting in a 2D interface, or as stitched adjacent monolayer crystals, resulting in one dimensional (1D) interfaces. Although most attention has been focused on vertical HSs, increasing theoretical and experimental interest in 1D interfaces is evident. In plane interfacial states between different 2D materials inherit properties from both crystals, giving rise to robust states with unique 1D non parabolic dispersion and strong spin orbit effects. With such unique characteristics, these states provide an exciting platform for realizing 1D physics. Here, we review and discuss advances in 1D heterojunctions, with emphasis on theoretical approaches for describing those between semiconducting transition metal dichalcogenides MX 2 (with M Mo, W and X S, Se, Te) and how the interfacial states can be characterized and utilized. We also address how the interfaces depend on edge geometries (such as zigzag and armchair) or strain, as lattice parameters differ across the interface, and how these features affect excitonic/optical response. This review is intended to serve as a resource for promoting theoretical and experimental studies in this rapidly evolving field.", "author_names": [ "Oscar Avalos-Ovando", "Diego Mastrogiuseppe", "Sergio E Ulloa" ], "corpus_id": 73507382, "doc_id": "73507382", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "Lateral heterostructures and one dimensional interfaces in 2D transition metal dichalcogenides.", "venue": "Journal of physics. Condensed matter an Institute of Physics journal", "year": 2019 }, { "abstract": "Atomically thin transition metal dichalcogenides (TMDC) have become a new platform for the development of next generation optoelectronic and light harvesting devices. Here, we report a Kelvin probe force microscopy (KPFM) investigation carried out on a type II photovoltaic heterojunction based on WSe2 monolayer flakes and a bilayer MoS2 film stacked in vertical configuration on a Si/SiO2 substrate. Band offset characterized by a significant interfacial dipole is pointed out at the WSe2/MoS2 vertical junction. The photocarrier generation process and phototransport are studied by applying a differential technique allowing to map directly two dimensional images of the surface photovoltage (SPV) over the vertical heterojunctions (vHJ) and in its immediate vicinity. Differential SPV reveals the impact of chemical defects on the photocarrier generation and that negative charges diffuse in the MoS2 a few hundreds of nanometers away from the vHJ. The analysis of the SPV data confirms unambiguously that light absorption results in the generation of free charge carriers that do not remain coulomb bound at the type II interface. A truly quantitative determination of the electron hole (e h) quasi Fermi levels splitting (i.e. the open circuit voltage) is achieved by measuring the differential vacuum level shift over the WSe2 flakes and the MoS2 layer. The dependence of the energy level splitting as a function of the optical power reveals that Shockley Read Hall processes significantly contribute to the interlayer recombination dynamics. Finally, a newly developed time resolved mode of the KPFM is applied to map the SPV decay time constants. The time resolved SPV images reveal the dynamics of delayed recombination processes originating from photocarriers trapping at the SiO2/TMDC interfaces.", "author_names": [ "Yann Almadori", "Nedjma Bendiab", "Benjamin Grevin" ], "corpus_id": 206472103, "doc_id": "206472103", "n_citations": 33, "n_key_citations": 0, "score": 0, "title": "Multimodal Kelvin Probe Force Microscopy Investigations of a Photovoltaic WSe2/MoS2 Type II Interface.", "venue": "ACS applied materials interfaces", "year": 2018 }, { "abstract": "Recent developments in synthesis and nanofabrication technologies offer the tantalizing prospect of realizing various applications from twodimensional (2D) materials. A revolutionary development is to flexibly construct many different kinds of heterostructures with a diversity of 2D materials. These 2D heterostructures play an important role in semiconductor and condensed matter physics studies and are promising candidates for new device designs in the fields of integrated circuits and quantum sciences. Theoretical and experimental studies have focused on both vertical and lateral 2D heterostructures; the lateral heterostructures are considered to be easier for planner integration and exhibit unique electronic and photoelectronic properties. In this review, we give a summary of the properties of lateral heterostructures with homogeneous junction and heterogeneous junction, where the homogeneous junctions have the same host materials and the heterogeneous junctions are combined with different materials. Afterward, we discuss the applications and experimental synthesis of lateral 2D heterostructures. Moreover, a perspective on lateral 2D heterostructures is", "author_names": [ "" ], "corpus_id": 198232920, "doc_id": "198232920", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Recent Advances in 2 D Lateral Heterostructures", "venue": "", "year": 2019 }, { "abstract": "Two dimensional (2 D) materials of atomic thickness have attracted considerable interest due to their excellent electrical, optoelectronic, mechanical, and thermal properties, which make them attractive for electronic devices, sensors, and energy systems. Scavenging the otherwise wasted energy from the ambient environment into electrical power holds promise to address the emerging energy needs, in particular for the portable and wearable devices. The versatile properties of 2 D materials together with their atomically thin body create diverse possibilities for the conversion of ambient energy. The present review focuses on the recent key advances in emerging energy harvesting devices based on monolayer 2 D materials through various mechanisms such as photovoltaic, thermoelectric, piezoelectric, triboelectric, and hydrovoltaic devices, as well as progress for harvesting the osmotic pressure and Wi Fi wireless energy. The representative achievements regarding the monolayer heterostructures and hybrid devices are also discussed. Finally, we provide a discussion of the challenges and opportunities for 2 D monolayer material based energy harvesting devices in the development of self powered electronics and wearable technologies.", "author_names": [ "Fengru Fan", "Wenzhuo Wu" ], "corpus_id": 208331438, "doc_id": "208331438", "n_citations": 15, "n_key_citations": 0, "score": 0, "title": "Emerging Devices Based on Two Dimensional Monolayer Materials for Energy Harvesting", "venue": "Research", "year": 2019 } ]

[ { "abstract": "Abstract Nanometer scale Pt metal islands formed by the dewetting of two dimensional film on SiO 2 dielectric materials during rapid thermal annealing were investigated. For the case of 30 nm thick Pt films, pattern formation and dewetting were initiated at temperatures of >600 degC. Controlling the annealing temperature and time as well as the thickness of the Pt metal film permitted the size and density of Pt islands to be controlled. Furthermore, the islands show good resistance to dry etching by a CF 4 based plasma for dielectric etching, indicating that the metal islands produced by dewetting are suitable for use as an etch mask in the fabrication of nano scale structures.", "author_names": [ "Ji-Myon Lee", "Byung-il Kim" ], "corpus_id": 137524195, "doc_id": "137524195", "n_citations": 67, "n_key_citations": 0, "score": 2, "title": "Thermal dewetting of Pt thin film Etch masks for the fabrication of semiconductor nanostructures", "venue": "", "year": 2007 }, { "abstract": "Transparent electronic devices formed on flexible substrates are expected to meet emerging technological demands where silicon based electronics cannot provide a solution. Examples of active flexible applications include paper displays and wearable computers. So far, mainly flexible devices based on hydrogenated amorphous silicon (a Si:H) and organic semiconductors have been investigated. However, the performance of these devices has been insufficient for use as transistors in practical computers and current driven organic light emitting diode displays. Fabricating high performance devices is challenging, owing to a trade off between processing temperature and device performance. Here, we propose to solve this problem by using a novel semiconducting material namely, a transparent amorphous oxide semiconductor from the In Ga Zn O system (a IGZO) for the active channel in transparent thin film transistors (TTFTs) The a IGZO is deposited on polyethylene terephthalate at room temperature and exhibits Hall effect mobilities exceeding 10 cm2 V 1 s 1, which is an order of magnitude larger than for hydrogenated amorphous silicon. TTFTs fabricated on polyethylene terephthalate sheets exhibit saturation mobilities of 6 9 cm2 V 1 s 1, and device characteristics are stable during repetitive bending of the TTFT sheet.", "author_names": [ "Kenji Nomura", "Hiromichi Ohta", "Akihiro Takagi", "Toshio Kamiya", "Masahiro Hirano", "Hideo Hosono" ], "corpus_id": 4302869, "doc_id": "4302869", "n_citations": 5272, "n_key_citations": 80, "score": 0, "title": "Room temperature fabrication of transparent flexible thin film transistors using amorphous oxide semiconductors", "venue": "Nature", "year": 2004 }, { "abstract": "A Review of Materials Science. Vacuum Science and Technology. Physical Vapor Deposition. Chemical Vapor Deposition. Film Formation and Structure. Characterization of Thin Films. Epitaxy. Interdiffusion and Reactions in Thin Films. Mechanical Properties of Thin Films. Electrical and Magnetic Properties of Thin Films. Optical Properties of Thin Films. Metallurgical and Protective Coatings. Modification of Surfaces and Films. Emerging Thin Film Materials and Applications. Appendixes. Index.", "author_names": [ "Milton Ohring" ], "corpus_id": 93992553, "doc_id": "93992553", "n_citations": 3087, "n_key_citations": 181, "score": 0, "title": "The Materials Science of Thin Films", "venue": "", "year": 1991 }, { "abstract": "This article provides a comprehensive review of current research activities that concentrate on one dimensional (1D) nanostructures wires, rods, belts, and tubes whose lateral dimensions fall anywhere in the range of 1 to 100 nm. We devote the most attention to 1D nanostructures that have been synthesized in relatively copious quantities using chemical methods. We begin this article with an overview of synthetic strategies that have been exploited to achieve 1D growth. We then elaborate on these approaches in the following four sections: i) anisotropic growth dictated by the crystallographic structure of a solid material; ii) anisotropic growth confined and directed by various templates; iii) anisotropic growth kinetically controlled by supersaturation or through the use of an appropriate capping reagent; and iv) new concepts not yet fully demonstrated, but with long term potential in generating 1D nanostructures. Following is a discussion of techniques for generating various types of important heterostructured nanowires. By the end of this article, we highlight a range of unique properties (e.g. thermal, mechanical, electronic, optoelectronic, optical, nonlinear optical, and field emission) associated with different types of 1D nanostructures. We also briefly discuss a number of methods potentially useful for assembling 1D nanostructures into functional devices based on crossbar junctions, and complex architectures such as 2D and 3D periodic lattices. We conclude this review with personal perspectives on the directions towards which future research on this new class of nanostructured materials might be directed.", "author_names": [ "Younan Xia", "Peidong Yang", "Yugang Sun", "Yiying Wu", "Brian T Mayers", "Byron D Gates", "Yadong Yin", "Franklin Kim", "Haoquan Yan" ], "corpus_id": 15196064, "doc_id": "15196064", "n_citations": 7118, "n_key_citations": 26, "score": 0, "title": "One Dimensional Nanostructures: Synthesis, Characterization, and Applications", "venue": "", "year": 2003 }, { "abstract": "A method for fabrication of nano scale GaN structure by inductively coupled plasma etching is proposed, exploiting a thermal dewetting of Pt thin film as an etch mask. The nano scale Pt metal islands were formed by dewetting of continuous film on SiO2 dielectric materials during the rapid thermal annealing process. For the Pt films with thickness of 30 nm, temperatures of 600degC initiate pattern formation and the dewetting of Pt films. Controlling the annealing temperature and time as well as the thickness of Pt metal film could manifest the size and density of Pt islands. The activation energy for initiation of Pt metal dewet was calculated to be 23.2 kJ/mole. The islands show good resistance against dry etching using CF4 based plasma for dielectric etching, indicating that the metal island by dewetting of thin film is suitable for etch mask in the fabrication of nano scale structures. This fabrication method was also proven to be effective in the fabrications of GaN nanocolumns with widths as small as nanometer scale.", "author_names": [ "Ji-Myon Lee", "Seong-Ju Park" ], "corpus_id": 119865175, "doc_id": "119865175", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Fabrication of nanostructures by dry etching using dewetted Pt islands as etch masks", "venue": "SPIE Optics Photonics", "year": 2005 }, { "abstract": "Principal goals in organic thin film transistor (OTFT) gate dielectric research include achieving: (i) low gate leakage currents and good chemical/thermal stability, (ii) minimized interface trap state densities to maximize charge transport efficiency, (iii) compatibility with both p and n channel organic semiconductors, (iv) enhanced capacitance to lower OTFT operating voltages, and (v) efficient fabrication via solution phase processing methods. In this Review, we focus on a prominent class of alternative gate dielectric materials: self assembled monolayers (SAMs) and multilayers (SAMTs) of organic molecules having good insulating properties and large capacitance values, requisite properties for addressing these challenges. We first describe the formation and properties of SAMs on various surfaces (metals and oxides) followed by a discussion of fundamental factors governing charge transport through SAMs. The last section focuses on the roles that SAMs and SAMTs play in OTFTs, such as surface treatments, gate dielectrics, and finally as the semiconductor layer in ultra thin OTFTs.", "author_names": [ "Sara A Dibenedetto", "Antonio F Facchetti", "Mark A Ratner", "Tobin J Marks" ], "corpus_id": 7268333, "doc_id": "7268333", "n_citations": 520, "n_key_citations": 2, "score": 0, "title": "Molecular self assembled monolayers and multilayers for organic and unconventional inorganic thin film transistor applications", "venue": "", "year": 2009 }, { "abstract": "Polymer solar cells are reviewed in the context of the processing techniques leading to complete devices. A distinction is made between the film forming techniques that are used currently such as spincoating, doctor blading and casting and the, from a processing point of view, more desirable film forming techniques such as slot die coating, gravure coating, knife over edge coating, off set coating, spray coating and printing techniques such as ink jet printing, pad printing and screen printing. The former are used almost exclusively and are not suited for high volume production whereas the latter are highly suited, but little explored in the context of polymer solar cells. A further distinction is made between printing and coating when a film is formed. The entire process leading to polymer solar cells is broken down into the individual steps and the available techniques and materials for each step are described with focus on the particular advantages and disadvantages associated with each case.", "author_names": [ "Frederik C Krebs" ], "corpus_id": 95382117, "doc_id": "95382117", "n_citations": 2813, "n_key_citations": 55, "score": 0, "title": "Fabrication and processing of polymer solar cells: A review of printing and coating techniques", "venue": "", "year": 2009 }, { "abstract": "A study of the dewetting behavior of platinum thin films on silicon was carried out to determine how variation of dewetting parameters affects the evolution of film morphology and to pinpoint which parameters yielded the smallest, most circular features. Platinum film thickness as well as dewetting time and temperature were varied and the film morphology characterized by means of scanning electron microscopy (SEM) analysis. Two different pathways of dewetting predicted in the literature (Vrij 1966 Discuss. Faraday Soc. 42 23, Becker et al 2003 Nat. Mater. 2 59 63) were observed. Depending on the initial criteria, restructuring of the film occurred via hole or droplet formation. With increased annealing time, a transition from an intermediate network structure to separated islands occurred. In addition, the formation of multilayered films, silicide crystals and nanowires occurred for certain parameters. Nevertheless, the dewetting behavior witnessed could be related to physical processes. Droplets with a mean diameter of 9 nm were formed by using a 1.5 nm thick platinum film annealed at 800 degC for 30 s. To demonstrate the suitability of the annealed films for further processing, we then used the dewetted films as masks for reactive ion etching to transfer the pattern into the silicon substrate, forming tapered nanopillars.", "author_names": [ "S Strobel", "Christopher R Kirkendall", "Jae-Byum Chang", "Karl K Berggren" ], "corpus_id": 10401777, "doc_id": "10401777", "n_citations": 77, "n_key_citations": 0, "score": 0, "title": "Sub 10 nm structures on silicon by thermal dewetting of platinum.", "venue": "Nanotechnology", "year": 2010 }, { "abstract": "In this paper, a simple and feasible method to fabricate a Ni nanodot mask on a silicon substrate is reported. Without using a high cost rapid thermal annealing (RTA) furnace, this method was based on the conventional thermal annealing of a Ni layer deposited on a Si substrate. In addition, the influences of the Ni layer thickness and annealing conditions on the size and density of the Ni nanodots were systematically investigated. The as prepared Ni nanodots were well distributed, having a uniform size and a regular spherical shape. Moreover, a Si nanopillar array could be fabricated by inductively coupled plasma (ICP) etching using the as obtained Ni nanodot array mask.", "author_names": [ "Xinliang Kuang", "J Tian", "H B Guo", "Yu Hou", "Hui Zhang", "T Y Liu" ], "corpus_id": 139834792, "doc_id": "139834792", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Feasible method to fabricate a nickel nanodot mask on a silicon substrate with conventional thermal annealing", "venue": "", "year": 2018 }, { "abstract": "This paper presents a non lithographic approach to generate wafer scale single crystal silicon nanowires (SiNWs) with controlled sidewall profile and surface morphology. The approach begins with silver (Ag) thin film thermal dewetting, gold (Au) deposition and lift off to generate a large scale Au mesh on Si substrates. This is followed by metal assisted chemical etching (MacEtch) where the Au mesh serves as a catalyst to produce arrays of smooth Si nanowires with tunable taper up to 13deg. The mean diameter of the thus fabricated SiNWs can be controlled to range from 62 to 300 nm with standard deviations as small as 13.6 nm, and the areal coverage of the wire arrays can be up to 46% Control of the mean wire diameter is achieved by controlling the pore diameter of the metallic mesh which is, in turn, controlled by adjusting the initial thin film thickness and deposition rate. To control the wire surface morphology, a post fabrication roughening step is added to the approach. This step uses Au nanoparticles and slow rate MacEtch to produce rms surface roughness up to 3.6 nm.", "author_names": [ "Bruno Azeredo", "Jyothi S Sadhu", "J W Ma", "Klaus Jacobs", "Jeongyong Kim", "Kipoong Lee", "James H Eraker", "Xufeng Li", "Sanjiv Sinha", "Nicholas Xuanlai Fang", "P N Ferreira", "Keng Hao Hsu" ], "corpus_id": 6072818, "doc_id": "6072818", "n_citations": 55, "n_key_citations": 0, "score": 0, "title": "Silicon nanowires with controlled sidewall profile and roughness fabricated by thin film dewetting and metal assisted chemical etching.", "venue": "Nanotechnology", "year": 2013 } ]

[ { "abstract": "We present a hybrid laser by using an InP reflective semiconductor optical amplifier chip butt coupled with a SiN tunable reflector chip. The laser wavelength tuning range is 160 nm and the linewidth is 30 kHz.", "author_names": [ "Yuyao Guo", "Linjie Zhou", "Gangqiang Zhou", "Ruiling Zhao", "Liangjun Lu", "Jianping Chen" ], "corpus_id": 221718481, "doc_id": "221718481", "n_citations": 0, "n_key_citations": 0, "score": 2, "title": "Hybrid External Cavity Laser with a 160 nm Tuning Range", "venue": "2020 Conference on Lasers and Electro Optics (CLEO)", "year": 2020 }, { "abstract": "We demonstrate a III V/silicon hybrid external cavity laser with a tuning range larger than 60 nm at the C band on a silicon on insulator platform. A III V semiconductor gain chip is hybridized into the silicon chip by edge coupling the silicon chip through a Si3N4 spot size converter. The demonstrated packaging method requires only passive alignment and is thus suitable for high volume production. The laser has a largest output power of 11 mW with a maximum wall plug efficiency of 4.2% tunability of 60 nm (more than covering the C band) and a side mode suppression ratio of 55 dB >46 dB across the C band) The lowest measured linewidth is 37 kHz <80 kHz across the C band) which is the narrowest linewidth using a silicon based external cavity. In addition, we successfully demonstrate all silicon photonics based transmission of 34 Gbaud (272 Gb/s) dual polarization 16 QAM using our integrated laser and silicon photonic coherent transceiver. The results show no additional penalty compared to commercially available narrow linewidth tunable lasers. To the best of our knowledge, this is the first experimental demonstration of a complete silicon photonic based coherent link. This is also the first experimental demonstration of >250 Gb/s coherent optical transmission using a silicon micro ring based tunable laser.", "author_names": [ "Hang Guan", "Ari Novack", "Tal Galfsky", "Yangjin Ma", "Saeed Fathololoumi", "Alexandre Horth", "Tam N Huynh", "Jose Roman", "Ruizhi Shi", "Michael Caverley", "Yang Liu", "Tom Baehr-Jones", "Keren Bergman", "Michael Hochberg" ], "corpus_id": 13747711, "doc_id": "13747711", "n_citations": 50, "n_key_citations": 1, "score": 0, "title": "Widely tunable, narrow linewidth III V/silicon hybrid external cavity laser for coherent communication.", "venue": "Optics express", "year": 2018 }, { "abstract": "An InGaAsP 1.5 mm laser, with one facet antireflection coated, has been incorporated into a diffraction grating external cavity. The lasing wavelength could be tuned over a 55 nm range about the centre wavelength of 1.5 mm by rotating the grating. Furthermore, it was found that the emission spectrum was extremely narrow; beat frequency measurements at 1523 nm against an HeNe laser showed it to be of the order of 10 kHz.", "author_names": [ "R Wyatt", "W J Devlin" ], "corpus_id": 111228155, "doc_id": "111228155", "n_citations": 300, "n_key_citations": 0, "score": 0, "title": "10 kHz linewidth 1.5 mm InGaAsP external cavity laser with 55 nm tuning range", "venue": "", "year": 1983 }, { "abstract": "We demonstrate two novel hybrid lasers with the same III V ultrawideband gain medium. An hybrid III V/Si laser and its III V/SiO2 counterpart exhibit high fiber coupled output power without booster semiconductor optical amplifier (up to +13 dBm for III V/Si and +10 dBm for III V/SiO2) and a record tuning range (respectively, 95 nm and 66 nm) over the C and L bands with side mode suppression ratio greater than 35 dB.", "author_names": [ "Agnes Verdier", "Guilhem de Valicourt", "Romain Brenot", "Helene Debregeas", "Po Dong", "Mark P Earnshaw", "Helene Carrere", "Young-Kai Chen" ], "corpus_id": 3399398, "doc_id": "3399398", "n_citations": 20, "n_key_citations": 1, "score": 0, "title": "Ultrawideband Wavelength Tunable Hybrid External Cavity Lasers", "venue": "Journal of Lightwave Technology", "year": 2018 }, { "abstract": "Summary from only given. InGaAsP InP strained multiquantum well structures similar to those described ins were used for tilted ridge waveguide (TRWG) gain chip fabrication. Lateral mode confinement is provided by a dual channel ridge waveguide structure prepared by conventional photolithography in conjunction with chemical etching.", "author_names": [ "I V Kudryashov", "A Komissarav", "N Morris", "Mikhail A Maiorov", "John C Connolly", "Dmitri Z Garbuzov", "Viktor Khalfin", "A M Braun", "G A Alphonse" ], "corpus_id": 117168233, "doc_id": "117168233", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "100 mW external cavity laser with a 1405 1575 nm tuning range", "venue": "CLEO 2002", "year": 2002 }, { "abstract": "We demonstrate a novel hybrid Ill V/Si laser, which exhibits high fiber coupled output power without booster SOA (up to +13 dBm at certain wavelengths) and a record tuning range (95nm) over the C and L band with side mode suppression ratio greater than 35 dB.", "author_names": [ "Guilhem de Valicourt", "Agnes Verdier", "Romain Brenot", "Y -K Chen", "Po Dong" ], "corpus_id": 38738122, "doc_id": "38738122", "n_citations": 7, "n_key_citations": 1, "score": 0, "title": "Integrated ultra wide band wavelength tunable hybrid external cavity silicon based laser", "venue": "2017 Optical Fiber Communications Conference and Exhibition (OFC)", "year": 2017 }, { "abstract": "A highly efficient silicon (Si) hybrid external cavity laser with a wavelength tunable ring reflector is fabricated on a complementary metal oxide semiconductor (CMOS) compatible Si on insulator (SOI) platform and experimental results with high output power are demonstrated. A III V semiconductor gain chip is edge coupled into a SOI cavity chip through a SiN(x) spot size converter and Si grating couplers are incorporated to enable wafer scale characterization. The laser output power reaches 20 mW and the highest wall plug efficiency of 7.8% is measured at 17.3 mW in un cooled condition. The laser wavelength tuning ranges are 8 nm for the single ring reflector cavity and 35 nm for the vernier ring reflector cavity, respectively. The Si hybrid laser is a promising light source for energy efficient Si CMOS photonic links.", "author_names": [ "Jin Hyoung Lee", "Ivan Shubin", "Jin Yao", "Justin Robert Bickford", "Ying Luo", "Shiyun Lin", "Stevan S Djordjevic", "Hiren D Thacker", "John E Cunningham", "Kannan Raj", "Xuezhe Zheng", "Ashok V Krishnamoorthy" ], "corpus_id": 31748867, "doc_id": "31748867", "n_citations": 60, "n_key_citations": 0, "score": 0, "title": "High power and widely tunable Si hybrid external cavity laser for power efficient Si photonics WDM links.", "venue": "Optics express", "year": 2014 }, { "abstract": "A Si/III V hybrid laser has been a highly sought after device for energy efficient and cost effective high speed silicon photonics communication. We present a high wall plug efficiency external cavity hybrid laser created by integrating an independently optimized SOI ring reflector and a III V gain chip. In our demonstration, the uncooled integrated laser achieved a waveguide coupled wall plug efficiency of 12.2% at room temperature with an optical output power of ~10 mW. The laser operated single mode near 1550 nm with a linewidth of 0.22 pm. This is a tunable light source with 8 nm wavelength tuning range. A proof of concept laser wavelength stabilization technique has also been demonstrated. Using a simple feedback loop, we achieved mode hop free operation in a packaged external cavity hybrid laser as bias current was varied by 60mA.", "author_names": [ "Jin-Hyoung Lee", "J T Bovington", "Ivan Shubin", "Ying Luo", "Jin Yao", "Shiyun Lin", "John E Cunningham", "Kannan Raj", "Ashok V Krishnamoorthy", "Xuezhe Zheng" ], "corpus_id": 21991550, "doc_id": "21991550", "n_citations": 32, "n_key_citations": 2, "score": 0, "title": "Demonstration of 12.2% wall plug efficiency in uncooled single mode external cavity tunable Si/III V hybrid laser.", "venue": "Optics express", "year": 2015 }, { "abstract": "Combining a semiconductor optical amplifier with a long and low loss external laser cavity made of dielectric integrated circuits has the advantage of obtaining extremely narrow laser linewidths. However, extending the cavity length also reduces the cavity mode spacing, and this spectral interval forms the fundamental limit for wavelength tuning without perturbing mode hops. The InP Si3N4 hybrid integrated laser we consider here has a mode spacing of 5 GHz. The external cavity consists of a phase section and a wavelength tunable filter, which is formed by two microring resonators. Via the phase section alone, mode hop free tuning was measured to be limited to 5 GHz as expected. We demonstrate that this range can be significantly extended, here to over 28 GHz, by tuning the phase section simultaneously and properly with the microring resonators. The results indicate that both a narrow linewidth and a broad mode hop free tuning range can be achieved with a chip based laser.", "author_names": [ "Albert van Rees", "Edwin Jan Klein", "Dimitri Geskus", "Youwen Fan", "Klaus J Boller" ], "corpus_id": 202214502, "doc_id": "202214502", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Mode hop free tuning of a chip based InP Si3N4 hybrid laser", "venue": "", "year": 2019 }, { "abstract": "We present an integrated semiconductor dielectric hybrid dual frequency laser operating in the 1.5 \\mu$m wavelength range for microwave and terahertz (THz) generation. Generating a microwave beat frequency near 11 GHz, we observe a record narrow intrinsic linewidth as low as about 2 kHz. This is realized by hybrid integration of a single diode amplifier based on indium phosphide (InP) with a long, low loss silicon nitride (Si$_3$N$_4$ feedback circuit to extend the cavity photon lifetime, resulting in a cavity optical roundtrip length of about 30 cm on a chip. Simultaneous lasing at two frequencies is enabled by introducing an external control parameter for balancing the feedback from two tunable, frequency selective Vernier mirrors on the Si$_3$N$_4$ chip. Each frequency can be tuned with a wavelength coverage of about 80 nm, potentially allowing for the generation of a broad range of frequencies in the microwave range up to the THz range.", "author_names": [ "Jesse Mak", "Albert van Rees", "Rob E M Lammerink", "Dimitri Geskus", "Youwen Fan", "Peter J M van der Slot", "Chris G H Roeloffzen", "Klaus J Boller" ], "corpus_id": 229155910, "doc_id": "229155910", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "High spectral purity microwave generation using a dual frequency hybrid integrated semiconductor dielectric waveguide laser", "venue": "OSA Continuum", "year": 2021 } ]

[ { "abstract": "In recent years, optical chaos as a new research hotspot has attracted extensive attention. In order to improve the performance of chaos based applications, we need to study the numerical value of its output chaotic signal. In this contribution, the effects of injection parameters, i.e. the frequency detuning and injection strength, on time delay signature (TDS) concealment and bandwidth enhancement of the three cascade coupled semiconductor ring lasers (SRLs) are numerically investigated. The results show that, under the proper conditions, both the TDS elimination and bandwidth enhancement can be reached in the third SRL of cascade coupled system.", "author_names": [ "Penghua Mu", "Junyan Tao" ], "corpus_id": 235716465, "doc_id": "235716465", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Numerical study of the time delay signature concealment and bandwidth enhancement in semiconductor ring laser", "venue": "International Conference on Laser, Optics and Optoelectronic Technology", "year": 2021 }, { "abstract": "Graphene has emerged excellent electronic, optical and mechanical properties as a layered semiconductor, and opening its bandgap through modulation further expands its practical applications. Direct laser writing has been widely used in material modulation, owing to its high precision, convenient local processing capacity. As an important factor, laser parameters play a crucial role in the ablation of materials. In this paper, the influence of laser parameters on the ablation was investigated by adjusting the energy and numbers of laser pulse. The saturation of ablation was found in the case of 500 pulses, and the ablation threshold of graphene paper was calculated to be 0.2 J/cm2. The results above have a positive effect on the modulation and the further devices fabrication of graphene paper.", "author_names": [ "ManLou Ye", "Baoshan Guo" ], "corpus_id": 235716602, "doc_id": "235716602", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Study on the ablation of layered semiconductor material by femtosecond laser", "venue": "International Conference on Laser, Optics and Optoelectronic Technology", "year": 2021 }, { "abstract": "Abstract We demonstrate a diode pumped femtosecond Yb:CaGdAlO4 (Yb:CALGO) laser with a semiconductor saturable absorber mirror (SESAM) for stable mode locking operation. A perfect beam profile is measured under 10 W output power with $M_{x}{2} 1.017 and $M_{y}{2} 1.016 in the horizontal and vertical directions, respectively. At the repetition rate of 71.66 MHz, the optical pulse duration is 247 fs and the pulse energy is 140 nJ at the central wavelength of 1041 nm, corresponding to a peak power of 0.56 MW. In addition, we also generate continuous wave (CW) power of more than 15 W with TEM00 mode, corresponding to an optical to optical efficiency of 44.1%", "author_names": [ "Jinfang Yang", "Jiajun Song", "Renchong Lv", "Xianzhi Wang", "Zhiyi Wei" ], "corpus_id": 235612928, "doc_id": "235612928", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Diode pumped 10 W femtosecond Yb:CALGO laser with high beam quality", "venue": "High Power Laser Science and Engineering", "year": 2021 }, { "abstract": "The current global situation has caused semiconductor fabless business organizations to be constantly under multiple constraints, such as forecasted customer demand changes, business flexibility needs, cash preservation and uncertain global macro economic conditions are leading to a laser sharp focus within supporting operations groups to manage the stakeholder expectations within a defined program. Focusing on supporting organization, this paper aims to demonstrate how to integrate the supporting operations organization to manage, address, align and prioritize urgencies across all internal stakeholders. This paper discusses key mechanisms to improve stakeholder alignment within the organization, and specifically addressing alignment, governance of Business Lines (BL) to support the group's strategies, and interfacing with external supplier partners. The application of these mechanisms have shown practical improvements in stakeholder expectations management, thereby resulting in speedier escalation resolutions with reference to wafer capacity, supply continuity and pricing.", "author_names": [ "Salvin Macwan", "Josephine Quek", "Scott Rogers", "Marc De Zwart" ], "corpus_id": 235206373, "doc_id": "235206373", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Fabless Semiconductor Challenge Internal Stakeholder Alignment Improvements", "venue": "2021 32nd Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC)", "year": 2021 }, { "abstract": "In complex integrated circuits, transistor elements are essential circuit elements that determine the overall performance of the semiconductor device. Improvements in the performance of transistor devices leads to differently doped regions that are formed in the semiconductor substrate. For high performance transistors, very shallow dopant junctions are in contact with the source/drain regions and partially beneath the gate electrode in the semiconductor substrate. Activation of the dopants in these junctions, as well as dopants in deep source/drain regions, can be achieved using a very fast laser heating process known as laser spike annealing (LSA).The Laser Spike Anneal (LSA) process has stringent quality requirements. On the one hand, temperature stable annealing must be guaranteed, which requires stable operation of the laser (e.g. energy density, beam profile) Accurate positioning of the wafer in the LSA process tool is also important. Should the wafer be misaligned, the laser may go beyond the edge die and make contact with the bevel, resulting in a high risk of wafer breakage. In addition, correct and stable alignment enables annealing with significantly smaller edge exclusions.The integrated SURFmonitor(tm) feature of the KLA Surfscan(r) SP5, a defect inspection system for blanket wafers, was utilized successfully to highlight the variation of the LSA process performance.The study will focus on ensuring correct positioning of the wafer during the anneal process. Monitoring the stability of the annealing process is well known and is only mentioned here in passing.", "author_names": [ "Karen M Wendt", "John N Newby" ], "corpus_id": 235206546, "doc_id": "235206546", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "The use of cross section haze measurements to monitor Laser Spike Anneal (LSA) stage alignment", "venue": "2021 32nd Annual SEMI Advanced Semiconductor Manufacturing Conference (ASMC)", "year": 2021 }, { "abstract": "In this study, the imaging of metal ions and nanoparticles deposited on a structured silicon surface was investigated using a laser ablation inductively coupled plasma mass spectrometry (LA ICP MS) For application, 8 <inline formula> <tex math notation=\"LaTeX\"\\times /tex math>/inline formula> 8 Petri dish pillars, each with a diameter of 250 <inline formula> <tex math notation=\"LaTeX\"\\mu \\text{m} /tex math>/inline formula> and height of 300 <inline formula> <tex math notation=\"LaTeX\"\\mu \\text{m} /tex math>/inline formula> were constructed on a silicon wafer. The etched pillar surface took a droplet of approximately 4.3 nL aqueous solution from a capillary tip through the surface liquid attraction. The dissolved materials were found at the intersecting edge of pillar bottom after evaporation, and their positions were matched with the peaks of elements in the mass spectrum for imaging. Results suggest that the trace contaminants in the cleaning solution are gathered at the intersecting edges of the patterned wafer, and the multi elemental images of the contaminants can be successfully obtained using LA ICP MS.", "author_names": [ "H B Lim", "Katherine M McLachlin", "Ciaran O'Connor", "Daniel R Wiederin", "Hyuck Ki Hong" ], "corpus_id": 233877355, "doc_id": "233877355", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Imaging of Metal Ions and Nanoparticles on Structured Silicon Surface Using Laser Ablation Inductively Coupled Plasma Mass Spectrometer for Contamination Control in Semiconductor Manufacturing Process", "venue": "IEEE Transactions on Semiconductor Manufacturing", "year": 2021 }, { "abstract": "Abstract Narrowband microwave generation with tuneable frequency is demonstrated by illuminating a photoconductive semiconductor switch (PCSS) with a burst mode fibre laser. The whole system is composed of a high power linearly polarized burst mode pulsed fibre laser and a linear state PCSS. To obtain a high performance microwave signal, a desired envelope of burst is necessary and a pulse pre compensation technique is adopted to avoid envelope distortion induced by the gain saturation effect. Resulting from the technique, homogenous peak power distribution in each burst is ensured. The maximum energy of the laser burst pulse reaches 200 mJ with a burst duration of 100 ns at the average power of 10 W, corresponding to a peak power of 4 kW. When the PCSS is illuminated by the burst mode fibre laser, narrowband microwave generation with tuneable frequency (0.80 1.12 GHz) is obtained with a power up to 300 W. To the best of the authors' knowledge, it is the first demonstration of frequency tuneable narrowband microwave generation based on a fibre laser. The high power burst mode fibre laser reported here has great potential for generating high power arbitrary microwave signals for a great deal of applicable demands such as smart adaptive radar and intelligent high power microwave systems.", "author_names": [ "Xuan He", "Bin Zhang", "Shuailin Liu", "Jinmei Yao", "Qilin Wu", "Yu-xin Zhao", "Tao Xun", "Jing Hou" ], "corpus_id": 233205851, "doc_id": "233205851", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "High power linear polarization burst mode all fibre laser and generation of frequency adjustable microwave signal", "venue": "High Power Laser Science and Engineering", "year": 2021 }, { "abstract": "Various forms of light therapy have been practiced around the world for many years. Among them the laser therapy has experienced a prosperous development in recent years. More and more laser equipment has been used in this field. In this study, we present an optical pumped vertical external cavity surface emitting laser (OP VECSEL) system using semiconductor gain chip as the lasering material. Through carefully design of the semiconductor gain chip structure, the fundamental and frequency doubled laser emitting wavelength can be set to the range of 1040 1160nm and 520nm 580nm which is the mainly laser tissue interact wavelength range for laser therapy. In a flat concave short cavity laser assembly test, the maximum fundamental frequency output power of the system is 1.6W using a 2% output coupler. Through a frequency doubling crystal, the continuous output power of the yellow green light can achieve 24mW.", "author_names": [ "Jonathan Li", "Chao Wang", "Xin Wei", "Chuanchuan Li" ], "corpus_id": 227075302, "doc_id": "227075302", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "530 580nm optical pumped vertical external cavity surface emitting lasers for laser therapy", "venue": "Applied Optics and Photonics China", "year": 2020 }, { "abstract": "We present the study on the dynamics of a semiconductor laser with a tunable Fabry Perot filter and a ring single mode fiber based long cavity. Theoretically and experimentally, we analyse dynamical regimes of the laser in various operation regimes, including stable and chaotic dynamics and the formation of coherent structures. The laser coherence build up is studied during the turn on, as well as different scenarios of coherence deterioration in such lasers are examined.", "author_names": [ "Svetlana Slepneva", "Amy Roche", "U Gouda", "Alexander Pimenov", "Anton Kovalev", "M Marconi", "M Giudici", "Evgeny A Viktorov", "Andrei G Vladimirov", "Guillaume Huyet" ], "corpus_id": 229311196, "doc_id": "229311196", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Nonlinear Dynamics in a Long Cavity Semiconductor Laser", "venue": "2020 International Conference Laser Optics (ICLO)", "year": 2020 }, { "abstract": "We demonstrate generation of \"droplet\" Bessel beams using semiconductor laser and an axicon with rounded tip. Interference of Bessel and Gaussian wave fronts leads to cancellation of side lobes of Bessel beam.", "author_names": [ "S H Abdulrazak", "D V Chistyakov", "Sergey N Losev", "V Yu Myl'nikov", "Yu M Zadiranov", "N G Deryagin", "Vladislav V Dudelev", "Vladimir I Kuchinskii", "Grigorii S Sokolovskii" ], "corpus_id": 229308390, "doc_id": "229308390", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Cancellation of side lobes in \"droplet\" Bessel beams generated with semiconductor laser", "venue": "2020 International Conference Laser Optics (ICLO)", "year": 2020 } ]

[ { "abstract": "Fluorescent carbon nanoparticles or carbon quantum dots (CQDs) are a new class of carbon nanomaterials that have emerged recently and have garnered much interest as potential competitors to conventional semiconductor quantum dots. In addition to their comparable optical properties, CQDs have the desired advantages of low toxicity, environmental friendliness low cost and simple synthetic routes. Moreover, surface passivation and functionalization of CQDs allow for the control of their physicochemical properties. Since their discovery, CQDs have found many applications in the fields of chemical sensing, biosensing, bioimaging, nanomedicine, photocatalysis and electrocatalysis. This article reviews the progress in the research and development of CQDs with an emphasis on their synthesis, functionalization and technical applications along with some discussion on challenges and perspectives in this exciting and promising field.", "author_names": [ "Shi Ying Lim", "Wei Shen", "Zhiqiang Gao" ], "corpus_id": 19393519, "doc_id": "19393519", "n_citations": 2473, "n_key_citations": 21, "score": 2, "title": "Carbon quantum dots and their applications.", "venue": "Chemical Society reviews", "year": 2015 }, { "abstract": "Abstract Background In recent years, carbon quantum dots (CQDs) has received a lot of attentions owing to their great physical and optical properties. There are different kinds of carbon sources applied in various fields, however, CQDs used in the food industry have higher requirements for their safety. Therefore, it is the best way to use natural materials for preparing CQDs without the participation of chemicals. Up to now, there are many natural food products for preparing CQDs. However, food waste is often overlooked. Actually, food waste is rich in carbon sources. And the efficient utilization of food waste plays a positive role in economic benefit and environmental pollution. Scope and approach Proper use of food waste as carbon source not only facilitates food safety detection but also increases byproduct value. This paper was intended to review the research progress of food waste utilization as carbon precursor and applications in food safety detection. The approaches of preparing CQDs from different sorts of food wastes, the characteristics and applications of CQDs were described in detail. Particularly the applications in food quality and safety detection including food additives, heavy metal ions were also elaborated. Key findings and conclusions Currently, food waste as carbon source could be divided into plant byproducts, animal food byproducts and food processing byproducts. Moreover, there are many applications of food waste as carbon precursor in CQDs technology to detect food additives and heavy metal ions. However, detection of pathogens and other harmful substances in food industry is rare. Last but not least, it was concluded that food waste had potential to prepare CQDs and be applied to food safety detection.", "author_names": [ "Hanzhi Fan", "Min Zhang", "Bhesh R Bhandari", "Chaohui Yang" ], "corpus_id": 209603758, "doc_id": "209603758", "n_citations": 37, "n_key_citations": 1, "score": 0, "title": "Food waste as a carbon source in carbon quantum dots technology and their applications in food safety detection", "venue": "", "year": 2020 }, { "abstract": "Carbon quantum dots (CQDs) as an emerging class of quantum dots (QDs) with advantages such as good photoluminescence (PL) properties, easy synthesis routes, economical synthesis, cheap starting materials, water solubility, low levels of toxicity, chemical stability, and easy functionalization have received great attention during recent years. CQDs have been used in versatile sensor applications. CQD sensors could be ultimately sensitive, and the limit of detection (LOD) for these sensors can reach the nanomolar, picomolar or even femtomolar ranges. CQD based sensors and biosensors work with different mechanisms including fluorescence quenching, static quenching, dynamic quenching, energy transfer, inner filter effect (IFE) photo induced electron transfer (PET) and fluorescence resonance energy transfer (FRET) CQD based sensors and biosensors have been applied for the detection of different species such as metal ions, acids, proteins, biothiols, polypeptides, DNA and miRNA, water pollutants, hematin, drugs, vitamins, and other chemicals. It seems that CQD based sensors and biosensors are promising candidates for high performance and yet accurate sensors in different areas. In this review, CQDs are introduced, and the synthesis methods and optical properties of CQDs are discussed. Different types of CQD based sensors and biosensors and their working mechanisms are clarified.", "author_names": [ "Mohammad Jafar Molaei" ], "corpus_id": 213782522, "doc_id": "213782522", "n_citations": 46, "n_key_citations": 0, "score": 0, "title": "Principles, mechanisms, and application of carbon quantum dots in sensors: a review", "venue": "", "year": 2020 }, { "abstract": "Carbon quantum dots (CQDs) are a fascinating class of carbon nanoparticles with sizes around 10 nm. The unique properties of CQDs are low toxicity, chemical inertness, excellent biocompatibility, photo induced electron transfer and highly tunable photoluminescence behaviour. Sustainable raw materials are commonly used for the fabrication of CQDs because they are cost effective, eco friendly and effective to minimise waste production. CQDs can be fabricated using laser ablation, microwave irradiation, hydrothermal reaction, electrochemical oxidation, reflux method and ultrasonication. These methods undergo several chemical reactions such as oxidation, carbonisation, pyrolysis and polymerisation processes to produce CQDs. Due to small particle sizes of CQDs, they possess strong tunable fluorescent properties and highly photo luminescent emissions. It also contains oxygen based functional groups and highly desired properties as semiconductor nanoparticles. Therefore, CQDs are promising nanomaterials for photo catalysis, ions sensing, biological imaging, heavy metal detection, adsorption treatment, supercapacitor, membrane fabrication and water pollution treatment. This review paper will discuss the physical and chemical properties of CQDs, raw materials and methods used in the fabrication of CQDs, the stability of CQDs as well as their potential applications in wastewater treatment and biomedical field.", "author_names": [ "Umairah Abd Rani", "Law Yong Ng", "Ching Yin Ng", "Ebrahim Mahmoudi" ], "corpus_id": 212621591, "doc_id": "212621591", "n_citations": 36, "n_key_citations": 0, "score": 0, "title": "A review of carbon quantum dots and their applications in wastewater treatment.", "venue": "Advances in colloid and interface science", "year": 2020 }, { "abstract": "Abstract Carbon quantum dots (CQDs) are emerging nanostructures which consist of carbon atoms and are typically below 10 nm in size. The CQDs are almost surface passivated or are functionalized with organics or biomolecules. CQDs have superior properties such as fluorescence emission, water solubility, cheap and easy synthesis methods, low toxicity, biocompatibility, easy functionalization, and chemical inertness. The CQDs have found versatile applications in different areas such as in vivo and in vitro bioimaging, drug delivery, gene delivery, sensors, solar energy conversion, photoelectrochemical (PEC) cells, photovoltaic solar cells, photocatalysis, and light emitting diodes (LEDs) CQDs could impart in photocatalytic reactions from two aspects; CQDs can be used alongside semiconductors as electron sink and could suppress electron hole recombination and also CQDs can generate electron hole pairs, as well. The CQDs with a wide spectral absorption and high absorption coefficients can enhance the photocatalytic activity. CQDs can also be used as sensitizers in the photoanode of solar cells. Due to the low cost and low toxicity of the CQDs in comparison to semiconductor quantum dots (QDs) they could be considered as potential alternatives in solar energy conversion applications. In this review, the CQDs are introduced and their optical properties are clarified. Recent advances of the CQDs in photocatalysis, PEC, and solar cells are reviewed.", "author_names": [ "Mohammad Jafar Molaei" ], "corpus_id": 214437247, "doc_id": "214437247", "n_citations": 44, "n_key_citations": 0, "score": 0, "title": "The optical properties and solar energy conversion applications of carbon quantum dots: A review", "venue": "", "year": 2020 }, { "abstract": "Carbon quantum dots (CQDs) have shown great potential in optoelectronic applications. Very recently, CQDs have attracted much attention in white emitting diodes (WLEDs) for lighting due to their characteristic broad emission, tunable fluorescence emission and high thermal stability. This mini review updates the latest research in the design of high performance WLEDs with different correlated color temperatures by tuning the red component using red emissive CQDs and single component white emissive CQDs (SCWE CQDs) The prospects for the development of CQD based WLEDs with higher efficiency and color quality will be discussed.", "author_names": [ "Ping He", "Yuxin Shi", "Ting Meng", "Ting Yuan", "Yunchao Li", "Xiaohong Li", "Yang Zhang", "Louzhen Fan", "Shihe Yang" ], "corpus_id": 211133823, "doc_id": "211133823", "n_citations": 30, "n_key_citations": 0, "score": 0, "title": "Recent advances in white light emitting diodes of carbon quantum dots.", "venue": "Nanoscale", "year": 2020 }, { "abstract": "Carbon quantum dots (CQDs) are widely used in optoelectronic catalysis, biological imaging, and ion probes owing to their low toxicity, stable photoluminescence, and ease of chemical modification. However, the low fluorescence yield and monochromatic fluorescence of CQDs limit their practical applications. This review summarizes the commonly used approaches for improving the fluorescence efficiency of CQDs doped with non metallic (heteroatom) elements. Herein, three types of heteroatom doped CQDs have been investigated: (1) CQDs doped with a single heteroatom; (2) CQDs doped with two heteroatoms; and (3) CQDs doped with three heteroatoms. The limitations and future perspectives of doped CQDs from the viewpoint of producing CQDs for specific applications, especially for bioimaging and light emitting diodes, have also been discussed herein.", "author_names": [ "Xiaoli Kou", "Shi-cui Jiang", "Soo-Jin Park", "Long-Yue Meng" ], "corpus_id": 218618610, "doc_id": "218618610", "n_citations": 23, "n_key_citations": 0, "score": 0, "title": "A review: recent advances in preparations and applications of heteroatom doped carbon quantum dots.", "venue": "Dalton transactions", "year": 2020 }, { "abstract": "Carbon quantum dots (CQDs) with stable physicochemical properties are one of the emerging carbon nanomaterials that have been studied in recent years. In addition to the excellent optical properties such as photoluminescence, photobleaching resistance and light stability, this material also has favorable advantages of good biocompatibility and easy functionalization, which make it an ideal raw material for constructing sensing equipment. In addition, CQDs can combined with other kinds of materials to form the nanostructured composites with unique properties, which provides new insights and ideas for the research of many fields. In the field of food analysis, emerging CQDs have been deeply studied in food composition analysis, detection and monitoring trace harmful substances and made remarkable research progress. This article introduces and compares the various methods for CQDs preparation and reviews its related sensing applications as a new material in food components analysis and food safety inspection in recent years. It is expected to provide a significant guidance for the further study of CQDs in the field of food analysis and detection.", "author_names": [ "Mingfei Pan", "Xiaoqian Xie", "Kaixin Liu", "Jingying Yang", "Liping Hong", "Shuo Wang" ], "corpus_id": 218634330, "doc_id": "218634330", "n_citations": 18, "n_key_citations": 0, "score": 1, "title": "Fluorescent Carbon Quantum Dots Synthesis, Functionalization and Sensing Application in Food Analysis", "venue": "Nanomaterials", "year": 2020 }, { "abstract": "Neuro transmitters have been considered to be essential biochemical molecules, which monitor physiological and behavioral function in the peripheral and central nervous systems. Thus, it is of high pharmaceutical and biological significance to analyze neuro transmitters in the biological samples. So far, researchers have devised a lot of techniques for assaying these samples. It has been found that electro chemical sensors possess features of robustness, selectivity, and sensitivity as well as real time measurement. Graphene quantum dots (GQDs) and carbon QDs (CQDs) are considered some of the most promising carbon based nanomaterials at the forefront of this research area. This is due to their characteristics including lower toxicity, higher solubility in various solvents, great electronic features, strong chemical inertness, high specific surface areas, plenty of edge sites for functionalization, and versatility, in addition to their ability to be modified via absorbent surface chemicals and the addition of modifiers or nano materials. Hence in the present review, the synthesis methods of GQDs and CQDs has been summarized and their characterization methods also been analyzed. The applications of carbon based QDs (GQDs and CQDs) in biological and sensing areas, such as biological imaging, drug/gene delivery, antibacterial and antioxidant activity, photoluminescence sensors, electrochemiluminescence sensors and electrochemical sensors, have also been discussed. This study then covers sensing features of key neurotransmitters, including dopamine, tyrosine, epinephrine, norepinephrine, serotonin and acetylcholine. Hence, issues and challenges of the GQDs and CQDs were analyzed for their further development.", "author_names": [ "S Tajik", "Zahra Dourandish", "Kaiqiang Zhang", "Hadi Beitollahi", "Quyet Van Le", "Ho Won Jang", "Mohammadreza Shokouhimehr" ], "corpus_id": 218818997, "doc_id": "218818997", "n_citations": 78, "n_key_citations": 0, "score": 0, "title": "Carbon and graphene quantum dots: a review on syntheses, characterization, biological and sensing applications for neurotransmitter determination", "venue": "", "year": 2020 }, { "abstract": "Abstract Graphene and carbon quantum dots (GQDs and CQDs) are relatively new nanomaterials that have demonstrated impact in multiple different fields thanks to their unique quantum properties and excellent biocompatibility. Biosensing, analyte detection and monitoring wherein a key feature is coupled molecular recognition and signal transduction, is one such field that is being greatly advanced by the use of GQDs and CQDs. In this review, recent progress on the development of biotransducers and biosensors enabled by the creative use of GQDs and CQDs is reviewed, with special emphasis on how these materials specifically interface with biomolecules to improve overall analyte detection. This review also introduces nano enabled biotransducers and different biosensing configurations and strategies, as well as highlights key properties of GQDs and CQDs that are pertinent to functional biotransducer design. Following relevant introductory material, the literature is surveyed with emphasis on work performed over the last 5 years. General comments and suggestions to advance the direction and potential of the field are included throughout the review. The strategic purpose is to inspire and guide future investigations into biosensor design for quality and safety, as well as serve as a primer for developing GQD and CQD based biosensors.", "author_names": [ "Brandon K Walther", "Cerasela Zoica Dinu", "Dirk Michael Guldi", "Vladimir G Sergeyev", "Stephen E Creager", "John P Cooke", "Anthony Guiseppi-Elie" ], "corpus_id": 219434545, "doc_id": "219434545", "n_citations": 15, "n_key_citations": 0, "score": 0, "title": "Nanobiosensing with graphene and carbon quantum dots: Recent advances", "venue": "", "year": 2020 } ]

[ { "abstract": "The Modular Multilevel Converter represents a really promising solution for several high power applications. Nevertheless, to furtherly enhance the penetration of such conversion structure and to fully exploit its advantages, some issues related to its operation need to be addressed. In particular, this converter features some circulating currents that deeply affect both the conduction losses occurring in the semiconductor devices and the voltage ripple across the capacitors of this conversion structure, which in turn influences the converter efficiency. In order to minimize the converter losses, this work proposes innovative control strategies of the circulating currents by calculating the optimal value of their reference. Alongside the increase of the converter efficiency, the proposed control strategies allow additional advantages in terms of enhancing the converter reliability and extending the overall system lifetime.", "author_names": [ "Luis Camurca", "Giovanni Monopoli", "Leonardo Falco", "Frederik Hahn", "Vito Giuseppe Monopoli", "Marco Liserre" ], "corpus_id": 209322291, "doc_id": "209322291", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Control Strategies for Losses Optimization in Modular Multilevel Converter", "venue": "IECON 2019 45th Annual Conference of the IEEE Industrial Electronics Society", "year": 2019 }, { "abstract": "The modular multilevel converter (MMC) is a new kind of voltage source converter (VSC) with a high number of voltage levels and considered to be suitable for HVDC transmission. Based on circuit configuration and operation mechanism, this paper presents an mathematical model of MMC. Then the vector control strategy widely used in two level VSC is applied to the control of MMC. Due to modular structure and cascaded connections, a very high number of voltage levels is obtained by MMC in HVDC applications, for which the nearest level modulation (NLM) become feasible. A combination of NLM and optimized capacitor voltage balancing control is presented to reduce the switching frequency as well as the switching losses of power semiconductors. Time domain simulation performed in PSCAD/EMTDC shows that the control and modulation methods provide good steady state and dynamic system performance and significantly reduce the switching frequency of power semiconductors.", "author_names": [ "Minyuan Guan", "Zheng Xu", "Hairong Chen" ], "corpus_id": 13641391, "doc_id": "13641391", "n_citations": 114, "n_key_citations": 6, "score": 0, "title": "Control and modulation strategies for modular multilevel converter based HVDC system", "venue": "IECON 2011 37th Annual Conference of the IEEE Industrial Electronics Society", "year": 2011 }, { "abstract": "A particle swarm optimization (PSO) algorithm based staircase modulation strategy for modular multilevel converters (MMC) is proposed. To reduce switching losses and device stress, the staircase modulation method has been adopted in high voltage and high power energy conversion applications. In particular, the selection of the appropriate iterative initial values of switching angles is a significant step to realize a staircase modulated MMC. The proposed method is able to find the optimum initial values of switching angles, while it has the advantages of global optimization and quadratic convergence, which benefit from the PSO algorithm and Newton method, respectively. The paper presents analytical discussion of the voltage balancing control approach with rotation of switching angles. The main benefit of the efficient switching patterns is that the MMC has lower switching losses and minimum dV/dt stress. Simulation and experimental results are presented to verify the practical feasibility of the proposed scheme for the MMC.", "author_names": [ "Ke Shen", "Dan Zhao", "Jun Mei", "Leon M Tolbert", "Jianze Wang", "Mingfei Ban", "Yanchao Ji", "Xingguo Cai" ], "corpus_id": 3096892, "doc_id": "3096892", "n_citations": 85, "n_key_citations": 5, "score": 0, "title": "Elimination of Harmonics in a Modular Multilevel Converter Using Particle Swarm Optimization Based Staircase Modulation Strategy", "venue": "IEEE Transactions on Industrial Electronics", "year": 2014 }, { "abstract": "Unlike conventional converters, modular multilevel converter (MMC) has a higher switching frequency which has direct implication on important parameters like converter loss and reliability mainly due to increased number of switching components. However, conventional switching techniques, where submodule sorting is just based on capacitor voltage balancing, are not able to achieve switching frequency reduction objective. A novel modulation algorithm for modular multilevel converters (MMCs) is proposed in this paper to reduce the switching frequency of MMC operation by defining a constrained multi objective optimization model. The optimized switching algorithm incorporates all control objectives required for the proper operation of MMC and adds new constraints to limit the number of submodule switching events at each time step. Variation of severity of the constraints leads to a desired level of controllability in MMC switching algorithm to trade off between capacitor voltage regulation and switching frequency reduction. Finally, performance of the proposed algorithm is validated against a seven level back to back MMC HVDC system under various operating conditions.", "author_names": [ "Saroj Khanal", "Vahid Rasouli Disfani" ], "corpus_id": 209405416, "doc_id": "209405416", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "A Novel Optimal Modulation Strategy for Modular Multilevel Converter Based HVDC Systems", "venue": "2019 IEEE 2nd International Conference on Renewable Energy and Power Engineering (REPE)", "year": 2019 }, { "abstract": "Lesnicar and Marquardt introduced a Modular Multilevel Converter (MMC) topology back in 2003. Although this topology has received a great deal of attention in recent years by both the research community and industry, hitherto no steady state model has been developed which accurately captured all the relevant power losses while being computationally light. Hence, the aim of this paper is to introduce a fast MMC loss model which captures the key sources of power losses in steady state operation. The model only requires information which is known a priori, e.g. datasheet information of the components. The proposed model was compared to a loss model developed by Marquardt. Both models presented similar results under the same assumptions. However, the proposed model captures the switching losses more realistically and considers the temperature of operation of the electronics, as well as the losses of the inductors and cooling system in the overall efficiency of the MMC. To validate these new additions, the proposed steady state model was compared to a dynamic model. Once again the proposed model was able to capture the different sources of power losses. Nonetheless, results demonstrated that the balancing strategy greatly influences the efficiency of the MMC. Therefore, information regarding the envisioned control strategy is necessary to accurately calculate the efficiency curve of the MMC.", "author_names": [ "Athanasios I Papadopoulos", "Silvio Miguel Fragoso Rodrigues", "Epameinondas Kontos", "Todor Todorcevic", "Pavol Bauer" ], "corpus_id": 28113411, "doc_id": "28113411", "n_citations": 11, "n_key_citations": 1, "score": 0, "title": "A fast steady state loss model of a modular multilevel converter for optimization purposes", "venue": "2015 9th International Conference on Power Electronics and ECCE Asia (ICPE ECCE Asia)", "year": 2015 }, { "abstract": "A new modular multilevel converter (MMC) sub module (SM) topology based on the reverse blocking insulated gate bipolar transistor (RB IGBT) is proposed in this brief for equipping the system with dc fault blocking capability. In addition, the proposed topology has lower conduction loss than all of the existing SM topologies with dc side fault blocking capability. By employing RB IGBTs in the sub module circuit, it is possible to change the fault current path to block the dc side fault without inserting extra semiconductor devices in the normal current path, thus reducing the conduction loss when compared to other topologies. A comparison between the proposed topology and the existing topologies in terms of components number, power loss and dc fault blocking capability is carried out to show the superiority of the proposed topology. To reduce the cost of the topology, a control strategy is introduced to reduce the capacitance of the proposed topology. By optimizing the amplitude of the second order and fourth order harmonic currents when injecting third order harmonic voltage, the capacitance can be reduced to about 37% of that of the conventional method. To verify the dc side fault blocking capability and the effect of the proposed method, the controller hardware in the loop experiment based on RT LAB is conducted. The reported study results confirm the dc side fault riding through capability of the proposed sub module topology and the effectiveness of the proposed method is also validated.", "author_names": [ "Cheng Peng", "Rui Li" ], "corpus_id": 201252118, "doc_id": "201252118", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "A Low Conduction Loss Modular Multilevel Converter Topology With DC Fault Blocking Capability and Reduced Capacitance", "venue": "IEEE Transactions on Circuits and Systems II: Express Briefs", "year": 2020 }, { "abstract": "Following Europe's 2020 growth program, the Energy Roadmap 2050 launched by the European Commission (EC) has officially set a long term path for a low carbon economy, assuming a reduction of at least 80% of greenhouse gas emissions by the year 2050. Meeting such ambitious requirements will imply a major change in paradigm, including the electricity grid infrastructure as we know it.The breakthroughs in semi conductor technology and the advances in power electronics topologies and control have added momentum to the on going process of turning the SuperGrid into a reality. Perhaps the most recent breakthrough occurred in 2003, when Prof. Marquardt introduced the Modular Multilevel Converter (MMC or M2C) which is now the preferred power electronic topology that is starting to be used in VSC HVDC stations. It does however, introduce a number of rather complex challenges such as \"additional\" circulating currents within the converter itself, causing extra losses and potentially unstable operation. In addition, the MMC will be required to properly balance the capacitive energy stored within its different arms, while transferring power between the AC and DC grids that it interfaces.The present Thesis project aimed to design adequate \"high level\" MMC control strategies suited for HVDC applications, under balanced and unbalanced AC grid conditions. The resulting control strategy is derived with a \"top to bottom\" design approach, inherent to optimization strategies, where the desired performance of the MMC results in the control scheme that will be applied. More precisely, the Lagrange multipliers optimization methodology is used to calculate the minimal MMC circulating current reference signals in phase coordinates, capable of successfully regulating the capacitive arm energies of the converter, while reducing losses and voltage fluctuations, and effectively decoupling any power oscillations that would take place in the AC grid and preventing them from propagating into the DC grid.", "author_names": [ "Gilbert Bergna Diaz" ], "corpus_id": 114839537, "doc_id": "114839537", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Modular Multilevel Converter Control for HVDC Operation Optimal Shaping of the Circulating Current Signal for Internal Energy Regulation", "venue": "", "year": 2015 }, { "abstract": "In this work, a generalized optimization methodology based on Lagrange Multipliers was used to propose circulating current references in order to properly control the Modular Multilevel Converter (MMC) under different conditions. The optimization strategy finds the local minima of the objective function, which is typically the power losses of the MMC system, subject to equality constraints, which are previously defined by the desired operating condition. Furthermore, this control approach is developed in the ABC frame, giving more insight into the physical phenomena related to the MMC internal dynamics. Finally, equivalent controllers to existing ones, which can be found in the literature, are obtained by means of this methodology with the objective to demonstrate the versatility and generality of the present control approach.", "author_names": [ "Gilbert Bergna", "Erik Berne", "Philippe Egrot", "Pierre Lefranc", "Jean-Claude Vannier", "Amir Arzande", "Marta Molinas" ], "corpus_id": 733878, "doc_id": "733878", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "A generalized power control approach in ABC frame for modular Multilevel Converters based on mathematical optimization", "venue": "2012 IEEE International Energy Conference and Exhibition (ENERGYCON)", "year": 2012 }, { "abstract": "Multilevel converters are widely employed in the 30 50 kW medium voltage grid connected photovoltaic (PV) generation systems due to their higher power quality and lower switching losses compared with the two level converters. Dual T type three level converters and one three level diode neutral point clamped circuit can be integrated to derive a simplified five level modular composited converter (5L MCC) for the medium voltage PV grid connected systems. However, realizing the capacitor voltage balance is a challenge to enhance its reliability. First, the model of dc capacitor voltage variation of the 5L MCC is discussed to expose a limitation once the nearest three vector synthesis method is employed with conventional space vector modulation (SVM) In order to extend the operational range, a hybrid space vector modulation (HSVM) strategy is proposed, which integrates the optimized SVM switching sequence for the low modulation <inline formula><tex math notation=\"LaTeX\"$M\\ ,0.5$/tex math> /inline formula> and a simplified vector synthesis method for the high modulation region <inline formula> <tex math notation=\"LaTeX\"$M\\geq 0.5$/tex math>/inline formula> The proposed hybrid modulation maintains the dc capacitor voltage balance over the full modulation range and power factor. Finally, the effectiveness of the proposed HSVM strategy is verified with the simulation and experimental results.", "author_names": [ "Wuhua Li", "Jiawei Hu", "Senjun Hu", "Heya Yang", "Huan Yang", "Xiangning He" ], "corpus_id": 4136733, "doc_id": "4136733", "n_citations": 16, "n_key_citations": 0, "score": 0, "title": "Capacitor Voltage Balance Control of Five Level Modular Composited Converter With Hybrid Space Vector Modulation", "venue": "IEEE Transactions on Power Electronics", "year": 2018 }, { "abstract": "Since the introduction of modular multilevel converters (MMC) various additional features have been introduced for MMCs, among them parallel inter module connectivity. However, such a parallel mode requires appropriate modulation and switching strategies to exploit its full potential. Low frequency switching modulation is widely used with half bridge modules and a large body of research focusses on the optimum control and scheduling of these methods. However, so far, a suitable adaptation for MMCs with parallel mode is missing, and existing methods perform suboptimum. This article proposes a generic scheduling algorithm for simple and low cost integration with low frequency switching modulation. The proposed method reduces control complexity, minimizes power loss, and can be combined with most modulation techniques, including nearest level modulation (NLM) and selective harmonic elimination. The text in this article provides a general algorithm for integrating this method with other control levels and analyzes its effect on MMCs with parallel functionality. Moreover, it examines the performance of the system with NLM combined with the proposed scheduler and compares it to other alternatives. Results show up to a 50% reduction in power loss with a similar modulation technique as well as significantly lower THD and power loss compared to optimized phase shifted carrier modulation as another sensorless alternative method.", "author_names": [ "Nima Tashakor", "Zhongxi Li", "Stefan M Goetz" ], "corpus_id": 221697785, "doc_id": "221697785", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "A Generic Scheduling Algorithm for Low Frequency Switching in Modular Multilevel Converters With Parallel Functionality", "venue": "IEEE Transactions on Power Electronics", "year": 2021 } ]

[ { "abstract": "", "author_names": [ "Aisha Salem" ], "corpus_id": 225647873, "doc_id": "225647873", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "On New Mathematical Modeling Measuringthe Band Gap of Semiconductor in Nanomaterial", "venue": "", "year": 2020 }, { "abstract": "Abstract In this paper, we consider a special case of vehicle routing problem that addresses the routing problem in a semiconductor supply chain. This paper proposes two Mixed Integer Linear Programming (MILP) models for solving the Green Vehicle Routing Problems with Pickups and Deliveries in a Semiconductor Supply Chain (G VRPPD SSC) The first MILP model considers the basic G VRPPD SSC problem, and the objective is to find the set of minimum cost routes and schedules for the alternative fuel vehicles in order to satisfy a set of requests which comprise pickup and delivery operations, without violating the product and vehicle compatibility, vehicle capacity, request priorities and request types, and start/completion time constraints. The second model extends the first model in order to handle the scenario of having different fuel prices at different refueling stations, and the objective is to minimize the sum of costs of operating alternative fuel vehicles, which include both the routing cost and the refueling cost. To relatively evaluate the performance of the proposed MILP models, we consider the Pickup and Delivery Problem in a Semiconductor Supply Chain (PDP SSC) without the presence of alternative fuel vehicles, and we present the corresponding MILP model. Our model is compared with an MILP model present in the literature. Our study indicates that the proposed model for the PDP SSC gives better lower bounds than that by the existing work, apart from performing better than the existing work in terms of requiring less CPU time. In all cases, the proposed three MILP models preform quite good in terms of the execution time to solve the generated problem instances.", "author_names": [ "Sakthivel Madankumar", "Chandrasekharan Rajendran" ], "corpus_id": 23739866, "doc_id": "23739866", "n_citations": 28, "n_key_citations": 1, "score": 1, "title": "Mathematical models for green vehicle routing problems with pickup and delivery: A case of semiconductor supply chain", "venue": "Comput. Oper. Res.", "year": 2018 }, { "abstract": "Abstract Corrosion rates of mild steel in different aqueous solutions at different operating conditions were studied by weight loss technique in the absence and presence of epoxy coating. It was found that corrosion rates increased with temperature and salt concentration and decreased with pH values. Presence of coating reduces the corrosion rates to significant values in acidic solutions. The performance of the coating was poor in saline solution. A magnesium oxide (MgO) nanoparticle was prepared via sol gel method and the diagnosis was carried out by XRD technique. Maximum coating efficiency was 97% in acidic solution, while the lower one was 29.8% in saline solution in absence of nanoparticles. Nano scale MgO was used effectively with epoxy coating in saline solutions and improve the coating performance with maximum value of 93.7% SEM test was also used to study the surface morphology. Several mathematical models were suggested to correlate the operating condition with corrosion rate. Polynomial interaction effect model was suitable to represent the data with a high correlation coefficient.", "author_names": [ "Ziad T Khodair", "Anees A Khadom", "Hassan A Jasim" ], "corpus_id": 44138159, "doc_id": "44138159", "n_citations": 43, "n_key_citations": 0, "score": 0, "title": "Corrosion protection of mild steel in different aqueous media via epoxy/nanomaterial coating: preparation, characterization and mathematical views", "venue": "", "year": 2019 }, { "abstract": "Edge emitting lasers started the era of semiconductor lasers and have existed up to nowadays, appearing as devices fabricated out of various materials, formed sometimes in very tricky ways to enhance light generation. However, in all cases radiative processes are accompanied by undesired heat generating processes, like non radiative recombination, Auger recombination, Joule effect or surface recombination. Even for highly efficient laser sources, great amount of energy supplied by pumping current is converted into heat. High temperature leads to deterioration of the main laser parameters, like threshold current, output power, spectral characteristics or lifetime. In some cases, it may result in irreversible destruction of the device via catastrophic optical damage (COD) of the mirrors. Therefore, deep insight into thermal effects is required while designing the improved devices. From the thermal point of view, the laser chip (of dimensions of 1 2mmor less) is a rectangular stack of layers of different thickness and thermal properties. This stack is fixed to a slightly larger heat spreader, which, in turn, is fixed to the huge heat sink (of dimensions of several cm) transferring heat to air by convection or cooled by liquid or Peltier cooler. Schematic view of the assembly is shown in Fig. 1. Complexity and large size differences between the elements often induce such simplifications like reduction of the dimensionality of equations, thermal scheme geometry modifications or using non uniform mesh in numerical calculations. Mathematical models of heat flow in edge emitting lasers are based on the heat conduction equation. In most cases, solving this equation provides a satisfactory picture of thermal behaviour of the device. More precise approaches use in addition the carrier diffusion equation. The most sophisticated thermal models take into consideration variable photon density found by solving photon rate equations. The heat generated inside the chip is mainly removed by conduction and, in a minor degree, by convection. Radiation can be neglected. Typical boundary conditions for heat conduction equation are the following: isothermal condition at the bottom of the device, thermally insulated side walls, convectively cooled upper surface. It must be said that obtaining reliable temperature profiles is often impossible due to individual features of particular devices, which are difficult to evaluate within the quantitative analysis. Mounting imperfections 1", "author_names": [ "Michal Szymanski" ], "corpus_id": 20101835, "doc_id": "20101835", "n_citations": 4, "n_key_citations": 0, "score": 1, "title": "Mathematical Models of Heat Flow in Edge Emitting Semiconductor Lasers", "venue": "", "year": 2011 }, { "abstract": "The adsorption desorption behavior of methylene blue, acid orange 7, bisphenol A, and phenol on the synthesized graphene based nanomaterials were studied. For this purpose, adsorption experiments were conducted in a batch setup and different parameters such as contact time, pH, adsorbent dose concentration, and initial micropollutant concentration were considered. In addition, linear and nonlinear kinetic and isotherm models were evaluated. The nonlinear pseudo second order models (R2 0.98) Elovich kinetic models (R2 0.94) and Langmuir isotherm models (R2 0.98) best fitted the experimental data. Because of the high specific surface area and the type of oxygen functional groups, mechanochemically synthesized graphite oxide exhibited high adsorption capacities for methylene blue, acid orange 7, bisphenol A, and phenol, with a maximum uptake of 288, 232, 110, and 68 mg g 1, respectively. Furthermore, the total costs of applying the mechanochemically synthesized graphite oxide were estimated in the adsorption process, revealing that these nanomaterials offer better uptake values than porous carbon.", "author_names": [ "Alaa El Din Mahmoud" ], "corpus_id": 220849212, "doc_id": "220849212", "n_citations": 16, "n_key_citations": 0, "score": 1, "title": "Graphene based nanomaterials for the removal of organic pollutants: Insights into linear versus nonlinear mathematical models.", "venue": "Journal of environmental management", "year": 2020 }, { "abstract": "Nanosized semiconductive Pd containing sensor materials based on SnO2 were obtained by sol gel technique. The highly sensitive gas sensor based on 1.41 wt% Pd/SnO2 nanomaterial showed the maximum response value of 12.4 to 930 ppm CH4, and the kinetics of the sensor conductivity response and recovery were studied. The average particle size of the material with the highest response to methane was 14 15 nm. Study of the CH4 oxidation kinetics on the surface of the 1.41 wt% Pd/SnO2 sensor nanomaterial allowed the proposal of a theoretical model that can describe the kinetics of the conductivity response and recovery for such Pd doped sensors to methane. The values of the methane oxidation activation energies obtained from the experimental kinetic data for the CH4 oxidation reaction on the 1.41 wt% Pd/SnO2 gas sensitive material and the model based on the data of the sensor conductivity response and recovery were almost the same, indicating a leading role for the heterogeneous catalytic oxidation reaction occurring on the sensor surface.", "author_names": [ "Ludmila Oleksenko", "George Fedorenko", "Nelly Maksymovych" ], "corpus_id": 198196948, "doc_id": "198196948", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Effect of heterogeneous catalytic methane oxidation on kinetics of conductivity response of adsorption semiconductor sensors based on Pd/SnO2 nanomaterial", "venue": "Research on Chemical Intermediates", "year": 2019 }, { "abstract": "A theoretical study of a second grade nanofluid over a porous medium has been conducted. Stagnation point flow is considered. Effects of nonlinear radiative heat flux, dissipation and Joule heating are considered in the modeling of energy equation. Furthermore, chemical reaction is accounted. The wall is not stationary, but stretching at rate a. Total irreversibility rate is obtained through the second thermodynamics law. Slip mechanism of nanoparticles like Brownian movement and thermophoresis are considered. Suitable transformations lead to ordinary system. Solution development is done through HAM. Effects of pertinent variables are graphically discussed. Skin friction and temperature gradient are examined graphically versus different parameters. It is observed that velocity field decreased versus larger magnetic parameter. Temperature enhances versus rising values of magnetic and radiation variables. Main idea of present flow is listed.", "author_names": [ "Mujeeb ur Rahman", "M Khan", "Fazal Haq", "Tasawar Hayat" ], "corpus_id": 202134949, "doc_id": "202134949", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Mathematical Modeling and Theoretical Analysis of Second Grade Nanomaterial with Entropy Optimization", "venue": "Iranian Journal of Science and Technology, Transactions A: Science", "year": 2019 }, { "abstract": "The development of physiologically based (PB) models to support safety assessments in the field of nanotechnology has grown steadily during the last decade. This review reports on the availability of PB models for toxicokinetic (TK) and toxicodynamic (TD) processes, including in vitro and in vivo dosimetry models applied to manufactured nanomaterials (MNs) In addition to reporting on the state of the art in the scientific literature concerning the availability of physiologically based kinetic (PBK) models, we evaluate their relevance for regulatory applications, mainly considering the EU REACH regulation. First, we performed a literature search to identify all available PBK models. Then, we systematically reported the content of the identified papers in a tailored template to build a consistent inventory, thereby supporting model comparison. We also described model availability for physiologically based dynamic (PBD) and in vitro and in vivo dosimetry models according to the same template. For completeness, a number of classical toxicokinetic (CTK) models were also included in the inventory. The review describes the PBK model landscape applied to MNs on the basis of the type of MNs covered by the models, their stated applicability domain, the type of (nano specific) inputs required, and the type of outputs generated. We identify the main assumptions made during model development that may influence the uncertainty in the final assessment, and we assess the REACH relevance of the available models within each model category. Finally, we compare the state of PB model acceptance for chemicals and for MNs. In general, PB model acceptance is limited by the absence of standardised reporting formats, psychological factors such as the complexity of the models, and technical considerations such as lack of blood:tissue partitioning data for model calibration/validation.", "author_names": [ "L Lamon", "D Asturiol", "Alejandro Vilchez", "Joan Cabellos", "J Damasio", "Gemma Janer", "Andrea-Nicole Richarz", "Andrew P Worth" ], "corpus_id": 57666310, "doc_id": "57666310", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Physiologically based mathematical models of nanomaterials for regulatory toxicology: A review", "venue": "Computational toxicology", "year": 2019 }, { "abstract": "In this study, we will compare the study done by different researchers on the semiconductor II VI group material by using different models including DMR (Diffusivity Mobility Ratio) We will check out the DMR and other model parameters used to compare the performance of semiconductor II VI group material. The basic formulation and the study of these models will help us to understand the basic properties of the nanomaterials studied so far. Keywords: DMR, Einstein relation, models, nanomaterial, semiconductor material group II VI", "author_names": [ "Rahul Jain", "Kh Gopal Krishna Singh" ], "corpus_id": 127554516, "doc_id": "127554516", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Comparative study of models for II VI group semiconductor nanomaterials using DMR", "venue": "", "year": 2018 }, { "abstract": "The distribution of constant electric current potential in case of probe measurement on anisotropic semiconductors and fields has been studied. The expressions for potential distribution have been obtained. It enables to identify the area of the probe field of the scanning microscope in case an anisotropic film is under study. The results of the research demonstrate the correlation between the size and anisotropy of specific electroconductivity and the resistance change of probe spreading in limited films.", "author_names": [ "Vladimir Filippov", "Sergey Mitsuk", "Sergey Luzyanin" ], "corpus_id": 209853444, "doc_id": "209853444", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Electric Field Mathematical Modelling at Probe Measurement in Anisotropic Semiconductor Films", "venue": "2019 1st International Conference on Control Systems, Mathematical Modelling, Automation and Energy Efficiency (SUMMA)", "year": 2019 } ]

[ { "abstract": "Abstract This review paper encompasses a detailed study of semiconductor metal oxide (SMO) gas sensors. It provides for a detailed comparison of SMO gas sensors with other gas sensors, especially for ammonia gas sensing. Different parameters which affect the performance (sensitivity, selectivity and stability) of SMO gas sensors are discussed here under. This paper also gives an insight about the dopant or impurity induced variations in the SMO materials used for gas sensing. It is concluded that dopants enhance the properties of SMOs for gas sensing applications by changing their microstructure and morphology, activation energy, electronic structure or band gap of the metal oxides. In some cases, dopants create defects in SMOs by generating oxygen vacancy or by forming solid solutions. These defects enhance the gas sensing properties. Different nanostructures (nanowires, nanotubes, heterojunctions) other than nanopowders have also been studied in this review. At the end, examples of SMOs are given to illustrate the potential use of different SMO materials for gas sensing.", "author_names": [ "Ananya Dey" ], "corpus_id": 104271227, "doc_id": "104271227", "n_citations": 667, "n_key_citations": 7, "score": 1, "title": "Semiconductor metal oxide gas sensors: A review", "venue": "", "year": 2018 }, { "abstract": "", "author_names": [ "K Govardhan", "G Nirmala" ], "corpus_id": 99090593, "doc_id": "99090593", "n_citations": 30, "n_key_citations": 0, "score": 0, "title": "Metal/Metal Oxide Doped Semiconductor Based Metal Oxide Gas Sensors A Review", "venue": "", "year": 2016 }, { "abstract": "Abstract Semiconductor metal oxide nanowires (SMO NWs) show great potential for novel gas sensor applications because of their distinct properties, such as a high surface area to volume aspect ratio, high crystallinity and perfect pathway for electron transfer (length of NW) SMO NW sensors can be configured as resistors or field effect transistors for gas detection and different configurations, such as a single NW, multiple NWs, and networked NW films, have been established. Surface functionalizing NWs with catalyst elements and self heating NWs provide additional advantages for highly selective and low power consumption gas sensors. However, an appropriate design of SMO NWs is of practical importance in enhancing the gas sensing performance of SMO NW sensors. The on chip growth of SMO NWs possesses many advantages which can thus be effectively used for the large scale fabrication of SMO NW sensors with improved gas response and stability. This review aims to provide up to date information on the on chip fabrication of SnO2, ZnO, WO3, CuO, and other SMO NW sensors. It also discusses a variety of promising approaches that help advance the on chip fabrication of SMO NW based gas sensors and other NW based devices.", "author_names": [ "Chu Manh Hung", "Dang Thi Thanh Le", "Nguyen Van Hieu" ], "corpus_id": 116446441, "doc_id": "116446441", "n_citations": 60, "n_key_citations": 0, "score": 0, "title": "On chip growth of semiconductor metal oxide nanowires for gas sensors: A review", "venue": "", "year": 2017 }, { "abstract": "Conductometric gas sensors facilitated by photons have been investigated for decades. Light illumination may enhance device attributes including operational temperature, sensing sensitivity and selectivity. This paper aims to provide an overview on the progress of light activated gas sensors, with a specific focus on sensors based on metal oxides. The material systems that have been studied include pure metal oxides, heterostructures of semiconductor metal oxides and metal metal oxides, and metal oxides with dopant. Other reported works on the use of different nanostructures such as one dimensional and porous nanostructures, study of sensing mechanisms and the interplay between various factors are also summarized. Possible directions for further improvement of sensing properties, through optimizing the size of nanomaterials, film thickness, light intensity and wavelength are discussed. Finally, we point out that the main challenge faced by light activated gas sensors is their low optical response, and we have analyzed the feasibility of using localized surface plasmon resonance to solve this drawback. This article should offer readers some key and instructive insights into the current and future development of light activated gas sensors.", "author_names": [ "Fang Xu", "Ho-Pui Ho" ], "corpus_id": 52214278, "doc_id": "52214278", "n_citations": 32, "n_key_citations": 0, "score": 0, "title": "Light Activated Metal Oxide Gas Sensors: A Review", "venue": "Micromachines", "year": 2017 }, { "abstract": "This paper gives a statistical view about important contributions and advances on semiconductor metal oxide (SMO) compounds based gas sensors developed to detect the air pollutants such as liquefied petroleum gas (LPG) H2S, NH3, CO2, acetone, ethanol, other volatile compounds and hazardous gases. Moreover, it is revealed that the alloy/composite made up of SMO gas sensors show better gas response than their counterpart single component gas sensors, i.e. they are found to enhance the 4S characteristics namely speed, sensitivity, selectivity and stability. Improvement of such types of sensors used for detection of various air pollutants, which are reported in last two decades, is highlighted herein.", "author_names": [ "S J Patil", "Arun Vitthal Patil", "C G Dighavkar", "K S Thakare", "Ratan Yadav Borase", "S J Nandre", "Nishad G Deshpande", "R R Ahire" ], "corpus_id": 98399093, "doc_id": "98399093", "n_citations": 75, "n_key_citations": 1, "score": 0, "title": "Semiconductor metal oxide compounds based gas sensors: A literature review", "venue": "Frontiers of Materials Science", "year": 2015 }, { "abstract": "Surface acoustic wave (SAW) gas sensors are of continuous development interest to researchers due to their sensitivity, short detection time, and reliability. Among the most used materials to achieve the sensitive film of SAW sensors are metal oxide semiconductors, which are highlighted by thermal and chemical stability, by the presence on their surface of free electrons and also by the possibility of being used in different morphologies. For different types of gases, certain metal oxide semiconductors are used, and ZnO is an important representative for this category of materials in the field of sensors. Having a great potential for the development of SAW sensors, the discussion related to the development of the sensitivity of metal oxide semiconductors, especially ZnO, by the synthesis method or by obtaining new materials, is suitable and necessary to have an overview of the latest results in this domain.", "author_names": [ "Izabela Constantinoiu", "Cristian Viespe" ], "corpus_id": 221624681, "doc_id": "221624681", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "ZnO Metal Oxide Semiconductor in Surface Acoustic Wave Sensors: A Review", "venue": "Sensors", "year": 2020 }, { "abstract": "In modern world, gas sensors play important role in many fields of technology used for air pollution, breath analysis, public safety and many others. Gas sensor based semiconductor metal oxide is mostly used in these applications because of low cost, ease to use, high sensitivity and lower power consumption. This paper gives an overview about the semiconductor metal oxide and reviews why using it as sensing of gases in electrical applications and then it addresses to the work mechanism of a sensor to sensing H2S gas.", "author_names": [ "Zaid Hameed Mahmoud", "Omar Dhaa Abdalstar", "Noor us Sabah" ], "corpus_id": 225382953, "doc_id": "225382953", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Semiconductor Metal Oxide Nanoparticles: A Review for the Potential of H2S Gas Sensor Application", "venue": "", "year": 2020 }, { "abstract": "Abstract Air pollution is nowadays a big issue regarding the health of human beings. Among the toxic gases emitted in the atmosphere, NO2 is the most problematic one and a lot of countries or cities want to monitor its concentration in order to be able to take measures to reduce it. Therefore, it is urgent to develop NO2 sensors with high performance, low power consumption and low cost. Several technologies have been developed for this purpose. A very popular technology is based on metal oxide semiconductor. The usual semiconductor gas sensors need to be operated at high temperature, but nowadays many efforts are put on metal oxide sensors that can work at room temperature. These sensors present many advantages: low power consumption, low manufacturing cost, as well as moderate stability and safety. However, due to the weak response to NO2 at room temperature, most semiconductor NO2 sensors need to be adapted. This review will present the main strategies and material modification methods studied so far. These include light illumination, sensitization with an organic, formation of heterojunctions, preparation of composites with 1D or 2D materials and an introduction of oxygen vacancies in high concentrations. The gas sensing mechanisms of these sensors are presented and discussed.", "author_names": [ "C Zhang", "Yifan Luo", "Jiaqiang Xu", "Marc Debliquy" ], "corpus_id": 117703669, "doc_id": "117703669", "n_citations": 48, "n_key_citations": 0, "score": 0, "title": "Room temperature conductive type metal oxide semiconductor gas sensors for NO2 detection", "venue": "Sensors and Actuators A: Physical", "year": 2019 }, { "abstract": "Abstract Flammable, explosive and toxic gases, such as hydrogen, hydrogen sulfide and volatile organic compounds vapor, are major threats to the ecological environment safety and human health. Among the available technologies, gas sensing is a vital component, and has been widely studied in literature for early detection and warning. As a metal oxide semiconductor, zinc ferrite (ZnFe2O4) represents a kind of promising gas sensing material with a spinel structure, which also shows a fine gas sensing performance to reducing gases. Due to its great potentials and widespread applications, this article is intended to provide a review on the latest development in zinc ferrite based gas sensors. We first discuss the general gas sensing mechanism of ZnFe2O4 sensor. This is followed by a review of the recent progress about zinc ferrite based gas sensors from several aspects: different micro morphology, element doping and heterostructure materials. In the end, we propose that combining ZnFe2O4 which provides unique microstructure (such as the multi layer porous shells hollow structure) with the semiconductors such as graphene, which provide excellent physical properties. It is expected that the mentioned composites contribute to improving selectivity, long term stability, and other sensing performance of sensors at room or low temperature.", "author_names": [ "Kaidi Wu", "Jianzhi Li", "C Zhang" ], "corpus_id": 139599993, "doc_id": "139599993", "n_citations": 42, "n_key_citations": 0, "score": 0, "title": "Zinc ferrite based gas sensors: A review", "venue": "Ceramics International", "year": 2019 }, { "abstract": "Abstract Metal oxide semiconductor (MOS) gas sensors possess extensive applications due to their high sensitivity, low cost, and simplicity. To boost their excellent sensing performance and meet the growing demand for applications, a series of strategies have been developed, such as the surface morphology engineering and function manipulation. Recently, the controlled morphology with exposed high energy facets and the facet dependent sensing properties have attracted much attention. Because of its abundant unsaturated active sites, the crystal planes with high surface energy usually serve as promising platform for gas sensing. After a lot of survey of literature, the authors provide a review of recent efforts on engineering crystal structures with exposed high energy facets of MOS nanomaterials and their improved gas sensitive performance, emphasis on six kinds of common gas sensitive MOS including ZnO, SnO2, TiO2, a Fe2O3, NiO and Cu2O. Also, the relationship between dangling bonds density and gas sensing properties has been systematically discussed and used as one significant factor to evaluate superior sensing surface of MOS. According to the research and calculation, surface engineering by selectively exposing high energy facets provides an effective way to obtain MOS gas sensitive materials with superior performance. The understanding of the facet dependent properties of MOS will assist in and guide the fabrication of more excellent gas sensors in the future.", "author_names": [ "Xing Gao", "Tong Zhang" ], "corpus_id": 104933227, "doc_id": "104933227", "n_citations": 119, "n_key_citations": 3, "score": 0, "title": "An overview: Facet dependent metal oxide semiconductor gas sensors", "venue": "", "year": 2018 } ]

[ { "abstract": "Stabilizing monolayer nitrides with silicon Transition metal carbides and nitrides are nonlayered materials that in monolayer form have potentially useful electronic and chemical properties. These monolayers are usually made by chemical etching that produces flakes with surface defects that have poor air and water stability. Hong et al. report that introducing silicon during chemical vapor deposition growth of molybdenum nitride passivates the surface and prevents island formation. Centimeter scale monolayer films of the semiconductor MoSi2N4 form as a MoN2 layer sandwiched by two Si N bilayers. These layers possess high mechanical strength and ambient stability. Science, this issue p. 670 Addition of silicon during film growth stabilized a molybdenum nitride monolayer by sandwiching it between two Si N bilayers. Identifying two dimensional layered materials in the monolayer limit has led to discoveries of numerous new phenomena and unusual properties. We introduced elemental silicon during chemical vapor deposition growth of nonlayered molybdenum nitride to passivate its surface, which enabled the growth of centimeter scale monolayer films of MoSi2N4. This monolayer was built up by septuple atomic layers of N Si N Mo N Si N, which can be viewed as a MoN2 layer sandwiched between two Si N bilayers. This material exhibited semiconducting behavior (bandgap ~1.94 electron volts) high strength ~66 gigapascals) and excellent ambient stability. Density functional theory calculations predict a large family of such monolayer structured two dimensional layered materials, including semiconductors, metals, and magnetic half metals.", "author_names": [ "Yi-Lun Hong", "Zhibo Liu", "Lingqian Wang", "Tianya Zhou", "Wei Ma", "Chuan Xu", "Shun Feng", "Long Chen", "Maolin Chen", "Dongming Sun", "Xing-Qiu Chen", "Hui-Ming Cheng", "Wencai Ren" ], "corpus_id": 221011978, "doc_id": "221011978", "n_citations": 64, "n_key_citations": 2, "score": 1, "title": "Chemical vapor deposition of layered two dimensional MoSi2N4 materials", "venue": "Science", "year": 2020 }, { "abstract": "Two dimensional (2D) materials with atomic thickness are promising candidates for the applications in future semiconductor devices, owing to their fascinating physical properties and superlative optoelectronic performance. Chemical vapor deposition (CVD) is considered to be an efficient method for large scale preparation of 2D materials toward practical applications. However, the high melting points of metal precursors and the thermodynamics instabilities of metastable phases limit the direct CVD synthesis of plenty of 2D materials. The salt has recently been introduced into the CVD process, which proved to be effective to address these issues. In this review, we highlighted the latest progress in the salt assisted CVD growth of 2D materials, including layered and non layered crystals. Firstly, strategies of adding salts are summarized. Then, the salt assisted growth of various layered materials is presented, emphasizing on the transition metal chalcogenides of stable and metastable phases. Furthermore, strategies to grow ultrathin non layered materials are discussed. We provide viewpoints into the techniques of using salt, the effects of salt, and the growth mechanisms of 2D crystals. Finally, we offer the challenges to be overcome and further research directions of this emerging salt assisted CVD technique.", "author_names": [ "Wei Han", "Kailang Liu", "Sanjun Yang", "Fakun Wang", "Jianwei Su", "Bao Jin", "Huiqiao Li", "Tianyou Zhai" ], "corpus_id": 201675265, "doc_id": "201675265", "n_citations": 23, "n_key_citations": 0, "score": 0, "title": "Salt assisted chemical vapor deposition of two dimensional materials", "venue": "Science China Chemistry", "year": 2019 }, { "abstract": "Quasi one dimensional (1D)/two dimensional (2D) ZrTe3 attracts intense interest as a typical charge density wave (CDW) bearing material. However, the conventional chemical vapor transport (CVT) synthesis of bulk ZrTe3 is limited by high time consumption, even up to weeks, and low morphological controllability, so it is highly desirable to develop feasible methods for fast and controlled ZrTe3 growth, and so far, these have not been demonstrated. In this work, we first demonstrated that ZrTe3 nanoribbons can be grown directly by a modified chemical vapor deposition (CVD) method. The growth time is significantly reduced to less than 90 min, and the size of ZrTe3 nanoribbons can be well tuned by controlling the growth time and growth temperature. Moreover, differing from most of the other transition metal trichalcogenides (TMTCs) we reveal that ZrTe3 nanoribbons exhibit both competing and synergistic magnetic properties originating from their intrinsic diamagnetism and unexpected ferromagnetism, which can be attributed to their structural imperfection and edge states due to the reduced dimensionality. Such observable ferromagnetism might favor the exploration of their spin electronic applications.", "author_names": [ "Xuegang Yu", "Xiaokun Wen", "Wenfeng Zhang", "Li Yang", "Hao Wu", "Xun Lou", "Zijian Xie", "Yuan Liu", "Haixin Chang" ], "corpus_id": 201215721, "doc_id": "201215721", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Fast and controlled growth of two dimensional layered ZrTe3 nanoribbons by chemical vapor deposition", "venue": "", "year": 2019 }, { "abstract": "Chemical vapor deposition (CVD) route has emerged as an effective method for the successful synthesis of two dimensional (2D) materials with satisfactory crystal quality, especially for the synthesis of wafer scale, uniform thickness or large domain size single crystal transition metal chalcogenides (TMCs) To achieve this, the salt assisted CVD strategy has been proved to be powerful to reduce the high melting point of the metal related precursor, decrease the nucleation density and increase the reaction rate on the solid template. However, the specific roles of alkali metals and halide components still remain unclear. Herein, the functions of salts in the growth of TMCs have been discussed by summarizing some recent achievements in salt assisted synthesis results, wherein salts are mainly introduced as additives in metal precursors to achieve the wafer scale uniform growth of monolayer and thickness tunable multi layered TMCs, and for serving as 3D templates (especially NaCl) to realize the scalable production of TMCs. Moreover, the existing challenges and viable future directions are also proposed for in depth understanding of salt assisted C4VD methods and for exploring more efficient CVD strategies.", "author_names": [ "Chunyu Xie", "Pengfei Yang", "Yahuan Huan", "Fangfang Cui", "Yanfeng Zhang" ], "corpus_id": 219913556, "doc_id": "219913556", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Roles of salts in the chemical vapor deposition synthesis of two dimensional transition metal chalcogenides.", "venue": "Dalton transactions", "year": 2020 }, { "abstract": "Two dimensional semiconducting transition metal dichalcogenides embedded in optical microcavities in the strong exciton photon coupling regime may lead to promising applications in spin and valley addressable polaritonic logic gates and circuits. One significant obstacle for their realization is the inherent lack of scalability associated with the mechanical exfoliation commonly used for fabrication of two dimensional materials and their heterostructures. Chemical vapor deposition offers an alternative scalable fabrication method for both monolayer semiconductors and other two dimensional materials, such as hexagonal boron nitride. Observation of the strong light matter coupling in chemical vapor grown transition metal dichalcogenides has been demonstrated so far in a handful of experiments with monolayer molybdenum disulfide and tungsten disulfide. Here we instead demonstrate the strong exciton photon coupling in microcavities comprising large area transition metal dichalcogenide hexagonal boron nitride heterostructures made from chemical vapor deposition grown molybdenum diselenide and tungsten diselenide encapsulated on one or both sides in continuous few layer boron nitride films also grown by chemical vapor deposition. These transition metal dichalcogenide hexagonal boron nitride heterostructures show high optical quality comparable with mechanically exfoliated samples, allowing operation in the strong coupling regime in a wide range of temperatures down to 4 Kelvin in tunable and monolithic microcavities, and demonstrating the possibility to successfully develop large area transition metal dichalcogenide based polariton devices.", "author_names": [ "Daniel Gillard", "Armando Genco", "Seongjoon Ahn", "T P Lyons", "Kyung Yeol Ma", "A-Rang Jang", "Toby Severs Millard", "Aurelien A P Trichet", "Rahul Jayaprakash", "Kyriacos Georgiou", "David G Lidzey", "Jason M Smith", "Hyeon Suk Shin", "Alexander I Tartakovskii" ], "corpus_id": 221186692, "doc_id": "221186692", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Strong exciton photon coupling in large area MoSe2 and WSe2 heterostructures fabricated from two dimensional materials grown by chemical vapor deposition", "venue": "", "year": 2020 }, { "abstract": "The insulator Na2Ta4O11 has been considered as a potential photocatalyst. However, little attention has been given to the synthesis of Na2Ta4O11 nanoparticles, let alone the growth of two dimensional (2D) layered Na2Ta4O11 flake, which may bring innovative properties and promising applications. Here, the 2D thin layer Na2Ta4O11 flake was first produced by chemical vapor deposition (CVD) method, with the smallest thickness reported currently. We have also synthesized 2D Na2Ta4O11 flake over 100 mm, which was the largest value over the 2D level reported to date. Our work proposed novel strategies to synthesize other 2D metal oxide material and endow the Na2Ta4O11 more properties and applications.", "author_names": [ "Yuanyuan Jin", "Huimin Li", "Song Liu" ], "corpus_id": 225626329, "doc_id": "225626329", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Growth of large scale two dimensional insulator Na2Ta4O11 through chemical vapor deposition", "venue": "", "year": 2020 }, { "abstract": "ConspectusSince the rise of two dimensional (2D) materials, synthetic methods including mechanical exfoliation, solution synthesis, and chemical vapor deposition (CVD) have been developed. Mechanical exfoliation prepares randomly shaped materials with small size. Solution synthesis introduces impurities that degrade the performances. CVD is the most successful one for low cost scalable preparation. However, when it comes to practical applications, disadvantages such as high operating temperature ~1000 degC) probable usage of metal catalysts, contamination, defects, and interstices introduced by postgrowth transfer are not negligible. These are the reasons why plasma enhanced CVD (PECVD) a method that enables catalyst free in situ preparation at low temperature, is imperatively desirable.In this Account, we summarize our recent progress on controllable preparation of 2D materials by PECVD and their applications. We found that there was a competition between etching and nucleation and deposition in PECVD, making it highly controllable to obtain desired materials. Under different equilibrium states of the competition, various 2D materials with diverse morphologies and properties were prepared including pristine or nitrogen doped graphene crystals, graphene quantum dots, graphene nanowalls, hexagonal boron nitride (h BN) B C N ternary materials (BCxN) etc. We also used mild plasma to modify or treat 2D materials (e.g. WSe2) for desired properties.PECVD has advantages such as low temperature, transfer free process, and industrial compatibility, which enable facile, scalable, and low cost preparation of 2D materials with clean surfaces and interfaces directly on noncatalytic substrates. These merits significantly benefit the as prepared materials in the applications. Field effect transistors with high motilities were directly fabricated on graphene and nitrogen doped graphene. By use of h BN as the dielectric interfacial layer, both mobilities and saturated power densities of the devices were improved owing to the clean, closely contacted interface and enhanced interfacial thermal dissipation. High quality materials and interfaces also enabled promising applications of these materials in photodetectors, pressure sensors, biochemical sensors, electronic skins, Raman enhancement, etc. To demonstrate the commercial applications, several prototypical devices were studied such as distributed pressure sensor arrays, touching module on a robot hand for braille recognition, and smart gloves for recording sign language. Finally, we discuss opportunities and challenges of PECVD as a comprehensive preparation methodology of 2D materials for future applications beyond traditional CVD.", "author_names": [ "Kongyang Yi", "Donghua Liu", "Xiaosong Chen", "Jun Yang", "Dapeng Wei", "Yunqi Liu", "Dacheng Wei" ], "corpus_id": 231804768, "doc_id": "231804768", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Plasma Enhanced Chemical Vapor Deposition of Two Dimensional Materials for Applications.", "venue": "Accounts of chemical research", "year": 2021 }, { "abstract": "The discovery of ferromagnetic two dimensional van der Waals materials has opened up opportunities to explore intriguing physics and to develop innovative spintronic devices. However, controllable synthesis of these 2D ferromagnets and enhancing their stability under ambient conditions remain challenging. Here, we report chemical vapor deposition growth of air stable 2D metallic 1T CrTe2 ultrathin crystals with controlled thickness. Their long range ferromagnetic ordering is confirmed by a robust anomalous Hall effect, which has seldom been observed in other layered 2D materials grown by chemical vapor deposition. With reducing the thickness of 1T CrTe2 from tens of nanometers to several nanometers, the easy axis changes from in plane to out of plane. Monotonic increase of Curie temperature with the thickness decreasing from ~130.0 to ~7.6 nm is observed. Theoretical calculations indicate that the weakening of the Coulomb screening in the two dimensional limit plays a crucial role in the change of magnetic properties.", "author_names": [ "Lingjia Meng", "Zhang Zhou", "Mingquan Xu", "Shiqi Yang", "Kunpeng Si", "Lixuan Liu", "Xingguo Wang", "Huaning Jiang", "Bixuan Li", "Peixin Qin", "Peng Zhang", "Jinliang Wang", "Zhiqi Liu", "Peizhe Tang", "Yu Ye", "Wu Zhou", "Lihong Bao", "Hongquing Gao", "Yongji Gong" ], "corpus_id": 231867608, "doc_id": "231867608", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Anomalous thickness dependence of Curie temperature in air stable two dimensional ferromagnetic 1T CrTe2 grown by chemical vapor deposition", "venue": "Nature communications", "year": 2021 }, { "abstract": "Two dimensional (2D) palladium diselenide (PdSe2 has strong interlayer coupling and a puckered pentagonal structure, leading to remarkable layer dependent electronic structures and highly anisotropic in plane optical and electronic properties. However, the lack of high quality, 2D PdSe2 crystals grown by bottom up approaches limits the study of their exotic properties and practical applications. In this work, chemical vapor deposition growth of highly crystalline few layer =2 layers) PdSe2 crystals on various substrates is reported. The high quality of the PdSe2 crystals is confirmed by low frequency Raman spectroscopy, scanning transmission electron microscopy, and electrical characterization. In addition, strong in plane optical anisotropy is demonstrated via polarized Raman spectroscopy and second harmonic generation maps of the PdSe2 flakes. A theoretical model based on kinetic Wulff construction theory and density functional theory calculations is developed and described the observed evolution of \"square like\" shaped PdSe2 crystals into rhombus due to the higher nucleation barriers for stable attachment on the (1,1) and (1, 1) edges, which results in their slower growth rates. Few layer PdSe2 field effect transistors reveal tunable ambipolar charge carrier conduction with an electron mobility up to 294 cm2 V 1 s 1 which is comparable to that of exfoliated PdSe2 indicating the promise of this anisotropic 2D material for electronics.", "author_names": [ "Yiyi Gu", "Hui Cai", "Jichen Dong", "Yiling Yu", "Anna N Hoffman", "Chenze Liu", "Akinola D Oyedele", "Yu-Chuan Lin", "Zhuozhi Ge", "Alexander A Puretzky", "Gerd Duscher", "Matthew F Chisholm", "Philip D Rack", "Christopher M Rouleau", "Zheng Gai", "Xiangmin Meng", "Feng Ding", "David B Geohegan", "Kai Xiao" ], "corpus_id": 220519224, "doc_id": "220519224", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Two Dimensional Palladium Diselenide with Strong In Plane Optical Anisotropy and High Mobility Grown by Chemical Vapor Deposition.", "venue": "Advanced materials", "year": 2020 }, { "abstract": "Due to the confinement of the charge, spin, and heat transport in the plane, graphene and related two dimensional (2D) materials have been demonstrated to own many unique and excellent properties and witnessed many breakthroughs in physics. They show great application potential in many fields, especially for electronics and optoelectronics. However, a bottleneck to widespread applications is precise and reliable fabrication, in which the control of the layer number and domain assembly is the most basic and important since they directly determine the qualities and properties of 2D materials. The chemical vapor deposition (CVD) strategy was regarded as the frontrunner to achieve this target, and the design of the catalytic substrate is of great significance since it has the most direct influence on the catalysis and mass transfer, which can be the most essential elemental steps. In recent years, as compared to traditional solid metal catalysts, the emergence of liquid metal catalysts has brought a brand new perspective and contributes to a huge change and optimization in the fabrication of 2D materials. On one hand, strictly self limited growth behavior is discovered and is robust to the variation of the growth parameters. The atoms in the liquid metal tend to move intensely and arrange in an amorphous and isotropic way. The liquid surface is smooth and isotropic, and the vacancies in the fluidic liquid phase enable the embedding of heteroatoms. The phase transition from liquid to solid will facilitate the unique control of the mass transfer path, which can trigger new growth mechanisms. On the other hand, the excellent rheological properties of liquid metals allow us to explore self assembly of the 2D materials grown on the surface, which can activate new applications based on the derived collective properties, such as the integrated devices. Indeed, liquid metals show many unique behaviors in the catalytic growth and assembly of 2D materials. Thus, this Account aims to highlight the controllable fabrication of graphene and related 2D materials on liquid metals. By utilizing the phase transition of liquid metals, the segregation of precursors in the bulk can be controlled, leading to self limited growth. By utilizing the fluidity of the liquid metals, 2D material crystals can achieve self assembly on their surface, including oriented stitching, ordered assembly, and heterostacking, which enables the creation of new multilevel or hybrid structures, leading to property and function extension and even the emergence of new physics. Finally, the unique liquid characteristic of liquid metals can also offer us new ideas about the transfer process. By utilizing the shear transformation of liquid metals, the direct sliding transfer of 2D materials onto arbitrary substrates can be realized. The research concerning the self limited growth, self assembly, and sliding transfer of 2D materials on liquid metals is just raising the curtain on the behavioral study of 2D materials on liquid metals. We believe these primary technology developments revealed by liquid metals will establish a solid foundation for both fundamental research and practical application of 2D materials.", "author_names": [ "Mengqi Zeng", "Lei Fu" ], "corpus_id": 52285259, "doc_id": "52285259", "n_citations": 31, "n_key_citations": 0, "score": 0, "title": "Controllable Fabrication of Graphene and Related Two Dimensional Materials on Liquid Metals via Chemical Vapor Deposition.", "venue": "Accounts of chemical research", "year": 2018 } ]

[ { "abstract": "ZigBee is a short range wireless networking standard backed by such industry leaders as Motorola, Texas Instruments, Philips, Samsung, Siemens, Freescale, etc. It supports mesh networking, each node can transmit and receive data, offers high security and robustness, and is being rapidly adopted in industrial, control/monitoring, and medical applications. This book will explain the ZigBee protocol, discuss the design of ZigBee hardware, and describe how to design and implement ZigBee networks. The book has a dedicated website for the latest technical updates, ZigBee networking calculators, and additional materials. Dr. Farahani is a ZigBee system engineer for Freescale semiconductors Inc.Table of ContentsChapter 1: ZigBee BasicsChapter 2: ZigBee IEEE 802.15.4 Networking ExamplesChapter 3: ZigBee IEEE 802.15.4 Protocol LayersChapter 4: Transceiver RequirementsChapter 5: RF Propagation, Antennas, and Regulatory RequirementsChapter 6: Battery Life AnalysisChapter 7: Location Estimating Using ZigBee Chapter 8: ZigBee CoexistenceChapter 9: Related TechnologiesAppendicesKEY FEATURES* Provides a comprehensive overview of ZigBee technology and networking, from RF/physical layer considerations to application layer development. Discusses ZigBee security features such as encryption. Describes how ZigBee can be used in location detection applications. Explores techniques for ZigBee co existence with other wireless technologies such as 802.11 and Bluetooth.", "author_names": [ "Shahin Farahani" ], "corpus_id": 108112680, "doc_id": "108112680", "n_citations": 571, "n_key_citations": 85, "score": 0, "title": "ZigBee Wireless Networks and Transceivers", "venue": "", "year": 2008 }, { "abstract": "Bluetooth (over IEEE 802.15.1) ultra wideband (UWB, over IEEE 802.15.3) ZigBee (over IEEE 802.15.4) and Wi Fi (over IEEE 802.11) are four protocol standards for short range wireless communications with low power consumption. From an application point of view, bluetooth is intended for a cordless mouse, keyboard, and hands free headset, UWB is oriented to high bandwidth multimedia links, ZigBee is designed for reliable wirelessly networked monitoring and control networks, while Wi Fi is directed at computer to computer connections as an extension or substitution of cabled networks. In this paper, we provide a study of these popular wireless communication standards, evaluating their main features and behaviors in terms of various metrics, including the transmission time, data coding efficiency, complexity, and power consumption. It is believed that the comparison presented in this paper would benefit application engineers in selecting an appropriate protocol.", "author_names": [ "Jin-Shyan Lee", "Yu-Wei Su", "Chung-Chou Shen" ], "corpus_id": 4812691, "doc_id": "4812691", "n_citations": 1065, "n_key_citations": 94, "score": 0, "title": "A Comparative Study of Wireless Protocols: Bluetooth, UWB, ZigBee, and Wi Fi", "venue": "IECON 2007 33rd Annual Conference of the IEEE Industrial Electronics Society", "year": 2007 }, { "abstract": "In recent years, the home environment has seen a rapid introduction of network enabled digital technology. This technology offers new and exciting opportunities to increase the connectivity of devices within the home for the purpose of home automation. Moreover, with the rapid expansion of the Internet, there is the added potential for the remote control and monitoring of such network enabled devices. However, the adoption of home automation systems has been slow. This paper identifies the reasons for this slow adoption and evaluates the potential of ZigBee for addressing these problems through the design and implementation of a flexible home automation architecture. A ZigBee based home automation system and Wi Fi network are integrated through a common home gateway. The home gateway provides network interoperability, a simple and flexible user interface, and remote access to the system. A dedicated virtual home is implemented to cater for the system's security and safety needs. To demonstrate the feasibility and effectiveness of the proposed system, four devices, a light switch, radiator valve, safety sensor and ZigBee remote control have been developed and evaluated with the home automation system.", "author_names": [ "Khusvinder Gill", "Shuanghua Yang", "Fang Yao", "Xin Lu" ], "corpus_id": 8602326, "doc_id": "8602326", "n_citations": 629, "n_key_citations": 19, "score": 0, "title": "A zigbee based home automation system", "venue": "IEEE Transactions on Consumer Electronics", "year": 2009 }, { "abstract": "Wireless personal area network and wireless sensor networks are rapidly gaining popularity, and the IEEE 802.15 Wireless Personal Area Working Group has defined no less than different standards so as to cater to the requirements of different applications. The ubiquitous home network has gained widespread attentions due to its seamless integration into everyday life. This innovative system transparently unifies various home appliances, smart sensors and energy technologies. The smart energy market requires two types of ZigBee networks for device control and energy management. Today, organizations use IEEE 802.15.4 and ZigBee to effectively deliver solutions for a variety of areas including consumer electronic device control, energy management and efficiency, home and commercial building automation as well as industrial plant management. We present the design of a multi sensing, heating and airconditioning system and actuation application the home users: a sensor network based smart light control system for smart home and energy control production. This paper designs smart home device descriptions and standard practices for demand response and load management \"Smart Energy\" applications needed in a smart energy based residential or light commercial environment. The control application domains included in this initial version are sensing device control, pricing and demand response and load control applications. This paper introduces smart home interfaces and device definitions to allow interoperability among ZigBee devices produced by various manufacturers of electrical equipment, meters, and smart energy enabling products. We introduced the proposed home energy control systems design that provides intelligent services for users and we demonstrate its implementation using a real testbad.", "author_names": [ "Dae-Man Han", "Jae-Hyun Lim" ], "corpus_id": 206634147, "doc_id": "206634147", "n_citations": 625, "n_key_citations": 25, "score": 0, "title": "Smart home energy management system using IEEE 802.15.4 and zigbee", "venue": "IEEE Transactions on Consumer Electronics", "year": 2010 }, { "abstract": "Wireless sensor networks are an emerging technology for low cost, unattended monitoring of a wide range of environments. Their importance has been enforced by the recent delivery of the IEEE 802.15.4 standard for the physical and MAC layers and the forthcoming ZigBee standard for the network and application layers. The fast progress of research on energy efficiency, networking, data management and security in wireless sensor networks, and the need to compare with the solutions adopted in the standards motivates the need for a survey on this field.", "author_names": [ "Paolo Baronti", "Prashant Pillai", "Vince W C Chook", "Stefano Chessa", "Alberto Gotta", "Yim-Fun Hu" ], "corpus_id": 8834682, "doc_id": "8834682", "n_citations": 1738, "n_key_citations": 121, "score": 0, "title": "Wireless sensor networks: A survey on the state of the art and the 802.15.4 and ZigBee standards", "venue": "Comput. Commun.", "year": 2007 }, { "abstract": "This paper introduced a system based on wireless network technology, which achieved node to node data collection and transmission. The ZigBee based wireless network of the system adopted the chip CC2530 of TI company. The system developed applications based on Z STACK for data collection and wireless transmission, it used VC+ to make a PC software for real time monitoring of temperature and humidity. The research results show the feasibility of the system, and it would be widely used in the measure field of agriculture.", "author_names": [ "Bo Xu", "Yongjun Zheng", "Yan Xin Yin", "Yu Tan" ], "corpus_id": 109405174, "doc_id": "109405174", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Temperature and Humidity Monitoring System Based on CC2530", "venue": "", "year": 2013 }, { "abstract": "Abstract This paper presents the development of an automatic wireless sensor monitoring system for civil engineering structures. The objective is to provide a solution to measure both temperature and humidity inside a concrete structure. The research has been focused in the early age and curing phase period. Four solutions have been addressed. The first one involves the use of a negative temperature coefficient (NTC) thermistor and an IRIS mote allowing for the creation of an IEEE 802.15.4 network. However, the results have shown that the sensor measurements present a 5 degC standard deviation between the actual and the experimental values. The second one considers the use of the SHT15 (humidity/temperature) sensor, together with the PIC18F4680 microcontroller or the Arduino platform. The third solution involves the use of the SHT21S (humidity/temperature) sensor and the eZ430 RF2500 wireless development tool platform for the MSP430 microcontroller. In this case, the temperature readings were successfully performed for the first 16 h, while the humidity values were successfully obtained for the first 24 h of the experiment. Although the set of measured values is very promising for the SHT15 and SHT21S sensors, both sensors have stopped working after some time, showing that direct contact between the sensor and the concrete alkaline environment causes its breakdown. Finally, the fourth solution considers both the SHT15 and SHT21S sensors completely shielded allowing for the creation of a long term solution. As, the SHT15 and SHT12S sensors have not been affected by the alkaline environment for more than two months of operation, enabling real time and continuous monitoring with almost non intrusive tiny devices, the potential of applying the proposed inexpensive wireless sensor network approach is verified.", "author_names": [ "Norberto Barroca", "Luis M Borges", "Fernando Jose Velez", "Filipe Monteiro", "Marcin Gorski", "Joao Castro-Gomes" ], "corpus_id": 108438532, "doc_id": "108438532", "n_citations": 105, "n_key_citations": 2, "score": 0, "title": "Wireless sensor networks for temperature and humidity monitoring within concrete structures", "venue": "", "year": 2013 }, { "abstract": "An animal health monitoring system for monitoring the physiological parameters, such as rumination, body temperature, and heart rate with surrounding temperature and humidity, has been developed. The developed system can also analyze the stress level corresponding to thermal humidity index. The IEEE802.15.4 and IEEE1451.2 standards based sensor module has been developed successfully. The Zigbee device and PIC18F4550 microcontroller are used in the implementation of sensor module. The graphical user interface (GUI) is implemented in LabVIEW 9 according to the IEEE1451.1 standard. The real time monitoring of physiological and behavioral parameters can be present on the GUI PC. The device is very helpful for inexpensive health care of livestock. A prototype model is developed and tested with high accuracy results.", "author_names": [ "Anuj Kumar", "Gerhard Petrus Hancke" ], "corpus_id": 32009868, "doc_id": "32009868", "n_citations": 113, "n_key_citations": 1, "score": 1, "title": "A Zigbee Based Animal Health Monitoring System", "venue": "IEEE Sensors Journal", "year": 2015 }, { "abstract": "Localization in wireless sensor networks gets more and more important, because many applications need to locate the source of incoming measurements as precise as possible. Weighted centroid localization (WCL) provides a fast and easy algorithm to locate devices in wireless sensor networks. The algorithm is derived from a centroid determination which calculates the position of devices by averaging the coordinates of known reference points. To improve the calculated position in real implementations, WCL uses weights to attract the estimated position to close reference points provided that coarse distances are available. Due to the fact that Zigbee provides the link quality indication (LQI) as a quality indicator of a received packet, it can also be used to estimate a distance from a node to reference points.", "author_names": [ "Jan Blumenthal", "Ralf Grossmann", "Frank Golatowski", "Dirk Timmermann" ], "corpus_id": 12820131, "doc_id": "12820131", "n_citations": 482, "n_key_citations": 58, "score": 0, "title": "Weighted Centroid Localization in Zigbee based Sensor Networks", "venue": "2007 IEEE International Symposium on Intelligent Signal Processing", "year": 2007 }, { "abstract": "Today, organizations use IEEE802.15.4 and ZigBee to effectively deliver solutions for a variety of areas including consumer electronic device control, energy management and efficiency home and commercial building automation as well as industrial plant management. The Smart home energy network has gained widespread attentions due to its flexible integration into everyday life. This next generation green home system transparently unifies various home appliances, smart sensors and wireless communication technologies. The green home energy network gradually forms a complex system to process various tasks. Developing this trend, we suggest a new Smart Home Energy Management System (SHEMS) based on an IEEE802.15.4 and ZigBee (we call it as a \"ZigBee sensor network\" The proposed smart home energy management system divides and assigns various home network tasks to appropriate components. It can integrate diversified physical sensing information and control various consumer home devices, with the support of active sensor networks having both sensor and actuator components. We develop a new routing protocol DMPR (Disjoint Multi Path based Routing) to improve the performance of our ZigBee sensor networks. This paper introduces the proposed home energy control system's design that provides intelligent services for users. We demonstrate its implementation using a real environment.", "author_names": [ "Dae-Man Han", "Jae-Hyun Lim" ], "corpus_id": 41836970, "doc_id": "41836970", "n_citations": 523, "n_key_citations": 15, "score": 0, "title": "Design and implementation of smart home energy management systems based on zigbee", "venue": "IEEE Transactions on Consumer Electronics", "year": 2010 } ]

[ { "abstract": "Hafnia ferroelectric materials have gained prominence as promising materials for advanced memory applications due to their high scalability and full complementary metal oxide semiconductor compatibility. In this paper, we present a comprehensive study on the electrical properties of Pt/Hf0.5Zr0.5O2/TiN asymmetric ferroelectric tunnel junction (FTJ) devices. The ferroelectric behavior of 4 and 5 nm Hf0.5Zr0.5O2 (HZO) thin films was confirmed by using piezoresponse force microscopy and conductive atomic force microscopy. The typical current voltage characteristics of the FTJ devices with two resistance states due to the tunneling electroresistance (TER) effect have been analyzed using a direct tunneling model based on the Wentzel Kramers Brillouin approximation. Further, we have proposed a method to extract the effective mass of the HZO thin film by numerical analysis using the MOS leakage current model. Finally, a dependence of the TER on the HZO thickness is analyzed to realize a high TER ratio.Hafnia ferroelectric materials have gained prominence as promising materials for advanced memory applications due to their high scalability and full complementary metal oxide semiconductor compatibility. In this paper, we present a comprehensive study on the electrical properties of Pt/Hf0.5Zr0.5O2/TiN asymmetric ferroelectric tunnel junction (FTJ) devices. The ferroelectric behavior of 4 and 5 nm Hf0.5Zr0.5O2 (HZO) thin films was confirmed by using piezoresponse force microscopy and conductive atomic force microscopy. The typical current voltage characteristics of the FTJ devices with two resistance states due to the tunneling electroresistance (TER) effect have been analyzed using a direct tunneling model based on the Wentzel Kramers Brillouin approximation. Further, we have proposed a method to extract the effective mass of the HZO thin film by numerical analysis using the MOS leakage current model. Finally, a dependence of the TER on the HZO thickness is analyzed to realize a high TER ratio.", "author_names": [ "Jung Ho Yoon", "Seung Hoon Hong", "Yong Won Song", "Ji-Hoon Ahn", "Seung-Eon Ahn" ], "corpus_id": 209976391, "doc_id": "209976391", "n_citations": 13, "n_key_citations": 1, "score": 0, "title": "Understanding tunneling electroresistance effect through potential profile in Pt/Hf0.5Zr0.5O2/TiN ferroelectric tunnel junction memory", "venue": "Applied Physics Letters", "year": 2019 }, { "abstract": "This paper presents a unique opportunity of HZO ferroelectric tunnel junction (FTJ) for in memory computing. The device operates at an extremely low sub nA current while simultaneously achieving 50 ns fast switching, 107 cycling endurance, 10 yr retention, minimal variability, and analog state modulation. We analyze an FTJ based deep binary neural network. It achieves better accuracy and remarkable 702, 101, and 7x104 times improvements in power, area, and energy area product efficiency compared with those using NVMs with a typical mA cell current designed for fast memory access.", "author_names": [ "Tzu-Yun Wu", "Tian-Sheuan Chang", "Heng-Yuan Lee", "Shyh-Shyuan Sheu", "Wei-Chung Lo", "Tuo-Hung Hou", "Hsin-Hui Huang", "Yueh-Hua Chu", "Chih-Cheng Chang", "Ming-Hung Wu", "Chien-Hua Hsu", "Chien Ting Wu", "Min-Ci Wu", "Wen-Wei Wu" ], "corpus_id": 211208116, "doc_id": "211208116", "n_citations": 9, "n_key_citations": 1, "score": 0, "title": "Sub nA Low Current HZO Ferroelectric Tunnel Junction for High Performance and Accurate Deep Learning Acceleration", "venue": "2019 IEEE International Electron Devices Meeting (IEDM)", "year": 2019 }, { "abstract": "Ferroelectric tunnel junctions (FTJs) composed by sandwiching a thin ferroelectric layer between two leads have attracted great interest for their potential applications in nonvolatile memories due to the tunnel electroresistance (TER) effect. So far, almost all FTJs studied focus on adopting three dimensional (3D) ferroelectric materials as the tunnel barrier. Recently, many two dimensional (2D) ferroelectric materials with in plane or out of plane spontaneous polarization have been theoretically proposed or even fabricated, providing a new type of candidate as the tunnel barrier in FTJs. However, very little has been known about whether such 2D ferroelectric materials may lead to an excellent TER effect. In this work, using first principles calculations, we demonstrate that a giant TER effect of around 623% which is comparable to 3D FTJs, can be realized through the ferroelectric tunnel junction constructed with the 2D ferroelectric materials BiP and B/N doped graphene. The analysis of the effective potential and electronic structure indicates that the large TER ratio arises from the unsymmetrical screening effects of the B/N doped vertical van der Waals graphene/BiP leads. Our findings demonstrate the great potential of novel application of 2D ferroelectric BiP in FTJs.", "author_names": [ "Lili Kang", "Peng Jiang", "Ning Cao", "Hua Hao", "Xiaohong Zheng", "Lei Zhang", "Zhi Zeng" ], "corpus_id": 201806054, "doc_id": "201806054", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Realizing giant tunneling electroresistance in two dimensional graphene/BiP ferroelectric tunnel junction.", "venue": "Nanoscale", "year": 2019 }, { "abstract": "Abstract This paper proposes a device incorporating ferroelectric tunnel junction which analyzes the concept of tunneling across a silicon doped hafnium oxide ferroelectric. Variation of electrical parameters with ferroelectric thickness has been examined. Subthreshold swing (SS) of 40 mV/dec has been achieved with ferroelectric thickness of 2 nm. An increasing trend in the ION/IOFF ratio is observed with the increase in ferroelectric thickness. Moreover, the impact of temperature (300 K 500 K) on drain current as well as various RF parameter performance such as gate capacitance (CGG) transconductance (gm) output conductance (gd) intrinsic delay, intrinsic gain (gm/gd) cut off frequency (ft) and transconductance frequency product (TFP) has been studied.", "author_names": [ "Pujarini Ghosh", "Rupam Goswami", "Brinda Bhowmick" ], "corpus_id": 203994986, "doc_id": "203994986", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Optimization of ferroelectric tunnel junction TFET in presence of temperature and its RF analysis", "venue": "Microelectron. J.", "year": 2019 }, { "abstract": "Abstract The ferroelectric tunnel junction represents a memory concept that allows a nondestructive readout by utilizing a very thin ferroelectric film between two metal electrodes. Application of an electric field across the thin ferroelectric changes the polarization orientation and an accompanying modulation of the barrier height of the stack, which alters the tunneling current. For a long time, this concept was neglected due to the expected difficulties using common perovskite ferroelectrics and epitaxy for depositing such a thin layer while maintaining high ferroelectric properties. The discovery of ferroelectricity in the hafnium oxide system represents a game changer. In this chapter, the crucial design parameters are discussed that have to be considered for controlling the current transport, reducing the depolarization field, and finally optimizing the tunneling electroresistance effect.", "author_names": [ "Shosuke Fujii", "Masumi Saitoh" ], "corpus_id": 141402471, "doc_id": "141402471", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Ferroelectric Tunnel Junction", "venue": "", "year": 2019 }, { "abstract": "Ferroelectric tunnel junction (FTJ) is a promising low power nonvolatile memory for beyond CMOS applications. In this paper, Co/BaTiO3/SrRuO3 FTJs are fabricated, simulated, and their electrical characteristics are measured by capacitance voltage {C} {V} current voltage {I} {V} and high frequency S parameter measurements. Ferroelectricity of the ultrathin BaTiO3 ~3.2 nm) film is first verified by a butterfly shaped hysteresis {C} {V} profile, from which saturation polarizations are calculated in the ON state and OFF state as {P}_{ \\mathrm{ON} {20}\\mu {C} \\text{cm} {2} and {P}_{ \\mathrm{OFF} {25}\\mu {C}\\text{cm} {2} respectively. The numerical simulation of the FTJ device is performed using experimental electronic band parameters of the heterostructure. The device structure was optimized for ON/OFF ratio, {I}_{ \\mathrm{ON} {I}_{ \\mathrm{OFF} {75} for a depolarization field, {E}_{{dpol} The calculated tunnel currents of {250}{nm}\\times {250}{nm} FTJ in ON state {I}_{ \\mathrm{ON} {250}\\times {250} {250}{A} and OFF state {I}_{{OFF}{1.75}\\times {250} 9}{A} match with experimental values. From the S parameters of RF measurements, the high frequency small signal device model of the FTJ in ON state {C}_{ \\mathrm{ON} {250}{fF}{R}_{ \\mathrm{ON}{0.8}{M}\\Omega$ and OFF state {C}_{ \\mathrm{OFF} {250}{fF}{R}_{ \\mathrm{OFF} {250}{M}\\Omega$ is developed for a frequency range from 50 MHz to 5 GHz. The extracted capacitor model of Co/BaTiO3/SrRuO3 FTJ is useful for high frequency simulation of benchmark FTJ circuits.", "author_names": [ "Mohammad Abuwasib", "Hyungwoo Lee", "Jung-Woo Lee", "C B Eom", "Alexei Gruverman", "Uttam Singisetti" ], "corpus_id": 133581437, "doc_id": "133581437", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Characterization and Modeling of Co/BaTiO3/SrRuO3 Ferroelectric Tunnel Junction Memory by Capacitance Voltage {C} {V} Current Voltage {I} {V} and High Frequency Measurements", "venue": "IEEE Transactions on Electron Devices", "year": 2019 }, { "abstract": "Resistive switching (RS) devices have attracted increasing attention for artificial synapse applications in neural networks because of their nonvolatile and analogue resistance changes. Among the neural networks, a spiking neural network (SNN) based on spike timing dependent plasticity (STDP) is highly energy efficient. To implement STDP in resistive switching devices, several types of voltage spikes have been proposed to date, but there have been few reports on the relationship between the STDP characteristics and spike types. Here, we report the STDP characteristics implemented in ferroelectric tunnel junctions (FTJs) by several types of spikes. Based on simulated time evolutions of superimposed spikes and taking the nonlinear current voltage (I V) characteristics of FTJs into account, we propose equations for simulating the STDP curve parameters of a magnitude of the conductance change (DG max) and a time window (tC) from the spike parameters of a peak amplitude (V peak) and time durations (t p and t d) for three spike types: triangle triangle, rectangular triangle, and rectangular rectangular. The power consumption experiments of the STDP revealed that the power consumption under the inactive synapse condition (spike timing |Dt| tC) was as large as 50 82% of that under the active synapse condition |Dt| tC) This finding indicates that the power consumption under the inactive synapse condition should be reduced to minimize the total power consumption of an SNN implemented by using FTJs as synapses.", "author_names": [ "P Stoliar", "H Yamada", "Yoshikiyo Toyosaki", "Akihito Sawa" ], "corpus_id": 208329505, "doc_id": "208329505", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Spike shape dependence of the spike timing dependent synaptic plasticity in ferroelectric tunnel junction synapses", "venue": "Scientific Reports", "year": 2019 }, { "abstract": "Ferroelectric tunnel junction (FTJ) is a promising low power nonvolatile memory for beyond CMOS applications. In this paper, Co/BaTiO₃/SrRuO₃ FTJs are fabricated, simulated, and their electrical characteristics are measured by capacitance voltage <inline formula> <tex math notation=\"LaTeX\"{C} /tex math>/inline formula> <inline formula> <tex math notation=\"LaTeX\"{V} /tex math>/inline formula> current voltage <inline formula> <tex math notation=\"LaTeX\"{I} /tex math>/inline formula> <inline formula> <tex math notation=\"LaTeX\"{V} /tex math>/inline formula> and high frequency S parameter measurements. Ferroelectricity of the ultrathin BaTiO₃ ~3.2 nm) film is first verified by a butterfly shaped hysteresis <inline formula> <tex math notation=\"LaTeX\"{C} /tex math>/inline formula> <inline formula> <tex math notation=\"LaTeX\"{V} /tex math>/inline formula> profile, from which saturation polarizations are calculated in the ON state and OFF state as <inline formula> <tex math notation=\"LaTeX\"{P}_{ \\mathrm{ON} {20}\\mu {C} \\text{cm} {2} /tex math>/inline formula> and <inline formula> <tex math notation=\"LaTeX\"{P}_{ \\mathrm{OFF} {25}\\mu {C}\\text{cm} {2} /tex math>/inline formula> respectively. The numerical simulation of the FTJ device is performed using experimental electronic band parameters of the heterostructure. The device structure was optimized for ON/OFF ratio, <inline formula> <tex math notation=\"LaTeX\"{I}_{ \\mathrm{ON} {I}_{ \\mathrm{OFF} {75} /tex math>/inline formula> for a depolarization field, <inline formula> <tex math notation=\"LaTeX\"{E}_{{dpol} {10} {6}{V} \\text{cm} /tex math>/inline formula> The calculated tunnel currents of <inline formula> <tex math notation=\"LaTeX\" {250}{nm}\\times {250}{nm} /tex math>/inline formula> FTJ in ON state <inline formula> <tex math notation=\"LaTeX\"{I}_{ \\mathrm{ON} {250}\\times {250} {250}{A} /tex math>/inline formula> and OFF state <inline formula> <tex math notation=\"LaTeX\"{I}_{{OFF}{1.75}\\times {250} 9}{A} /tex math>/inline formula> match with experimental values. From the S parameters of RF measurements, the high frequency small signal device model of the FTJ in ON state <inline formula> <tex math notation=\"LaTeX\"{C}_{ \\mathrm{ON} {250}{fF}{R}_{ \\mathrm{ON}{0.8}{M}\\Omega$ /tex math>/inline formula> and OFF state <inline formula> <tex math notation=\"LaTeX\"{C}_{ \\mathrm{OFF} {250}{fF}{R}_{ \\mathrm{OFF} {250}{M}\\Omega$ /tex math>/inline formula> is developed for a frequency range from 50 MHz to 5 GHz. The extracted capacitor model of Co/BaTiO₃/SrRuO₃ FTJ is useful for high frequency simulation of benchmark FTJ circuits.", "author_names": [ "Mohammad Abuwasib", "Hyungwoo Lee", "Jung-Woo Lee", "C B Eom", "Alexei Gruverman", "Uttam Singisetti" ], "corpus_id": 140090986, "doc_id": "140090986", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Characterization and Modeling of Co/BaTiO3/SrRuO3 Ferroelectric Tunnel Junction Memory by Capacitance Voltage {C} {V} Current", "venue": "IEEE Transactions on Electron Devices", "year": 2019 }, { "abstract": "Abstract We report successful synthesis of superconducting Bi Sr Ca Cu2 OX (BSCCO) target for fabrication of heterostructure thin films. For the first time, we have grown LSMO (50 nm)/PZT (5 nm)/BSCCO (100 nm)/LAO (100) heterostructure by pulsed laser deposition technique to understand the tunneling effect and role of the superconducting electrode on transport and magnetic properties. The bulk superconductor Bi Sr Ca Cu2 OX (BSCCO) and heterostructure shows superconducting phase transition near 92 K and 110 K, respectively. Magnetic susceptibility data indicate large negative susceptibility below 110 K which confirms the superconducting nature of heterostructure bottom electrode. A large hysteresis in current voltage data has been obtained at 78 K below the superconducting state of bottom electrode. These results suggest that the ferromagnetic/ferroelectric/superconductor tunnel structure may provide four distinct resistance states depending on the direction of ferroelectric polarization.", "author_names": [ "", "V N Ojha", "Ashok Kumar" ], "corpus_id": 106391404, "doc_id": "106391404", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Fabrication of ferroelectric tunnel junction using superconducting and magnetic electrodes", "venue": "", "year": 2019 }, { "abstract": "Brain inspired neuromorphic computing has shown great promise beyond the conventional Boolean logic. Nanoscale electronic synapses, which have stringent demands for integration density, dynamic range, energy consumption, etc. are key computational elements of the brain inspired neuromorphic system. Ferroelectric tunneling junctions have been shown to be ideal candidates to realize the functions of electronic synapses due to their ultra low energy consumption and the nature of ferroelectric tunneling. Here, we report a new electronic synapse based on a three dimensional vertical Hf0.5Zr0.5O2 based ferroelectric tunneling junction that meets the full functions of biological synapses. The fabricated three dimensional vertical ferroelectric tunneling junction synapse (FTJS) exhibits high integration density and excellent performances, such as analog like conductance transition under a training scheme, low energy consumption of synaptic weight update (1.8 pJ per spike) and good repeatability >103 cycles) In addition, the implementation of pattern training in hardware with strong tolerance to input faults and variations is also illustrated in the 3D vertical FTJS array. Furthermore, pattern classification and recognition are achieved, and these results demonstrate that the Hf0.5Zr0.5O2 based FTJS has high potential to be an ideal electronic component for neuromorphic system applications.", "author_names": [ "Lin Chen", "Tian-Yu Wang", "Ya-Wei Dai", "Ming-Yang Cha", "Hao Zhu", "Qingqing Sun", "S J Ding", "Peng Zhou", "Leon Ong Chua", "David-Wei Zhang" ], "corpus_id": 206136502, "doc_id": "206136502", "n_citations": 60, "n_key_citations": 0, "score": 0, "title": "Ultra low power Hf0.5Zr0.5O2 based ferroelectric tunnel junction synapses for hardware neural network applications.", "venue": "Nanoscale", "year": 2018 } ]

[ { "abstract": "Advanced oxidation processes via semiconductor photocatalysis for water treatment have been the subject of extensive research over the past three decades, producing many scientific reports focused on elucidating mechanisms and enhancing kinetics for the treatment of contaminants in water. Many of these reports imply that the ultimate goal of the research is to apply photocatalysis in municipal water treatment operations. However, this ignores immense technology transfer problems, perpetuating a widening gap between academic advocation and industrial application. In this Feature, we undertake a critical examination of the trajectory of photocatalytic water treatment research, assessing the viability of proposed applications and identifying those with the most promising future. Several strategies are proposed for scientists and engineers who aim to support research efforts to bring industrially relevant photocatalytic water treatment processes to fruition. Although the reassessed potential may not live up to initial academic hype, an unfavorable assessment in some areas does not preclude the transfer of photocatalysis for water treatment to other niche applications as the technology retains substantive and unique benefits.", "author_names": [ "Stephanie K Loeb", "Pedro J J Alvarez", "Jonathon Brame", "Ezra L Cates", "Wonyong Choi", "John C Crittenden", "Dionysios D Dionysiou", "Qilin Li", "Gianluca Li-Puma", "Xie Quan", "David L Sedlak", "T David Waite", "Paul K Westerhoff", "Jae-Hong Kim" ], "corpus_id": 58569309, "doc_id": "58569309", "n_citations": 179, "n_key_citations": 2, "score": 0, "title": "The Technology Horizon for Photocatalytic Water Treatment: Sunrise or Sunset?", "venue": "Environmental science technology", "year": 2019 }, { "abstract": "Growing worldwide population, climate change, and decaying water infrastructure have all contributed to a need for a better water treatment and conveyance model. Distributed water treatment is one possible solution, which relies on the local treatment of water from various sources to a degree dependent on its intended use and, finally, distribution to local consumers. This distributed, fit for purpose water treatment strategy requires the development of new modular point of use and point of entry technologies to bring this idea to fruition. Electrochemical technologies have the potential to contribute to this vision, as they have several advantages over established water treatment technologies. Electrochemical technologies have the ability to simultaneously treat multiple classes of contaminants through the in situ production of chemicals at the electrode surfaces with low power and energy demands, thereby allowing the construction of compact, modular water treatment technologies that require little maintenance and can be easily automated or remotely controlled. In addition, these technologies offer the opportunity for energy recovery through production of fuels at the cathode, which can further reduce their energy footprint. In spite of these advantages, there are several challenges that need to be overcome before widespread adoption of electrochemical water treatment technologies is possible. This Account will focus primarily on destructive electrolytic technologies that allow for removal of water contaminants without the need for residual treatment or management. Most important to the development of destructive electrochemical technologies is a need to fabricate nontoxic, inexpensive, high surface area electrodes that have a long operational life and can operate without the production of unwanted toxic byproducts. Overcoming these barriers will decrease the capital costs of water treatment and allow the development of the point of use and point of entry technologies that are necessary to promote more sustainable water treatment solutions. However, to accomplish this goal, a reprioritization of research is needed. Current research is primarily focused on investigating individual contaminant transformation pathways and mechanisms. While this research is important for understanding these technologies, additional work is needed in developing inexpensive, high surface area, stable electrode materials, minimizing toxic byproduct formation, and determining the life cycle and technoeconomic analyses necessary for commercialization. Better understanding of these critical research areas will allow for strategic deployment of electrochemical water treatment technologies to promote a more sustainable future.", "author_names": [ "Brian P Chaplin" ], "corpus_id": 73423457, "doc_id": "73423457", "n_citations": 91, "n_key_citations": 0, "score": 1, "title": "The Prospect of Electrochemical Technologies Advancing Worldwide Water Treatment.", "venue": "Accounts of chemical research", "year": 2019 }, { "abstract": "In recent years, semiconductor photocatalytic process has shown a great potential as a low cost, environmental friendly and sustainable treatment technology to align with the \"zero\" waste scheme in the water/wastewater industry. The ability of this advanced oxidation technology has been widely demonstrated to remove persistent organic compounds and microorganisms in water. At present, the main technical barriers that impede its commercialisation remained on the post recovery of the catalyst particles after water treatment. This paper reviews the recent R&D progresses of engineered photocatalysts, photoreactor systems, and the process optimizations and modellings of the photooxidation processes for water treatment. A number of potential and commercial photocatalytic reactor configurations are discussed, in particular the photocatalytic membrane reactors. The effects of key photoreactor operation parameters and water quality on the photo process performances in terms of the mineralization and disinfection are assessed. For the first time, we describe how to utilize a multi variables optimization approach to determine the optimum operation parameters so as to enhance process performance and photooxidation efficiency. Both photomineralization and photo disinfection kinetics and their modellings associated with the photocatalytic water treatment process are detailed. A brief discussion on the life cycle assessment for retrofitting the photocatalytic technology as an alternative waste treatment process is presented. This paper will deliver a scientific and technical overview and useful information to scientists and engineers who work in this field.", "author_names": [ "Meng Nan Chong", "Bo Jin", "Christopher W K Chow", "Christopher P Saint" ], "corpus_id": 11490118, "doc_id": "11490118", "n_citations": 3562, "n_key_citations": 105, "score": 0, "title": "Recent developments in photocatalytic water treatment technology: a review.", "venue": "Water research", "year": 2010 }, { "abstract": "Natural organic matter (NOM) is a complex matrix of organic substances produced in (or channeled to) aquatic ecosystems via various biological, geological and hydrological cycles. Such variability is posing a serious challenge to most water treatment technologies, especially the ones designed to treat drinking water supplies. Lately, in addition to the fluctuating composition of NOM, a substantial increase of its concentration in fresh waters, and also municipal wastewater effluents, has been reported worldwide, which justifies the urgent need to develop highly efficient and versatile water treatment processes. Coagulation is among the most applied processes for water and wastewater treatment. The application of coagulation to remove NOM from drinking water supplies has received a great deal of attention from researchers around the world because it was efficient and helped avoiding the formation of disinfection by products (DBPs) Nonetheless, with the increased fluctuation of NOM in water (concentration and composition) the efficiency of conventional coagulation was substantially reduced, hence the need to develop enhanced coagulation processes by optimizing the operating conditions (mainly the amount coagulants and pH) developing more efficient inorganic or organic coagulants, as well as coupling coagulation with other water treatment technologies. In the present review, recent research studies dealing with the application of coagulation for NOM removal from drinking water supplies are presented and compared. In addition, integration schemes combining coagulation and other water treatment processes are presented, including membrane filtration, oxidation, adsorption and others processes.", "author_names": [ "Mika Sillanpaa", "Mohamed Chaker Ncibi", "Anu Matilainen", "Mikko Vepsalainen" ], "corpus_id": 3662863, "doc_id": "3662863", "n_citations": 286, "n_key_citations": 3, "score": 0, "title": "Removal of natural organic matter in drinking water treatment by coagulation: A comprehensive review.", "venue": "Chemosphere", "year": 2018 }, { "abstract": "The global presence of microplastic (MP) in aquatic ecosystems has been shown by various studies. However, neither MP concentrations nor their sources or sinks are completely known. Waste water treatment plants (WWTPs) are considered as significant point sources discharging MP to the environment. This study investigated MP in the effluents of 12 WWTPs in Lower Saxony, Germany. Samples were purified by a plastic preserving enzymatic oxidative procedure and subsequent density separation using a zinc chloride solution. For analysis, attenuated total reflection Fourier transform infrared spectroscopy (ATR FT IR) and focal plane array (FPA) based transmission micro FT IR imaging were applied. This allowed the identification of polymers of all MP down to a size of 20 mm. In all effluents MP was found with quantities ranging from 0 to 5 x 101 m 3 MP 500 mm and 1 x 101 to 9 x 103 m 3 MP 500 mm. By far, polyethylene was the most frequent polymer type in both size classes. Quantities of synthetic fibres ranged from 9 x 101 to 1 x 103 m 3 and were predominantly made of polyester. Considering the annual effluxes of tested WWTPs, total discharges of 9 x 107 to 4 x 109 MP particles and fibres per WWTP could be expected. Interestingly, one tertiary WWTP had an additionally installed post filtration that reduced the total MP discharge by 97% Furthermore, the sewage sludge of six WWTPs was examined and the existence of MP, predominantly polyethylene, revealed. Our findings suggest that WWTPs could be a sink but also a source of MP and thus can be considered to play an important role for environmental MP pollution.", "author_names": [ "Svenja M Mintenig", "Ivo Int-Veen", "Martin G J Loder", "Sebastian Primpke", "Gunnar Gerdts" ], "corpus_id": 46880864, "doc_id": "46880864", "n_citations": 499, "n_key_citations": 20, "score": 0, "title": "Identification of microplastic in effluents of waste water treatment plants using focal plane array based micro Fourier transform infrared imaging.", "venue": "Water research", "year": 2017 }, { "abstract": "Centralized water treatment has dominated in developed urban areas over the past century, although increasing challenges with this model demand a shift to a more decentralized approach wherein advanced oxidation processes (AOPs) can be appealing treatment options. Efforts to overcome the fundamental obstacles that have thus far limited the practical use of traditional AOPs, such as reducing their chemical and energy input demands, target the utilization of heterogeneous catalysts. Specifically, recent advances in nanotechnology have stimulated extensive research investigating engineered nanomaterial (ENM) applications to AOPs. In this Perspective, we critically evaluate previously studied ENM catalysts and the next generation treatment technologies they seek to enable. Opportunities for improvement exist at the intersection of materials science and treatment process engineering, as future research should aim to enhance catalyst properties while considering the unique roadblocks to practical ENM implementation in water treatment.This Perspective evaluates catalysts based on engineered nanomaterials and the next generation water treatment technologies they seek to enable.", "author_names": [ "Brenna C Hodges", "Ezra L Cates", "Jae-Hong Kim" ], "corpus_id": 51929334, "doc_id": "51929334", "n_citations": 226, "n_key_citations": 1, "score": 0, "title": "Challenges and prospects of advanced oxidation water treatment processes using catalytic nanomaterials", "venue": "Nature Nanotechnology", "year": 2018 }, { "abstract": "Abstract Nitrate contamination in surface and ground waters is one of this century's major engineering challenges due to negative environmental impacts and the risk to human health in drinking water. Electrochemical reduction is a promising water treatment technology to manage nitrate in drinking water. This critical review describes the fundamental principles necessary to understand electrochemical reduction technologies and how to apply them. The focus is on electrochemical nitrate reduction mechanisms and pathways that form undesirable products (nitrite, ammonium) or the more desirable product (dinitrogen) Factors influencing the conversion rates and selectivity of electrochemical nitrate reduction, such as electrode material and operating parameters, are also described. Finally, the applicability for treating drinking water matrices using electrochemical processes is analyzed, including existing implementation of commercial treatment systems. Overall, this critical review contributes to the understanding of the potential applications and constraints of electrochemical reduction to manage nitrate in drinking waters and highlights directions for future research required for implementation.", "author_names": [ "Sergi Garcia-Segura", "Mariana Lanzarini-Lopes", "Kiril D Hristovski", "Paul K Westerhoff" ], "corpus_id": 102700098, "doc_id": "102700098", "n_citations": 181, "n_key_citations": 2, "score": 0, "title": "Electrocatalytic reduction of nitrate: Fundamentals to full scale water treatment applications", "venue": "", "year": 2018 }, { "abstract": "Solar steam generation is emerging as promising solar energy conversion technology for potential applications in desalination, sterilization and chemical purification. Despite the recent use of photon management and thermal insulation, achieving optimum solar steam efficiency requires simultaneous minimization of radiation, convection and conduction losses without compromising light absorption. Inspired by the natural transpiration process in plants, here we report a 3D artificial transpiration device with all three components of heat loss and angular dependence of light absorption minimized, which enables over 85% solar steam efficiency under one sun without external optical or thermal management. It is also demonstrated that this artificial transpiration device can provide a complementary path for waste water treatment with a minimal carbon footprint, recycling valuable heavy metals and producing purified water directly from waste water contaminated with heavy metal ions.", "author_names": [ "Xiuqiang Li", "Renxing Lin", "George Ni", "Ning Xu", "Xiaozhen Hu", "Bin Zhu", "Guangxin Lv", "Jinlei Li", "Shining Zhu", "Jia Zhu" ], "corpus_id": 90187036, "doc_id": "90187036", "n_citations": 218, "n_key_citations": 0, "score": 0, "title": "Three dimensional artificial transpiration for efficient solar waste water treatment", "venue": "", "year": 2018 }, { "abstract": "The high concentrations of pharmaceuticals and personal care products (PPCP) that found in water in many locations are of concern. Among the available water treatment methods, heterogeneous photocatalysis using TiO2 is an emerging and viable technology to overcome the occurrence of PPCP in natural and waste water. The combination of carbonaceous materials (e.g. activated carbon, carbon nanotubes and graphene nanosheets) with TiO2, a recent development, gives significantly improved performance. In this article, we present a critical review of the development and fabrication of carbonaceous TiO2 and its application to PPCP removal including its influence on water chemistry, and the relevant operational parameters. Finally, we present an analysis of current priorities in the ongoing research and development of carbonaceous TiO2 for the photodegradation of PPCP.", "author_names": [ "Dion Awfa", "Mohamed Ateia", "Manabu Fujii", "Matthew Stanley Johnson", "Chihiro Yoshimura" ], "corpus_id": 44123626, "doc_id": "44123626", "n_citations": 148, "n_key_citations": 3, "score": 0, "title": "Photodegradation of pharmaceuticals and personal care products in water treatment using carbonaceous TiO2 composites: A critical review of recent literature.", "venue": "Water research", "year": 2018 }, { "abstract": "Electrocoagulation is an effective electrochemical approach for the treatment of different types of contaminated water and has received considerable attention in recent years due its high efficiency in dealing with numerous stubborn pollutants. It has been successful in dealing with organic and inorganic contaminants with negligible or almost no generation of by product wastes. During the past decade, vast amount of research has been devoted to utilizing electrocoagulation for the treatment of several types of wastewater, ranging from polluted groundwater to highly contaminated refinery wastewater. This paper offers a comprehensive review of recent literature that has been dedicated to utilizing electrocoagulation for water treatment, focusing on current successes on specific applications in water and wastewater treatment, as well as potentials for future applications. The paper examines such aspects as theory, potential applications, current challenges, recent developments as well as economical concerns associated with the technology. Most of the recent EC research has been focusing on pollutant specific evaluation without paying attention to cell design, process modeling or industrial applications. This review attempts to highlight the main achievements in the area and outlines the major shortcomings with recommendations for promising research options that can enhance the technology and broaden its range of applications.", "author_names": [ "Dina T Moussa", "Muftah H El-Naas", "Mustafa S Nasser", "Mohammed J Al-Marri" ], "corpus_id": 1664813, "doc_id": "1664813", "n_citations": 315, "n_key_citations": 10, "score": 0, "title": "A comprehensive review of electrocoagulation for water treatment: Potentials and challenges.", "venue": "Journal of environmental management", "year": 2017 } ]

[ { "abstract": "Reinforcement learning algorithms that use deep neural networks are a promising approach for the development of machines that can acquire knowledge and solve problems without human input or supervision. At present, however, these algorithms are implemented in software running on relatively standard complementary metal oxide semiconductor digital platforms, where performance will be constrained by the limits of Moore's law and von Neumann architecture. Here, we report an experimental demonstration of reinforcement learning on a three layer 1 transistor 1 memristor (1T1R) network using a modified learning algorithm tailored for our hybrid analogue digital platform. To illustrate the capabilities of our approach in robust in situ training without the need for a model, we performed two classic control problems: the cart pole and mountain car simulations. We also show that, compared with conventional digital systems in real world reinforcement learning tasks, our hybrid analogue digital computing system has the potential to achieve a significant boost in speed and energy efficiency.A reinforcement learning algorithm can be implemented on a hybrid analogue digital platform based on memristive arrays for parallel and energy efficient in situ training.", "author_names": [ "Zhongrui Wang", "Can Li", "Wenhao Song", "Mingyi Rao", "Daniel Belkin", "Yunning Li", "Peng Yan", "Hao Jiang", "Peng Lin", "Miao Hu", "John Paul Strachan", "Ning Ge", "Mark D Barnell", "Qing Liang Wu", "Andrew G Barto", "Qinru Qiu", "R Stanley Williams", "Qiangfei Xia", "J Joshua Yang" ], "corpus_id": 88499156, "doc_id": "88499156", "n_citations": 107, "n_key_citations": 0, "score": 0, "title": "Reinforcement learning with analogue memristor arrays", "venue": "Nature Electronics", "year": 2019 }, { "abstract": "A memristor with a bilayer electrolyte structure (Pt/C/NbOx/TiN) is proposed as a self rectification and quasi linear electronic synapse. The device shows self rectifying analogue memristive behavior with 106 rectification ratio, which can solve the sneak current problem in crossbar array without additional hardware burden. Under identical pulses in potentiation process, the device conductance is quasi linearly changed with 9.16% nonlinearity. In addition, the conductance change rate of device is effectively tuned by altering amplitudes and frequencies of spike pulses. Benefiting from the quasi linear conductance change characteristics, excellent classification accuracy (95.7% is achieved for the application of handwritten digit classification with a two layer perceptron based on MINST stimulation.", "author_names": [ "Weilong Wang", "Rui Wang", "Tuo Shi", "Jinsong Wei", "Rongrong Cao", "Xiaolong Zhao", "Zuheng Wu", "Xumeng Zhang", "Jian Lu", "Hui Xu", "Qingjiang Li", "Qi Liu", "Ming Liu" ], "corpus_id": 199071607, "doc_id": "199071607", "n_citations": 15, "n_key_citations": 0, "score": 0, "title": "A Self Rectification and Quasi Linear Analogue Memristor for Artificial Neural Networks", "venue": "IEEE Electron Device Letters", "year": 2019 }, { "abstract": "A report is presented on the operation of an analogue programming circuit for accurately setting the state of a memristor. The circuit exploits the dynamic modulation of resistance under a constant DC bias while real time measurements of the memristance are performed using an AC signal. The circuit employs feedback for converging the state of a device at any required level within a decade. This allows the memristor to act as an analogue potentiometer, with its resistance corresponding to an input analogue voltage. This implementation was tested with the HP memristor model revealing an accuracy of less than 0.4% (8 bit precision) in relation to the full dynamic range.", "author_names": [ "Radu Berdan", "Themistoklis Prodromakis", "Christofer Toumazou" ], "corpus_id": 111164999, "doc_id": "111164999", "n_citations": 45, "n_key_citations": 0, "score": 0, "title": "High precision analogue memristor state tuning", "venue": "", "year": 2012 }, { "abstract": "Memristor crossbars offer reconfigurable non volatile resistance states and could remove the speed and energy efficiency bottleneck in vector matrix multiplication, a core computing task in signal and image processing. Using such systems to multiply an analogue voltage amplitude vector by an analogue conductance matrix at a reasonably large scale has, however, proved challenging due to difficulties in device engineering and array integration. Here we show that reconfigurable memristor crossbars composed of hafnium oxide memristors on top of metal oxide semiconductor transistors are capable of analogue vector matrix multiplication with array sizes of up to 128 x 64 cells. Our output precision (5 8 bits, depending on the array size) is the result of high device yield (99.8% and the multilevel, stable states of the memristors, while the linear device current voltage characteristics and low wire resistance between cells leads to high accuracy. With the large memristor crossbars, we demonstrate signal processing, image compression and convolutional filtering, which are expected to be important applications in the development of the Internet of Things (IoT) and edge computing.MainMemristor crossbars with array sizes of up to 128 x 64 cells are capable of analogue vector matrix multiplication and can be used for signal processing, image compression and convolutional filtering.", "author_names": [ "Can Li", "Miao Hu", "Yunning Li", "Hao Jiang", "Ning Ge", "Eric Montgomery", "Jiaming Zhang", "Wenhao Song", "Noraica Davila", "Catherine E Graves", "Zhiyong Li", "John Paul Strachan", "Peng Lin", "Zhongrui Wang", "Mark D Barnell", "Qing Wu", "R Stanley Williams", "Jianhua Joshua Yang", "Qiangfei Xia" ], "corpus_id": 189930362, "doc_id": "189930362", "n_citations": 427, "n_key_citations": 16, "score": 1, "title": "Analogue signal and image processing with large memristor crossbars", "venue": "", "year": 2018 }, { "abstract": "An important cornerstone of data processing is the ability to efficiently capture structure in data and perform data classification. More recently, memristive technologies enabled the incorporation of continuous tuneable resistive elements directly in hardware, thus increasing the efficiency of reconfigurable systems power and area wise. Memristors are a promising candidate for reconfigurable circuits capable of carrying out classification with physical computing, such as dot product vector multiplication and accumulation technique. In this work, we demonstrate a novel proof of concept memristor based Digital In Analogue Out logic circuit and present preliminary results highlighting the effect of non uniform non linear memristor IV characteristics that result in device to device behavioural variation.", "author_names": [ "Georgios Papandroulidakis", "Loukas Michalas", "Alexantrou Serb", "Ali Khiat", "Geoff V Merrett", "Themistoklis Prodromakis" ], "corpus_id": 155367598, "doc_id": "155367598", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A Digital In Analogue Out Logic Gate Based on Metal Oxide Memristor Devices", "venue": "2019 IEEE International Symposium on Circuits and Systems (ISCAS)", "year": 2019 }, { "abstract": "An important aspect for implementing neuro inspired circuits and systems is the data pattern recognition and classification circuits. Memristor is one of the most prominent emerging technology to take effectively the place of synaptic weights, in neuro inspired techniques such as Threshold Logic (TL) [1] by showcasing continuously tunable resistance capabilities [2] The design and experimental validation of such circuits, by taking into consideration the practical non linearities of the memristor components, is worth investigating. The introduction of Digital InAnalogue Out (DI AO) memristive TL will enable us to complete the picture of the available circuit modalities that can process information using memristors, by additionally taking into consideration the more conventional digital [3] analogue [4] and Analogue In Digital Out (AI DO) memristor based logic families [1] In this work, a DI AO method of performing reconfigurable memristor based TL is proposed and experimentally validated using real memristor devices and incorporating 1T1R based mixed signal circuit modalities, to compute physically (Kirchhoff's law at the intermediate node) the comparison between two adverse dot products, one pulling towards VDD and the other pulling down to GND (see Fig.1) Hence, the computation is equivalent to a digital in (MOS gate control) analogue out (readout voltage from the intermediate node) TL operation. The circuit performs the TL operation physically in the form of distance of the readout circuit response from VDD/2 voltage level. An example of the experimental validation of the circuit is presented in Fig. 2, where the pull up (PU) pMOS and pull down (PD) nMOS vectors are defined as {Ip11, Ip12, Ip13} and {In21, In22} respectively. The memristor weights [2] used for this configuration are configured as{5.5kO, 10.8kO, 11.5kO} and {7.3kO, 6kO} for the PU and the PD arrays, respectively.", "author_names": [ "Georgios Papandroulidakis", "Alexantrou Serb", "Ali Khiat", "Geoff V Merrett", "Themistoklis Prodromakis" ], "corpus_id": 201881296, "doc_id": "201881296", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Practical implementation of digital in analogue out memristor based threshold logic circuit", "venue": "", "year": 2019 }, { "abstract": "", "author_names": [ "Takuya Ashida", "Tetsuhito Shinohara", "Minoru Ohta", "Kuniyasu Ito", "Shogo Yamada", "Shibata Tatsuo", "Yukio Terasaki", "Tomoyuki Sasaki" ], "corpus_id": 229289108, "doc_id": "229289108", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Domain Wall Type Spin Memristor for Analogue Neuromorphic Devices", "venue": "", "year": 2019 }, { "abstract": "The data processing efficiency of traditional computers is suffering from the intrinsic limitation of physically separated processing and memory units. Logic in memory and brain inspired neuromorphic computing are promising in memory computing paradigms for improving the computing efficiency and avoiding high power consumption caused by extra data movement. However, memristors that can conduct digital memcomputing and neuromorphic computing simultaneously are limited by the difference in the information form between digital data and analogue data. In order to solve this problem, this paper proposes a flexible low dimensional memristor based on boron nitride (BN) which has ultralow power non volatile memory characteristic, reliable digital memcomputing capabilities, and integrated ultrafast neuromorphic computing capabilities in a single in situ computing system. The logic in memory basis, including FALSE, material implication (IMP) and NAND, are implemented successfully. The power consumption of the proposed memristor per synaptic event (198 fJ) can be as low as biology (fJ level) and the response time (1 ms) of the neuromorphic computing is four orders of magnitude shorter than that of the human brain (10 ms) paving the way for wearable ultrahigh efficient next generation in memory computing architectures.", "author_names": [ "Jia-Lin Meng", "Tian-Yu Wang", "He Zhenyu", "Lin Chen", "Hao Zhu", "Li Ji", "Qingqing Sun", "S J Ding", "Wenzhong Bao", "Pengcheng Zhou", "David-Wei Zhang" ], "corpus_id": 233947132, "doc_id": "233947132", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Flexible boron nitride based memristor for in situ digital and analogue neuromorphic computing applications", "venue": "", "year": 2021 }, { "abstract": "", "author_names": [ "Francesco Marrone" ], "corpus_id": 69391275, "doc_id": "69391275", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Memristor Oscillators for Bio Inspired Analogue Computing", "venue": "", "year": 2018 }, { "abstract": "The theory of memristor was postulated in the year of 1971 by Leon O. Chua. The intensive interest on memristive systems is given by the researchers since after the physical realization of the hysteresis behavior in a nanoscale TiO\\(_{\\mathrm {2} memristor in 2008 by a group of researchers at HP Labs lead by Stanley Williams. Research on memristive systems has been carried out on various capacities such as understanding the mathematics of memristor, finding new materials which have memristive properties, studying the underlying dynamics of memristive systems and revisiting the existing concepts with memristor as a nonlinear element. As a result, memristors have potential applications in various domains. It ranges from neural networks, memory devices, artificial intelligence, high speed computing, nano batteries and human skin modeling, etc. In the recent times, much attention is given to explore the nonlinear dynamics of memristor based circuits. In this chapter, we consider a smooth continuous cubic memristor as nonlinear element. It is applied to (a) an autonomous and (b) a non autonomous dynamical systems namely, the Chua's circuit and Duffing Oscillator, to study the associated dynamics of these systems. The numerical simulation of the circuit systems as well as its hardware experimental studies are performed in the laboratory. An inductor free realization and volume expanded period doubling scenario in a memristive Chua's circuit is studied. The complex behaviors, like, bifurcations and chaos, three tori, transient chaos and intermittency in a memristive Duffing oscillator are described. In addition, \"0 1 test\" for the experimental time series data characterizing the regular and chaotic dynamics of the proposed circuits are also discussed.", "author_names": [ "R Jothimurugan", "S Sabarathinam", "K Suresh", "Kathamuthu Thamilmaran" ], "corpus_id": 114482048, "doc_id": "114482048", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Experimental Analogue Implementation of Memristor Based Chaotic Oscillators", "venue": "", "year": 2017 } ]

[ { "abstract": "Among the beyond complementary metal oxide semiconductor (CMOS) devices being explored, ferroelectric field effect transistors (FeFETs) are considered as one of the most promising. FeFETs are being studied by all major semiconductor manufacturers, and experimentally, FeFETs are making rapid progress. FeFETs also stand out with the unique hysteretic <inline formula> <tex math notation=\"LaTeX\"$I_{\\text {ds} /tex math>/inline formula> <inline formula> <tex math notation=\"LaTeX\"$V_{\\text {gs} /tex math>/inline formula> characteristic that allows a device to function as both a switch and a nonvolatile (NV) storage element. We exploit this FeFET property to build two categories of fine grained logic in memory (LiM) circuits: 1) ternary content addressable memory (TCAM) which integrates efficient and compact logic/processing elements into various levels of memory hierarchy; 2) basic logic function units for constructing larger and more complex LiM circuits. Two writing schemes (with and without negative supply voltages respectively) for FeFETs are introduced in our LiM designs. The resulting designs are compared with existing LiM approaches based on CMOS, magnetic tunnel junctions (MTJs) resistive random access memories (ReRAMs) ferrorelectric tunnel junctions (FTJs) etc. that afford the same circuit level functionality. Simulation results show that FeFET based NV TCAMs offer lower area overhead than MTJ (79% and CMOS (42% less) equivalents, as well as better search energy delay products (EDPs) than TCAM designs based on MTJ <inline formula> <tex math notation=\"LaTeX\"$149\\times /tex math>/inline formula> ReRAM <inline formula> <tex math notation=\"LaTeX\"$1.7\\times /tex math>/inline formula> and CMOS <inline formula> <tex math notation=\"LaTeX\"$1.3\\times /tex math>/inline formula> in array evaluations. NV FeFET based LiM basic circuit blocks are also more efficient than functional equivalents based on MTJs in terms of propagation delay <inline formula> <tex math notation=\"LaTeX\"$4.2\\times /tex math>/inline formula> and dynamic power <inline formula> <tex math notation=\"LaTeX\"$2.5\\times /tex math>/inline formula> A case study for an FeFET based LiM accumulator further demonstrates that by employing FeFET as both a switch and an NV storage element, the FeFET based accumulator can save area (36% and power consumption (40% when compared with a conventional CMOS accumulator with the same structure.", "author_names": [ "Xunzhao Yin", "Xiaoming Chen", "Michael Thaddeus Niemier", "Xiaobo Sharon Hu" ], "corpus_id": 56819955, "doc_id": "56819955", "n_citations": 26, "n_key_citations": 2, "score": 1, "title": "Ferroelectric FETs Based Nonvolatile Logic in Memory Circuits", "venue": "IEEE Transactions on Very Large Scale Integration (VLSI) Systems", "year": 2019 }, { "abstract": "Due to their CMOS compatibility, hafnium oxide based ferroelectric field effect transistors (FeFET) gained remarkable attention recently, not only in the context of nonvolatile memory applications but also for being an auspicious candidate for novel combined memory and logic applications. In addition to bringing nonvolatility into existing logic circuits (Memory in Logic) FeFETs promise to guide the way to compact Logic in Memory solutions, where logic computations are examined in memory arrays or array like structures. To increase the area efficiency of such circuits, a dense integration of FeFETs and standard FETs is essential. In this paper, we show that the ultra dense co integration of FeFETs and nFETs (28nm HKMG) with shared active area does not alter the FeFET's switching behavior, nor does it affect the baseline CMOS. Based on this, we propose the integration of a FeFET based, 2 input look up table (memory) directly into a 4 to 1 multiplexer (logic) which is utilized directly in a 2TNOR memory array or stand alone circuit. The latter one dramatically reduces the transistor count by at least 33% compared to similar FeFET based circuits. By storing values of the look up table in a nonvolatile manner, no energy is consumed during standby mode, which enables normally off computing. To take another step towards novel Logic in Memory designs, we experimentally demonstrate a very compact in array 2T half adder and simulate an array like 14T full adder, which exploit the advantages of the array arrangement: easy write procedure and a very compact, robust design. The proposed circuits exhibit energy efficiency in the (sub)fJ range and operation speeds of 1GHz.", "author_names": [ "Evelyn T Breyer", "Halid Mulaosmanovic", "Jens Trommer", "Thomas Melde", "Stefan Dunkel", "Martin Trentzsch", "Sven Beyer", "Stefan Slesazeck", "Thomas Mikolajick" ], "corpus_id": 216332895, "doc_id": "216332895", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Compact FeFET Circuit Building Blocks for Fast and Efficient Nonvolatile Logic in Memory", "venue": "IEEE Journal of the Electron Devices Society", "year": 2020 }, { "abstract": "As an emerging nonvolatile device, ferroelectric field effect transistors (FeFETs) have the potential to reduce the power and area by integrating nonvolatile storage elements with logic. The hysteretic behavior allows an FeFET to function as both a nonvolatile storage element and a switch. This paper exploits this feature of FeFETs to design lookup tables (LUTs) and routing switches, which have obvious utility in field programmable gate arrays (FPGAs) Read and write schemes are also designed for the proposed LUTs and routing switches. Evaluation results based on a calibrated FeFET model show that the proposed designs are competitive in power and performance. For example, compared with conventional complementary metal oxide semiconductor (CMOS) based equivalents, the proposed FeFET based LUTs and routing elements improve the power delay product (PDP) by 5.8 <inline formula> <tex math notation=\"LaTeX\"$16\\times /tex math>/inline formula> respectively, while compared with resistive random access memory (RRAM) based equivalents, the proposed designs improve the PDP by 1.14 <inline formula> <tex math notation=\"LaTeX\"$1.8\\times /tex math>/inline formula> The area of an FeFET based FPGA is 8% smaller than a conventional CMOS based FPGA.", "author_names": [ "Xiaoming Chen", "Kai Ni", "Michael Thaddeus Niemier", "Yinhe Han", "Suman Datta", "Xiaobo Sharon Hu" ], "corpus_id": 115450515, "doc_id": "115450515", "n_citations": 7, "n_key_citations": 2, "score": 0, "title": "Power and Area Efficient FPGA Building Blocks Based on Ferroelectric FETs", "venue": "IEEE Transactions on Circuits and Systems I: Regular Papers", "year": 2019 }, { "abstract": "Logic in memory circuits promise to overcome the von Neumann bottleneck, which constitutes one of the limiting factors to data throughput and power consumption of electronic devices. In the following we present four input logic gates based on only two ferroelectric FETs (FeFETs) with hafnium oxide as the ferroelectric material. By utilizing two complementary inputs, a XOR and a XNOR gate are created. The use of only two FeFETs results in a compact and nonvolatile design. This realization, moreover, directly couples the memory and logic function of the FeFET. The feasibility of the proposed structures is revealed by electrical measurements of HKMG FeFET memory arrays manufactured in 28nm technology.", "author_names": [ "Evelyn T Breyer", "Halid Mulaosmanovic", "Stefan Slesazeck", "Thomas Mikolajick" ], "corpus_id": 53085818, "doc_id": "53085818", "n_citations": 8, "n_key_citations": 1, "score": 0, "title": "Demonstration of versatile nonvolatile logic gates in 28nm HKMG FeFET technology", "venue": "2018 IEEE International Symposium on Circuits and Systems (ISCAS)", "year": 2018 }, { "abstract": "Systematic design space exploration of negative capacitance ferroelectric field effect transistors (FeFETs) for nonvolatile memory operations was performed, combining load line analyses and circuit simulations. Unlike those FeFETs aiming at a steep subthreshold slope, the key design target here is to achieve bi stable current versus voltage FET characteristics with appropriate hysteresis width (i.e. memory window) Remanent polarization, coercive voltage, and interfacial layer thickness were selected as design parameters. The results show that, if a ferroelectric gate dielectric film obeying ideal single domain Landau Khalatnikov model dynamics with reduced remanent polarization is available, ultralow voltage nonvolatile memories operating with sub one volt voltage swing would become possible. An interesting feature of the negative capacitance FeFETs is that, unlike conventional multiple domain FeFETs, the memory window can be adjusted to a much smaller value than twice the coercive voltage. The lowered remanent polarization is required to suppress the depolarization field to an acceptable level for reliability. It is proposed that considering the abrupt polarization switching, three transistor and two transistor memory cells would be suitable for working and code storage memories, respectively.", "author_names": [ "Kiyoshi Takeuchi", "Masaharu Kobayashi", "Toshiro Hiramoto" ], "corpus_id": 233936203, "doc_id": "233936203", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Design space exploration of hysteretic negative capacitance ferroelectric FETs based on static solutions of Landau Khalatnikov model for nonvolatile memory applications", "venue": "", "year": 2021 }, { "abstract": "Compute in memory (CiM) is a promising method for mitigating the memory wall problem in data intensive applications. The proposed bitwise logic in memory (BLiM) is targeted at data intensive applications, such as database, data encryption. This work proposes a low power BLiM approach using the emerging nonvolatile ferroelectric FETs with direct write back and data adaptive dynamic sensing interface. Apart from general purpose random access memory, it also supports BLiM operations such as copy, not, nand, xor, and full adder (FA) The novel features of the proposed architecture include: (i) direct result write back based on the remnant bitline BLiM charge that avoids bitline sensing and charging operations; (ii) a fully dynamic sensing interface that needs no static reference current, but adopts data adaptive voltage references for certain multi operand operations, and (iii) selective bitline charging from wordline (instead of pre charging all bitlines) to save power and also enable direct write back. Detailed BLiM operations and benchmarking against conventional approaches show the promise of low power computing with the FeFET based circuit techniques.", "author_names": [ "Ming-En Lee", "Wenjun Tang", "Bowen Xue", "Juejian Wu", "Mingyuan Ma", "Yongpan Liu", "Deliang Fan", "Narayanan Vijaykrishnan", "Huazhong Yang", "Xueqing Li" ], "corpus_id": 221035215, "doc_id": "221035215", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "FeFET based low power bitwise logic in memory with direct write back and data adaptive dynamic sensing interface", "venue": "ISLPED", "year": 2020 }, { "abstract": "Emerging non volatile memories are getting new interest in the system design community. They are used to design logic in memory circuits and propose alternatives to von Neuman architectures. Hafnium oxide based based ferroelectric memory technology, which is fully compatible with CMOS technologies is particularly interesting for logic in memory designs. Indeed, this compatibility leads to various possibilities for fine grain logic in memory applications where the memory capable element is tightly integrated with the transistors in the system. Nonvolatile and energy efficient computing for Internet of things and embedded artificial intelligence are among the potential applications for this technology.In this article, we focus on ferroelectric field effect transistors (FeFET) and present an overview of three different fine grain logic in memory possibilities with FeFETs: custom operation designs, reconfigurable circuits and a hybrid memory element accessible by content or by address. All presented circuits have been designed within a test chip using 28nm technology provided by GLOBALFOUNDRIES.", "author_names": [ "Cedric Marchand", "Ian O'Connor", "Mayeul Cantan", "Evelyn T Breyer", "Stefan Slesazeck", "Thomas Mikolajick" ], "corpus_id": 236981002, "doc_id": "236981002", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "FeFET based Logic in Memory: an overview", "venue": "2021 16th International Conference on Design Technology of Integrated Systems in Nanoscale Era (DTIS)", "year": 2021 }, { "abstract": "In this work, we report hafnium zirconium oxide (HZO)/indium gallium zinc oxide (IGZO) based programmable ferroelectric (FE) diode memory array with ultra fast sub ns switching speed, thus extremely low sub fJ switching energy for future in memory and neuromorphic computing applications for the first time. The fabricated devices have electroresistance ratio of 3x105 and show robust cyclic endurance up to 109. In particular, we demonstrated a nonvolatile logic in memory circuit to implement NOT gate and incremental conductance changes to mimic analog nature of synaptic weights.", "author_names": [ "Taehwan Moon", "Sang Hee Hong", "Duk-Hyun Choe" ], "corpus_id": 236982329, "doc_id": "236982329", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Ferroelectric Diodes with Sub ns and Sub fJ Switching and Its Programmable Network for Logic in Memory Applications", "venue": "2021 Symposium on VLSI Technology", "year": 2021 }, { "abstract": "This paper presents an overview of the operation and applications of reconfigurable ferroelectric transistors (R FEFETs) which offer unique logic memory coupling in the device characteristics leading to novel circuit design possibilities. R FEFETs feature dynamic reconfiguration between (a) volatile mode for logic operations and (b) nonvolatile mode for memory operation. An R FEFET consists of two FE stacks which interact with each other and a common underlying transistor, to enable run time tuning of hysteresis and the aforementioned reconfigurability. We discuss how such novel features of R FEFETs can be utilized to design energy efficient non volatile memory (NVM) and non volatile flip flop (NVFF) designs. For NVMs, read write conflicts can be effectively mitigated. In particular, R FEFETs based 3T NVM exhibit significant advantage over existing standard FEFET based NVM design with 55% lower write power and 37 72% lower read power at iso access time. R FEFET based NVFFs offer the design options of an auto backup (RNVFF 1) without the need of any additional circuitry back up control signals, or on demand backup (RNVFF 2) with lower normal operational energy over RNVFF 1. Compared to an FEFET based NVFF, RNVFF 1 achieves 47% lower check pointing energy, with a penalty of 6% in operation energy. RNVFF 2 shows 30% lower check pointing energy with similar operation energy. At the system level, the RNVFFs achieve 25 33% register level energy savings, in a state of the art intermittently powered platform.", "author_names": [ "Sandeep Krishna Thirumala", "Arnab Raha", "Narayanan Vijaykrishnan", "Vijay Raghunathan", "Sumeet Kumar Gupta" ], "corpus_id": 218473105, "doc_id": "218473105", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Non volatile Logic and Memory based on Reconfigurable Ferroelectric Transistors", "venue": "2019 IEEE/ACM International Symposium on Nanoscale Architectures (NANOARCH)", "year": 2019 }, { "abstract": "Future data intensive applications will have integrated circuit architectures combining energy efficient transistors, high density data storage and electro optic sensing arrays in a single chip to perform in situ processing of captured data. The costly dense wire connections in 3D integrated circuits and in conventional packaging and chip stacking solutions could affect data communication bandwidths, data storage densities, and optical transmission efficiency. Here we investigated all ferroelectric nonvolatile LiNbO 3 transistors to function through redirection of conducting domain walls between the drain, gate and source electrodes. The transistor operates as a single pole, double throw digital switch with complementary on/off source and gate currents controlled using either the gate or source voltages. The conceived device exhibits high wall current density and abrupt off and on state switching without subthreshold swing, enabling nonvolatile memory and sensor in logic and logic in memory and sensor capabilities with superior energy efficiency, ultrafast operation/communication speeds, and high logic/storage densities. There is growing interest in non traditional materials for logic applications. Here, the authors demonstrate a domain device architecture based on ferroelectric LiNbO 3 crystals with gate voltage controlled transistor without subthreshold swing and source voltage controlled nonvolatile transistor.", "author_names": [ "Xiaojie Chai", "Jun Jiang", "Qinghua Zhang", "Xu Hou", "Fanqi Meng", "Jianbao Wang", "Lin Gu", "David-Wei Zhang", "An Quan Jiang" ], "corpus_id": 219281546, "doc_id": "219281546", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "Nonvolatile ferroelectric field effect transistors", "venue": "Nature Communications", "year": 2020 } ]

[ { "abstract": "Wide bandgap semiconductors show superior material properties enabling potential power device operation at higher temperatures, voltages, and switching speeds than current Si technology. As a result, a new generation of power devices is being developed for power converter applications in which traditional Si power devices show limited operation. The use of these new power semiconductor devices will allow both an important improvement in the performance of existing power converters and the development of new power converters, accounting for an increase in the efficiency of the electric energy transformations and a more rational use of the electric energy. At present, SiC and GaN are the more promising semiconductor materials for these new power devices as a consequence of their outstanding properties, commercial availability of starting material, and maturity of their technological processes. This paper presents a review of recent progresses in the development of SiC and GaN based power semiconductor devices together with an overall view of the state of the art of this new device generation.", "author_names": [ "Jose Millan", "Philippe Godignon", "Xavier Perpina", "Amador Perez-Tomas", "Jose Rebollo" ], "corpus_id": 23719999, "doc_id": "23719999", "n_citations": 1075, "n_key_citations": 33, "score": 1, "title": "A Survey of Wide Bandgap Power Semiconductor Devices", "venue": "IEEE Transactions on Power Electronics", "year": 2014 }, { "abstract": "Wide bandgap (WBG) power semiconductor devices have become increasingly popular due to their superior characteristics compared to their Si counterparts. However, their fast switching speed and the ability to operate at high frequencies brought new challenges, among which the electromagnetic interference (EMI) is one of the major concerns. Many works investigated the structures of WBG power devices and their switching performance. In some cases, the conductive or radiated EMI was measured. However, the EMI related topics, including their influence on noise sources, noise propagation paths, EMI reduction techniques, and EMC reliability issues, have not yet been systematically summarized for WBG devices. In this article, the literature on EMI research in power electronics systems with WBG devices is reviewed. Characteristics of WBG devices as EMI noise sources are reviewed. EMI propagation paths, near field coupling, and radiated EMI are surveyed. EMI reduction techniques are categorized and reviewed. Specifically, the EMI related reliability issues are discussed, and solutions and guidelines are presented.", "author_names": [ "Boyi Zhang", "Shuo Wang" ], "corpus_id": 210279101, "doc_id": "210279101", "n_citations": 28, "n_key_citations": 2, "score": 0, "title": "A Survey of EMI Research in Power Electronics Systems With Wide Bandgap Semiconductor Devices", "venue": "IEEE Journal of Emerging and Selected Topics in Power Electronics", "year": 2020 }, { "abstract": "High frequency power converters enabled by wide bandgap (WBG) and silicon semiconductor devices offer distinct advantages in power density and dynamic performance. However, switching oscillations are commonly observed in these circuits with undesirable consequences. This paper reviews the impacts, root causes, and mitigation techniques of switching oscillations through literature survey, modeling analysis, and experimental investigation. We categorize the following root causes for oscillations during switching transients: 1) damped oscillation triggered by high di/dt and/or dv/dt coupled with parasitic elements; 2) undamped oscillation of WBG devices as part of a negative resistance oscillator; and 3) semiconductor device physical mechanisms such as the negative capacitance phenomenon due to conductivity modulation in insulated gate bipolar transistors or impact ionization in MOSFETs, the plasma extraction transit time effect in bipolar power devices, and the reverse conduction property of GaN HEMTs. Furthermore, this paper discusses various circuit techniques to suppress switching oscillations, and techniques of extracting parasitic inductances of power devices.", "author_names": [ "Tianjiao Liu", "Thomas T Y Wong", "Z John Shen" ], "corpus_id": 126982112, "doc_id": "126982112", "n_citations": 21, "n_key_citations": 2, "score": 0, "title": "A Survey on Switching Oscillations in Power Converters", "venue": "IEEE Journal of Emerging and Selected Topics in Power Electronics", "year": 2020 }, { "abstract": "The design considerations for power converters operating at room or at ultra low temperatures are the same in terms of power density, reliability, and efficiency. In order to design power converters at cryogenic temperatures, the passive and active components should be carefully selected. Understanding the behavior of the components at cryogenic temperatures leads to power converter systems that have many superior advantages such as high power density (reduced size and volume) higher efficiency (reduced system losses) and even increased system reliability. This paper reviews the status of the recent research on the cryogenic temperature behavior of Si semiconductor devices, wide bandgap semiconductor devices, passive components, and power converter topologies.", "author_names": [ "Haider Mhiesan", "Md Maksudul Hossain", "Arman Ur Rashid", "Yuqi Wei", "Alan Mantooth" ], "corpus_id": 221280089, "doc_id": "221280089", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Survey of Cryogenic Power Electronics for Hybrid Electric Aircraft Applications", "venue": "2020 IEEE Aerospace Conference", "year": 2020 }, { "abstract": "Since the introduction of wide bandgap (WBG) power semiconductor devices, high power density (PD) inverter design has become an increasingly popular topic in modern research literature. The 2014 2015 Little Box Challenge (LBC) cosponsored by Google and the IEEE sparked even more interest in this area because WBG based designs aspired to achieve upward of 215 W/in³ power densities. This article reviews several key topics of importance that are related to realizing such high PD gallium nitride (GaN) WBG based inverter designs. More specifically, this article includes a comprehensive survey of technologies employed by participating LBC finalists in their efforts to achieve new levels of PD in 400 Vdc to single phase 240 Vac conversion applications while maintaining tight specifications on dc ripple, ac ripple, and aggressive requirements on efficiency. Both singlephase dc to ac conversion and the related active energy buffer circuit topologies used by all LBC finalists are documented and compared. Additionally, a graphical trend line and figure of merit (FOM) are developed that compare PD vis vis efficiency of all proposed solutions. These are used to gain insight into how particular designs were able to achieve relatively higher PD levels and to illustrate how the GaN based design from the University of Illinois at Urbana Champaign (UIUC) was able to achieve the highest density power conversion in this competition. Furthermore, enhanced auxiliary devices and techniques used in the CE+T and Virginia Tech (VT) designs are discussed as well.", "author_names": [ "Clint W Halsted", "Madhav D Manjrekar" ], "corpus_id": 56597613, "doc_id": "56597613", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "A Critique of Little Box Challenge Inverter Designs: Breaking from Traditional Design Tradeoffs", "venue": "IEEE Power Electronics Magazine", "year": 2018 }, { "abstract": "Galvanic isolation between the grid and energy storage unit is typically required for bidirectional power distribution systems. Due to the recent advancement in wide bandgap semiconductor devices, it has become feasible to achieve the galvanic isolation using bidirectional isolated DC/DC converters instead of line frequency transformers. A survey of the latest generation SiC MOSFET is performed. The devices were compared against each other based on their key parameters. It was determined that under the given specifications, the most suitable devices are X3M0016120K 1.2 kV 16 mO and C3M0010090K 900 V 10 mO SiC MOSFETs from Wolfspeed. Two of the most commonly utilized bidirectional isolated DC/DC converter topologies, dual active bridge and CLLC resonant converter are introduced. The operating principle of these converter topologies are explained. A comparative analysis between the two converter topologies, focusing on total device loss, has been performed. It was found that the CLLC converter has lower total device loss compared to the dual active bridge converter under the given specifications. Loss analysis for the isolation transformer in the CLLC resonant converter was also performed at different switching frequencies. It was determined that the total converter loss was lowest at a switching frequency of 250 kHz A prototype for the CLLC resonant converter switching at 250 kHz was then designed and built. Bidirectional power delivery for the converter was verified for power levels up to 25 kW. The converter waveforms and efficiency data were captured at different power levels. Under forward mode operation, a peak efficiency of 98.3% at 15 kW was recorded, along with a full load efficiency value of 98.1% at 25 kW. Under reverse mode operation, a peak efficiency of 98.8% was measured at 17.8 kW. The full load efficiency at 25 kW under reverse mode operation is 98.5% Evaluation and Design of a SiC Based Bidirectional Isolated DC/DC Converter Alex Chu General Audience Abstract Electrical isolation between the grid and energy storage unit is typically required for bidirectional power distribution systems. Traditionally, this isolation is achieved via line frequency transformers, which tend to be bulky and heavy. This imposes a limit on the overall system power density, which is a crucial performance metric for bidirectional power distribution systems. Alternatively, the required electrical isolation can be implemented through bidirectional power converters. As a result, the overall system power density can be drastically improved. However, the losses incurred by the semiconductor devices in such converters could significantly reduce the overall system efficiency, which is another important performance metric. Due to the recent advancement in semiconductor devices, it has become feasible to design the required bidirectional power converters with high efficiency and high power density. A survey of the latest generation semiconductor devices is performed. A 25 kW converter prototype was designed and built using the selected semiconductor devices. Experimental testing was conducted for the converter prototype and efficiency values exceeding 98% were captured across the entire load range. The converter prototype has a power density of 78 W/in.", "author_names": [ "Alex Chu" ], "corpus_id": 115511778, "doc_id": "115511778", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Evaluation and Design of a SiC Based Bidirectional Isolated DC/DC Converter", "venue": "", "year": 2018 }, { "abstract": "At the heart of modern power electronics converters are power semiconductor switching devices. The emergence of wide bandgap (WBG) semiconductor devices, including silicon carbide and gallium nitride, promises power electronics converters with higher efficiency, smaller size, lighter weight, and lower cost than converters using the established siliconbased devices. However, WBG devices pose new challenges for converter design and require more careful characterization, in particular due to their fast switching speed and more stringent need for protection. Characterization of Wide Bandgap Power Semiconductor Devices presents comprehensive methods with examples for the characterization of this important class of power devices. After an introduction, the book covers pulsed static characterization; junction capacitance characterization; fundamentals of dynamic characterization; gate drive for dynamic characterization; layout design and parasitic management; protection design for double pulse test; measurement and data processing for dynamic characterization; cross talk consideration; impact of three phase system; and topology considerations.", "author_names": [ "Fei Wang", "Zheyu Zhang", "Edward A Jones" ], "corpus_id": 139454903, "doc_id": "139454903", "n_citations": 18, "n_key_citations": 3, "score": 0, "title": "Characterization of Wide Bandgap Power Semiconductor Devices", "venue": "", "year": 2018 }, { "abstract": "The emergence of wide bandgap semiconductors has led to development of new generation semiconductor switches that are highly efficient and scalable. To exploit the advantages of GaNFETs in power converters, in terms of reduction in the size of heat sinks and filters, a thorough understanding of the thermal behavior of the device is essential. This paper aims to establish a thermal model for wideband gap semiconductor GaNFETs commercially available, which will enable power electronic designers to obtain the thermal characteristics of the device more effectively. The model parameters is obtained from the manufacturer's data sheet by adopting an exponential curve fitting technique and the thermal model is validated using PSPICE simulations. The model was developed based on the parametric equivalence that exists between the thermal and electrical components, such that it responds for transient thermal stresses. A suitable power profile has been generated to evaluate the GaNFET model under different power dissipation scenarios. The results were compared with a Silicon MOSFETs to further highlight the advantages of the GaN devices. The proposed modeling approach can be extended for other GaN devices and can provide a platform for the thermal study and heat sink optimization.", "author_names": [ "Shri Ram", "Anupa A Vijayakumari" ], "corpus_id": 116344498, "doc_id": "116344498", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Thermal modeling of wide bandgap semiconductor devices for high frequency power converters", "venue": "", "year": 2018 }, { "abstract": "Photovoltaic (PV) energy conversion systems require fast switching power devices that are highly efficient with low semiconductor loss under harsh environmental conditions. Silicon (Si) semiconductor devices are nearing their practical limits in meeting the ever increasing requirements of power converters. However, wide bandgap (WBG) semiconductor devices made from silicon carbide (SiC) are exceeding these limits. SiC power devices enable more efficient and higher performance power converters. This paper presents a non isolated dc dc boost converter based on SiC power devices optimized for use in PV systems. The performance of two otherwise identical converters is compared, one with a new SiC MOSFET/SiC Schottky diode, and one with a conventional Si MOSFET/Si diode. A comparison of switching characteristics and energy loss of each semiconductor device is performed at different switch currents. Converter total loss and overall efficiency are evaluated at different switching frequencies, input voltages, and output power levels. The results indicate that the SiC MOSFET/SiC Schottky diode in the converter is more efficient, performs better, and has reduced power loss compared to the Si MOSFET/Si diode.", "author_names": [ "Saleh S Alharbi", "Ali M S Al-bayati", "Salah S Alharbi", "Mohammad A Matin" ], "corpus_id": 4707429, "doc_id": "4707429", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Performance evaluation of a DC DC boost converter with wide bandgap power devices", "venue": "2017 IEEE Conference on Technologies for Sustainability (SusTech)", "year": 2017 }, { "abstract": "This paper presents a high performance dc dc flyback converter design based on wide bandgap (WBG) semiconductor devices for photovoltaic (PV) applications. Two different power devices, a gallium nitride (GaN) transistor and a silicon (Si) MOSFET, are implemented individually in the flyback converter to examine their impact on converter performance. The total power loss of the converter with different power devices is analyzed for various switching frequencies. Converter efficiency is evaluated at different switching frequencies, input voltages, and output power levels. The results reveal that the converter with the GaN transistor has lower total power loss and better efficiency compared to the converter with the conventional Si MOSFET.", "author_names": [ "Salah S Alharbi", "Saleh S Alharbi", "Ali M S Al-bayati", "Mohammad A Matin" ], "corpus_id": 115341370, "doc_id": "115341370", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Design and performance study of a DC DC flyback converter based on wide bandgap power devices for photovoltaic applications", "venue": "Optical Engineering Applications", "year": 2017 } ]

[ { "abstract": "Indium phosphide (InP) is the most developed platform for photonic integrated circuits (PICs) Of interest is the advancement of this platform for applications that demand high performance, especially high output power, including free space communications and microwave photonics. In this paper, we summarize development of InP based PIC transmitters. Two transmitter types were fabricated: one based on an offset quantum wells (OQW) platform and the other on a quantum well intermixing (QWI) platform. The OQW based transmitter consists of a widely tunable laser, a high speed semiconductor optical amplifier (SOA) a Mach Zehnder modulator, and an output SOA. This transmitter demonstrates a 44 nm tuning range, >45 dB side mode suppression ratio, 14.5 dBm off chip power, and a data rate of 7 Gbps. The second transmitter, based on QWI, utilizes an alternate epitaxial structure to achieve a lower confinement factor for higher SOA output saturation power. This QWI transmitter consists of a distributed Bragg reflector laser, a high speed SOA, an electroabsorption modulator, and an output SOA. The measured off chip power is 19.5 dBm, and a data rate of 20 Gbps is demonstrated. Based on the improved performance with the new epitaxial structure, a novel platform for high power PIC transmitters integrated with low confinement and high power SOAs is described.", "author_names": [ "Hongwei Zhao", "Sergio Pinna", "Fengqiao Sang", "Bowen Song", "Simone Tommaso &#x0160;uran Brunelli", "Larry A Coldren", "Jonathan Klamkin" ], "corpus_id": 132343282, "doc_id": "132343282", "n_citations": 13, "n_key_citations": 1, "score": 0, "title": "High Power Indium Phosphide Photonic Integrated Circuits", "venue": "IEEE Journal of Selected Topics in Quantum Electronics", "year": 2019 }, { "abstract": "Photonic integration is essential for high performance communications and now becomes directly exploitable in sensing, metrology and imaging. InP PICs provide lasers, amplifiers, modulators and detectors in one platform, and a roadmap for higher density integration.", "author_names": [ "Meint K Smit", "Kevin A Williams" ], "corpus_id": 216222762, "doc_id": "216222762", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Indium Phosphide Photonic Integrated Circuits", "venue": "2020 Optical Fiber Communications Conference and Exhibition (OFC)", "year": 2020 }, { "abstract": "An indium phosphide (InP) based photonic integrated circuit (PIC) transmitter for free space optical communications was demonstrated. The transmitter consists of a sampled grating distributed Bragg reflector (SGDBR) laser, a high speed semiconductor optical amplifier (SOA) a Mach Zehnder modulator, and a high power output booster SOA. The SGDBR laser tunes from 1521 to 1565 nm with >45 dB side mode suppression ratio. The InP PIC was also incorporated into a free space optical link to demonstrate the potential for low cost, size, weight, and power. Error free operation was achieved at 3 Gb/s for an equivalent link length of 180 m (up to 300 m with forward error correction)", "author_names": [ "Hongwei Zhao", "Sergio Pinna", "Bowen Song", "Ludovico Megalini", "Simone Tommaso Suran Brunelli", "Larry A Coldren", "Jonathan Klamkin" ], "corpus_id": 52305367, "doc_id": "52305367", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Indium Phosphide Photonic Integrated Circuits for Free Space Optical Links", "venue": "IEEE Journal of Selected Topics in Quantum Electronics", "year": 2018 }, { "abstract": "A summary of photonic integrated circuit (PIC) platforms is provided with emphasis on indium phosphide (InP) Examples of InP PICs were fabricated and characterized for free space laser communications, Lidar, and microwave photonics. A novel high performance hybrid integration technique for merging InP devices with silicon photonics is also discussed.", "author_names": [ "Jonathan Klamkin", "Hongwei Zhao", "Bowen Song", "Yuan Liu", "Brandon J Isaac", "Sergio Pinna", "Fengqiao Sang", "Larry A Coldren" ], "corpus_id": 54440161, "doc_id": "54440161", "n_citations": 11, "n_key_citations": 1, "score": 0, "title": "Indium Phosphide Photonic Integrated Circuits: Technology and Applications", "venue": "2018 IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium (BCICTS)", "year": 2018 }, { "abstract": "We demonstrate photonic circuits monolithically integrated on an InP based platform for use in coherent communication links. We describe a technology platform that allows for the integration of numerous circuit elements. We show examples of an integrated transmitter which offers an on chip wavelength division multiplexing source with a flat gain profile across a 2 THz band and a new device design to provide a flatted gain over a 5 THz band. We show coherent receivers incorporating an integrated widely tunable local oscillator as well as an optical PLL. Finally, we demonstrate a tunable optical bandpass filter for use in analog coherent radio frequency links with a measured spurious free dynamic range of 86.3 dB Hz2/3 as well as an improved design to exceed 117 dB Hz2/3.", "author_names": [ "Pietro R A Binetti", "Mingzhi Lu", "Erik J Norberg", "Robert S Guzzon", "John S Parker", "Abirami Sivananthan", "Ashish Bhardwaj", "Leif A Johansson", "Mark J W Rodwell", "Larry A Coldren" ], "corpus_id": 10367323, "doc_id": "10367323", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "Indium Phosphide Photonic Integrated Circuits for Coherent Optical Links", "venue": "IEEE Journal of Quantum Electronics", "year": 2012 }, { "abstract": "High power photonic integrated circuits (PICs) are of interest for a variety of applications including microwave photonics, free space optical communications and coherent LiDAR systems [1] [2] Indium phosphide (InP) is the most advanced platform for high performance PICs. InP PICs are particularly attractive for free space optical communications, which requires low cost, size, weight and power (CSWaP) [3] [5] In conventional InP PICs, saturation power of semiconductor optical amplifiers (SOAs) is limited by small modal size and high confinement factor 5\\ To improve the SOA saturation power, one approach is to increase the modal size with a flared waveguide, but the large beam dimension in the horizontal direction imposes challenges on the coupling to singlemode fiber [6] A second approach is to reduce the confinement factor. Slab coupled optical waveguides (SCOW) with small confinement factor have been investigated for high power SOAs and lasers. However, it is very challenging to monolithically integrate the SCOW SOAs with other optical elements required for a PIC such as a seed laser and modulator [7] In this work, we have proposed a novel platform enabling the monolithic integration of low confinement SOAs with other high confinement components including a distributed Bragg reflector (DBR) laser and high speed electro absorption modulator (EAM)", "author_names": [ "Hongwei Zhao", "Sergio Pinna", "Fengqiao Sang", "Simone Tommaso Suran Brunelli", "Larry A Coldren", "Jonathan Klamkin" ], "corpus_id": 214692896, "doc_id": "214692896", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "High Power Indium Phosphide Photonic Integrated Circuit Platform", "venue": "2019 Device Research Conference (DRC)", "year": 2019 }, { "abstract": "In the recent years, relentless push for higher transmission capacity with lower cost, size, and power dissipation necessitated adoption of photonic integration in all optical communication link hardware. InP photonic technology enables monolithic integration of wide range of photonic functions delivering high performance photonic integrated circuits (PICs) In this article we will review available InP integration technologies and discussed how optical link performance requirements drive the selection of PIC functional sections and integration approaches. We will also present design, integration technology, and performance for several InP PICs that have been commercialized in Datacom, Metro, and Long haul transmission systems.", "author_names": [ "Yuliya Akulova" ], "corpus_id": 115989385, "doc_id": "115989385", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Indium Phosphide Photonic Integrated Circuits", "venue": "", "year": 2014 }, { "abstract": "Photonic integration in a micrometer thick indium phosphide (InP) membrane on silicon (IMOS) offers intrinsic and high performance optoelectronic functions together with high index contrast nanophotonic circuitries. Recently demonstrated devices have shown competitive performances, including high side mode suppression ratio (SMSR) lasers, ultrafast photodiodes, and significant improvement in critical dimensions. Applications of the IMOS devices and circuits in optical wireless, quantum photonics, and optical cross connects have proven their performances and high potential.", "author_names": [ "Yuqing Jiao", "Jos J G M van der Tol", "Vadim Pogoretskii", "Jorn P van Engelen", "Amir Abbas Kashi", "Sander F G Reniers", "Xinran Zhao", "Weiming Yao", "Tianran Liu", "Francesco Pagliano", "Andrea Fiore", "Xuebing Zhang", "Zizheng Cao", "Rakesh Ranjan Kumar", "Hon Ki Tsang", "Rene P J van Veldhoven", "Tjibbe de Vries", "Erik Jan Geluk", "Jeroen Bolk", "Huub Ambrosius", "Meint Smit", "Kevin A Williams" ], "corpus_id": 212995546, "doc_id": "212995546", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Indium Phosphide Membrane Nanophotonic Integrated Circuits on Silicon", "venue": "", "year": 2019 }, { "abstract": "S. Latkowski1* P.J. van Veldhoven1, A. Hansel2, D. D'Agostino1, H. Rabbani Haghighi1, B. Docter3, N. Bhattacharya2, P. Thijs1, H. Ambrosius1, M. Smit1, K. Williams1 and E.A.J.M. Bente1 1COBRA Research Institute, Eindhoven University of Technology De Zaale, 5612 AJ, Eindhoven, The Netherlands 2Optics Research roup, TU Delft, 2628 Delft, The Netherlands 3EFFECT Photonics B.V. Torenallee 20, Eindhoven, The Netherlands [email protected]", "author_names": [ "Sylwester Latkowski", "P J van Veldhoven", "Andreas Hansel", "Domenico D'Agostino", "H Hadi Rabbani Haghighi", "Boudewijn Docter", "Nandini Bhattacharya", "Peter J A Thijs", "Huub Ambrosius", "Mk Meint Smit", "Kevin A Williams", "Erwin Bente" ], "corpus_id": 114712613, "doc_id": "114712613", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Indium phosphide monolithic photonic integrated circuits for gas sensing applications", "venue": "", "year": 2016 }, { "abstract": "A dual laser indium phosphide photonic integrated circuit for precision spectroscopy lidar was designed and fabricated. A stabilization experiment demonstrated a twentyfold improvement in the long term frequency stability of the master laser.", "author_names": [ "Joseph Fridlander", "Victoria Rosborough", "Fengqiao Sang", "Michael Nickerson", "Jeffrey R Chen", "Kenji Numata", "Paul Verrinder", "Fabrizio Gambini", "Sergio Pinna", "Stephan R Kawa", "Mark A Stephen", "Larry A Coldren", "Jonathan Klamkin" ], "corpus_id": 221717511, "doc_id": "221717511", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Photonic Integrated Circuits for Precision Spectroscopy", "venue": "2020 Conference on Lasers and Electro Optics (CLEO)", "year": 2020 } ]

[ { "abstract": "Nanoelectromechanical (NEM) switches have received widespread attention as promising candidates in the drive to surmount the physical limitations currently faced by complementary metal oxide semiconductor technology. The NEM switch has demonstrated superior characteristics including quasi zero leakage behaviour, excellent density capability and operation in harsh environments. However, an unacceptably high operating voltage (4 20 V) has posed a major obstacle in the practical use of the NEM switch in low power integrated circuits. To utilize the NEM switch widely as a core device component in ultralow power applications, the operation voltage needs to be reduced to 1 V or below. However, sub 1 V actuation has not yet been demonstrated because of fabrication difficulties and irreversible switching failure caused by surface adhesion. Here, we report the sub 1 V operation of a NEM switch through the introduction of a novel pipe clip device structure and an effective air gap fabrication technique. This achievement is primarily attributed to the incorporation of a 4 nm thick air gap, which is the smallest reported so far for a NEM switch generated using a 'top down' approach. Our structure and process can potentially be utilized in various nanogap related applications, including NEM switch based ultralow power integrated circuits, NEM resonators, nanogap electrodes for scientific research and sensors.", "author_names": [ "Jeong Oen Lee", "Yong-Ha Song", "Min-Wu Kim", "Min-Ho Kang", "Jaehyun Oh", "Hyun-Ho Yang", "Jun-Bo Yoon" ], "corpus_id": 41687724, "doc_id": "41687724", "n_citations": 162, "n_key_citations": 4, "score": 1, "title": "A sub 1 volt nanoelectromechanical switching device.", "venue": "Nature nanotechnology", "year": 2013 }, { "abstract": "Nanoscale metal oxide memristors have potential in the development of brain inspired computing systems that are scalable and efficient. In such systems, memristors represent the native electronic analogues of the biological synapses. In this work, we show cerium oxide based bilayer memristors that are forming free, low voltage |0.8 V| energy efficient (full on/off switching at ~8 pJ with 20 ns pulses, intermediate states switching at ~fJ) and reliable. Furthermore, pulse measurements reveal the analog nature of the memristive device; that is, it can directly be programmed to intermediate resistance states. Leveraging this finding, we demonstrate spike timing dependent plasticity, a spike based Hebbian learning rule. In those experiments, the memristor exhibits a marked change in the normalized synaptic strength >30 times) when the pre and post synaptic neural spikes overlap. This demonstration is an important step towards the physical construction of high density and high connectivity neural networks.", "author_names": [ "Cheng-Chih Hsieh", "Anupam Roy", "Yao-Feng Chang", "Davood Shahrjerdi", "Sanjay K Banerjee" ], "corpus_id": 34418493, "doc_id": "34418493", "n_citations": 46, "n_key_citations": 0, "score": 0, "title": "A sub 1 volt analog metal oxide memristive based synaptic device with large conductance change for energy efficient spike based computing systems", "venue": "", "year": 2016 }, { "abstract": "The new class of fully silicon compatible hafnia based ferroelectrics with high switchable polarization and good endurance and thickness scalability shows a strong promise for new generations of logic and memory devices. Among other factors, their competitiveness depends on the power efficiency that requires reliable low voltage operation. Here, we show genuine ferroelectric switching in Hf xZr(1 x)O2 (HZO) layers in the application relevant capacitor geometry, for driving signals as low as 800 mV and coercive voltage below 500 mV. Enhanced piezoresponse force microscopy with sub picometer sensitivity allowed for probing individual polarization domains under the top electrode and performing a detailed analysis of hysteretic switching. The authentic local piezoelectric loops and domain wall movement under bias attest to the true ferroelectric nature of the detected nanodomains. The systematic analysis of local piezoresponse loop arrays reveals a totally unexpected thickness dependence of the coercive fields in HZO capacitors. The thickness decrease from 10 to 7 nm is associated with a remarkably strong decrease of the coercive field, with about 50% of the capacitor area switched at coercive voltages =0.5 V. Our explanation consistent with the experimental data involves a change of mechanism of nuclei assisted switching when the thickness decreases below 10 nm. The practical implication of this effect is a robust ferroelectric switching under the millivolt range driving signal, which is not expected for the standard coercive voltage scaling law. These results demonstrate a strong potential for further aggressive thickness reduction of HZO layers for low power electronics.", "author_names": [ "Igor Stolichnov", "Matteo Cavalieri", "Enrico Colla", "Tony Schenk", "Terence Mittmann", "Thomas Mikolajick", "Uwe Schroeder", "Adrian M Ionescu" ], "corpus_id": 206487330, "doc_id": "206487330", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "Genuinely Ferroelectric Sub 1 Volt Switchable Nanodomains in Hf xZr(1 x)O2 Ultrathin Capacitors.", "venue": "ACS applied materials interfaces", "year": 2018 }, { "abstract": "Nonvolatile memory design is a discipline that employs digital and analog circuit design techniques and requires knowledge of semiconductor physics and quantum mechanics. Methods for programming and erasing memory are discussed here, and simulation models are provided for Impact Hot Electron Injection (IHEI) Fowler Nordheim (FN) tunneling, and direct tunneling. Extensive testing of analog memory cells was used to derive a set of equations that describe the floating gate characteristics. Measurements of charge retention also revealed several leakage mechanisms, and methods for mitigating leakage are presented. Fabrication of flash memory in a standard CMOS process presents significant design challenges. The absence of multiple polysilicon layers requires that additional devices be used to control the floating gate voltage. Furthermore high voltage devices are often required to isolate the selected memory cells during write and erase cycles. However, a single poly design allows portability to another standard process provided that the floating gate characteristics are known. A flash memory system is presented here that has been fabricated in a standard 130 nanometer CMOS process. The design utilizes capacitive feedback to maintain desired injection current during programming. It also includes a sense amplifier design which features auto zeroing of inherent offsets. Comparisons to existing memory designs show that a significant improvement in areal density was achieved through the elimination of on die high voltage charge pumps and switches. Measurements were performed over a range of clock frequencies and supply voltages. Results show that this memory system is capable of a read access time of 3.5 microseconds with a 1 megahertz clock while consuming less than", "author_names": [ "David A Basford" ], "corpus_id": 115436246, "doc_id": "115436246", "n_citations": 2, "n_key_citations": 1, "score": 0, "title": "Design and Evaluation of a Sub 1 Volt Read Flash Memory in a Standard 130 Nanometer CMOS Process", "venue": "", "year": 2017 }, { "abstract": "Abstract This paper presents the results on the design, fabrication and characterization of a cantilever type NEM relay featuring a hammer shaped tip and built in the back end of a conventional 0.35 mm CMOS technology. A high on/off current ratio (higher than 107) a subthreshold swing of only 285 mV/dec, and zero off state leakage current were experimentally observed. Through an endurance test of 3*103 switching cycles, the relay showed a stable pull in voltage of 31.25 V with an absolute variation of only 0.5 V. The resonant frequency was also characterized, and observed at 456.97 kHz. Finally, the paper discusses the usability of the presented device as a mass sensor with mass stiffness decoupling capability for on chip detection. This innovative feature, which could benefit the application portfolio of the emerging IoT era, lies on the fact that both pull in voltage and resonant frequency can be fully electrically determined.", "author_names": [ "Martin Riverola", "Arantxa Uranga", "Francesc Torres", "Nuria Barniol" ], "corpus_id": 115674865, "doc_id": "115674865", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Fabrication and characterization of a hammer shaped CMOS/BEOL embedded nanoelectromechanical (NEM) relay", "venue": "", "year": 2018 }, { "abstract": "There has been remarkable interest in nanomechanical computing elements that can potentially lead to a new era in computation due to their re configurability, high integration density, and high switching speed. Here we present a nanomechanical device capable of dynamically performing logic operations (NOR, NOT, XNOR, XOR, and AND) The concept is based on the active tuning of the resonance frequency of a doubly clamped nanoelectromechanical beam resonator through electro thermal actuation. The performance of this re configurable logic device is examined at elevated temperatures, ranging from 25 degC to 85 degC, demonstrating its resilience for most of the logic operations. The proposed device can potentially achieve switching rate in ms, switching energy in nJ, and an integration density up to 106 per cm2. The practical realization of this re configurable device paves the way for nano element based mechanical computing.", "author_names": [ "Syed N R Kazmi", "Md Abdullah Al Hafiz", "Karumbaiah N Chappanda", "Saad Ilyas", "Jorge Holguin", "Pedro M F J Costa", "Mohammad Ibrahim Younis" ], "corpus_id": 5082872, "doc_id": "5082872", "n_citations": 28, "n_key_citations": 2, "score": 0, "title": "Tunable nanoelectromechanical resonator for logic computations.", "venue": "Nanoscale", "year": 2017 }, { "abstract": "As CMOS scaling limit is reached, no charge based devices and non equilibrium systems need to be investigated as alternative switching units. We present a non volatile nanoelectromechanical switch with state variable mechanical positioning of a single walled CNT bundle suspended over metal electrodes deposited in dry etched trenches. The switch is fabricated using a single mask fabrication process followed by dielectrophoresis based directed assembly of the CNT bundle. The design exhibits symmetric behavior with the same actuation voltage <5 V) for both ON and OFF states. A coarse grain model is used to investigate the effect of the slack of the assembled CNT bundle over the shoulder of the trench, CNT bundle diameter, surface interaction between the CNT bundle and the underlying substrate, and the actuation voltage on the operational dynamics of these devices.", "author_names": [ "Salman Ali Abbasi", "Taehoon Kim", "Sivasubramanian Somu", "Hailong Wang", "Zhimin Chai", "Moneesh Upmanyu", "Ahmed Busnaina" ], "corpus_id": 216295728, "doc_id": "216295728", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Fabrication of a nanoelectromechanical bistable switch using directed assembly of SWCNTs", "venue": "", "year": 2020 }, { "abstract": "Nanoelectromechanical (NEM) switches have the potential to complement or replace traditional CMOS transistors in the area of ultra low power digital electronics. This paper reports the demonstration of prototype circuits including the first 3 stage ring oscillator built using cell level digital logic elements based on curved NEM switches. The ring oscillator core occupies an area of 30 mu m x 10 mu m using 6 NEM switches. Each NEM switch device has a footprint of 5 mu m x 3 mu m, an air gap of 60 mu m and is coated with amorphous carbon (a C) for reliable operation. The ring oscillator operates at a frequency of 6.7 MHz, and confirms the simulated inverter propagation delay of 25 ns. The successful fabrication and measurement of this demonstrator are key milestones on the way towards an optimized, scaled technology with sub nanosecond switching times, lower operating voltages and VLSI implementation. (C) 2015 Elsevier Ltd. All rights reserved.", "author_names": [ "Christopher Lawrence Ayala", "Daniel Grogg", "Antonios Bazigos", "Simon J Bleiker", "Montserrat Fernandez-Bolanos", "Frank Niklaus", "Christoph Hagleitner" ], "corpus_id": 108744918, "doc_id": "108744918", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Nanoelectromechanical digital logic circuits using curved cantilever switches with amorphous carbon coated contacts", "venue": "", "year": 2015 }, { "abstract": "Abrupt switching behavior and near zero leakage current of nanoelectromechanical (NEM) switches are advantageous properties through which NEMs can outperform conventional semiconductor electrical switches. To date, however, typical NEMs structures require high actuation voltages and can prematurely fail through permanent adhesion (defined as stiction) of device components. To overcome these challenges, in the present work we propose a NEM switch, termed a \"squitch,\" which is designed to electromechanically modulate the tunneling current through a nanometer scale gap defined by an organic molecular film sandwiched between two electrodes. When voltage is applied across the electrodes, the generated electrostatic force compresses the sandwiched molecular layer, thereby reducing the tunneling gap and causing an exponential increase in the current through the device. The presence of the molecular layer avoids direct contact of the electrodes during the switching process. Furthermore, as the layer is compressed, the increasing surface adhesion forces are balanced by the elastic restoring force of the deformed molecules which can promote zero net stiction and recoverable switching. Through numerical analysis, we demonstrate the potential of optimizing squitch design to enable large on off ratios beyond 6 orders of magnitude with operation in the sub 1 V regime and with nanoseconds switching times. Our preliminary experimental results based on metal molecule graphene devices suggest the feasibility of the proposed tunneling switching mechanism. With optimization of device design and material engineering, squitches can give rise to a broad range of low power electronic applications.", "author_names": [ "Farnaz Niroui", "Annie Wang", "Ellen M Sletten", "Yi Song", "Jing Kong", "Eli Yablonovitch", "Timothy M Swager", "Jeffrey H Lang", "Vladimir Bulovic" ], "corpus_id": 5017994, "doc_id": "5017994", "n_citations": 20, "n_key_citations": 0, "score": 0, "title": "Tunneling Nanoelectromechanical Switches Based on Compressible Molecular Thin Films.", "venue": "ACS nano", "year": 2015 }, { "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": "Intrachip optical interconnects (OIs) have the potential to outperform electrical wires and to ultimately solve the communication bottleneck in high performance integrated circuits. Performance targets and critical directions for ICs progress are yet to be fully explored. In this paper, the International Technology Roadmap for Semiconductors (ITRS) is used as a reference to explore the requirements that silicon based ICs must satisfy to successfully outperform copper electrical interconnects (IEs) Considering the state of the art devices, these requirements are extended to specific IC components", "author_names": [ "Mikhail Haurylau", "Guoqing Chen", "Hui Chen", "Jidong Zhang", "Nicholas Nelson", "David H Albonesi", "Eby G Friedman", "Philippe M Fauchet" ], "corpus_id": 2720738, "doc_id": "2720738", "n_citations": 255, "n_key_citations": 6, "score": 1, "title": "On Chip Optical Interconnect Roadmap: Challenges and Critical Directions", "venue": "IEEE Journal of Selected Topics in Quantum Electronics", "year": 2006 }, { "abstract": "Intrachip optical interconnects can outperform electrical wires but the required parameters for optical components are yet unknown. Here the ITRS is used as a reference point to derive the requirements that optical components must meet.", "author_names": [ "Mikhail Haurylau", "Hui Chen", "Jidong Zhang", "Guoqing Chen", "Nicholas Nelson", "David H Albonesi", "Eby G Friedman", "Philippe M Fauchet" ], "corpus_id": 122012530, "doc_id": "122012530", "n_citations": 180, "n_key_citations": 7, "score": 0, "title": "On chip optical interconnect roadmap: challenges and critical directions", "venue": "", "year": 2005 }, { "abstract": "Intrachip optical interconnects(OIs) have the potential to outperform electrical wires and to ultimately solve the communication bottleneck in high performance integrated circuits. Performance targets and critical directions for Ics progress are yet to be fully explored. In this paper, the International Technology Roadmap for Semiconductors (ITRS) is used as a reference to explore the requirements that silicon based Ics must satisfy to successfully outperform copper electrical interconnects (IEs) Consiering the state of art devices, these requirements are extended to specific IC components.", "author_names": [ "Nemi Chand Neel", "Ajay Kumar Banyal", "Manu Sharma", "Mikhail Haurylau", "G Chen", "John X J Zhang", "E G Fried", "Philippe M Fauchet" ], "corpus_id": 17396456, "doc_id": "17396456", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "On Chip High Speed Optical Interconnect with RLCG Electrical Interconnect: Challenges and Dimensions", "venue": "", "year": 2013 }, { "abstract": "VLSI/ULSI and the evolutions being driven by the International Technology Roadmap for Semiconductors (ITRS) are once again presenting severe challenges to the metal interconnect. Clock skew and other timing delays are becoming application critical design factors. The RC induced delays as well as parasitics (due to the trace density) are causing severe limitations to designs. Unfortunately these issues are very difficult to deal with using conventional computer aided design tools although efforts are being made, notably via DARPA funded programmes. We shall review techniques (and design elements) for on chip optical communications. Through this we will present a new proposition for optical interconnects integrated upon otherwise conventional CMOS devices. We believe that the illustrated methodologies can be developed to provide very effective optical functionality appropriate to alleviating high speed communications and timing issues.", "author_names": [ "Terry V Clapp", "Laurence W Cahill" ], "corpus_id": 108655317, "doc_id": "108655317", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Applications of CMOS processing to realize functional on chip optical interconnects for VLSI", "venue": "SPIE OPTO", "year": 2003 }, { "abstract": "We present a computing microsystem that uniquely leverages the bandwidth, density, and latency ad vantages of silicon photonic interconnect to enable highly compact supercomputer scale systems. We describe and justify single node and multinode systems interconnected with wave length routed optical links, quantify their benefits vis a` vis electrically connected systems, analyze the constituent optical component and system requirements, and provide an overview of the critical technologies needed to fulfill this system vision. This vision calls for more than a hundredfold reduction in energy to communicate an optical bit of information. We explore the power dissipation of a photonic link, suggest a roadmap to lower the energy per bit of silicon photonic interconnects, and identify the challenges that will be faced by device and circuit designers towards this goal.", "author_names": [ "Ashok V Krishnamoorthy", "Ron Ho", "Xuezhe Zheng", "Herb Schwetman", "Jon K Lexau", "Pranay Koka", "Guoliang Li", "Ivan Shubin", "John E Cunningham" ], "corpus_id": 110820121, "doc_id": "110820121", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Computer Systems Based on Silicon Photonic Interconnects A proposed supercomputer on a chip with optical interconnections between processing elements will require development of new lower energy optical components and new circuit architectures that match electrical datapaths to complementary optical", "venue": "", "year": 2009 }, { "abstract": "Emerging telecommunication and data routing applications anticipate a photonic roadmap leading to ultra compact photonic integrated circuits. Consequently, photonic devices will soon have to meet footprint and efficiency requirements similar to their electronic counterparts calling for extreme capabilities to create, guide, modulate, and detect deep subwavelength optical fields. For active devices such as modulators, this means fulfilling optical switching operations within light propagation distances of just a few wavelengths. Plasmonics, or metal optics, has emerged as one potential solution for integrated on chip circuits that can combine both high operational speeds and ultra compact architectures rivaling electronics in both speed and critical feature sizes. This article describes the current status, challenges, and future directions of the various components required to realize plasmonic integrated circuitry.", "author_names": [ "Volker J Sorger", "Rupert F Oulton", "Ren-Min Ma", "Xiang Zhang" ], "corpus_id": 15391453, "doc_id": "15391453", "n_citations": 220, "n_key_citations": 3, "score": 0, "title": "Toward integrated plasmonic circuits", "venue": "", "year": 2012 }, { "abstract": "High density interconnect microelectronics emphasizes the effective integration of several critical and complex electronic packages and technologies. This Roadmap introduces current technologies in use, related strategic issues and trends, and research recommendations for space applications. Electronic packages are optimized for low cost, portability, robustness, high speed, power efficiency, and for small size and low weight. Satisfying these increasing demands will require enhanced electronic performance with an associated improvement in packaging performance and better relief from thermal and mechanical stresses. Technical challenges and directions for high density interconnect microelectronics packaging include understanding latent electromigration and dendritic growth, multilayer board hole wall wicking reliability issues, and characterization of reworkable inexpensive underfill. Current research directions include Vertical Cavity Surface Emitting Laser (VCSEL) packaging for low cost optical interconnects, high density vias, and stencil printing with conductive adhesives for direct chip attach. Technology challenges are described first for components. Forecasts and recommendations for research direction are given for components, materials, and packaging.", "author_names": [ "Stephen R Bolin", "Loren Rideout" ], "corpus_id": 31966540, "doc_id": "31966540", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "HIGH DENSITY MICROELECTRONICS PACKAGING ROADMAP FOR SPACE APPLICATIONS", "venue": "", "year": 2001 }, { "abstract": "Severe information latency and power consumption are key technology challenges facing the traditional copper interconnects which impose tremendous constraints to keep up with the performance roadmap driven by the Moore's Law. Converging electronic and photonic integrated circuits (EPIC) on a single chip platform to enable functional diversification emerges as one promising approach which could be realized by taking the advantage of low energy and huge data capacity of optical interconnects. By leveraging on the wealth of CMOS technology know how and infrastructures, the fundamental photonics building blocks constructing the EPIC platform have been successfully developed in this work. We present an overview on the current status of this critical technology development and provide an outlook for the monolithic integration of Si microand nano photonics. It is our belief that a seamless integration of EPIC is poised to become a promising technology to meet the bandwidth and energy requirements of future data communication.", "author_names": [ "G Q Lo", "Kah-Wee Ang", "Tsung-Yang Liow", "Qing Fang", "Jinsong Zhang", "Shiyang Zhu", "Junfeng Song", "Yong-Zhong Xiong", "F F Ren", "Mingbin Yu", "Dim Lee Kwong" ], "corpus_id": 110422239, "doc_id": "110422239", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "(Invited) Silicon Photonics Technologies for Monolithic Electronic Photonic Integrated Circuit", "venue": "", "year": 2010 }, { "abstract": "We report on migrating multiple lane link into an L band VCSEL based WDM system. Experimental validation achieves successful transmission over 10 km of SMF at 4x14Gbps. Inter channel crosstalk penalty is observed to be less than 0.5 dB and a transmission penalty around 1 dB. The power budget margin ranges within 6 dB and 7 dB. (c) 2012 Optical Society of America OCIS codes: (060.0060) Fiber optics and optical communications; (200.4650) Optical interconnects. References and links 1. H. Liu, C. F. Lam, and C. Johnson, \"Scaling optical interconnects in datacenter networks opportunities and challenges for WDM,\" in Proceedings of the 18th Annual Symposium on High Performance Interconnects, 2010, 113 116. 2. A. Vahdat, H. Liu, X. Zhao, and C. Johnson, \"The emerging optical data center\" in Proceedings of OFC/NOEFC '11, Los Angeles Convention Center, Los Angeles, CA, 2011, OTuH2. 3. C. Kachris and I. Tomkos, \"Power consumption evaluation of hybrid WDM PON networks for data centers,\" in Proceedings of the 16th European Conference on Networks and Optical Communication (NOC) 2011, 118 121. 4. DatacenterDynamics (DCD) white paper, \"The 2011 census,\" (DCD Industry CENSUS, 2011) 5. InfiniBand Trade Association, 2012. http:/www.infinibandta.org/index.php. 6. Fiber Channel Industry Association, 2012.http:/www.fibrechannel.org/roadmaps. 7. H. S. Hamza and J. S. Deogun, \"WDM optical interconnects: a balanced design approach,\" IEEE/ACM Trans. Netw. 15(6) 1565 1578 (2007) 8. J. Cheng, \"Topics in VCSEL based high speed WDM optical interconnects,\" in IEEE Avionics, Fiber Optics and Photonics Technology Conference, 2008, 65 66. 9. M. Haurylau, G. Chen, H. Chen, J. Zhang, N. A. Nelson, D. H. Albonesi, E. G. Friedman, and P. M. Fauchet, \"On chip optical interconnect roadmap: challenges and critical directions,\" IEEE J. Sel. Top. Quantum Electron. 12(6) 1699 1705 (2006) 10. R. Rodes, J. Estaran, B. Li, M. Mueller, J. B. Jensen, T. Grundl, M. Ortsiefer, C. Neumeyr, J. Rosskopf, K. J. Larsen, M. Amann, and I. Tafur Monroy, \"100 Gb/s single VCSEL data transmission link,\" in OFC/NOEFC'12, OSA Technical Digest (Optical Society of America, 2012) paper PDP5D.10. 11. L. Chrostowski, C. H. Chang, R. Stone, and C. J. Chang Hasnain, \"Demonstration of long wavelength directly modulated VCSEL transmission using SOAs,\" IEEE Photon. Technol. Lett. 14(9) 1369 1371 (2002) 12. R. J. Stone, R. F. Nabiev, J. Boucart, W. Yuen, P. Kner, G. S. Li, R. Carico, L. Scheffel, M. Jansen, D. P. Worland, and C. J. Chang Hasnain, \"50 km error free 10 Gbit/s WDM transmission using directly modulated long wavelength VCSELs,\" Electron. Lett. 36(21) 1793 1794 (2000) 13. FP7 European project GigaWam, \"Next generation WDM PON enabling gigabit per user data bandwidth\" http:/www.gigawam.org/ 14. J. C. Charlier and S. Kruger, \"Long wavelength VCSELs ready to benefit 40/100 GbE modules,\" Lightwave(r) 2012.http:/www.lightwaveonline.com/articles/print/volume 28/issue 6/technology/long wavelength vcseltechnology improves.html. 15. A. Ran, IEEE P802.3bj 100 Gb/s Backplane and Copper Cable TaskForce 14 January 2012. 16. F. Chang, K. Onohara, and T. Mizuochi, \"Forward error correction for 100 G transport networks,\" IEEE Commun. Mag. 48(3) S48 S55 (2010) #177306 $15.00 USD Received 1 Oct 2012; revised 17 Nov 2012; accepted 19 Nov 2012; published 10 Dec 2012 (C) 2012 OSA 17 December 2012 Vol. 20, No. 27 OPTICS EXPRESS 28524", "author_names": [ "Jose Manuel Estaran", "Roberto Rodes", "T T Pham", "Markus Ortsiefer", "Christian Neumeyr", "J Rosskopf", "Idelfonso Tafur Monroy" ], "corpus_id": 116511353, "doc_id": "116511353", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Quad 14Gbps L band VCSEL based system for WDM migration of 4 lanes 56 Gbps optical data links", "venue": "", "year": 2014 }, { "abstract": "In this paper we present a computing system that uniquely leverages the bandwidth, density, and latency advantages of silicon photonic interconnects to enable highly compact supercomputerscale systems. We present the details of an optically enabled \"macrochip\" which is a set of contiguous, optically interconnected chips that deploy wavelength division multiplexed (WDM) enabled by silicon photonics. We describe the system architecture and the WDM point to point network implementation of a \"macrochip\" providing bisection bandwidth of 10 TBps and discuss system and device level challenges, constraints, and the critical technologies needed to implement this system. We present a roadmap to lowering the energy per bit of a silicon photonic interconnect and highlight recent advances in silicon photonics under the UNIC program that facilitate implementation of a \"macrochip\" system made of arrayed chips.", "author_names": [ "Kannan Raj", "John E Cunningham", "Ron Ho", "Xuezhe Zheng", "Herb Schwetman", "Pranay Koka", "Michael O McCracken", "Jon K Lexau", "Guoliang Li", "Hiren D Thacker", "Ivan Shubin", "Ying Luo", "Jin Yao", "Mehdi Asghari", "Thierry Pinguet", "James G Mitchell", "Ashok V Krishnamoorthy" ], "corpus_id": 109521682, "doc_id": "109521682", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "\"Macrochip\" computer systems enabled by silicon photonic interconnects", "venue": "OPTO", "year": 2010 } ]

[ { "abstract": "Abstract Because of the high cost of failure, the reliability performance of power semiconductor devices is becoming a more and more important and stringent factor in many energy conversion applications. Thus, the need for appropriate reliability analysis of the power electronics emerges. Due to its conventional approach, mainly based on failure statistics from the field, the reliability evaluation of the power devices is still a challenging task. In order to address the given problem, a reliability assessment platform is proposed in this paper. An advanced reliability design tool software, which can provide valuable reliability information based on given mission profiles and system specification is first developed and its main concept is presented. In order to facilitate the test and access to the loading and lifetime information of the power devices, a novel mission profile based stress emulator experimental setup is proposed and designed. The link between the stress emulator setup and the reliability tool software is highlighted. Finally, the reliability assessment platform is demonstrated on a 3 phase grid connected inverter application study case.", "author_names": [ "Ionut Vernica", "Ke Ma", "Frede Blaabjerg" ], "corpus_id": 36663167, "doc_id": "36663167", "n_citations": 4, "n_key_citations": 0, "score": 1, "title": "Reliability assessment platform for the power semiconductor devices Study case on 3 phase grid connected inverter application", "venue": "Microelectron. Reliab.", "year": 2017 }, { "abstract": "Abstract Recently, a tendency in the growing of grid connected building integrated photovoltaic (BIPV) systems has been noticed in most countries. Hence, high penetration of PV power into the system network can be observed in many points in the network. This may cause severe problems on the distribution network due to the intermittent nature of PV systems. As a feasible solution, the reactive power capability of voltage source inverter in PV systems can be employed rather than approaching expensive grid infrastructures in the distribution network. The purpose of this study is to implement a 3 phase grid connected (BIPV) system with reactive power control to regulate the system voltage and improve the system power factor. Subsequent to this, a specific system model has been designed and developed in MATLAB Simulink application. The selection of PV system specifications is based on practical system implementation. The inverter control system along with the reactive power control has been developed for the proper system operation at different system conditions to reduce the var compensation on the utility grid. Better system accuracy of the developed system model has been found by validating with real system data. The overall system performance has indicated that the effective utilization of reactive power control of a grid connected PV system yields to a stable, reliable and cost effective system network operation which reduces the heavy burden on the utility grid to control the PV system effects.", "author_names": [ "Mohan Lal Kolhe", "Mohamed J M A Rasul" ], "corpus_id": 216450602, "doc_id": "216450602", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "3 Phase grid connected building integrated photovoltaic system with reactive power control capability", "venue": "", "year": 2020 }, { "abstract": "Recently, a tendency in the growing of grid connected building integrated photovoltaic (BIPV) systems has been noticed in most countries. Hence, high penetration of PV power into the system network can be observed in many points in the network. This may cause severe problems in the distribution network originated by the intermittent behaviour of PV systems. As a feasible solution, the reactive power capability of voltage source inverter in PV systems can be employed rather than approaching expensive grid infrastructures in the distribution network. The purpose of this study is to implement a 3 phase grid connected BIPV system with reactive power control to regulate the system voltage and improve the system power factor. Subsequent to this, the system model is designed and developed in MATLAB Simulink application. The inverter control system along with the reactive power control is developed for the proper system operation at different system conditions to reduce the var compensation on the utility grid. A better system accuracy of the developed system model is verified by validating with real system data.", "author_names": [ "Mohamed J M A Rasul", "Mohan Lal Kolhe" ], "corpus_id": 202769562, "doc_id": "202769562", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Reactive Power Control of a 3 phase Grid Connected Building Integrated Photovoltaic System", "venue": "IOP Conference Series: Materials Science and Engineering", "year": 2019 }, { "abstract": "The utilization of renewable energy sources nowadays is increasing rapidly due to the cheaper price of the photovoltaic cells, wind turbines or other renewable sources. But as a system, these sources usually require power converters either to provide the correct voltage to electric loads or to provide the required currents as in the grid connected application. Many converter topologies are developed for the grid connected applications and one of the topologies is the 3 phase boost inverter. This converter topology, although has a uni directional power flow, allows the low dc to high ac voltage direct conversion, thus the amount of the power switches is minimum. The particularity of this topology is its non linearity, where applying the linear control is somewhat more difficult. In this research, a hybrid control approach is proposed to this topology, the 3 phase converter is grid connected and the whole system is simulated using the PSIM software.", "author_names": [ "Tri Desmana Rachmildha", "Mustafa Abbas Fadel", "Yanuarsyah Haroen" ], "corpus_id": 155106990, "doc_id": "155106990", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Hybrid Control Method Applied on Grid Connected 3 phase Boost Inverter", "venue": "2019 IEEE PES GTD Grand International Conference and Exposition Asia (GTD Asia)", "year": 2019 }, { "abstract": "Abstract In this research, FPGA implementation of high gain topologies are proposed for 3 phase grid connected quasi Z Source Inverter(qZSI) desirable for application that involve solar photovoltaic systems, like continuous input current configuration of qZSI with two switched impedance network. Identical with Diode Assisted quasi Z source inverter (DA qZSI) the newly introduced Partition input Union output Dual Impedance quasi Z Source Inverter (PUDL qZSI) topology achieves great boost factor inversion at low Shoot Through (ST) duty cycle and a higher Non Shoot Through (NST) period to yield an increased Total Harmonic Distortion (THD) output current. This research investigates about the working principles and assessment of the newly introduced PUDL qZSI with continuous input PV current configured two switched impedance networks and thereafter it is comparable with qZSI, and DA qZSI. The topologies analysis is performed in the steady state and the validation of their dynamic performances are carried out using the simulated results obtained from MATLAB/Simulink. In addition, the experimental results shows that the proposed FPGA based controller achieve a good performance at small calculation time, which is precise for PUDL qZSI PV based grid connected system.", "author_names": [ "S Victor P Selvakumar", "V Kamatchi Kannan" ], "corpus_id": 214536829, "doc_id": "214536829", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "FPGA based PV grid connected inverter using partition input union output dual impedance qZSI", "venue": "Microprocess. Microsystems", "year": 2020 }, { "abstract": "Second and third order passive filters (LC and LCL) are interesting filters to use for grid connected PWM inverters. Because of the stability problems of this filter around resonance frequency, series and damping resistor can be add to an LCL filter. However, the resistor value has impact on the filter respond, voltage and current harmonic distortion and system power loss. In this paper, the mathematic characteristics of LC, LCL filter, series and parallel damping LCL filters will be described with their design to apply in 3 phase PV grid connected inverter. And, simulations are used to validate the theoretical analysis of the filters on filter performance and power quality of the grid in 3 phase grid connected inverter. Keywordfilter design, LCL filter, Passive resonance damping, harmonic, Grid connected inverter and power quality", "author_names": [ "Mojgan Hojabri", "Mehrdad Hojabri", "Arash Toudeshki" ], "corpus_id": 212533057, "doc_id": "212533057", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "PASSIVE DAMPING FILTER DESIGN AND APPLICATION FOR THREE PHASE PV GRID CONNECTED INVERTER", "venue": "", "year": 2015 }, { "abstract": "In this paper author discussed PI and fuzzy controllers with the three phase inverter concept and this converter connected to induction motor drive as load. This presents a unified control strategy that enables both islanded and grid tied operations of three phase inverter in distributed generation, with no need for switching between two corresponding controllers or critical islanding detection. Intentional islanding describes the condition in which a microgrid or a portion of the power grid, which consists of a load and a distributed generation (DG) system, is isolated from the remainder of the utility system. When the microgrid is cut off from the main grid, each DG inverter system must detect this islanding situation and must switch to a voltage control mode. The control strategy composes of an inner inductor current loop, and a novel voltage loop in the synchronous reference frame. Induction motor is one of the load in grid. The inverter is regulated as a current source just by the inner inductor current loop in grid tied operation, and the voltage controller is automatically activated to regulate the load voltage upon the occurrence of islanding. This paper mainly depends on PI and fuzzy controller by using fuzzy controller to improve the power quality compare to PI controller. The proposed converter tested with Matlab/simulink software.", "author_names": [ "Kolla Uma", "Chandramouli Srinivas" ], "corpus_id": 212522391, "doc_id": "212522391", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "FUZZY CONTROLLER BASED 3 PHASE INVERTER FOR MICRO GRID WITH INDUCTION MOTOR DRIVE APPLICATION", "venue": "", "year": 2014 }, { "abstract": "The renewable energy market is expanding, and this creates a demand for efficient control for energy conversion. Most renewable energy is harnessed as DC and needs to be converted into 3 phase voltage with a voltage source inverter (VSI) to be connected to the grid. PI control is commonly utilized to control the VSI. It provides good steady state performance but suffers from poor disturbance rejection and limited bandwidth. This paper introduces the application of an \\mathcal{L}_\\infty feedback control; an iterative algorithm based on LMIs (Linear Matrix Inequalities) The control objective is to provide the grid voltage and regulate the real and reactive power injected to the grid. The performance of the proposed control scheme is validated analytically and through Matlab/Simulink simulations under nominal conditions, input voltage disturbances and grid impedance uncertainties. The proposed method is compared with existing method (PI controller) showing that the proposed scheme can provide better reference tracking, and improved transient and steady state performance with low implementation cost.", "author_names": [ "Daniela Caneque Fernandez", "Sara Ahmed", "Ahmad F Taha" ], "corpus_id": 220258880, "doc_id": "220258880", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "An L Feedback Control Strategy for Grid Connected Three Phase Voltage Source Inverters", "venue": "2020 IEEE Applied Power Electronics Conference and Exposition (APEC)", "year": 2020 }, { "abstract": "Second and third order passive filters (LC and LCL) are interesting filters to use for grid connected PWM inverters. Because of the stability problems of these filters around resonance frequency, series and damping resistor can be add to an LCL filter. However, the resistor value has impact on the filter respond, voltage and current harmonic distortion and filter power loss. In this paper, the mathematic characteristics of LC, LCL filter, series and parallel damping LCL filters will be described with their design to apply in 3 phase PV grid connected inverter. And, simulations have down to validate the theoretical analysis of the filters on filter performance, power quality and filter power loss for 3 phase grid connected renewable energy system application.", "author_names": [ "Mojgan Hojabri", "Mehrdad Hojabri" ], "corpus_id": 32177059, "doc_id": "32177059", "n_citations": 9, "n_key_citations": 1, "score": 0, "title": "Design, Application and Comparison of Passive Filters for Three Phase Grid Connected Renewable Energy Systems", "venue": "", "year": 2015 }, { "abstract": "The application of photovoltaic (PV) as a source of electrical energy in the distributed generation (DG) systems are gaining more attention with the advances in power electronics technology. The one of the key technologies in the PV based DG systems is grid connected inverter that is utilized to interface PV power systems into the utility grid. Multilevel multifunctional grid connected inverters (ML MFGCIs) are new breed of power converter used in large scale PV applications and have superior advantages such as lower switching power dissipation, lower harmonic distortion and lower electromagnetic interference (EMI) outputs. ML MFGCIs perform the high quality power from PV systems and provide flexible functionality with improved power quality (PQ) voltage and reactive power support and increased capability of the auxiliary service for the utility grid. This paper presents a detailed analysis of various ML MFGCI configurations for 1 phase and 3 phase systems and control strategies to compensate the different PQ problems. Almost 100 papers including the practical applications and recent research studies on ML MFGCIs are reviewed and analysed.", "author_names": [ "Mohammad Barghi Latran", "Ahmet Teke" ], "corpus_id": 109996362, "doc_id": "109996362", "n_citations": 108, "n_key_citations": 1, "score": 0, "title": "Investigation of multilevel multifunctional grid connected inverter topologies and control strategies used in photovoltaic systems", "venue": "", "year": 2015 } ]

[ { "abstract": "Recent discussions concerning the continuation of Moore's law have focused on announcements by several major corporations to transition from traditional 2D planar to new 3D multi gate field effect transistor devices. However, the growth and progression of the semiconductor microelectronics industry over the previous 4 decades has been largely driven by combined advances in new materials, lithography, and materials related process technologies. Looking forward, it is therefore anticipated that new materials and materials technologies will continue to play a significant role in both the pursuit of Moore's law and the evolution of the industry. In this research update, we discuss and illustrate some of the required and anticipated materials innovations that could potentially lead to the continuation of Moore's law for another decade (or more) We focus primarily on the innovations needed to achieve single digit nanometer technologies and illustrate how at these dimensions not only new materials but new metro.", "author_names": [ "Sean W King", "Harsono S Simka", "Dan Herr", "Hiroyuki Akinaga", "Mike Garner" ], "corpus_id": 97172669, "doc_id": "97172669", "n_citations": 63, "n_key_citations": 2, "score": 0, "title": "Research Updates: The three M's (materials, metrology, and modeling) together pave the path to future nanoelectronic technologies", "venue": "", "year": 2013 }, { "abstract": "Author(s) Chen, Zijun Advisor(s) Martinis, John M Abstract: Quantum computers have the potential to solve problems which are classically intractable. Superconducting qubits present a promising path to building such a computer. Recent experiments with these qubits have demonstrated the principles of quantum error correction, quantum simulation, quantum annealing, and more. Current research with superconducting qubits is focused on two primary goals: creating a fully fault tolerant logical qubit out of many physical qubits using surface code error correction, and demonstrating an exponential speedup over any classical computer for a well defined computational problem. To achieve either of these goals requires high precision control of three components: single qubit gates, two qubit gates, and qubit measurement. In this thesis, we use randomized benchmarking to characterize single qubit gates with 99.95\\ fidelity and two qubit gates wiht 99.5\\ fidelity in superconducting transmon qubits. In addition, we use standard decoherence measurements as well as newly developed extensions of randomized benchmarking to determine the limiting sources of error. Finally, we explore the surprisingly complicated dynamics of measuring the transmon state through a coupled resonator, and show that fully understanding this process requires breaking a few \"standard\" assumptions.", "author_names": [ "Zijun Chen" ], "corpus_id": 196194358, "doc_id": "196194358", "n_citations": 18, "n_key_citations": 3, "score": 0, "title": "Metrology of Quantum Control and Measurement in Superconducting Qubits", "venue": "", "year": 2018 }, { "abstract": "Food integrity is a general term for sound, nutritive, healthy, tasty, safe, authentic, traceable, as well as ethically, safely, environment friendly, and sustainably produced foods. In order to verify these properties, analytical methods with a higher degree of accuracy, sensitivity, standardization and harmonization and a harmonized system for their application in analytical laboratories are required. In this view, metrology offers the opportunity to achieve these goals. In this perspective article the current global challenges in food analysis and the principles of metrology to fill these gaps are presented. Therefore, the pan European project METROFOOD RI within the framework of the European Strategy Forum on Research Infrastructures (ESFRI) was developed to establish a strategy to allow reliable and comparable analytical measurements in foods along the whole process line starting from primary producers until consumers and to make all data findable, accessible, interoperable, and re usable according to the FAIR data principles. The initiative currently consists of 48 partners from 18 European Countries and concluded its \"Early Phase\" as research infrastructure by organizing its future structure and presenting a proof of concept by preparing, distributing and comprehensively analyzing three candidate Reference Materials (rice grain, rice flour, and oyster tissue) and establishing a system how to compile, process, and store the generated data and how to exchange, compare them and make them accessible in data bases.", "author_names": [ "Michael Rychlik", "Giovanna Zappa", "Larraitz Anorga", "Nastasia Belc", "Isabel Castanheira", "Olivier F X Donard", "Lenka Kourimska", "Nives Ogrinc", "Marga C Ocke", "Karl Presser", "Claudia Zoani" ], "corpus_id": 29165101, "doc_id": "29165101", "n_citations": 14, "n_key_citations": 1, "score": 0, "title": "Ensuring Food Integrity by Metrology and FAIR Data Principles", "venue": "Front. Chem.", "year": 2018 }, { "abstract": "A key requirement of traceability is that measurement results can be linked to references, e.g. measurement units, through a documented unbroken chain. To an ever increasing degree, such chains nowadays involve computation, and it is important that computational links are known to be operating correctly. Analogous to physical artefacts are reference data sets (sometimes referred to as \"numerical artefacts\" that may be used to test that software components in a measurement chain are operating correctly. The European Metrology Research Programme (EMRP) is currently funding the Joint Research Project (JRP) NEW06 \"Traceability for computationally intensive metrology\" (referred to as \"TraCIM\" The main objective of the JRP, which runs from June 2012 to May 2015, is to develop new technology that will deliver traceability of computationally intensive metrology, transparently and efficiently, at point of use. This paper provides a broad overview of the JRP, providing a general description of each of the main tasks listed above, and acts as an introduction to other papers that describe in more detail various aspects of the technical work being undertaken within the JRP.", "author_names": [ "Alistair Forbes", "I M Smith", "F Hartig", "Klaus Dr Wendt" ], "corpus_id": 113519966, "doc_id": "113519966", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Overview of EMRP Joint Research Project NEW06 \"Traceability for Computationally Intensive Metrology\"", "venue": "", "year": 2015 }, { "abstract": "Scientific metrology is one evergreen and Omni present field that has been continuously experiencing a great deal of research in developing new measurement benchmarks to cope up with the real time advancement in the current market. This has been greatly aided in recent times with the advent of intelligent computing networks and communication protocols through which there has been a great deal of migration towards cloud based services on a demand basis. The essential feature of cloud is the provision of quality service to the clients. The proposed research paper has taken the metrology of monitoring the flow rate in an industrial piping system towards a boiler as the case study and real time implementation achieved with the help of Labview and MyDAQ environment. The data from this DAQ is interpreted into the cloud network with subset reduction and regrouping based on features using a fuzzy c means clustering approach. The experimentation has been done for varying values of tuning constants in order to maintain constant flow and compared with existing research contributions. The results clearly indicate a fast computation time with low complexity overhead which is achieved with the help of cloud distribution.", "author_names": [ "Yumin Wang", "Jiangbo Li", "Harry Haoxiang Wang" ], "corpus_id": 27015172, "doc_id": "27015172", "n_citations": 65, "n_key_citations": 1, "score": 0, "title": "Cluster and cloud computing framework for scientific metrology in flow control", "venue": "Cluster Computing", "year": 2017 }, { "abstract": "Thermal imaging cameras are expensive, particularly those designed for measuring high temperature objects with low measurement uncertainty. A wide range of research and industrial applications would benefit from lower cost temperature imaging sensors with improved metrology. To address this problem, we present the first ever quantification methodology for the temperature measurement performance of an ultra low cost thermal imaging system based on a smartphone sensor. The camera was formed from a back illuminated silicon Complementary Metal Oxide Semiconductor (CMOS) sensor, developed for the smartphone camera market. It was packaged for use with a Raspberry Pi computer. We designed and fitted a custom made triplet lens assembly. The system performance was characterised with a range of state of the art techniques and metrics: establishing a temperature resolution of below 10 degC in the range 600 1000 degC. Furthermore, the scene dependent aspects of combined uncertainty were considered. The minimum angular subtense for which an accurate thermal measurement could be made was determined to be 1.35deg, which corresponds to a 23 mm bar at a distance of 1 m, or 45:1 field of view in radiation thermometer nomenclature.", "author_names": [ "Leigh Russell Stanger", "Thomas Charles Wilkes", "Nicholas Andrew Boone", "Andrew John Samuel McGonigle", "Jon Raffe Willmott" ], "corpus_id": 51612574, "doc_id": "51612574", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Thermal Imaging Metrology with a Smartphone Sensor", "venue": "Sensors", "year": 2018 }, { "abstract": "Since the large scale use of paralleled controllable fiber positioner in LAMOST, the newly designed spectral survey telescope project generally uses the fiber position unit which similar to LAMOST to obtain the target spectrum. The positioning accuracy of the fiber positioner is directly related to the performance of the telescope. In order to further improve the positioning accuracy of positioners system, it is an important way to improve the accuracy by measuring the position of the optical fiber end on the positioners by using the visual metrology system. This paper mainly introduces the research design of LAMOST closed loop metrology system, and the closed loop system was established in different positions within the telescope to acquire best results. The metrology system will improve the fiber positioner system operation accuracy and reliability after the completion of the entire system in the future.", "author_names": [ "Kang Zhao", "Zhigang Liu", "Hongzhuan Hu", "Jianping Wang", "Chao Zhai", "Zengxiang Zhou" ], "corpus_id": 115371170, "doc_id": "115371170", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "The fiber view metrology system design for spectral survey telescope", "venue": "Astronomical Telescopes Instrumentation", "year": 2018 }, { "abstract": "Although investigators in the imaging community have been active in developing and evaluating quantitative imaging biomarkers (QIBs) the development and implementation of QIBs have been hampered by the inconsistent or incorrect use of terminology or methods for technical performance and statistical concepts. Technical performance is an assessment of how a test performs in reference objects or subjects under controlled conditions. In this article, some of the relevant statistical concepts are reviewed, methods that can be used for evaluating and comparing QIBs are described, and some of the technical performance issues related to imaging biomarkers are discussed. More consistent and correct use of terminology and study design principles will improve clinical research, advance regulatory science, and foster better care for patients who undergo imaging studies.", "author_names": [ "Daniel C Sullivan", "Nancy A Obuchowski", "Larry G Kessler", "David L Raunig", "Constantine Gatsonis", "Erich P Huang", "Marina V Kondratovich", "Lisa M McShane", "Anthony P Reeves", "Daniel P Barboriak", "Alexander Ramos Guimaraes", "Richard L Wahl" ], "corpus_id": 32973169, "doc_id": "32973169", "n_citations": 228, "n_key_citations": 8, "score": 0, "title": "Metrology Standards for Quantitative Imaging Biomarkers.", "venue": "Radiology", "year": 2015 }, { "abstract": "The field of Large Scale Metrology has been studied extensively for many decades and represents the combination and competition of topics as diverse as geodesy and laboratory calibration. A primary reason that Large Scale Metrology continues to represent the research frontier is that technological advances introduced and perfected at a conventional scale face additional challenges which increase non linearly with size. This necessitates new ways of considering the entire measuring process, resulting in the application of concepts such as virtual measuring processes and cyber physical systems. This paper reports on the continuing evolution of Large Scale Metrology.", "author_names": [ "Robert H Schmitt", "Martin Peterek", "Edward P Morse", "Wolfgang Knapp", "Maurizio Galetto", "Frank Hartig", "Gert Goch", "Ben Richard Hughes", "Alistair Forbes", "William T Estler" ], "corpus_id": 113899871, "doc_id": "113899871", "n_citations": 113, "n_key_citations": 6, "score": 0, "title": "Advances in Large Scale Metrology Review and future trends", "venue": "", "year": 2016 }, { "abstract": "The European metrology programme for innovation and research (EMPIR) is the current main programme for European research on metrology. In 2016, within the EMPIR call, the project \"Metrology for inductive charging of electric vehicles\" (MICEV) was approved and it started in September 2017. Inductive charging is a wireless charging technology that will be widely used with electric vehicles (EVs) in the near future, offering many advantages over traditionally fuelled and current EVs. The project aims to advance inductive power transfer (IPT) for EV charging by developing metrology techniques for measuring power transfer efficiency and reliable demonstration of compliance with existing safety standards for human exposure. The main research topics are: measurement of the power transmitted on board, transmission efficiency, requirements for measurements in the dynamic charging, assessment of magnetic field exposure.", "author_names": [ "Mauro Zucca", "Benjamin Loader", "M Schmidt", "Jan Welinder", "Kari Tammi", "J Bruna Romero", "Lionel Pichon", "Fabio Freschi", "Pavol Bauer", "Volker Blandow", "Antonio Maffucci", "Nicola Femia", "Niels Kuster" ], "corpus_id": 53043425, "doc_id": "53043425", "n_citations": 2, "n_key_citations": 1, "score": 1, "title": "The Project \"Metrology for Inductive Charging of Electric Vehicles\"", "venue": "2018 Conference on Precision Electromagnetic Measurements (CPEM 2018)", "year": 2018 } ]

[ { "abstract": "The photovoltaics of organic inorganic lead halide perovskite materials have shown rapid improvements in solar cell performance, surpassing the top efficiency of semiconductor compounds such as CdTe and CIGS (copper indium gallium selenide) used in solar cells in just about a decade. Perovskite preparation via simple and inexpensive solution processes demonstrates the immense potential of this thin film solar cell technology to become a low cost alternative to the presently commercially available photovoltaic technologies. Significant developments in almost all aspects of perovskite solar cells and discoveries of some fascinating properties of such hybrid perovskites have been made recently. This Review describes the fundamentals, recent research progress, present status, and our views on future prospects of perovskite based photovoltaics, with discussions focused on strategies to improve both intrinsic and extrinsic (environmental) stabilities of high efficiency devices. Strategies and challenges regarding compositional engineering of the hybrid perovskite structure are discussed, including potentials for developing all inorganic and lead free perovskite materials. Looking at the latest cutting edge research, the prospects for perovskite based photovoltaic and optoelectronic devices, including non photovoltaic applications such as X ray detectors and image sensing devices in industrialization, are described. In addition to the aforementioned major topics, we also review, as a background, our encounter with perovskite materials for the first solar cell application, which should inspire young researchers in chemistry and physics to identify and work on challenging interdisciplinary research problems through exchanges between academia and industry.", "author_names": [ "Ajay Kumar Jena", "Ashish Kulkarni", "Tsutomu Miyasaka" ], "corpus_id": 73480878, "doc_id": "73480878", "n_citations": 727, "n_key_citations": 0, "score": 1, "title": "Halide Perovskite Photovoltaics: Background, Status, and Future Prospects.", "venue": "Chemical reviews", "year": 2019 }, { "abstract": "Despite significant development recently, improving the power conversion efficiency of organic photovoltaics (OPVs) is still an ongoing challenge to overcome. One of the prerequisites to achieving this goal is to enable efficient charge separation and small voltage losses at the same time. In this work, a facile synthetic strategy is reported, where optoelectronic properties are delicately tuned by the introduction of electron deficient core based fused structure into non fullerene acceptors. Both devices exhibited a low voltage loss of 0.57 V and high short circuit current density of 22.0 mA cm 2, resulting in high power conversion efficiencies of over 13.4% These unconventional electron deficient core based non fullerene acceptors with near infrared absorption lead to low non radiative recombination losses in the resulting organic photovoltaics, contributing to a certified high power conversion efficiency of 12.6%.Improving the power conversion efficiency is the main target of the organic solar cell research. Here Yuan et al. develop unconventional electron deficient core based non fullerene acceptors to achieve both low voltage loss and high current density, leading to a certified high efficiency of 12.6%", "author_names": [ "Jun Yuan", "Tianyi Huang", "Pei Cheng", "Yingping Zou", "Huotian Zhang", "Jonathan Lee Yang", "Sheng-Yung Chang", "Zhenzhen Zhang", "Wenchao Huang", "Rui Wang", "Dong Meng", "Feng Gao", "Yang Yang" ], "corpus_id": 59603407, "doc_id": "59603407", "n_citations": 181, "n_key_citations": 0, "score": 0, "title": "Enabling low voltage losses and high photocurrent in fullerene free organic photovoltaics", "venue": "Nature Communications", "year": 2019 }, { "abstract": "Over the past three years, a particularly exciting and active area of research within the field of organic photovoltaics has been the use of non fullerene acceptors (NFAs) Compared with fullerene acceptors, NFAs possess significant advantages including tunability of bandgaps, energy levels, planarity and crystallinity. To date, NFA solar cells have not only achieved impressive power conversion efficiencies of ~13 14% but have also shown excellent stability compared with traditional fullerene acceptor solar cells. This Review highlights recent progress on single junction and tandem NFA solar cells and research directions to achieve even higher efficiencies of 15 20% using NFA based organic photovoltaics are also proposed.This Review describes how non fullerene electron acceptor materials are bringing improvements in the power conversion efficiency and stability of organic solar cells.", "author_names": [ "Pei Cheng", "Gang Li", "Xiaowei Zhan", "Yang Yang" ], "corpus_id": 44135243, "doc_id": "44135243", "n_citations": 878, "n_key_citations": 0, "score": 0, "title": "Next generation organic photovoltaics based on non fullerene acceptors", "venue": "", "year": 2018 }, { "abstract": "2D materials have attracted considerable attention due to their exciting optical and electronic properties, and demonstrate immense potential for next generation solar cells and other optoelectronic devices. With the scaling trends in photovoltaics moving toward thinner active materials, the atomically thin bodies and high flexibility of 2D materials make them the obvious choice for integration with future generation photovoltaic technology. Not only can graphene, with its high transparency and conductivity, be used as the electrodes in solar cells, but also its ambipolar electrical transport enables it to serve as both the anode and the cathode. 2D materials beyond graphene, such as transition metal dichalcogenides, are direct bandgap semiconductors at the monolayer level, and they can be used as the active layer in ultrathin flexible solar cells. However, since no 2D material has been featured in the roadmap of standard photovoltaic technologies, a proper synergy is still lacking between the recently growing 2D community and the conventional solar community. A comprehensive review on the current state of the art of 2D materials based solar photovoltaics is presented here so that the recent advances of 2D materials for solar cells can be employed for formulating the future roadmap of various photovoltaic technologies.", "author_names": [ "Sonali Das", "Deepak Pandey", "Jayan Thomas", "Tania Roy" ], "corpus_id": 52166082, "doc_id": "52166082", "n_citations": 132, "n_key_citations": 0, "score": 0, "title": "The Role of Graphene and Other 2D Materials in Solar Photovoltaics.", "venue": "Advanced materials", "year": 2019 }, { "abstract": "The power of a pair of perovskites In the past several years, perovskite solar cells have emerged as a low cost experimental alternative to more traditional silicon devices. Luo et al. now show that a pair of perovskite cells connected in series can power the electrochemical breakdown of water into hydrogen and oxygen efficiently (see the Perspective by Hamann) Hydrogen generation from water is being actively studied as a supplement in solar power generation to smooth out the fluctuations due to variations in sunlight. Science, this issue p. 1593; see also p. 1566 A pair of perovskite solar cells can power efficient hydrogen generation from water. [Also see Perspective by Hamann] Although sunlight driven water splitting is a promising route to sustainable hydrogen fuel production, widespread implementation is hampered by the expense of the necessary photovoltaic and photoelectrochemical apparatus. Here, we describe a highly efficient and low cost water splitting cell combining a state of the art solution processed perovskite tandem solar cell and a bifunctional Earth abundant catalyst. The catalyst electrode, a NiFe layered double hydroxide, exhibits high activity toward both the oxygen and hydrogen evolution reactions in alkaline electrolyte. The combination of the two yields a water splitting photocurrent density of around 10 milliamperes per square centimeter, corresponding to a solar to hydrogen efficiency of 12.3% Currently, the perovskite instability limits the cell lifetime.", "author_names": [ "Jingshan Luo", "Jeong Hyeok Im", "Matthew T Mayer", "Marcel Schreier", "Mohammad Khaja Nazeeruddin", "Nam-Gyu Park", "S David Tilley", "Hong Jin Fan", "Michael Gratzel" ], "corpus_id": 24613846, "doc_id": "24613846", "n_citations": 1714, "n_key_citations": 4, "score": 0, "title": "Water photolysis at 12.3% efficiency via perovskite photovoltaics and Earth abundant catalysts", "venue": "Science", "year": 2014 }, { "abstract": "Impedance spectroscopy has been widely applied over the last decades to study electrochemical systems and solid state devices. However, performing impedance spectroscopy on emerging photovoltaics presents new challenges related to the unusual material properties and complex device architectures. This review provides an introduction to impedance spectroscopy for researchers in photovoltaics and closely related fields. The review begins with a list of practical guidelines for performing measurements and analyzing data. After this, the mathematical basics are reviewed, and an introduction to circuit elements is given. This is followed by tips for collecting reliable data and reducing artifacts in the frequency spectra. The review then surveys common approaches in the field for analyzing data, including performing equivalent circuit modeling, analysis of capacitance frequency spectra, and carrier mobility measurements. The underlying assumptions of each analysis approach, as well as the advantages, limitation.", "author_names": [ "Elizabeth von Hauff" ], "corpus_id": 131989029, "doc_id": "131989029", "n_citations": 91, "n_key_citations": 0, "score": 0, "title": "Impedance Spectroscopy for Emerging Photovoltaics", "venue": "The Journal of Physical Chemistry C", "year": 2019 }, { "abstract": "", "author_names": [ "Karin Schneider" ], "corpus_id": 4378616, "doc_id": "4378616", "n_citations": 306, "n_key_citations": 34, "score": 0, "title": "Recent Facts about Photovoltaics in Germany", "venue": "", "year": 2017 }, { "abstract": "Hybrid perovskites are currently one of the most active fields of research owing to their enormous potential for photovoltaics. The performance of 3D hybrid organic inorganic perovskite solar cells has increased at an incredible rate, reaching power conversion efficiencies comparable to those of many established technologies. However, the commercial application of 3D hybrid perovskites is inhibited by their poor stability. Relative to 3D hybrid perovskites, low dimensional that is, 2D hybrid perovskites have demonstrated higher moisture stability, offering new approaches to stabilizing perovskite based photovoltaic devices. Furthermore, 2D hybrid perovskites have versatile structures, enabling the fine tuning of their optoelectronic properties through compositional engineering. In this Review, we discuss the state of the art in 2D perovskites, providing an overview of structural and materials engineering aspects and optical and photophysical properties. Moreover, we discuss recent developments along with the main limitations of 3D perovskites and assess the advantages of 2D perovskites over their 3D parent structures in terms of stability. Finally, we review recent achievements in combining 3D and 2D perovskites as an approach to simultaneously boost device efficiency and stability, paving the way for mixed dimensional perovskite solar cells for commercial applications.Combining low dimensional and 3D perovskites is a promising approach to achieve stable and efficient solar cells. In this Review, we discuss the structural, optical and photophysical properties of low dimensional perovskites, compare the stability and efficiency of 2D and 3D perovskite devices, and consider 2D/3D composites as a strategy to increase the stability of perovskite solar cells.", "author_names": [ "Giulia Grancini", "Mohammad Khaja Nazeeruddin" ], "corpus_id": 139270295, "doc_id": "139270295", "n_citations": 279, "n_key_citations": 1, "score": 0, "title": "Dimensional tailoring of hybrid perovskites for photovoltaics", "venue": "Nature Reviews Materials", "year": 2018 }, { "abstract": "The performance of organic photovoltaics is largely dependent on the balance of short circuit current density (JSC) and open circuit voltage (VOC) For instance, the reduction of the active materials' optical bandgap, which increases the JSC, would inevitably lead to a concomitant reduction in VOC. Here, we demonstrate that careful tuning of the chemical structure of photoactive materials can enhance both JSC and VOC simultaneously. Non fullerene organic photovoltaics based on a well matched materials combination exhibit a certified high power conversion efficiency of 12.25% on a device area of 1 cm2. By combining Fourier transform photocurrent spectroscopy and electroluminescence, we show the existence of a low but non negligible charge transfer state as the possible origin of VOC loss. This study highlights that the reduction of the bandgap to improve the efficiency requires a careful materials design to minimize non radiative VOC losses.Materials design rules play a key role in enabling high performance in organic photovoltaics. Here the authors achieve 12.25% efficiency on 1 cm2 non fullerene solar cells by tuning the side chains' branching point and the fluorine substitutions in donor and acceptor materials.", "author_names": [ "Baobing Fan", "Xiaoyang Du", "Feng Liu", "Wenkai Zhong", "Lei Ying", "Ruihao Xie", "Xiaofeng Tang", "Kang An", "Jingming Xin", "Ning Li", "Wei Ma", "Christoph J Brabec", "Fei Huang", "Yongli Cao" ], "corpus_id": 139378319, "doc_id": "139378319", "n_citations": 195, "n_key_citations": 0, "score": 0, "title": "Fine tuning of the chemical structure of photoactive materials for highly efficient organic photovoltaics", "venue": "", "year": 2018 }, { "abstract": "The development of organic semiconductors for photovoltaic devices, over the last three decades, has led to unexpected performance for an alternative choice of materials to convert sunlight to electricity. New materials and developed concepts have improved the photovoltage in organic photovoltaic devices, where records are now found above 13% power conversion efficiency in sunlight. The author has stayed with the topic of organic materials for energy conversion and energy storage during these three decades, and makes use of the Hall of Fame now built by Advanced Materials, to present his view of the path travelled over this time, including motivations, personalities, and ambitions.", "author_names": [ "Olle Inganas" ], "corpus_id": 205286589, "doc_id": "205286589", "n_citations": 257, "n_key_citations": 0, "score": 0, "title": "Organic Photovoltaics over Three Decades.", "venue": "Advanced materials", "year": 2018 } ]

[ { "abstract": "Preface PART I: Fundamentals Chapter 1: Introduction Chapter 2: Fundamentals and Phase Changes Chapter 3: Metallic Solution Growth Techniques Chapter 4: Crystal Growth Modeling PART II: Numerical Simulations Chapter 5: Liquid Phase Epitaxy Chapter 6: Liquid Phase Electroepitaxy Chapter 7: Travelling Heater Method Chapter 8: Liquid Phase Diffusion Bibliography", "author_names": [ "Sadik Dost", "Brian Lent" ], "corpus_id": 92745083, "doc_id": "92745083", "n_citations": 44, "n_key_citations": 1, "score": 2, "title": "Single Crystal Growth of Semiconductors from Metallic Solutions", "venue": "", "year": 2006 }, { "abstract": "In order to study the metallic ferromagnetism induced by electron doping in the narrow gab semiconductor FeSb$_2$ single crystals of FeSb$_2$ Fe$_{1 x}$Co$_x$Sb$_2$ $0 \\le x \\le 0.5$ and FeSb$_{2 y}$Te$_y$ $0 \\le y \\le 0.4$ were grown by a simplified self flux method. From powder x ray diffraction (XRD) patterns, wavelength dispersive x ray spectroscopy (WDX) and x ray Laue diffraction, pure and doped high quality single crystals, within the selected solubility range, show only the orthorhombic $Pnnm$ structure of FeSb$_2$ with a monotonic change in lattice parameters with increasing the doping level. In consistence with the model of nearly ferromagnetic small gap semiconductor, the energy gap of FeSb$_2$ Pauli paramagnet gradually collapses by electron doping before it closes at about $x$ or $y$ 0.15 and subsequent itinerant electron anisotropic ferromagnetic states are observed with higher doping levels. A magnetic phase diagram is established and discussed in view of proposed theoretical scenarios.", "author_names": [ "Mohamed A Kassem", "Yoshikazu Tabata", "Takeshi Waki", "Hiroyuki Nakamura" ], "corpus_id": 227119105, "doc_id": "227119105", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Crystal growth and metallic ferromagnetism induced by electron doping in FeSb$_2$", "venue": "", "year": 2020 }, { "abstract": "Single crystal growth that invented by Jan Czochralski, was essentially used in AEG laboratory in 1916. Further development was about obtaining bulk crystals according to matching of the crystallization velocity and pulling rate. Gomperz improved the Czochralski process by changing die, crucible, and cooling system in 1922. One year later, Goens and Gruneisen applied different method to obtain crystal having certain orientation. Henry Walter from Bells Laboratory designed a new furnace and succeeded about crystal rotation, producing non metallic and enhancing dimensions. After the WWII with invention of contact transistors, importance of the Czochralski method significantly increased. Using microprocessors provided automatic control of crystal growing process. In the end of 1960s, the process of single crystal technique became similar to today's process. Research and development activities on single crystal processes have been continued due to necessity of improving semiconductor technology. In this study, manufacturing of single crystal, Czochralski method, its parameters, and historical developments have been discussed in detail.", "author_names": [ "Ayberk Yenice" ], "corpus_id": 198958423, "doc_id": "198958423", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Historical Development of Czochralski Process and Single Crystal Growth", "venue": "", "year": 2019 }, { "abstract": "The photochemical growth of metallic particles on relaxor ferroelectric tetragonal tungsten bronze strontium barium niobate (SBN) is reported in this work. Silver and gold particles were deposited on the unpoled (001) and the (100) surfaces of single crystal SBN:60 and SBN:61 via reduction of silver nitrate and gold chloride solutions, respectively, under UV illumination. Wavelength dependent experiments reveal that differences in particle deposition on the unpoled (001) and (100) surfaces are primarily due to the optical absorption of the UV light and not due to the surface termination or local ferroelectric domain structure. Particle deposition on electric field poled (001) surfaces is enhanced on positive domains and is suppressed on negative domains. Unusual particle deposition was observed on the perimeter of domains obtained from incomplete switching of the unpoled (001) surface. On the basis of our experimental observations, we propose a band diagram for the SBN interface and we discuss the underly.", "author_names": [ "Eftihia Barnes", "Erik M Alberts", "L Christopher Mimun", "Jonathon Brame", "Christopher M Warner", "Ashley R Harmon", "Aimee R Poda" ], "corpus_id": 102982454, "doc_id": "102982454", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Photoinduced Metallic Particle Growth on Single Crystal Relaxor Ferroelectric Strontium Barium Niobate", "venue": "", "year": 2018 }, { "abstract": "NH4I has been proven to be a promising cosolvent for cuprous iodide (CuI) single crystal growth from aqueous solutions by the temperature reduction method. In our work, as compared with NH4Cl and NH4Br, NH4I offers more advantages for single crystal growth, such as by remarkably increasing the solubility and growth rate of CuI crystals, effectively reducing the impurity concentration, and enhancing the crystal quality and crystallinity. A regular, centimeter sized, high optical quality single crystal was successfully obtained using NH4I as a cosolvent. The electronic and optical properties of the as grown crystal were characterized by Hall effect measurements and optical transmission and photoluminescence spectra, respectively. The results demonstrated that the CuI crystal is conductive (high p type mobility of 12.81 cm2 V 1 s 1) and transparent (great transmittance over 80%", "author_names": [ "Lv Yangyang", "Zhihuang Xu", "Liwang Ye", "Zhaojun Zhang", "Genbo Su", "Xinxin Zhuang" ], "corpus_id": 96165016, "doc_id": "96165016", "n_citations": 14, "n_key_citations": 0, "score": 0, "title": "Large g CuI semiconductor single crystal growth by a temperature reduction method from an NH4I aqueous solution", "venue": "", "year": 2015 }, { "abstract": "Single crystals of Bis (glycine) Strontium Chloride (BGSC) were grown by means of slow evaporation process by using analar grade Glycine and Strontium Chloride Hexahydrate as a parent compound from its aqueous solution at room temperature. The final chemical composition, formed were metallic light colorless block, about the size of 28 mm x 9 mm x 8 mm. A single crystal x ray diffraction study revealed an ordered superstructure with orthorhombic symmetry that could be assigned to the space group Pbcn. The structure in BGSC, revealed in the electron density distribution was analyzed by the direct methods (SHELXS 2014) and refined by least squares full matrix method (SHELXL 2014) The crystal structure, including anisotropic atomic displacement parameters for each atom and isotropic atomic displacement parameters for hydrogen atom, was refined to R1 0.0395, wR2 0.0776 using 1097 independent reflections. The FTIR spectrum of BGSC confirms the protonation of amino groups and the different molecular groups present in BGSC vibrate in different modes. Reverse Indentation Size Effect (RISE) was revealed in BGSC in the micro hardness analysis using Vicker's micro hardness analysis. DTA and DSC results ruled out the possibility of structural change independent of mass change. The AFM studies shows fine nano size fiber like structure of the grown crystals.", "author_names": [ "S R Balaji", "T Balu", "Thanjavur Renganathan Rajasekaran" ], "corpus_id": 104259986, "doc_id": "104259986", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Single crystal growth, structure refinement and the properties of Bis(glycine) Strontium Chloride", "venue": "", "year": 2018 }, { "abstract": "Abstract A single crystal of the non centrosymmetric low temperature modification of Tl2CdSnSe4 (space group I 4 2m) was grown, for the first time, and its electronic and optical properties were studied from both experimental and theoretical viewpoints. The Tl2CdSnSe4 crystal was grown from the solution melt by vertical Bridgman Stockbarger method. Centimeter dimensions of the crystal allow its application in practice. The bandgap energy, Eg 1.32 eV, estimated from the optical absorption coefficient agrees well with the value of Eg 1.29 eV calculated from the photosensitivity measurements. X ray photoelectron spectroscopy (XPS) was used to investigate the electronic structure and charge states of atoms composing the crystal under consideration. To detect the best agreement of the curve of total densities of states (DOS) with the experimental XPS spectrum of valence electrons of Tl2CdSnSe4, we performed theoretical calculations within a density functional theory (DFT) framework treating different models for exchange correlation (XC) potential. Our findings yield that the best agreement of the experimental and theoretical distributions of the valence electronic states is derived when using in the computation procedure for XC potential the modified Becke Johnson potential in the form of Tran Blaha (TB mBJ) which involves also the Hubbard parameter U for strongly correlated d electrons and spin orbit coupling (SOC) effect (TB mBJ U SOC model) Based on this approach, we calculated partial densities of states, energy band dispersion, and main optical constants of Tl2CdSnSe4. Importantly, the TB mBJ U SOC model reveals the Eg value which is close to those determined experimentally; therefore, scissors correction adjustment is not required when performing DFT calculations of the optical constants in such a case. The present experimental XPS measurements of the treated with middle energy Ar+ ions Tl2CdSnSe4 crystal surface and the theoretical DFT calculations data indicate, in spite of its rather hazardous chemical elements, thallium and cadmium, the crystal surface is rather stable and, coupled with suitable energy band gap, makes quaternary selenide under discussion a very promising material for using in thin film solar cells and optoelectronics as well as in highly efficient photocatalytic devices.", "author_names": [ "Tuan V Vu", "A A Lavrentyev", "B V Gabrelian", "Andrii Selezen", "L V Piskach", "G L Myronchuk", "M Denysyuk", "V A Tkach", "Khang D Pham", "Oleg Yu Khyzhun" ], "corpus_id": 229446554, "doc_id": "229446554", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Crystal growth, electronic and optical properties of Tl2CdSnSe4, a recently discovered prospective semiconductor for application in thin film solar cells and optoelectronics", "venue": "", "year": 2021 }, { "abstract": "Halide perovskites are promising semiconductor materials for optoelectronics. One of their unique features is the synthesis, that could be performed by the crystallization from the solution. This method is fast, but practically couldn't be optimized due to the strongly non equilibrium conditions of crystal growth. Another quality limitation is the typical incorporation of organic solvent molecules into crystals when perovskite crystallization is performed from solution with organic solvent. Here we report an alternative method of perovskite single crystal growth based on the counterdiffusion of reagents in the gel medium. This counterdiffusion in gel crystallization (CGC) method is based on the difference of solubility between perovskites and lead halide in the corresponding halide acid, HX. The difference of solubility between perovskites and lead halide leads to the formation of perovskite single crystals of sufficiently large size with an excellent optical quality at constant room temperature. Particularly, here we report the growth of MAPbI3 and MAPbBr3 halide perovskite single crystals (MA CH3NH3 by the counterdiffusion of the organicsolvent free reagents in the U tube filled with the silica gel. Their photoluminescence spectra recorded at 4 K demonstrate the excitonic resonances with the full width 2.5 meV, which proves their excellent optical quality. The proposed method can be used in fabrication of high quality halide perovskite single crystals for both fundamental research, and for applications where the absence of defects is a critical requirement.", "author_names": [ "Nikita I Selivanov", "Aleksei O Murzin", "Vsevolod I Yudin", "Yury V Kapitonov", "Alexei V Emeline" ], "corpus_id": 233169047, "doc_id": "233169047", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Counterdiffusion in gel growth of high optical and crystal quality MAPbX3 (MA CH3NH3+ X I Br lead halide perovskite single crystals", "venue": "", "year": 2021 }, { "abstract": "Growth of semiconductor single crystals under electric and magnetic fields is of interest to increase and better control of crystal growth rate, to suppress and control the adverse effect of natural convection and to obtain better mixing in the growth melt (liquid solution) for better crystal uniformity, which all are favorable conditions for a prolonged growth of high quality crystals. To this end, in parallel to well designed experiments, modeling is essential to shed light on various aspects of these growth processes and also to better understand the transport phenomena involved. In this article the models developed over the years, mostly based on Professor Gerard Maugin's well known contributions to \"electromagnetic interactions\" are briefly presented for \"solution growth\" conducted under electric and magnetic fields. Basic and constitutive equations of a binary electromagnetic continuum mixture are specialized for two important solution growth techniques Liquid Phase Electroepitaxy (LPEE) and Travelling Heater Method (THM) As an application, an LPEE growth of GaAs bulk crystals under a strong static magnetic field is considered. Experimental results, that have shown that the growth rate under an applied static magnetic field is also proportional to the applied magnetic field and increases with the field intensity level, are predicted from these models. The contribution of a third order material constant in LPEE is also predicted from these models. The prediction of increasing growth rate in THM growth under rotating magnetic fields from modeling was verified by experiments.", "author_names": [ "Sadik Dost" ], "corpus_id": 125984668, "doc_id": "125984668", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Modeling Semiconductor Crystal Growth Under Electromagnetic Fields", "venue": "", "year": 2018 }, { "abstract": "Organic single crystals are an established part of the emerging field of organic optoelectronics, because they provide an ideal platform for the studies of the intrinsic physical properties of organic semiconductors. As organic crystals have low melting temperatures and high vapor pressures and are soluble in numerous organic solvents, both solution and gas phase methods can be used for crystal growth. The nature of the individual molecules and the interactions between molecules determine which growth method is preferred for particular materials. Organic semiconductors with very low decomposition or melting temperatures can be grown from solutions, whereas semiconductors with high vapor pressures can be grown using physical vapor transport methods. High quality crystals can be obtained using both methods. Crystal growth and crystal engineering of multicomponent organic compounds are emerging fields that can provide a variety of new materials with different physical properties. The growth of large crystals from the melt by zone melting, the Bridgman, or the Czochralski methods has been used to produce stable materials used in wafer manufacturing or large scintillator detectors. In this article, single crystal growth methods for organic semiconductors are discussed with the aim of preparing high quality specimens for determination of the basic properties of organic semiconductors.", "author_names": [ "Hui Jiang", "Christian Kloc" ], "corpus_id": 135648774, "doc_id": "135648774", "n_citations": 82, "n_key_citations": 5, "score": 0, "title": "Single crystal growth of organic semiconductors", "venue": "", "year": 2013 } ]

[ { "abstract": "Abstract The complexity involved in demand forecast for supply chain management of electronics components is exponentially increasing owing to demand fluctuations in consumer electronics, shortening of product life cycles, continuous technology migration, lengthy production cycle time, and long lead time for capacity expansion. While global manufacturing networks often suffer the risks of oversupply and shortage of key components, the distributor that is the key intermediate participator in electronics product supply chain buys components from the suppliers, warehouses them, and resells different parts to a number of electronics manufacturers with vendor managed inventories. Thus, the component distributors forecast the demands for large assortments of stock keeping units (SKUs) with distinct dynamics for inventory control and supply chain management. To address realistic needs to enhance demand forecast performance, this study aims to develop a UNISON data driven analytics framework that integrates machine learning technologies and temporal aggregation mechanism to forecast the demands of intermittent electronics components. An empirical study is conducted in a world leading semiconductor distributor for validation. The results have shown practical vitality of the proposed approach with better performance than conventional approaches and the existing practice. Indeed, the developed solution has been employed in this company to support flexible decisions to empower agile logistics and supply chain resilience for smart production.", "author_names": [ "Wenhan Fu", "Chen-Fu Chien" ], "corpus_id": 198485826, "doc_id": "198485826", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "UNISON data driven intermittent demand forecast framework to empower supply chain resilience and an empirical study in electronics distribution", "venue": "Comput. Ind. Eng.", "year": 2019 }, { "abstract": "Abstract Policymakers during 1 1 We conducted this research in April June 2020 during the COVID 19 pandemic. The aim is to provide tools for immediate use during the pandemic: desperate times call for desperate academic measures, and as such this is our direct response to inform practice. We employ a phenomenon based research methodological approach, engaging in an early phase of a scientific inquiry, observing, researching, and providing solutions for a developing and novel phenomenon. COVID 19 operate in uncharted 2 2 Opinions expressed are solely my own and do not express the views or opinions of my previous or current employers. territory and must make tough decisions. Operational Research the ubiquitous 'science of better' plays a vital role in supporting this decision making process. To that end, using data from the USA, India, UK, Germany, and Singapore up to mid April 2020, we provide predictive analytics tools for forecasting and planning during a pandemic. We forecast COVID 19 growth rates with statistical, epidemiological, machine and deep learning models, and a new hybrid forecasting method based on nearest neighbors and clustering. We further model and forecast the excess demand for products and services during the pandemic using auxiliary data (google trends) and simulating governmental decisions (lockdown) Our empirical results can immediately help policymakers and planners make better decisions during the ongoing and future pandemics.", "author_names": [ "Konstantinos Nikolopoulos", "Sushil Punia", "Andreas Schafers", "Christos Dimitris Tsinopoulos", "Chrysovalantis Vasilakis" ], "corpus_id": 221035283, "doc_id": "221035283", "n_citations": 71, "n_key_citations": 4, "score": 1, "title": "Forecasting and planning during a pandemic: COVID 19 growth rates, supply chain disruptions, and governmental decisions", "venue": "European Journal of Operational Research", "year": 2020 }, { "abstract": "We address the reservation pricing problem for a two echelon fashion supply chain in which the downstream manufacturer with private information on its operations cost (low or high type) reserves the capacity for a critical component from the upstream supplier before placing the final order. We consider the case when the demand forecast is partially updated. We find that a novel menu of reservation contracts containing the unit reservation fee with reservation quantity and final order could induce the manufacturer to reveal its operations cost information truthfully. We also show that the supplier should require less capacity reservation and charge a lower unit reservation fee if it has asymmetric information about the manufacturer's operations cost. Finally, we analyse the effects of forecast update, and our results indicate that: (i) the supplier benefits from forecast update because the optimal reservation pricing strategy is designed to reveal the true information and meanwhile induce a higher capacity reservation; and (ii) a greater amount of forecast update decreases the supply chain deficit and increases the supplier's agency cost.", "author_names": [ "Danqin Yang", "Tiaojun Xiao", "Tsan-Ming Choi", "T C Edwin Cheng" ], "corpus_id": 109644907, "doc_id": "109644907", "n_citations": 75, "n_key_citations": 0, "score": 0, "title": "Optimal reservation pricing strategy for a fashion supply chain with forecast update and asymmetric cost information", "venue": "Int. J. Prod. Res.", "year": 2018 }, { "abstract": "We investigate RFID adoption strategies under wholesale price and buy back contracts in a supply chain with one manufacturer and one retailer who faces inventory misplacement and demand forecast error. RFID can alleviate the misplacement problem, and can reduce demand forecast error by shortening order lead time. By a newsvendor model, we characterise the optimal contract terms in the supply chain without and with RFID adoption, respectively. We further analyse how the contract terms depend on RFID related parameters (e.g. salable rate and demand forecast error) We find that both without and with RFID, the wholesale price contract will lead to the double marginalisation problem, while the buy back contract can coordinate the supply chain. We show that the supply chain adopts RFID if and only if the tagging cost is below a threshold; the threshold is in negative correlation to the demand forecast error. The supply chain is more willing to adopt RFID under the buy back contract than under the wholesale price contract. RFID adoption can sometimes lessen the double marginalisation problem under the wholesale price contract, improving the supply chain efficiency. A smaller RFID tagging cost or a reduced forecast error do not necessarily lead to higher supply chain efficiency.", "author_names": [ "Lihao Zhang", "Tian Li", "Tijun Fan" ], "corpus_id": 115155702, "doc_id": "115155702", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Inventory misplacement and demand forecast error in the supply chain: profitable RFID strategies under wholesale and buy back contracts", "venue": "Int. J. Prod. Res.", "year": 2018 }, { "abstract": "The demand for a particular product or service is typically associated with different uncertainties that can make them volatile and challenging to predict. Demand unpredictability is one of the managers' concerns in the supply chain that can cause large forecasting errors, issues in the upstream supply chain and impose unnecessary costs. We investigate 843 real demand time series with different values of coefficient of variations (CoV) where promotion causes volatility over the entire demand series. In such a case, forecasting demand for different CoV require different models to capture the underlying behavior of demand series and pose significant challenges due to very different and diverse demand behavior. We decompose demand into baseline and promotional demand and propose a hybrid model to forecast demand. Our results indicate that our proposed hybrid model generates robust and accurate forecast across series with different levels of volatilities. We stress the necessity of decomposition for volatile demand series. We also model demand series with a number of well known statistical and machine learning (ML) models to investigate their performance empirically. We found that ARIMA with covariate (ARIMAX) works well to forecast volatile demand series, but exponential smoothing with covariate (ETSX) has a poor performance. Support vector regression (SVR) and dynamic linear regression (DLR) models generate robust forecasts across different categories of demands with different CoV values.", "author_names": [ "Mahdi Abolghasemi", "Eric J Beh", "Garth Tarr", "Richard Gerlach" ], "corpus_id": 203593833, "doc_id": "203593833", "n_citations": 18, "n_key_citations": 0, "score": 1, "title": "Demand forecasting in supply chain: The impact of demand volatility in the presence of promotion", "venue": "Comput. Ind. Eng.", "year": 2020 }, { "abstract": "Purpose The purpose of this paper is to design a model that can accurately forecast the supply chain sales. Design/methodology/approach This paper proposed a new model based on lightGBM and LSTM to forecast the supply chain sales. In order to verify the accuracy and efficiency of this model, three representative supply chain sales data sets are selected for experiments. Findings The experimental results show that the combined model can forecast supply chain sales with high accuracy, efficiency and interpretability. Practical implications With the rapid development of big data and AI, using big data analysis and algorithm technology to accurately forecast the long term sales of goods will provide the database for the supply chain and key technical support for enterprises to establish supply chain solutions. This paper provides an effective method for supply chain sales forecasting, which can help enterprises to scientifically and reasonably forecast long term commodity sales. Originality/value The proposed model not only inherits the ability of LSTM model to automatically mine high level temporal features, but also has the advantages of lightGBM model, such as high efficiency, strong interpretability, which is suitable for industrial production environment.", "author_names": [ "Tingyu Weng", "Wenyang Liu", "Junjun Xiao" ], "corpus_id": 203997853, "doc_id": "203997853", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Supply chain sales forecasting based on lightGBM and LSTM combination model", "venue": "Ind. Manag. Data Syst.", "year": 2020 }, { "abstract": "Abstract Demand forecasts are the lifeblood of supply chains. Academic literature and common industry practices indicate that demand forecasts are often subject to human interventions. Judgmental forecasting or judgmental forecast adjustments can cause both positive and negative repercussions to the rest of the supply chain. This paper provides the first systematic literature review of judgmental forecasting and adjustments focusing on key features that impact various decisions in supply chains. A carefully assembled and shortlisted literature pool is analyzed for systematic mapping of the published works using bibliometric tools. The primary sub streams of research within the broader scope of the field are synthesized from a rigorous keyword cluster analysis and a thorough discussion is presented. Our review concludes by encapsulating the key learnings from four decades of academic research in judgmental forecasting and suggests future research avenues to expand our understanding of the role of humans in demand forecasting and supply chain decision making.", "author_names": [ "H Niles Perera", "Jason Hurley", "Behnam Fahimnia", "Mohsen Reisi" ], "corpus_id": 57380068, "doc_id": "57380068", "n_citations": 29, "n_key_citations": 1, "score": 0, "title": "The human factor in supply chain forecasting: A systematic review", "venue": "Eur. J. Oper. Res.", "year": 2019 }, { "abstract": "Abstract To comply with the stricter emission control regulations of recent years, shipping carriers, who may be risk averse, need to make decisions regarding their investments in environmental sustainability before market uncertainty is realized. The ports, as service providers of the carriers, may help the carriers on making such decisions through sharing market forecast information. In this study, we aim to examine the incentives of forecast information sharing from port and the effect of carrier's risk behavior on such sustainability investment decisions in a maritime supply chain. For this, we propose a two period game theoretic model framework. In this framework, both the port and the carrier face market uncertainty during the first period. The port determines whether to share its market forecast information with the carrier, and the carrier needs to decide her sustainability investment level. Then, in the second period, the port determines the service fee, and the carrier determines the freight rate to the customers. We analyze four different scenarios, based on the types of carrier's risk behavior and on whether the port decides to share the forecast information. We find that the relationship between sustainability investment level, and the port's service fee/the carrier's freight rate can be either positive or negative. We also show that the risk averse behavior reduces the carrier's profit, and lowers the level of sustainability investment, which in turn either positively or negatively influences the carrier's freight rate as before. Interestingly, the risk averse behavior always lowers the port's service fee. Moreover, we find that the forecast sharing from the port can not only improve the profits for both parties, but also facilitate the sustainability investment, even when the carrier is risk averse. We also find that the port always receives a larger percentage of the profit than the carrier.", "author_names": [ "Xiaofan Lai", "Yi Tao", "Fan Wang", "Zongbao Zou" ], "corpus_id": 159134491, "doc_id": "159134491", "n_citations": 26, "n_key_citations": 0, "score": 0, "title": "Sustainability investment in maritime supply chain with risk behavior and information sharing", "venue": "", "year": 2019 }, { "abstract": "Abstract This paper investigates after sale service deployment and information sharing strategies in a supply chain environment including the role of a manufacturer and an independent retailer. The manufacturer first needs to decide whether it is necessary to undertake the after sale service by herself or delegate it to the retailer. Then, the retailer possessing better demand forecast information decides whether to share their information with the manufacturer. When the manufacturer undertakes the after sale service, we find that the retailer prefers to share the information with the manufacturer on the condition of highly cost efficiency for the manufacturer's after sale service. However, we also find that information sharing does not always mean a win win benefit for the whole supply chain partners. When the after sale service is delegated to the retailer, our results show that only when the retailer's after sale service cost efficiency and forecast variability are relatively low, the retailer prefers not to share information. Our analysis also indicates that the manufacturer may delegate the after sale service to the retailer, even if the retailer does not have cost advantage. Compared with the situation where asymmetric information does not exist between the manufacturer and the retailer, the information advantage of the retailer may harm both parties and lead to a \"prisoner's dilemma\" By examining the value of information forecast, we demonstrate that enhancing the forecast accuracy may be harmful to not only the manufacturer but also the retailer.", "author_names": [ "Shuguang Zhang", "Bin Dan", "Maosen Zhou" ], "corpus_id": 189987973, "doc_id": "189987973", "n_citations": 21, "n_key_citations": 0, "score": 0, "title": "After sale service deployment and information sharing in a supply chain under demand uncertainty", "venue": "Eur. J. Oper. Res.", "year": 2019 }, { "abstract": "In this study, the impact of information sharing on bullwhip effect (BWE) is investigated using a four echelon supply chain simulation model where each echelon shares some of the customer demand forecast information with a retailer, the lowest echelon. The level of the demand forecast shared at each echelon is represented as information sharing rate (ISR) Four different levels of ISR are considered to evaluate its impact on BWE. A full factorial design with 64 cases is used, followed by statistical analysis. The results show that (1) overall, higher ISR more significantly reduce BWE than lower ISR at all echelons; (2) further, the impact of ISR is not same between echelons. The ISR at an echelon where BWE is measured has the highest impact. However, its impact decreases at downstream echelons; (3) BWE is affected by not only the magnitude but also the balance of ISR's across echelons, while the former has three times more impact than the latter; (4) lastly, we demonstrate that a highly unbalanced ISR may cause reverse bullwhip effect (RBWE) particularly when the level of unblance at downstream echelons is high and the uppermost echelon where BWE is measured has the highest ISR. Based on this demonstration, we derive a functional relationship between ISR's and RBWE using regression analysis. We believe that results from this study provide useful implications and insights for better coordination and collaboration in a supply chain.", "author_names": [ "Ki-Young Jeong", "Jae-Dong Hong" ], "corpus_id": 115887303, "doc_id": "115887303", "n_citations": 18, "n_key_citations": 0, "score": 0, "title": "The impact of information sharing on bullwhip effect reduction in a supply chain", "venue": "J. Intell. Manuf.", "year": 2019 } ]

[ { "abstract": "Computing systems are conventionally designed to operate as accurately as possible. However, this trend faces severe technology challenges, such as power consumption, circuit reliability, and high performance. For nearly half a century, performance and power consumption of computing systems have been consistently improved by relying mostly on technology scaling. As per Dennard's scaling, the size of a transistor has been considerably shrunk and the supply voltage has been reduced over the years, such that circuits operate at higher frequencies but nearly at the same power dissipation level. However, as Dennard's scaling tends toward an end, it is difficult to further improve performance under the same power constraints. Power consumption has been a major concern, and it is now an industry wide problem of critical importance. In addition to power, reliability deteriorates when the feature size of complementary metal oxide semiconductor (CMOS) technology is reduced below 7 nm, because parameter variations and faults at advanced nanoscales become difficult to control and prevent. Thus, to ensure the complete accuracy of signals, logic values, devices, and interconnects, manufacturing and verification costs will increase significantly.", "author_names": [ "Weiqiang Liu", "Fabrizio Lombardi", "Michael Shulte" ], "corpus_id": 215969028, "doc_id": "215969028", "n_citations": 22, "n_key_citations": 1, "score": 0, "title": "A Retrospective and Prospective View of Approximate Computing [Point of View}", "venue": "Proc. IEEE", "year": 2020 }, { "abstract": "Numerous application domains (e.g. signal and image processing, computer graphics, computer vision, and machine learning) are inherently error tolerant, which can be exploited to produce approximate ASIC implementations with low power consumption at the expense of negligible or small reductions in application quality. A major challenge is the need for approximate and high level design generation tools that can automatically work on arbitrary designs. In this article, we provide an expanded and improved treatment of our ABACUS methodology, which aims to automatically generate approximate designs directly from their behavioral register transfer level (RTL) descriptions, enabling a wider range of possible approximations. ABACUS starts by creating an abstract syntax tree (AST) from the input behavioral RTL description of a circuit, and then applies variant operators to the AST to create acceptable approximate designs. The devised variant operators include data type simplifications, arithmetic operation approximations, arithmetic expressions transformations, variable to constant substitutions, and loop transformations. A design space exploration technique is devised to explore the space of possible variant approximate designs and to identify the designs along the Pareto frontier that represents the trade off between accuracy and power consumption. In addition, ABACUS prioritizes generating approximate designs that, when synthesized, lead to circuits with simplified critical paths, which are exploited to realize complementary power savings through standard voltage scaling. We integrate ABACUS with a standard ASIC design flow, and evaluate it on four realistic benchmarks from three different domains machine learning, signal processing, and computer vision. Our tool automatically generates many approximate design variants with large power savings, while maintaining good accuracy. We demonstrate the scalability of ABACUS by parallelizing the flow and use of recent standard synthesis tools. Compared to our previous efforts, the new ABACUS tool provides up to 20.5x speed up in runtime, while able to generate approximate circuits that lead to additional power savings reaching up to 40 percent.", "author_names": [ "Kumud Nepal", "Soheil Hashemi", "Hokchhay Tann", "R Iris Bahar", "Sherief Reda" ], "corpus_id": 44246172, "doc_id": "44246172", "n_citations": 42, "n_key_citations": 6, "score": 1, "title": "Automated High Level Generation of Low Power Approximate Computing Circuits", "venue": "IEEE Transactions on Emerging Topics in Computing", "year": 2019 }, { "abstract": "In scientific computing, the acceleration of atomistic computer simulations by means of custom hardware is finding ever growing application. A major limitation, however, is that the high efficiency in terms of performance and low power consumption entails the massive usage of low precision computing units. Here, based on the approximate computing paradigm, we present an algorithmic method to rigorously compensate for numerical inaccuracies due to low accuracy arithmetic operations, yet still obtaining exact expectation values using a properly modified Langevin type equation.", "author_names": [ "Varadarajan Rengaraj", "Michael Lass", "Christian Plessl", "Thomas D Kuhne" ], "corpus_id": 197935237, "doc_id": "197935237", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Accurate Sampling with Noisy Forces from Approximate Computing", "venue": "Comput.", "year": 2020 }, { "abstract": "In this article, we review some of the classical methods used for quickly obtaining low precision approximations to the elementary functions. Then, for each of the three main classes of elementary function algorithms (shift and add algorithms, polynomial or rational approximations, and table based methods) and for the additional, specific to approximate computing, \"bit manipulation\" techniques, we examine what can be done for obtaining very fast estimates of a function, at the cost of a (controlled) loss in terms of accuracy.", "author_names": [ "Jean-Michel Muller" ], "corpus_id": 219047769, "doc_id": "219047769", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Elementary Functions and Approximate Computing", "venue": "Proceedings of the IEEE", "year": 2020 }, { "abstract": "The Internet of Things significantly increases the amount of data generated, straining the processing capability of current computing systems. Approximate computing is a promising solution to accelerate computation by trading off energy and accuracy. In this paper, we propose a resistive content addressable memory (CAM) accelerator, called RCA, which exploits data locality to have an approximate memory based computation. RCA stores high frequency patterns and performs computation inside CAM without using processing cores. During execution time, RCA searches an input operand among all prestored values on a CAM and returns the row with the nearest distance. To manage accuracy, we use a distance metric which considers the impact of each bit indices on computation accuracy. We evaluate an application of proposed RCA on CPU approximation, where RCA can be used as a stand alone or as a hybrid computing unit besides CPU cores for tunable CPU approximation. We evaluate the architecture of the proposed RCA using HSPICE and multi2sim by testing our results on x86 CPU processor. Our evaluation shows that RCA can accelerate CPU computation by 12.6x and improve the energy efficiency by 6.6x as compared to a traditional CPU architecture, while providing acceptable quality of service.", "author_names": [ "Mohsen Imani", "Daniel Peroni", "Abbas Rahimi", "Tajana Simunic Rosing" ], "corpus_id": 37730373, "doc_id": "37730373", "n_citations": 29, "n_key_citations": 4, "score": 0, "title": "Resistive CAM Acceleration for Tunable Approximate Computing", "venue": "IEEE Transactions on Emerging Topics in Computing", "year": 2019 }, { "abstract": "This paper presents a novel method for applying approximate computing at the level of a complete application. The method decomposes the application into processing blocks which types define the classes of approximate computing techniques they may tolerate. By applying these approximation techniques to the most computationally intensive blocks, drastic energy reduction can be obtained at a limited cost in terms of Quality of Service. The algorithmic level approximate computing method is applied to a software High Efficiency Video Coding (HEVC) video decoder. The method is shown to offer multiple trade offs between the quality of the decoded video and the energy required for the decoding process. The algorithmic level approximate computing method offers new possibilities in terms of application energy budgeting. Energy reductions of up to 40 percent are demonstrated for a limited degradation of the application Quality of Service.", "author_names": [ "Erwan Nogues", "Daniel Menard", "Maxime Pelcat" ], "corpus_id": 64484616, "doc_id": "64484616", "n_citations": 26, "n_key_citations": 1, "score": 0, "title": "Algorithmic Level Approximate Computing Applied to Energy Efficient HEVC Decoding", "venue": "IEEE Transactions on Emerging Topics in Computing", "year": 2019 }, { "abstract": "Approximate computing systems improve energy efficiency and computation speed at the cost of reduced accuracy on system outputs. Existing efforts mainly explore the feasible approximation mechanisms and their implementation methods. There is limited work that investigates the security threats brought by approximate computing. To fill this gap, we first analyze the approximate mechanisms used in approximate system, software, storage, and arithmetic circuits, and then propose potential attacks that will challenge the integrity and security of approximate systems. Some illustrative examples are provided accordingly to showcase the consequences of the proposed new attacks.", "author_names": [ "Pruthvy Yellu", "Novak Boskov", "Michel A Kinsy", "Qiaoyan Yu" ], "corpus_id": 155100423, "doc_id": "155100423", "n_citations": 13, "n_key_citations": 4, "score": 0, "title": "Security Threats in Approximate Computing Systems", "venue": "ACM Great Lakes Symposium on VLSI", "year": 2019 }, { "abstract": "In the autonomic computing context, the system is perceived as a set of autonomous elements capable of self management, where end users define high level goals and the system shall adapt to achieve the desired behaviour. Runtime adaptation creates several optimization opportunities, especially if we consider approximate computing applications, where it is possible to trade off the accuracy of the result and the performance. Given that modern systems are limited by the power dissipated, autonomic computing is an appealing approach to increase the computation efficiency. In this paper, we introduce mARGOt, a dynamic autotuning framework to enhance the target application with an adaptation layer to provide self optimization capabilities. The framework is implemented as a C+ library that works at function level and provides to the application a mechanism to adapt in a reactive and a proactive way. Moreover, the application is capable to change dynamically its requirements and to learn online the underlying application knowledge. We evaluated the proposed framework in three real life scenarios, ranging from embedded to HPC applications. In the three use cases, experimental results demonstrate how, thanks to mARGOt, it is possible to increase the computation efficiency by adapting the application at runtime with a limited overhead.", "author_names": [ "Davide Gadioli", "Emanuele Vitali", "Gianluca Palermo", "Cristina Silvano" ], "corpus_id": 70279045, "doc_id": "70279045", "n_citations": 15, "n_key_citations": 2, "score": 0, "title": "mARGOt: A Dynamic Autotuning Framework for Self Aware Approximate Computing", "venue": "IEEE Transactions on Computers", "year": 2019 }, { "abstract": "Energy efficient computing is a much needed technological advantage for future. Approximate or inexact computing is a computing paradigm that can trade energy and computing time with accuracy of output. Recent years have seen a lot of researches in industry as well as academia. The aim of these researches is to fruitfully realize the dream of a greener and energy efficient computing era. This paper presents a comprehensive and concise survey of the current research trends and contributions in energy efficient computing from computational point of view. Recent developments in approximate computing hardware, software and approximate data communication have also been discussed in this article.", "author_names": [ "Hrishav Bakul Barua", "Kartick Chandra Mondal" ], "corpus_id": 195363553, "doc_id": "195363553", "n_citations": 16, "n_key_citations": 2, "score": 0, "title": "Approximate Computing: A Survey of Recent Trends Bringing Greenness to Computing and Communication", "venue": "Journal of The Institution of Engineers (India) Series B", "year": 2019 }, { "abstract": "", "author_names": [ "Weiqiang Liu", "Chongyan Gu", "Maire O'Neill", "Gang Qu", "Paolo Montuschi", "Fabrizio Lombardi" ], "corpus_id": 226375978, "doc_id": "226375978", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Security for Approximate Computing, Approximate Computing for Security", "venue": "", "year": 2020 } ]

[ { "abstract": "Research on small molecule based organic semiconductors has undoubtedly been strongly influenced by xerographic photoconductors like triarylamines, the first important organic electronic materials in market products. Their development was strongly influenced by the B ssler model, which provided a rationale for the design of amorphous organic photoand semiconductors. According to this model, only compounds that lack dipole moments are considered promising for charge carrier transport because the increased energetic disorder associated with dipole moments is thought to impede charge hopping. Recently, we questioned this paradigm in the field of organic photovoltaics (OPV) and successfully implemented highly dipolar merocyanine dyes as active components for light harvesting as well as exciton and hole transport in solution cast bulk heterojunction (BHJ) solar cells. The rationale behind our concept was that highly dipolar donor acceptor (D A) substituted p systems (also called push pull dyes) self assemble into centrosymmetric dimers, thus effectively eliminating molecular dipole moments on the supramolecular and material levels. Two drawbacks of our BHJ materials, however, limited the acceptance of our concept so far. Firstly, the best solar cells were obtained for merocyanine dyes whose molecular scaffolds were equipped with rather bulky substituents that interfere with close face to face antiparallel dimerization. Secondly, the power conversion efficiencies (h) under standard AM1.5, 100 mW cm 2 simulated solar illumination conditions for solution cast BHJ cells with fullerenes although significantly advanced by more sophisticated vacuum processing could not be improved beyond 2.6% which is significantly lower than the best solutionprocessed small molecule based BHJ devices fabricated with A D A and D A D chromophores, for example, acceptorsubstituted oligothiophenes (up to 3.7% and triarylamines (up to 4.3% diketopyrrolopyrroles (up to 4.4% and squaraines (up to 5.2 Herein, we introduce dipolar D A dyes with flat structures that undoubtedly form centrosymmetric dimers with perfectly cancelled dipole moments in the solid state. Solution processed BHJ solar cells derived thereof exhibit power conversion efficiencies up to 4.5 5.1% (dependent on light intensity) clearly placing D A dyes now among the top performing small molecules in the field of organic photovoltaics. Scheme 1 outlines the synthetic route that follows our earlier work on merocyanine dyes for photorefractive materials and the simple access to 5 dialkylamino thiophene 2carbaldehydes by Hartmann. Detailed synthetic procedures and characterization data are described in the Supporting Information.", "author_names": [ "Hannah Burckstummer", "Elena V Tulyakova", "Manuela Deppisch", "Martin R Lenze", "Nils M Kronenberg", "Marcel Gsanger", "Matthias Stolte", "Klaus Meerholz", "Frank Wurthner" ], "corpus_id": 38402489, "doc_id": "38402489", "n_citations": 205, "n_key_citations": 0, "score": 1, "title": "Efficient solution processed bulk heterojunction solar cells by antiparallel supramolecular arrangement of dipolar donor acceptor dyes.", "venue": "Angewandte Chemie", "year": 2011 }, { "abstract": "A solution processed small molecule with low band gap, dicyanovinyl substituted oligothiophene (DCN7T) was used as the donor in bulk heterojunctions solar cells and a power conversion efficiency of 2.45% has been obtained for the device using simply spin coating without special treatment.", "author_names": [ "Yongsheng Liu", "Xiangjian Wan", "Bin Yin", "Jiaoyan Zhou", "Guankui Long", "Shougen Yin", "Yongsheng Chen" ], "corpus_id": 96851622, "doc_id": "96851622", "n_citations": 93, "n_key_citations": 0, "score": 0, "title": "Efficient solution processed bulk heterojunction solar cells based a donor acceptor oligothiophene", "venue": "", "year": 2010 }, { "abstract": "A conjugated acceptor donor acceptor (A p D p A) with the Zn porphyrin core and the di cyanovinyl substituted thiophene (A) connected at meso positions denoted as was designed and synthesized. The optical and electrochemical properties of were investigated. This new porphyrin exhibits a broad and intense absorption in the visible and near infrared regions. Bulk heterojunction (BHJ) solution processed organic solar cells based on this porphyrin, as electron donor material, and PC71BM [6,6] phenyl C71 butyric acid methyl ester) as electron acceptor material, were fabricated using THF and a pyridine THF solvent exhibiting a power conversion efficiency of 3.65% and 5.24% respectively. The difference in efficiencies is due to the enhancement of the short circuit current J(sc) and FF of the solar cell, which is ascribed to a stronger and broader incident photon to current efficiency (IPCE) response and a better balanced charge transport in the device processed with the pyridine THF solvent.", "author_names": [ "Challuri Vijay Kumar", "Lydia Cabau", "Emmanuel N Koukaras", "Ganesh D Sharma", "Emilio Jose Palomares" ], "corpus_id": 34029301, "doc_id": "34029301", "n_citations": 42, "n_key_citations": 0, "score": 0, "title": "Synthesis, optical and electrochemical properties of the A p D p A porphyrin and its application as an electron donor in efficient solution processed bulk heterojunction solar cells.", "venue": "Nanoscale", "year": 2015 }, { "abstract": "Efficient conventional bulk heterojunction (BHJ) perovskite hybrid solar cells (pero HSCs) solution processed from a composite of CH3NH3PbI3 mixed with PC61BM [6,6] phenyl C61 butyric acid methyl ester) where CH3NH3PbI3 acts as the electron donor and PC61BM acts as the electron acceptor, are reported for the first time. The efficiency of 12.78% is twofold enhancement in comparison with the conventional planar heterojunction pero HSCs (6.90% fabricated by pristine CH3NH3PbI3. The BHJ pero HSCs are further optimized by using PC61BM/TiO2 bi electron extraction layer (EEL) which are both solution processed and then followed with low temperature thermal annealing. Due to higher electrical conductivity of PC61BM over that of TiO2, an efficiency of 14.98% the highest reported efficiency for the pero HSCs without incorporating high temperature processed mesoporous TiO2 and Al2O3 as the EEL and insulating scaffold, is observed from PC61BM modified BHJ pero HSCs. Thus, the findings provide a simple way to approach high efficiency low cost pero HSCs.", "author_names": [ "Chang Liu", "Kai Wang", "Pengcheng Du", "Chao Yi", "Tianyu Meng", "Xiong Gong" ], "corpus_id": 95872194, "doc_id": "95872194", "n_citations": 81, "n_key_citations": 2, "score": 0, "title": "Efficient Solution Processed Bulk Heterojunction Perovskite Hybrid Solar Cells", "venue": "", "year": 2015 }, { "abstract": "Abstract Two molecules denoted as VC96 and VC97 have been synthesized for efficient e 6.13% 100 mW/cm 2 sun simulated light) small molecule solution processed organic solar cells. These molecules have been designed with the D 1 A D 2 A D 1 structure bearing different central donor unit, same benzothiadiazole (BT) as p acceptor and end capping triphenylamine. Moreover, the optical and electrochemical properties (both experimental and theoretical) of these molecules have been systematically investigated. The solar cells prepared from VC96 :PC 71 BM and VC97 :PC 71 BM (1:2) processed from CF (chloroform) exhibit a PCE (power conversion efficiency) of e 4.06% J sc 8.36 mA/cm 2 V oc 0.90 V and FF 0.54) and e 3.12% J sc 6.78 mA/cm 2 V oc 0.92 V and FF 0.50) respectively. The higher PCE of the device with VC96 as compared to VC97 is demonstrated to be due to the higher hole mobility and broader IPCE spectra. The devices based on VC96 :PC 71 BM and VC97 :PC 71 BM processed with solvent additive (3 v% DIO, 1,8 diiodooctane) showed PCE of e 5.44% and e 4.72% respectively. The PCE device of optimized VC96 :PC 71 BM processed with DIO/CF (thermal annealed) has been improved up to 6.13% J sc 10.72 mA/cm 2 V oc 0.88 V and FF 0.61) The device optimization results from the improvement of the balanced charge transport and better nanoscale morphology induced by the solvent additive plus the thermal annealing.", "author_names": [ "Challuri Vijay Kumar", "Lydia Cabau", "Emmanuel N Koukaras", "Ganesh D Sharma", "Emilio Jose Palomares" ], "corpus_id": 94201899, "doc_id": "94201899", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "Efficient solution processed D1 A D2 A D1 small molecules bulk heterojunction solar cells based on alkoxy triphenylamine and benzo[1,2 b:4,5 b']thiophene units", "venue": "", "year": 2015 }, { "abstract": "The work reported here was supported by the King Abdullah University of Science and Technology (KAUST)", "author_names": [ "Flurin D Eisner", "Akmaral Seitkhan", "Yang Han", "Dongyoon Khim", "Emre Yengel", "Ahmad R Kirmani", "Jixian Xu", "F Pelayo Garcia Arquer", "Edward H Sargent", "Aram Amassian", "Zhuping Fei", "Martin Heeney", "Thomas D Anthopoulos" ], "corpus_id": 96455546, "doc_id": "96455546", "n_citations": 23, "n_key_citations": 0, "score": 0, "title": "Solution Processed In2O3/ZnO Heterojunction Electron Transport Layers for Efficient Organic Bulk Heterojunction and Inorganic Colloidal Quantum Dot Solar Cells", "venue": "", "year": 2018 }, { "abstract": "In this study, we employed polyethylenimine doped sol gel processed zinc oxide composites (ZnO:PEI) as efficient electron transport layers (ETL) for facilitating electron extraction in inverted polymer solar cells. Using ultraviolet photoelectron spectroscopy, synchrotron grazing incidence small angle X ray scattering and transmission electron microscopy, we observed that ZnO:PEI composite films' energy bands could be tuned considerably by varying the content of PEI up to 7 wt the conduction band ranged from 4.32 to 4.0 eV and the structural order of ZnO in the ZnO:PEI thin films would be enhanced to align perpendicular to the ITO electrode, particularly at 7 wt PEI, facilitating electron transport vertically. We then prepared two types of bulk heterojunction systems based on poly(3 hexylthiophene) (P3HT):phenyl C61 butryric acid methyl ester (PC61BM) and benzo[1,2 b:4,5 b]dithiophene thiophene 2,1,3 benzooxadiazole (PBDTTBO):phenyl C71 butryric acid methyl ester (PC71BM) that incorporated the ZnO:PEI composite layers. When using a composite of ZnO:PEI (93:7, w/w) as the ETL, the power conversion efficiency (PCE) of the P3HT:PC61BM (1:1, w/w) device improved to 4.6% from a value of 3.7% for the corresponding device that incorporated pristine ZnO as the ETL a relative increase of 24% For the PBDTTBO:PC71BM (1:2, w/w) device featuring the same amount of PEI blended in the ETL, the PCE improved to 8.7% from a value of 7.3% for the corresponding device that featured pure ZnO as its ETL a relative increase of 20% Accordingly, ZnO:PEI composites can be effective ETLs within organic photovoltaics.", "author_names": [ "Hsiu-Cheng Chen", "Shu-Wei Lin", "Jian-ming Jiang", "Yu-Wei Su", "Kung-Hwa Wei" ], "corpus_id": 206387106, "doc_id": "206387106", "n_citations": 88, "n_key_citations": 1, "score": 0, "title": "Solution processed zinc oxide/polyethylenimine nanocomposites as tunable electron transport layers for highly efficient bulk heterojunction polymer solar cells.", "venue": "ACS applied materials interfaces", "year": 2015 }, { "abstract": "In this study we used simultaneous grazing incidence small and wide angle X ray scattering (GISAXS and GIWAXS, respectively) to probe the multilength scale structures of thin active layers comprising the linear A D A type p conjugated donor molecule TBDTCNR and the fullerene acceptor molecule PC61BM for use in solution processed small molecule based organic solar cells (SMOSCs) We found that the pseudo two dimensional fractal like networks in the bulk heterojunction (BHJ) structure were determined by mutual interactions between the small molecule (SM) crystallites and the nanoscale PC61BM clusters during their formation and phase separation, and deduced quantitatively, at multiple length scales, the BHJ structures comprising these SM crystallites and PC61BM clusters. We also conducted in situ GIWAXS measurements to study the temporal behavior and kinetics of SM crystallization from solution to the solid film state. Our GISAXS/GIWAXS study revealed that the multilength scale BHJ structures in the thin fi.", "author_names": [ "Yu-Ching Huang", "Cheng-Si Tsao", "Tzu-Yen Huang", "Hou-Chin Cha", "Dhananjaya Patra", "Chun-Jen Su", "U-Ser Jeng", "Kuo-Chuan Ho", "Kung-Hwa Wei", "Chih-Wei Chu" ], "corpus_id": 100960004, "doc_id": "100960004", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Quantitative Characterization and Mechanism of Formation of Multilength scale Bulk Heterojunction Structures in Highly Efficient Solution Processed Small Molecule Organic Solar Cells", "venue": "", "year": 2015 }, { "abstract": "We report the synthesis, characterization, and optical and electrochemical of properties of two novel molecules DRT3 BDT (1) and DTT3 BDT (2) comprising the same BDT central core (donor) and different end capped acceptor units, i.e. rhodanine with ethyl hexyl and thiazolidione with ethylhexyl, respectively, linked via an alkyl substituted terthiophene (3 T) p conjugation bridge. The electrochemical properties of these small molecules indicate that their energy levels are compatible with energy levels of PC71BM for efficient exciton dissociation. These molecules have been used as electron donors along with PC71BM as an electron acceptor, for the fabrication of solution processed \"small molecule\" bulk heterojunction (BHJ) solar cells (smOPV) The device prepared from optimized 1:PC71BM(1:1) processed cast from DIO (3%v)/CF solvent exhibited a power conversion efficiency of 6.76% with Jsc 11.92 mA cm( 2) Voc 0.90 and FF 0.63. The device with 2:PC71BM under the same conditions showed a lower PCE of 5.25% with Jsc 10.52 mA cm( 2) Voc 0.86 and FF 0.56. The AFM, TEM and PL quenching measurements revealed that the high Jsc is a result of the appropriate morphology and exciton dissociation. The performances were compared for the devices based on two small molecules. The higher Jsc for device 1 was attributed to its better nanoscale phase separation, smooth surface and higher carrier mobility in the 1:PC71BM blend film. Moreover, the higher value of FF for the 1:PC71BM based device was ascribed to a good balance between the electron and hole mobilities.", "author_names": [ "Challuri Vijay Kumar", "Lydia Cabau", "Emmanuel N Koukaras", "Shahbaz Ahmed Siddiqui", "Ganesh D Sharma", "Emilio Jose Palomares" ], "corpus_id": 205975767, "doc_id": "205975767", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Efficient bulk heterojunction solar cells based on solution processed small molecules based on the same benzo[1,2 b:4, 5 b']thiophene unit as core donor and different terminal units.", "venue": "Nanoscale", "year": 2015 }, { "abstract": "We demonstrate the efficiency enhancement and efficient hole extraction achieved by undoped Si nanocrystals (NCs) and p type Si (p Si) NCs in solution processed bulk heterojunction (BHJ) organic solar cells (OSCs) and planar heterojunction (PHJ) perovskite solar cells (PrSCs) We observed that the surface coverage of Si NCs on the substrate significantly affected the photovoltaic performance of the BHJ OSCs and PHJ PrSCs. The undoped Si NCs and p Si NCs enhanced the power conversion efficiencies (PCEs) of the BHJ OSCs by ~6% and ~11% respectively, and those of PHJ PrSCs by ~22% and ~23% correspondingly, compared with the PCEs of devices without Si NCs. The p Si NCs had a highest occupied molecular orbital (HOMO) energy level ~0.16 eV higher than that of undoped Si NCs and showed better balances with the HOMO energy levels of the PTB7 Th and MAPbI3 perovskite materials, achieving an increase in the hole mobility of the BHJ system, and thus demonstrating their key role as hole extracting materials.", "author_names": [ "Hanbin Jeong", "Hansol Kim", "Won-Il Song", "Kyung-Hoon Yoo", "Jason Eric Rama", "Jae Kwan Lee" ], "corpus_id": 99087561, "doc_id": "99087561", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Improved efficiency of solution processed bulk heterojunction organic solar cells and planar heterojunction perovskite solar cells with efficient hole extracting Si nanocrystals", "venue": "", "year": 2016 } ]

[ { "abstract": "Computing systems are conventionally designed to operate as accurately as possible. However, this trend faces severe technology challenges, such as power consumption, circuit reliability, and high performance. For nearly half a century, performance and power consumption of computing systems have been consistently improved by relying mostly on technology scaling. As per Dennard's scaling, the size of a transistor has been considerably shrunk and the supply voltage has been reduced over the years, such that circuits operate at higher frequencies but nearly at the same power dissipation level. However, as Dennard's scaling tends toward an end, it is difficult to further improve performance under the same power constraints. Power consumption has been a major concern, and it is now an industry wide problem of critical importance. In addition to power, reliability deteriorates when the feature size of complementary metal oxide semiconductor (CMOS) technology is reduced below 7 nm, because parameter variations and faults at advanced nanoscales become difficult to control and prevent. Thus, to ensure the complete accuracy of signals, logic values, devices, and interconnects, manufacturing and verification costs will increase significantly.", "author_names": [ "Weiqiang Liu", "Fabrizio Lombardi", "Michael Shulte" ], "corpus_id": 215969028, "doc_id": "215969028", "n_citations": 22, "n_key_citations": 1, "score": 0, "title": "A Retrospective and Prospective View of Approximate Computing [Point of View}", "venue": "Proc. IEEE", "year": 2020 }, { "abstract": "Numerous application domains (e.g. signal and image processing, computer graphics, computer vision, and machine learning) are inherently error tolerant, which can be exploited to produce approximate ASIC implementations with low power consumption at the expense of negligible or small reductions in application quality. A major challenge is the need for approximate and high level design generation tools that can automatically work on arbitrary designs. In this article, we provide an expanded and improved treatment of our ABACUS methodology, which aims to automatically generate approximate designs directly from their behavioral register transfer level (RTL) descriptions, enabling a wider range of possible approximations. ABACUS starts by creating an abstract syntax tree (AST) from the input behavioral RTL description of a circuit, and then applies variant operators to the AST to create acceptable approximate designs. The devised variant operators include data type simplifications, arithmetic operation approximations, arithmetic expressions transformations, variable to constant substitutions, and loop transformations. A design space exploration technique is devised to explore the space of possible variant approximate designs and to identify the designs along the Pareto frontier that represents the trade off between accuracy and power consumption. In addition, ABACUS prioritizes generating approximate designs that, when synthesized, lead to circuits with simplified critical paths, which are exploited to realize complementary power savings through standard voltage scaling. We integrate ABACUS with a standard ASIC design flow, and evaluate it on four realistic benchmarks from three different domains machine learning, signal processing, and computer vision. Our tool automatically generates many approximate design variants with large power savings, while maintaining good accuracy. We demonstrate the scalability of ABACUS by parallelizing the flow and use of recent standard synthesis tools. Compared to our previous efforts, the new ABACUS tool provides up to 20.5x speed up in runtime, while able to generate approximate circuits that lead to additional power savings reaching up to 40 percent.", "author_names": [ "Kumud Nepal", "Soheil Hashemi", "Hokchhay Tann", "R Iris Bahar", "Sherief Reda" ], "corpus_id": 44246172, "doc_id": "44246172", "n_citations": 42, "n_key_citations": 6, "score": 0, "title": "Automated High Level Generation of Low Power Approximate Computing Circuits", "venue": "IEEE Transactions on Emerging Topics in Computing", "year": 2019 }, { "abstract": "In scientific computing, the acceleration of atomistic computer simulations by means of custom hardware is finding ever growing application. A major limitation, however, is that the high efficiency in terms of performance and low power consumption entails the massive usage of low precision computing units. Here, based on the approximate computing paradigm, we present an algorithmic method to rigorously compensate for numerical inaccuracies due to low accuracy arithmetic operations, yet still obtaining exact expectation values using a properly modified Langevin type equation.", "author_names": [ "Varadarajan Rengaraj", "Michael Lass", "Christian Plessl", "Thomas D Kuhne" ], "corpus_id": 197935237, "doc_id": "197935237", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Accurate Sampling with Noisy Forces from Approximate Computing", "venue": "Comput.", "year": 2020 }, { "abstract": "This work is a survey on approximate computing and its impact on fault tolerance, especially for safety critical applications. It presents a multitude of approximation methodologies, which are typically applied at software, architecture, and circuit level. Those methodologies are discussed and compared on all their possible levels of implementations (some techniques are applied at more than one level) Approximation is also presented as a means to provide fault tolerance and high reliability: Traditional error masking techniques, such as triple modular redundancy, can be approximated and thus have their implementation and execution time costs reduced compared to the state of the art.", "author_names": [ "Gennaro Severino Rodrigues", "Fernanda Lima Kastensmidt", "Alberto Bosio" ], "corpus_id": 216264721, "doc_id": "216264721", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Survey on Approximate Computing and Its Intrinsic Fault Tolerance", "venue": "", "year": 2020 }, { "abstract": "In this article, we review some of the classical methods used for quickly obtaining low precision approximations to the elementary functions. Then, for each of the three main classes of elementary function algorithms (shift and add algorithms, polynomial or rational approximations, and table based methods) and for the additional, specific to approximate computing, \"bit manipulation\" techniques, we examine what can be done for obtaining very fast estimates of a function, at the cost of a (controlled) loss in terms of accuracy.", "author_names": [ "Jean-Michel Muller" ], "corpus_id": 219047769, "doc_id": "219047769", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Elementary Functions and Approximate Computing", "venue": "Proceedings of the IEEE", "year": 2020 }, { "abstract": "The Internet of Things significantly increases the amount of data generated, straining the processing capability of current computing systems. Approximate computing is a promising solution to accelerate computation by trading off energy and accuracy. In this paper, we propose a resistive content addressable memory (CAM) accelerator, called RCA, which exploits data locality to have an approximate memory based computation. RCA stores high frequency patterns and performs computation inside CAM without using processing cores. During execution time, RCA searches an input operand among all prestored values on a CAM and returns the row with the nearest distance. To manage accuracy, we use a distance metric which considers the impact of each bit indices on computation accuracy. We evaluate an application of proposed RCA on CPU approximation, where RCA can be used as a stand alone or as a hybrid computing unit besides CPU cores for tunable CPU approximation. We evaluate the architecture of the proposed RCA using HSPICE and multi2sim by testing our results on x86 CPU processor. Our evaluation shows that RCA can accelerate CPU computation by 12.6x and improve the energy efficiency by 6.6x as compared to a traditional CPU architecture, while providing acceptable quality of service.", "author_names": [ "Mohsen Imani", "Daniel Peroni", "Abbas Rahimi", "Tajana Simunic Rosing" ], "corpus_id": 37730373, "doc_id": "37730373", "n_citations": 29, "n_key_citations": 4, "score": 0, "title": "Resistive CAM Acceleration for Tunable Approximate Computing", "venue": "IEEE Transactions on Emerging Topics in Computing", "year": 2019 }, { "abstract": "This paper presents a novel method for applying approximate computing at the level of a complete application. The method decomposes the application into processing blocks which types define the classes of approximate computing techniques they may tolerate. By applying these approximation techniques to the most computationally intensive blocks, drastic energy reduction can be obtained at a limited cost in terms of Quality of Service. The algorithmic level approximate computing method is applied to a software High Efficiency Video Coding (HEVC) video decoder. The method is shown to offer multiple trade offs between the quality of the decoded video and the energy required for the decoding process. The algorithmic level approximate computing method offers new possibilities in terms of application energy budgeting. Energy reductions of up to 40 percent are demonstrated for a limited degradation of the application Quality of Service.", "author_names": [ "Erwan Nogues", "Daniel Menard", "Maxime Pelcat" ], "corpus_id": 64484616, "doc_id": "64484616", "n_citations": 26, "n_key_citations": 1, "score": 0, "title": "Algorithmic Level Approximate Computing Applied to Energy Efficient HEVC Decoding", "venue": "IEEE Transactions on Emerging Topics in Computing", "year": 2019 }, { "abstract": "Approximate computing systems improve energy efficiency and computation speed at the cost of reduced accuracy on system outputs. Existing efforts mainly explore the feasible approximation mechanisms and their implementation methods. There is limited work that investigates the security threats brought by approximate computing. To fill this gap, we first analyze the approximate mechanisms used in approximate system, software, storage, and arithmetic circuits, and then propose potential attacks that will challenge the integrity and security of approximate systems. Some illustrative examples are provided accordingly to showcase the consequences of the proposed new attacks.", "author_names": [ "Pruthvy Yellu", "Novak Boskov", "Michel A Kinsy", "Qiaoyan Yu" ], "corpus_id": 155100423, "doc_id": "155100423", "n_citations": 13, "n_key_citations": 4, "score": 0, "title": "Security Threats in Approximate Computing Systems", "venue": "ACM Great Lakes Symposium on VLSI", "year": 2019 }, { "abstract": "In the autonomic computing context, the system is perceived as a set of autonomous elements capable of self management, where end users define high level goals and the system shall adapt to achieve the desired behaviour. Runtime adaptation creates several optimization opportunities, especially if we consider approximate computing applications, where it is possible to trade off the accuracy of the result and the performance. Given that modern systems are limited by the power dissipated, autonomic computing is an appealing approach to increase the computation efficiency. In this paper, we introduce mARGOt, a dynamic autotuning framework to enhance the target application with an adaptation layer to provide self optimization capabilities. The framework is implemented as a C+ library that works at function level and provides to the application a mechanism to adapt in a reactive and a proactive way. Moreover, the application is capable to change dynamically its requirements and to learn online the underlying application knowledge. We evaluated the proposed framework in three real life scenarios, ranging from embedded to HPC applications. In the three use cases, experimental results demonstrate how, thanks to mARGOt, it is possible to increase the computation efficiency by adapting the application at runtime with a limited overhead.", "author_names": [ "Davide Gadioli", "Emanuele Vitali", "Gianluca Palermo", "Cristina Silvano" ], "corpus_id": 70279045, "doc_id": "70279045", "n_citations": 15, "n_key_citations": 2, "score": 0, "title": "mARGOt: A Dynamic Autotuning Framework for Self Aware Approximate Computing", "venue": "IEEE Transactions on Computers", "year": 2019 }, { "abstract": "Approximate computing trades off computation quality with effort expended, and as rising performance demands confront plateauing resource budgets, approximate computing has become not merely attractive, but even imperative. In this article, we present a survey of techniques for approximate computing (AC) We discuss strategies for finding approximable program portions and monitoring output quality, techniques for using AC in different processing units (e.g. CPU, GPU, and FPGA) processor components, memory technologies, and so forth, as well as programming frameworks for AC. We classify these techniques based on several key characteristics to emphasize their similarities and differences. The aim of this article is to provide insights to researchers into working of AC techniques and inspire more efforts in this area to make AC the mainstream computing approach in future systems.", "author_names": [ "Sparsh Mittal" ], "corpus_id": 4668902, "doc_id": "4668902", "n_citations": 598, "n_key_citations": 31, "score": 1, "title": "A Survey of Techniques for Approximate Computing", "venue": "ACM Comput. Surv.", "year": 2016 } ]

[ { "abstract": "Advanced applications in optical metrology demand improved lasers with high spectral purity, in form factors that are small and insensitive to environmental perturbations. While laboratory scale lasers with extraordinarily high stability and low noise have been reported, all integrated chip scale devices with sub 100 Hz linewidth have not been previously demonstrated. Lasers integrated with optical microresonators as external cavities have the potential for substantial reduction of noise. However, stability and spectral purity improvements of these lasers have only been validated with rack mounted support equipment, assembled with fibre lasers to marginally improve their noise performance. In this work we report on a realization of a heterogeneously integrated, chip scale semiconductor laser featuring 30 Hz integral linewidth as well as sub Hz instantaneous linewidth.", "author_names": [ "Wei Liang", "Vladimir Ilchenko", "Danny Eliyahu", "Anatoliy Savchenkov", "Andrey B Matsko", "David Seidel", "Lute Maleki" ], "corpus_id": 5241737, "doc_id": "5241737", "n_citations": 172, "n_key_citations": 3, "score": 1, "title": "Ultralow noise miniature external cavity semiconductor laser", "venue": "Nature communications", "year": 2015 }, { "abstract": "Abstract In this article, the window based complexity and output modulation of a time delayed chaotic semiconductor laser (SL) model has been investigated. The window based optical complexity (OC) is measured by introducing the recurrence sample entropy (SampEn) The analysis has been done without and in the presence of external noise. The significant changes in the dynamics can be observed under induced noise with weak strength. It has also been found that there is a strong positive correlation between the output power and the complexity of the system with various sets of parameters. The laser intensity, as well as the OC can be increased with the incremental noise strength and the associated system parameters. Thus, optical complexity quantifies the system dynamics and its instabilities, since is strongly correlated with the laser outputs. This analysis can be applied to measure the laser instabilities and modulation of output power.", "author_names": [ "Lamberto Rondoni", "Muhammad Rezal Kamel Ariffin", "Renuganth Varatharajoo", "Sayan Mukherjee", "Sanjay Kumar Palit", "Santo Banerjee" ], "corpus_id": 114782560, "doc_id": "114782560", "n_citations": 16, "n_key_citations": 0, "score": 0, "title": "Optical complexity in external cavity semiconductor laser", "venue": "", "year": 2017 }, { "abstract": "Abstract A commercially available high power GaN based blue laser diode has been operated in a simple Littrow type external cavity (EC) Two kinds of EC configurations with the grating lines perpendicular (A configuration) and parallel (B configuration) to the p n junction are evaluated. Good performance has been demonstrated for the EC laser with B configuration due to the better mode selection effect induced by the narrow feedback wavelength range from the grating. Under an injection current of 1100 mA, the spectral linewidth is narrowed significantly down to ~0.1 nm from ~1 nm (the free running width) with a good wavelength locking behavior and a higher than 35 dB amplified spontaneous emission suppression ratio. Moreover, a tuning bandwidth of 3.6 nm from 443.9 nm to 447.5 nm is realized with output power of 1.24 W and EC coupling efficiency of 80% at the central wavelength. The grating coupled blue EC laser with narrow spectral linewidth, flexible wavelength tunability, and high output power shows potential applications in atom cooling and trapping, high resolution spectroscopy, second harmonic generation, and high capacity holographic data storage.", "author_names": [ "Ding Ding", "Xueqin Lv", "Xinyi Chen", "Fei Wang", "Jiangyong Zhang", "Kaijun Che" ], "corpus_id": 125539726, "doc_id": "125539726", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Tunable high power blue external cavity semiconductor laser", "venue": "", "year": 2017 }, { "abstract": "We report a continuous wave highly coherent and tunable dual frequency laser emitting at two frequencies separated by 30 GHz to 3 THz, based on compact III V diode pumped quantum well surface emitting semiconductor laser technology. The concept is based on the stable simultaneous operation of two Laguerre Gauss transverse modes in a single axis short cavity, using an integrated sub wavelength thick metallic mask. Simultaneous operation is demonstrated theoretically and experimentally by recording intensity noises and beat frequency, and time resolved optical spectra. We demonstrated a >80 mW output power, diffraction limited beam, narrow linewidth of <300 kHz, linear polarization state >45 dB) and low intensity noise class A dynamics of <0.3% rms, thus opening the path to a compact low cost coherent GHz to THz source development.", "author_names": [ "Romain Paquet", "Stephane Blin", "Mikhael Myara", "Luc le Gratiet", "Mohamed Sellahi", "Baptiste Chomet", "Gregoire Beaudoin", "Isabelle Sagnes", "Arnaud Garnache" ], "corpus_id": 23157126, "doc_id": "23157126", "n_citations": 23, "n_key_citations": 4, "score": 0, "title": "Coherent continuous wave dual frequency high Q external cavity semiconductor laser for GHz THz applications.", "venue": "Optics letters", "year": 2016 }, { "abstract": "This Letter is the first to report experimental bifurcation diagrams of an external cavity semiconductor laser (ECSL) in the low to moderate current injection regime and long cavity case. Based on the bifurcation cascade behavior which was unveiled by Hohl and Gavrielides [Phys. Rev. Lett. 82, 1148 1151 (1999) we present a detailed experimental investigation of the nonlinear dynamics of ECSLs and of the robustness of the cascade to changes in the current and cavity length. Also, we report for the first time a well resolved experimental Hopf bifurcation in an ECSL. Based on the Lang and Kobayashi model, we identify the dynamical regimes and the instabilities involved in the cascade, as well as the influence of the current and cavity length on the cascade.", "author_names": [ "Byungchil Kim", "Nianqiang Li", "Alexandre Locquet", "David S Citrin" ], "corpus_id": 29696931, "doc_id": "29696931", "n_citations": 20, "n_key_citations": 2, "score": 0, "title": "Experimental bifurcation cascade diagram of an external cavity semiconductor laser.", "venue": "Optics express", "year": 2014 }, { "abstract": "We experimentally investigate the timing jitter (TJ) of a passively mode locked external cavity diode laser. Variation of the gain current and the absorber reverse bias voltage allows transitions from fundamental mode locking up to seventh harmonic mode locking. Hereby, a reduction of the TJ as a function of the harmonic mode locking order is found. Furthermore, the application of optical feedback results in an additional reduction of TJ for almost the whole investigated operation range. In particular, the reduction increases with harmonic mode locking order. The highest observed reduction of TJ amounts to a factor of 10 as compared with the free running case which corresponds to a repetition rate linewidth reduction by a factor of 100.", "author_names": [ "Simon Rauch", "Lukas Drzewietzki", "Andreas Klehr", "Joachim Sacher", "Wolfgang Elsassar", "Stefan Breuer" ], "corpus_id": 24709183, "doc_id": "24709183", "n_citations": 15, "n_key_citations": 0, "score": 0, "title": "Experimental Study of the Timing Jitter of a Passively Mode Locked External Cavity Semiconductor Laser Subject to Repetition Rate Transitions and Optical Feedback", "venue": "IEEE Journal of Quantum Electronics", "year": 2015 }, { "abstract": "A simple design of a hybrid integrated short external cavity chaotic semiconductor laser module is presented and fabricated. A distributed feedback laser chip is directed to the transflective mirror through a collimating micro lens, and a part of the light is reflected by the mirror into the laser chip to induce chaos. Transmitted through the mirror, the generated chaotic light is coupled into a pigtail fiber as output by a focusing micro lens. It should be pointed out that the part between the transflective mirror and the emitting surface of the chip works as a short external straight feedback cavity. All the components above together with chip submount, heat sink, and thermoelectric cooler are encapsulated by a commercial 14 pin butterfly package. In our experimental fabrication, the intensity reflectivity of the transflective mirror is optimized as 5% and the external cavity length is 2 mm. Experimental tests show that chaotic light with a bandwidth larger than 4.5 GHz is readily obtained from the chaotic laser module by adjusting laser bias current.", "author_names": [ "Mingjiang Zhang", "Yuhang Xu", "Tong Zhao", "Yanan Niu", "Tianshuang Lv", "Yu Liu", "Zhike Zhang", "Jianzhong Zhang", "Yi Liu", "Yuncai Wang", "Anbang Wang" ], "corpus_id": 19790153, "doc_id": "19790153", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "A Hybrid Integrated Short External Cavity Chaotic Semiconductor Laser", "venue": "IEEE Photonics Technology Letters", "year": 2017 }, { "abstract": "Abstract In this paper, at first the stability of the dynamics of semiconductor laser is analyzed through the Lyapunov exponent spectra, bifurcation diagrams and time series of electric field intensity. The analysis is performed with respect to applied feedback phase C p and feedback strength e of the laser. Then the dynamical chaos control method introduced by Behnia and Akhshani (2009) [26] is used for controlling dynamical behavior of an External Cavity Semiconductor Laser (ECSL) A great virtue of this method is its flexibility. Also, unlike other chaos control techniques, in this method not need to know more than one variable. In this paper, by considering a chaotic dynamical system as a pump current source, the ECSL is stabilized properly. Furthermore, the proposed method is used to design a simple circuit as a controller.", "author_names": [ "Sohrab Behnia", "Saeid Afrang", "Afshin Akhshani", "Khosro Mabhouti" ], "corpus_id": 123451806, "doc_id": "123451806", "n_citations": 26, "n_key_citations": 0, "score": 0, "title": "A novel method for controlling chaos in external cavity semiconductor laser", "venue": "", "year": 2013 }, { "abstract": "We study the symbolic dynamics of a stochastic excitable optical system with periodic forcing. Specifically, we consider a directly modulated semiconductor laser with optical feedback in the low frequency fluctuations (LFF) regime. We use a method of symbolic time series analysis that allows us to uncover serial correlations in the sequence of intensity dropouts. By transforming the sequence of inter dropout intervals into a sequence of symbolic patterns and analyzing the statistics of the patterns, we unveil correlations among several consecutive dropouts and we identify clear changes in the dynamics as the modulation amplitude increases. To confirm the robustness of the observations, the experiments were performed using two lasers under different feedback conditions. Simulations of the Lang Kobayashi (LK) model, including spontaneous emission noise, are found to be in good agreement with the observations, providing an interpretation of the correlations present in the dropout sequence as due to the interplay of the underlying attractor topology, the external forcing, and the noise that sustains the dropout events.", "author_names": [ "Andres Aragoneses", "T Sorrentino", "Sandro Perrone", "Daniel J Gauthier", "M C Torrent", "Cristina Masoller" ], "corpus_id": 6903326, "doc_id": "6903326", "n_citations": 18, "n_key_citations": 1, "score": 0, "title": "Experimental and numerical study of the symbolic dynamics of a modulated external cavity semiconductor laser.", "venue": "Optics express", "year": 2014 }, { "abstract": "We describe the dual frequency and dual polarization emission of a diode pumped vertical external cavity semiconductor laser at 852 nm dedicated to the coherent population trapping of cesium atoms. The output power reaches ~20 mW on each frequency, with a frequency difference in the gigahertz range.", "author_names": [ "Fabiola A Camargo", "Jessica Barrientos", "Ghaya Baili", "Loic Morvan", "Daniel Dolfi", "David Holleville", "Stephane Guerandel", "Isabelle Sagnes", "Patrick M Georges", "Gaelle Lucas-Leclin" ], "corpus_id": 37700850, "doc_id": "37700850", "n_citations": 24, "n_key_citations": 2, "score": 0, "title": "Coherent Dual Frequency Emission of a Vertical External Cavity Semiconductor Laser at the Cesium \\rm D}_{2} Line", "venue": "IEEE Photonics Technology Letters", "year": 2012 } ]

[ { "abstract": "The semiconductor ZnO has gained substantial interest in the research community in part because of its large exciton binding energy (60meV) which could lead to lasing action based on exciton recombination even above room temperature. Even though research focusing on ZnO goes back many decades, the renewed interest is fueled by availability of high quality substrates and reports of p type conduction and ferromagnetic behavior when doped with transitions metals, both of which remain controversial. It is this renewed interest in ZnO which forms the basis of this review. As mentioned already, ZnO is not new to the semiconductor field, with studies of its lattice parameter dating back to 1935 by Bunn [Proc. Phys. Soc. London 47, 836 (1935) studies of its vibrational properties with Raman scattering in 1966 by Damen et al. [Phys. Rev. 142, 570 (1966) detailed optical studies in 1954 by Mollwo [Z. Angew. Phys. 6, 257 (1954) and its growth by chemical vapor transport in 1970 by Galli and Coker [Appl. Phys.", "author_names": [ "Umit Ozgur", "Yahya Alivov", "C Liu", "Ali Teke", "Michael A Reshchikov", "Seydi Dogan", "Vitaliy Avrutin", "Sang-Jun Cho", "Hadis Morkoc" ], "corpus_id": 120256746, "doc_id": "120256746", "n_citations": 9095, "n_key_citations": 113, "score": 2, "title": "A COMPREHENSIVE REVIEW OF ZNO MATERIALS AND DEVICES", "venue": "", "year": 2005 }, { "abstract": "Persistent organic pollutants (POPs) are carbon based chemical substances that are resistant to environmental degradation and may not be completely removed through treatment processes. Their persistence can contribute to adverse health impacts on wild life and human beings. Thus, the solar photocatalysis process has received increasing attention due to its great potential as a green and eco friendly process for the elimination of POPs to increase the security of clean water. In this context, ZnO nanostructures have been shown to be prominent photocatalyst candidates to be used in photodegradation owing to the facts that they are low cost, non toxic and more efficient in the absorption across a large fraction of the solar spectrum compared to TiO2. There are several aspects, however, need to be taken into consideration for further development. The purpose of this paper is to review the photo degradation mechanisms of POPs and the recent progress in ZnO nanostructured fabrication methods including doping, heterojunction and modification techniques as well as improvements of ZnO as a photocatalyst. The second objective of this review is to evaluate the immobilization of photocatalyst and suspension systems while looking into their future challenges and prospects.", "author_names": [ "Chin Boon Ong", "Law Yong Ng", "Abdul Wahab Mohammad" ], "corpus_id": 116389546, "doc_id": "116389546", "n_citations": 862, "n_key_citations": 5, "score": 0, "title": "A review of ZnO nanoparticles as solar photocatalysts: Synthesis, mechanisms and applications", "venue": "", "year": 2018 }, { "abstract": "Abstract Among the popular photocatalysts, ZnO is one of the most potent photocatalysts considering its green properties, cheap price, and durability. However, the practical application of ZnO is limited because of its large band gap energy and rapid recombination of the photoinduced electron hole pairs. This paper reviews the main advancements in overcoming the barriers accompanied by pure ZnO and the criteria for fabrication of effective visible light responsive ZnO based photocatalysts. Herein, the binary ZnO based nanocomposites with p n heterojunctions, n n heterojunctions, and ternary ZnO based nanocomposites based on different heterostructures, and their mechanism for enhanced light harvesting and charge separation/transfer were thoroughly discussed.", "author_names": [ "Mahsa Pirhashemi", "Aziz Habibi-Yangjeh", "Shima Rahim Pouran" ], "corpus_id": 103835967, "doc_id": "103835967", "n_citations": 549, "n_key_citations": 1, "score": 0, "title": "Review on the criteria anticipated for the fabrication of highly efficient ZnO based visible light driven photocatalysts", "venue": "", "year": 2018 }, { "abstract": "Abstract Among the most challenging problems that human beings appear to face are depleting energy sources and increasing environmental pollutions. Heterogeneous photocatalytic processes are the most rewarding technology to generate renewable energy and degrade environmental pollutants. In these processes, semiconductors are used as photocatalysts. ZnO is a widely used photocatalyst, because of its strong oxidation ability, cost effectiveness, non toxicity, versatility in synthesis, abundance in nature, and ease of crystallization. However, pure ZnO has some drawbacks, due to its wide band gap, poor solar light utilization, and rapid recombination of the photoinduced charge carriers. Modification of ZnO using different strategies including coupling with narrow band gap semiconductors, noble metal deposition, surface sensitization by organic dyes, and elemental doping can easily address these shortcomings. In addition, separation of photocatalysts from the treated systems limits their broad applications. Incorporation of photocatalysts in magnetic materials will help their recycling using external magnetic field. This combination leads to a new generation of photocatalysts, known as magnetically separable photocatalysts. The present review provides helpful insights into preparation of magnetically separable photocatalysts based on ZnO and their applications for degradations of different pollutants.", "author_names": [ "Maryam Shekofteh-Gohari", "Aziz Habibi-Yangjeh", "M Abitorabi", "A Maureen Rouhi" ], "corpus_id": 106297420, "doc_id": "106297420", "n_citations": 363, "n_key_citations": 0, "score": 0, "title": "Magnetically separable nanocomposites based on ZnO and their applications in photocatalytic processes: A review", "venue": "", "year": 2018 }, { "abstract": "Abstract Different photocatalysts based on commercial ZnO modified by silver photodeposition were prepared in this work. The samples were characterized by X ray fluorescence spectrometry (XRF) specific surface area (SSA) transmission electron microscopy (TEM) X ray photoelectron spectroscopy (XPS) X ray diffraction (XRD) and UV vis diffuse reflectance (UV vis DRS) XRD and XPS showed that Ag/ZnO samples are composed of metallic Ag (Ag0) and ZnO structure was identified. Furthermore, TEM analysis evidenced that the number of silver particles increased with the Ag content. At last, UV vis DRS results revealed a reflectance band for Ag/ZnO samples, ascribed to the surface plasmon resonance (SPR) absorption of metal silver particles. Commercial ZnO and Ag/ZnO samples were evaluated in the phenol removal under UV light irradiation. It was observed an enhancement of photocatalytic phenol removal from aqueous solutions by silver addition in comparison to commercial ZnO. In particular, the phenol removal increased with the silver content from 0.14 to 0.88 wt% after this content (i.e 1.28 wt% the phenol degradation significantly decreased indicating that the optimal Ag content was equal to 0.88 wt% The influence of the best photocatalyst dosage and the change of the initial phenol concentration in solution were also investigated in this work and the best photocatalytic performance was obtained by using 50 mg L 1 of phenol initial concentration and 0.15 g L 1 of photocatalyst dosage. Finally, the optimized Ag/ZnO photocatalyst was employed for the treatment of a real drinking wastewater containing phenol in which the almost total phenol removal was achieved after 180 min of UV irradiation time.", "author_names": [ "Vincenzo Vaiano", "Mariantonietta Matarangolo", "J J Murcia", "Hugo A Rojas", "Jose Antonio Navio", "M C Hidalgo" ], "corpus_id": 104260706, "doc_id": "104260706", "n_citations": 257, "n_key_citations": 1, "score": 0, "title": "Enhanced photocatalytic removal of phenol from aqueous solutions using ZnO modified with Ag", "venue": "", "year": 2018 }, { "abstract": "Synergy between copper and zinc oxide on a catalyst surface facilitates methanol synthesis via CO2 hydrogenation. Metal oxide synergy The hydrogenation of carbon dioxide is a key step in the industrial production of methanol. Catalysts made from copper (Cu) and zinc oxide (ZnO) on alumina supports are often used. However, the actual active sites for this reaction Zn Cu bimetallic sites or ZnO Cu interfacial sites are debated. Kattel et al. studied model catalysts and found that ZnCu became as active as ZnO/Cu only after surface oxidation formed ZnO. Theoretical studies favor a formate intermediate pathway at a ZnO Cu interface active site. Science, this issue p. 1296 The active sites over commercial copper/zinc oxide/aluminum oxide (Cu/ZnO/Al2O3) catalysts for carbon dioxide (CO2) hydrogenation to methanol, the Zn Cu bimetallic sites or ZnO Cu interfacial sites, have recently been the subject of intense debate. We report a direct comparison between the activity of ZnCu and ZnO/Cu model catalysts for methanol synthesis. By combining x ray photoemission spectroscopy, density functional theory, and kinetic Monte Carlo simulations, we can identify and characterize the reactivity of each catalyst. Both experimental and theoretical results agree that ZnCu undergoes surface oxidation under the reaction conditions so that surface Zn transforms into ZnO and allows ZnCu to reach the activity of ZnO/Cu with the same Zn coverage. Our results highlight a synergy of Cu and ZnO at the interface that facilitates methanol synthesis via formate intermediates.", "author_names": [ "Shyam Kattel", "Pedro J Ramirez", "Jingguang G Chen", "Jose Antonio Rodriguez", "Ping Liu" ], "corpus_id": 206655295, "doc_id": "206655295", "n_citations": 584, "n_key_citations": 2, "score": 0, "title": "Active sites for CO2 hydrogenation to methanol on Cu/ZnO catalysts", "venue": "Science", "year": 2017 }, { "abstract": "Abstract Photocatalytic degradation is an effective method to alleviate environmental pollution caused by organic pollutants. In this work, research progress on the application of photocatalytic degradation and the antibacterial properties of zinc oxide (ZnO) nanomaterials is reviewed. The visible light photo response of ZnO has been expanded by employing various strategies, such as enhancing the photocatalytic activity of ZnO through modification of its electronic and optical properties, doping metal/nonmetal atoms, depositing noble metals, constructing heterojunctions, and coupling carbon materials, because the wide band gap of ZnO likely restricts its applications in photocatalysis. Although ZnO nanomaterials are commonly used for antibacterial applications, our understanding on the toxicity mechanisms of ZnO is limited. Some of the main toxicity mechanisms of this compound include reactive oxygen species generation, Zn2+ release, membrane dysfunction, and nanoparticle internalization into cells. Some of the main methods that improve antibacterial activities are coating inorganic or organic antimicrobial agents, doping ZnO, and tuning the size, morphological characteristics, and concentration of ZnO nanomaterials. This review aims to examine the current research progress on ZnO based nanomaterials developed for the photocatalysis of organic contaminant degradation and antibacterial applications.", "author_names": [ "Kezhen Qi", "Bei Cheng", "Jiaguo Yu", "Wingkei Ho" ], "corpus_id": 139442026, "doc_id": "139442026", "n_citations": 471, "n_key_citations": 3, "score": 0, "title": "Review on the improvement of the photocatalytic and antibacterial activities of ZnO", "venue": "", "year": 2017 }, { "abstract": "Abstract In the last 15 years, more than 50,000 papers with zinc oxide (ZnO) in the title are listed within ISI database. The outstanding popularity of ZnO has many reasons; the most important one appears to be its multi functionality, resulting in applications in physics, chemistry, electrical engineering, material science, energy, textile, rubber, additive manufacturing, cosmetics, and pharmaceutical or medicine, as well as the ease to grow all kinds of nano and microstructures. A key structure is the tetrapod shaped ZnO (T ZnO) which we want to focus on in this mini review to demonstrate the remarkable properties and multifunctionality of ZnO and motivate why even much more research and applications are likely to come in near future. As T ZnO came into focus again mainly during the last 10 years, the big data problem in T ZnO is not as severe as in ZnO; nevertheless, a complete overview is impossible. However, this brief T ZnO overview attempts to cover the scopes toward advanced technologies; nanoelectronics/optoelectronics sensing devices; multifunctional composites/coatings; novel biomedical engineering materials; versatile energy harvesting candidates; and unique structures for applications in chemistry, cosmetics, pharmaceuticals, food, agriculture, engineering technologies, and many others. The 3D nanotechnology is a current mainstream in materials science/nanotechnology research, and T ZnO contributes to this field by its simple synthesis of porous networks as sacrificial templates for any desired new cellular materials.", "author_names": [ "Yogendra Kumar Mishra", "Rainer Adelung" ], "corpus_id": 139204788, "doc_id": "139204788", "n_citations": 325, "n_key_citations": 2, "score": 0, "title": "ZnO tetrapod materials for functional applications", "venue": "", "year": 2017 }, { "abstract": "The power conversion efficiency of perovskite solar cells (PSCs) has ascended from 3.8% to 22.1% in recent years. ZnO has been well documented as an excellent electron transport material. However, the poor chemical compatibility between ZnO and organo metal halide perovskite makes it highly challenging to obtain highly efficient and stable PSCs using ZnO as the electron transport layer. It is demonstrated in this work that the surface passivation of ZnO by a thin layer of MgO and protonated ethanolamine (EA) readily makes ZnO as a very promising electron transporting material for creating hysteresis free, efficient, and stable PSCs. Systematic studies in this work reveal several important roles of the modification: (i) MgO inhibits the interfacial charge recombination, and thus enhances cell performance and stability; (ii) the protonated EA promotes the effective electron transport from perovskite to ZnO, further fully eliminating PSCs hysteresis; (iii) the modification makes ZnO compatible with perovskite, nicely resolving the instability of ZnO/perovskite interface. With all these findings, PSCs with the best efficiency up to 21.1% and no hysteresis are successfully fabricated. PSCs stable in air for more than 300 h are achieved when graphene is used to further encapsulate the cells.", "author_names": [ "Jing Cao", "Binghui Wu", "Ruihao Chen", "Youyunqi Wu", "Yong Hui", "Bingwei Mao", "Nanfeng Zheng" ], "corpus_id": 3874707, "doc_id": "3874707", "n_citations": 228, "n_key_citations": 0, "score": 0, "title": "Efficient, Hysteresis Free, and Stable Perovskite Solar Cells with ZnO as Electron Transport Layer: Effect of Surface Passivation.", "venue": "Advanced materials", "year": 2018 }, { "abstract": "Perovskite solar cells (PSCs) have developed rapidly over the past few years, and the power conversion efficiency of PSCs has exceeded 20% Such high performance can be attributed to the unique properties of perovskite materials, such as high absorption over the visible range and long diffusion length. Due to the different diffusion lengths of holes and electrons, electron transporting materials (ETMs) used in PSCs play a critical role in PSCs performance. As an alternative to TiO2 ETM, ZnO materials have similar physical properties to TiO2 but with much higher electron mobility. In addition, there are many simple and facile methods to fabricate ZnO nanomaterials with low cost and energy consumption. This review focuses on recent developments in the use of ZnO ETM for PSCs. The fabrication methods of ZnO materials are briefly introduced. The influence of different ZnO ETMs on performance of PSCs is then reviewed. The limitations of ZnO ETM based PSCs and some solutions to these challenges are also discussed. The review provides a systematic and comprehensive understanding of the influence of different ZnO ETMs on PSCs performance and potentially motivates further development of PSCs by extending the knowledge of ZnO based PSCs to TiO2 based PSCs.", "author_names": [ "Peng Zhang", "Jiang Wu", "Ting Zhang", "Yafei Wang", "Detao Liu", "Hao Chen", "Long Ji", "Chunhua Liu", "Waseem Ahmad", "Zhi David Chen", "Shibin Li" ], "corpus_id": 32467962, "doc_id": "32467962", "n_citations": 200, "n_key_citations": 1, "score": 0, "title": "Perovskite Solar Cells with ZnO Electron Transporting Materials.", "venue": "Advanced materials", "year": 2018 } ]

[ { "abstract": "The ferromagnetism of two dimensional (2D) materials has aroused great interest in recent years, which may play an important role in the next generation magnetic devices. Herein, a series of 2D transition metal organic framework materials (TM NH MOF, TM Sc Zn) are designed, and their electronic and magnetic characters are systematically studied by means of first principles calculations. Their structural stabilities are examined through binding energies and ab initio molecular dynamics simulations. Their optimized lattice constants are correlated to the central TM atoms. These 2D TM NH MOF nanosheets exhibit various electronic and magnetic performances owing to the effective charge transfer and interaction between TM atoms and graphene linkers. Interestingly, Ni and Zn NH MOFs are nonmagnetic semiconductors (SM) with band gaps of 0.41 eV and 0.61 eV, respectively. Co and Cu NH MOFs are bipolar magnetic semiconductors (BMS) while Fe NH MOF monolayer is a half semiconductor (HSM) Furthermore, the elastic strain could tune their magnetic behaviors and transformation, which ascribes to the charge redistribution of TM 3d states. This work predicts several new 2D magnetic MOF materials, which are promising for applications in spintronics and nanoelectronics.", "author_names": [], "corpus_id": 237846902, "doc_id": "237846902", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Magnetic and electronic properties of two dimensional metal organic frameworks TM3(C2NH)12", "venue": "Chinese Physics B", "year": 2021 }, { "abstract": "The peculiar magnetic properties of rare earth nitrides (RENs) make them suitable for a wide range of applications. Here, we report on a density functional theory (DFT) study of an interesting member of the family, two dimensional (2D) NdN film, using the generalized gradient approximation (GGA) including the Hubbard (U) parameter. We consider different film thicknesses, taking into account the effects of N vacancies (VN) and dopants (C and O) Formation energy values show that, even though N vacancy is the predominant defect, C and O dopants are also probable impurities in these films. Individual Nd and N magnetic moments oscillate in the presence of VN and dopants owing to the induced lattice distortions. The density of states calculations show that the 2D NdN film has a semi metallic nature, while the f orbitals are separated into fully filled and empty bands. A magnetic anisotropy energy of ~50 meV is obtained, and the easy axis aligns along the film orientation as the film thickness increases, revealing that such films are ideal candidates for spintronic applications.", "author_names": [ "S Assa Aravindh", "Iman S Roqan" ], "corpus_id": 208975666, "doc_id": "208975666", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Structural, magnetic and electronic properties of two dimensional NdN: an ab initio study", "venue": "", "year": 2019 }, { "abstract": "Two dimensional CrI3 has attracted much attention as it is reported to be a ferromagnetic semiconductor with a Curie temperature of around 45 K. By performing first principles calculations, we find that the magnetic ground state of CrI3 is variable under biaxial strain. Our theoretical investigations show that the ground state of monolayer CrI3 is ferromagnetic under compression, but becomes antiferromagnetic under tension. Particularly, the transition occurs under a feasible in plane strain of around 1.8% Accompanied by the transition of the magnetic ground state, CrI3 undergoes a transition from magnetic metal to half metal to half semiconductor to spin relevant semiconductor when the strain varies from 15% to 10% We attribute these transitions to the variation of the d orbitals of Cr atoms and the p orbitals of I atoms. Generally, we report a series of magnetic and electronic phase transitions in strained CrI3, which will help both theoretical and experimental researchers in further understanding the tunable electronic and magnetic properties of CrI3 and its analogs.", "author_names": [ "Zewen Wu", "Jin Yu", "Shengjun Yuan" ], "corpus_id": 59251165, "doc_id": "59251165", "n_citations": 65, "n_key_citations": 0, "score": 0, "title": "Strain tunable magnetic and electronic properties of monolayer CrI3.", "venue": "Physical chemistry chemical physics PCCP", "year": 2019 }, { "abstract": "We investigate the electronic and magnetic structures of two dimensional transition metal tri chalcogenide CrSiTe3 and CrGeTe3 materials by carrying out first principles calculations. The single layer CrSiTe3 and CrGeTe3 are found to be a ferromagnetic insulator, where the presence of the strong dps hybridization of Cr eg Te p plays a crucial role for the ferromagnetic coupling between Cr ions. We observe that the bandgaps and the interlayer magnetic order vary notably depending on the magnitude of on site Coulomb interaction U for Cr d electrons. The bandgaps are formed between the Cr eg conduction bands and the Te p valence bands for both CrSiTe3 and CrGeTe3 in the majority spin channel. The dominant Te p antibonding character in the valence bands just below the Fermi level is related to the decrease of the bandgap for the increase of U. We elucidate the energy band diagram, which may serve to understand the electronic and magnetic properties of the ABX3 type transition metal tri chalcogenides in general.", "author_names": [ "Sungmo Kang", "Seungjin Kang", "Jaejun Yu" ], "corpus_id": 62884139, "doc_id": "62884139", "n_citations": 17, "n_key_citations": 0, "score": 0, "title": "Effect of Coulomb Interactions on the Electronic and Magnetic Properties of Two Dimensional CrSiTe3 and CrGeTe3 Materials", "venue": "Journal of Electronic Materials", "year": 2018 }, { "abstract": "Layered MAX phases are exfoliated into 2D single layers and multilayers, so called MXenes. Using fi rst principles calculations, the formation and electronic properties of various MXene systems, M 2 C (M Sc, Ti, V, Cr, Zr, Nb, Ta) and M 2 N (M Ti, Cr, Zr) with surfaces chemically functionalized by F, OH, and O groups, are examined. Upon appropriate surface functionalization, Sc 2 C, Ti 2 C, Zr 2 C, and Hf 2 C MXenes are expected to become semiconductors. It is also derived theoretically that functionalized Cr 2 C and Cr 2 N MXenes are magnetic. Thermoelectric calculations based on the Boltzmann theory imply that semiconducting MXenes attain very large Seebeck coeffi cients at low temperatures.", "author_names": [ "Mohammad Khazaei", "Masao Arai", "Taizo Sasaki", "C Y Chung", "Natarajan Sathiyamoorthy Venkataramanan", "Mehdi Estili", "Yoshio Sakka", "Yoshiyuki Kawazoe" ], "corpus_id": 98277691, "doc_id": "98277691", "n_citations": 770, "n_key_citations": 7, "score": 0, "title": "Novel Electronic and Magnetic Properties of Two Dimensional Transition Metal Carbides and Nitrides", "venue": "", "year": 2013 }, { "abstract": "Two dimensional (2D) nanomaterials have received increasing interest because of their unique properties for versatile applications. In this work, we present a first principles study on a new family of 2D nanostructures, Janus transition metal chalcogenide MSX (M Ti or V; and X C, N, Si, or P) monolayers, for their multifunctional applications. In this work, we show that the Janus MSXs possess diverse electronic and magnetic properties, and can be semiconducting or metallic, and nonmagnetic or magnetic, depending on their composition. We find that a TiSC monolayer with a 1H phase (TiSC 1H) is suitable as a cathode for Li ion batteries and anode materials for Na and Mg ion batteries due to its high open circuit voltage (OCV) (2.121 eV) for Li, and low OCVs upon Na (0.676 eV) and Mg (1.044 eV) intercalation, respectively. Importantly, TiSC 1H shows fast charge/discharge rates, good cycling stability, and high storage density as electrode materials for rechargeable batteries because of low ion diffusion barriers, small volume expansion and high specific capacity. We further show that TiSP 1H has the best performance in the hydrogen evolution reaction due to both its catalytic activities on the surfaces and relatively low overpotentials upon hydrogenation. Our study demonstrates that the 2D Janus MSXs may find multifunctional applications in nanodevices, spintronics, catalysis, and electrochemical energy storage.", "author_names": [ "Wenzhou Chen", "Yuanju Qu", "Lingmin Yao", "Xianhua Hou", "Xingqiang Shi", "Hui Pan" ], "corpus_id": 103966702, "doc_id": "103966702", "n_citations": 26, "n_key_citations": 0, "score": 0, "title": "Electronic, magnetic, catalytic, and electrochemical properties of two dimensional Janus transition metal chalcogenides", "venue": "", "year": 2018 }, { "abstract": "A two dimensional ferromagnetic semiconductor Cr2Ge2Te6 (CGT) was recently found to possess extraordinary characteristics and has great potential in the emerging field of spintronics. Using first principles calculations, we examined the stabilities of this layered system by studying the cleavage energies and phonon dispersion. The ferromagnetic ground state has an in plane spin polarization and bandgaps of about 0.26 eV by Perdew Burke Ernzerhof van der Waals and 0.91 eV by the Heyd Scuseria Ernzerhof functional. Furthermore, we employed strain engineering and an external electric field to control the electronic and magnetic properties. In addition, we studied the magnetic anisotropy energy as well as its modulation under the electric field. We predict the CGT monolayer to be the easy plane ferromagnet, and the perpendicular electric field could affect the ferromagnetic stability along different directions. Our obtained results provide guidance for the potential applications of monolayer CGT for magnetic nanodevices, spintronic, and straintronic applications.", "author_names": [ "Kangying Wang", "Tao Hu", "Fanhao Jia", "Guodong Zhao", "Yuyu Liu", "Igor V Solovyev", "Alexander P Pyatakov", "Anatoly K Zvezdin", "Wei Ren" ], "corpus_id": 127550174, "doc_id": "127550174", "n_citations": 35, "n_key_citations": 0, "score": 0, "title": "Magnetic and electronic properties of Cr2Ge2Te6 monolayer by strain and electric field engineering", "venue": "Applied Physics Letters", "year": 2019 }, { "abstract": "Low dimensional materials exhibit many exceptional properties and functionalities which can be efficiently tuned by externally applied force or fields. Here we review the current status of research on tuning the electronic and magnetic properties of low dimensional carbon, boron nitride, metal dichalcogenides, phosphorene nanomaterials by applied engineering strain, external electric field and interaction with substrates, etc, with particular focus on the progress of computational methods and studies. We highlight the similarities and differences of the property modulation among one and two dimensional nanomaterials. Recent breakthroughs in experimental demonstration of the tunable functionalities in typical nanostructures are also presented. Finally, prospective and challenges for applying the tunable properties into functional devices are discussed. WIREs Comput Mol Sci 2016, 6:324 350. doi: 10.1002/wcms.1251", "author_names": [ "Zhuhua Zhang", "Xiaofei Liu", "Jin Zhong Yu", "Yang Hang", "Y Li", "Yufeng Guo", "Ying Xu", "Xu Sun", "Jianxin Zhou", "Wanlin Guo" ], "corpus_id": 14135481, "doc_id": "14135481", "n_citations": 46, "n_key_citations": 0, "score": 0, "title": "Tunable electronic and magnetic properties of two dimensional materials and their one dimensional derivatives", "venue": "Wiley interdisciplinary reviews. Computational molecular science", "year": 2016 }, { "abstract": "Two dimensional (2D) nanomaterials have attracted extensive interest due to their unique properties and versatile applications. In the current work, a new family of 2D nanostructures, 2D transition metal phosphide monolayer (M2P) is designed to find its multifunctional applications on the basis of density functional theory (DFT) calculations. We show that the 2D M2P monolayers are thermodynamically stable by carrying out molecular dynamic simulations, analyzing their phonon dispersions, and calculating their mechanical properties. We find that all of the stable 2D M2P monolayers are metallic, and their magnetic states strongly depend on the transition metals and geometric phases. We further demonstrate that 2D W2P and Fe2P monolayers in the 2H phase show the best catalytic performance in hydrogen evolution reaction (HER) due to the relatively low overpotentials at high hydrogen coverage. Importantly, oxygen functionalization can efficiently improve the HER activities of the 2D M2P monolayers at low hydro.", "author_names": [ "Yangfan Shao", "Xingqiang Shi", "Hui Pan" ], "corpus_id": 102994704, "doc_id": "102994704", "n_citations": 36, "n_key_citations": 0, "score": 0, "title": "Electronic, Magnetic, and Catalytic Properties of Thermodynamically Stable Two Dimensional Transition Metal Phosphides", "venue": "", "year": 2017 }, { "abstract": "Abstract We report a detailed density functional theory investigation for ACr2As2 (A Sr, Ba) which are isostructural to their iron counterparts AFe2As2, parent compounds of iron based superconductors. The calculated results for these two compounds are quite similar, indicating that the A site ions have only a relatively small impact on the magnetic and electronic structures. It is found that both ACr2As2 favor an itinerant antiferromagnetic ground state with G type spin arrangement, and possess a sizable magnetocrystalline anisotropy energy with the easy axis directed along the c axis perpendicular to the CrAs plane. Furthermore, the optimized lattice constants and internal atomic parameter of ACr2As2 are found to be sensitive to magnetic ordering, which implies the presence of a magnetostructural coupling effect.", "author_names": [ "Wenqi Zhou", "P Hu", "Shu-wei Li", "Shuxiang Wu" ], "corpus_id": 125424210, "doc_id": "125424210", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "First principles study of the magnetic and electronic properties of ACr2As2 (A Sr, Ba)", "venue": "Journal of Magnetism and Magnetic Materials", "year": 2019 } ]

[ { "abstract": "Power electronics are crucial elements in more electric aircraft (MEA) applications. Existing hardware is almost exclusively silicon (Si) based. However, recent advances in semiconductor technology yielded silicon carbide (SiC) components with current ratings suitable for aerospace applications. These devices have much strength that can increase power density and improve performance over Si based hardware. High switching speeds are characteristic of SiC devices, and there is much concern about their impact on electromagnetic interference (EMI) This may necessitate larger EMI filters to comply with EMI standards, which would decrease power density and negate some of SiC's benefits. The following research explores the tradeoff between efficiency and EMI. It compares the performance of two high power three phase converters: one built from SiC MOSFETs and the other from Si IGBTs. The test setup consists of a 250 kW drive stand capable of sourcing and regeneratively sinking power as well as a 40 kVA aerospace rated machine. Experimental results are obtained at a bus voltage of 270 Vdc with power levels exceeding 1.5 p.u. The findings demonstrate comparable EMI performance for Si and SiC under MIL STD 461 with the SiC converter achieving higher efficiency.", "author_names": [ "Will Perdikakis", "Mark J Scott", "Kevin J Yost", "Chase Kitzmiller", "Bailey Hall", "Katherine A Sheets" ], "corpus_id": 226293636, "doc_id": "226293636", "n_citations": 4, "n_key_citations": 1, "score": 1, "title": "Comparison of Si and SiC EMI and Efficiency in a Two Level Aerospace Motor Drive Application", "venue": "IEEE Transactions on Transportation Electrification", "year": 2020 }, { "abstract": "In this paper, a preliminary PCB board for the electromagnetic interference (EMI) characterization of innovative silicon carbide (SiC) based switching devices is presented. Packaging technological issues can determine hurdles in the high frequency switching and high power regime where wide band gap semiconductors are intended today for Electric Vehicle (EV) applications. In particular, the parasitic inductances that emerge in such devices, must be assessed, by using e.g. EMI techniques. In this specific case, the EMI characterization is supposed to be carried out in a semi anechoic chamber, available at the University of Palermo (UNIPA) to assess the electromagnetic disturbances according to the levels of compliance indicated by the standards. The proposed prototype can work properly at the following levels of voltage, frequency and load power: 28.5 V, 2 MHz and 40 W. Details concerning the layout design and the prototype manufacturing are discussed.", "author_names": [ "Filippo Pellitteri", "Massimo Caruso", "Salvatore Stivala", "Antonino Parisi", "Vincenzo Vinciguerra", "Angelo Alberto Messina", "Guido Ala", "Fabio Viola", "Rosario Miceli", "Alessandro Busacca" ], "corpus_id": 220604993, "doc_id": "220604993", "n_citations": 4, "n_key_citations": 1, "score": 0, "title": "A prototypal PCB board for the EMI characterization of SiC based innovative switching devices", "venue": "2020 IEEE 20th Mediterranean Electrotechnical Conference MELECON)", "year": 2020 }, { "abstract": "Abstract Although silicon carbide (SiC) devices can greatly improve the energy efficiency of electric motor drive systems and increase the power density of inverters as well in electric vehicle applications, fast switching and high frequency operations of the devices bring more serious electromagnetic compatibility (EMC) problems. It is very important to predict the electromagnetic interference (EMI) level of SiC motor drive systems at design phase. However, since the megahertz resonances caused by the system parasitic parameters can't be ignored, conventional EMI prediction methods need to be improved. In this paper, the fast switching transient of SiC devices, the power module parasitic parameters, and other detailed circuit parameters are modeled into the EMI sources and propagation paths. In the differential mode (DM) and common mode (CM) EMI sources modeling, both the equivalent switching current sources and the equivalent switching voltage sources of SiC devices are simultaneously taken into account. The proposed analytical method can accurately predict conducted EMI in the SiC motor drive system in frequency range from 150 kHz to 30 MHz. Compared with the previous conventional methods, the proposed method improves DM EMI prediction accuracy of the SiC motor drive system in high frequency range.", "author_names": [ "Zhuolin Duan", "Xuhui Wen" ], "corpus_id": 213969063, "doc_id": "213969063", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "A new analytical conducted EMI prediction method for SiC motor drive systems", "venue": "", "year": 2020 }, { "abstract": "The motor drive has been widely adopted in modern power applications. With the emergency of the next generation wide bandgap semiconductor device, such as silicon carbide (SiC) MOSFET, performance of the motor drive can be improved in terms of efficiency, power density, and reliability. However, the fast switching transient and serious switching ringing of the SiC MOSFET can cause unwanted high frequency (HF) electromagnetic interference (EMI) which may significantly reduce the reliability of the motor drive in many aspects. In order to comprehensively reveal the mechanism of the EMI previously used in motor drives using SiC MOSFET, this paper plans to analyze the influences of both HF impedance of the motor and switching characteristics of the SiC MOSFET. A simulation model for motor drives has been proposed, which contains the HF circuit model of the motor as well as a semi behavioral analytical model of the SiC MOSFET. Since the model shows a good agreement with the experimentally measured results on spectra of drain source voltage of the SiC MOSFET (vds) phase to ground voltage of the motor (vphase) CM voltage (vcm) phase current of the motor (idm) and CM current (icm) it can be adopted to quantitatively investigate the influence of the motor impedance on EMI through frequency domain analysis. Additionally, the impacts of switching characteristics of SiC MOSFET on EMI are also well studied according to relative experiment results in terms of switching speed, switching frequency, and switching ringing. Based on the analysis above, the relationship between motor impedance, switching characteristics of the SiC MOSFET, and HF EMI can be figured out, which is able to provide much helpful assistance for application of the motor drive.", "author_names": [ "Yingzhe Wu", "Shan Yin", "Hu Li", "Minghai Dong" ], "corpus_id": 225163166, "doc_id": "225163166", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Modeling and Experimental Investigation of Electromagnetic Interference (EMI) for SiC Based Motor Drive", "venue": "", "year": 2020 }, { "abstract": "This paper investigates the system level conducted EMI model for SiC powertrain of electric vehicles. Firstly, a conducted EMI model for the whole powertrain is presented, which includes battery, inverter, PMSM, AC cables and DC cables. Then, a conducted emission test platform for EV powertrain is built to verify the system level EMI model. Finally, impact of system layout on EMI noise, including AC cable length, grounding schemes of AC and DC cable shielding layers, PWM schemes, and auxiliary power supply are investigated according to both proposed system level EMI model and experiment test results.", "author_names": [ "Xiaoyu Jia", "Changsheng Hu", "Bitao Dong", "Fengchun He", "Hui Wang", "Dehong Xu" ], "corpus_id": 220260971, "doc_id": "220260971", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "System Level Conducted EMI Model for SiC Powertrain of Electric Vehicles", "venue": "2020 IEEE Applied Power Electronics Conference and Exposition (APEC)", "year": 2020 }, { "abstract": "The SiC mosfet in the medium voltage direct current (MVdc) transportation electrification system features faster switching performance, while simultaneously binging more significant electromagnetic interference (EMI) issues within the rolling stocks, substations, and radiated disturbance into space along the catenaries and tracks. Due to the necessity to involve both the transient characteristics of power semiconductor devices and the stray parameters of all the equipment in the analysis of EMI, it is considerably challenging to perform wideband device level simulation on traditional commercial software for such a complex system with numerous trains and stations. A computationally efficient method for wideband modeling and simulation of the MVdc high speed railway system for the assessment of conducted EMI during the project design stage is proposed in this article. Physical characteristics of the semiconductor devices, parasitic parameters of the mosfet package, and converter topology are all taken into consideration to provide not only accurate system level performance of the system but also an insight into high frequency characteristics under different operation conditions. The calculation burden is alleviated by a hierarchical circuit partitioning architecture based on the frequency dependent time domain transmission line model and the Norton equivalent parameter extraction of each mosfet module to split the whole system into several smaller subcircuits in terms of matrix size, and a fully parallel implementation of the MVdc system is carried out on the graphics processor. The developed program is used to study the case of Jing Zhang high speed railway system topology, which is compatible to be modified to the MVdc project. Simulation results show that it is essential to estimate the EMI level comprehensively considering the alternative of speed and dc voltage.", "author_names": [ "Ruimin Zhu", "Tian Liang", "Venkata R Dinavahi", "Guishu Liang" ], "corpus_id": 216320244, "doc_id": "216320244", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Wideband Modeling of Power SiC mosfet Module and Conducted EMI Prediction of MVDC Railway Electrification System", "venue": "IEEE Transactions on Electromagnetic Compatibility", "year": 2020 }, { "abstract": "This paper describes conducted Electromagnetic Interference (EMI) simulation of a buck converter using a compact model for an SiC MOSFET. The model simulates the peak values of leakage current flowing out of a heatsink ileak accurately since the model reproduces the experimental results of drain source voltage and its time derivative. In addition, the simulated spectrum of conducted disturbance voltage is in good agreement with the experimental one up to 20 MHz within a maximum error of 6 dB. From 20 to 30 MHz, the simulated spectrum shows the similar peak values to the experimental one with a little deviation in the resonant frequency. The simulated results indicate that the model would be a promising tool for conducted EMI analysis of the power converters using SiC MOSFETs.", "author_names": [ "Yuki Ishii", "Shinobu Nagasawa", "Takeshi Horiguchi", "Yasushige Mukunoki", "Takushi Jimichi", "Masaki Kuzumoto", "Makoto Hagiwara" ], "corpus_id": 220258780, "doc_id": "220258780", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Accurate Conducted EMI Simulation of a Buck Converter With a Compact Model for an SiC MOSFET", "venue": "2020 IEEE Applied Power Electronics Conference and Exposition (APEC)", "year": 2020 }, { "abstract": "version of this paper was presented at 9th International Conference on Advanced Technologies (ICAT'20) 10 12 August 2020, Istanbul, Turkey with the title of \"Determination of Conducted Emi in Sic Based Dual Active Bridge Converter\"", "author_names": [ "Samet Yalcin", "Tuna Goksu", "Selami Kesler", "Okan Bingol" ], "corpus_id": 229441121, "doc_id": "229441121", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Determination of Conducted EMI in SiC Based Dual Active Bridge Converter", "venue": "", "year": 2020 }, { "abstract": "The combination of the Si IGBT and SiC MOSFET inside the Si/SiC hybrid switch will bring serious conducted electromagnetic interference (EMI) noise in the application of the power converters. Compared with the differential mode (DM) EMI noise, the common mode (CM) EMI noise has a greater impact on the total conducted EMI noise, and it is relatively difficult to suppress the common mode EMI noise. However, there is still lack of research on the CM EMI emission characteristics of Si/SiC hybrid switch based converters. In this paper, the CM EMI noise caused by the Si/SiC hybrid switch, Si IGBT, and SiC MOSFET are compared at first. Then, the influence of different current ratios of the Si/SiC hybrid switch on the CM EMI is analyzed.", "author_names": [ "Bo Hu", "Zishun Peng", "Pei Xiao", "Yuxing Dai", "Chao Zhang", "Jun Wang" ], "corpus_id": 231825615, "doc_id": "231825615", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Comparative Analysis of CM EMI for Boost Converter Using Si/SiC hybrid switch", "venue": "2020 IEEE 1st China International Youth Conference on Electrical Engineering (CIYCEE)", "year": 2020 }, { "abstract": "The motor drive is widely applied in industry applications. With the emergency of the next generation wide bandgap semiconductor device, such as silicon carbide (SiC) MOSFET, performance of the motor drive can be improved. However, the fast switching speed and serious switching ringing brought by SiC MOSFET can cause unwanted high frequency (HF) electromagnetic interference (EMI) which may significantly reduce the reliability of the motor drive in many aspects. In order to reveal mechanism of the EMI existing in the motor drive, this paper has analyzed the influences of both HF impedance of the motor and switching characteristics of the SiC MOSFET based on relative experiment results. Influences of motor impedance on EMI have been elaborated through spectra analysis of the drain source voltage of the SiC MOSFET, phase to ground voltage of the motor, CM voltage, phase current of the motor, and CM current. Additionally, impacts of switching performance of the SiC MOSFET on EMI are also discussed in detail. Based on the analysis above, the relationship between motor impedance, switching performance of the SiC MOSFET, and HF EMI can be figured out, which is able to provide much helpful assistance in motor drive applications.", "author_names": [ "Yingzhe Wu", "Shan Yin", "Zhaoyi Liu", "Haiqing Li", "Kye Yak See" ], "corpus_id": 226848112, "doc_id": "226848112", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Experimental Investigation on Electromagnetic Interference (EMI) in Motor Drive Using Silicon Carbide (SiC) MOSFET", "venue": "2020 International Symposium on Electromagnetic Compatibility EMC EUROPE", "year": 2020 } ]

[ { "abstract": "This paper proposes a Six Sigma based framework to deploy high product reliability commitment in distributed subcontractor manufacturing processes. The study aims to expand the Six Sigma tools in applications, where products are designed and developed under the fast time to market requirement. The reliability deployment is driven by two incentives: the customer satisfaction and the reduction of the warranty cost. A closed loop control mechanism is created between the upper and the lower manufacturing streams to identify and remove the early life failures occurred during the initial system installation. A cross functional team is formed to implement Six Sigma tools for resolving critical failures arising in the upper manufacturing stream. The ultimate goal is to achieve high product reliability in the shortest time when the product time to market is essential for gaining the market share. Finally, the proposed control mechanism is demonstrated on the system designs drawn from the semiconductor testing industry.", "author_names": [ "Tongdan Jin", "Balaji Janamanchi", "Qianmei Feng" ], "corpus_id": 153512099, "doc_id": "153512099", "n_citations": 42, "n_key_citations": 3, "score": 1, "title": "RELIABILITY DEPLOYMENT IN DISTRIBUTED MANUFACTURING CHAINS VIA CLOSED LOOP SIX SIGMA METHODOLOGY", "venue": "", "year": 2011 }, { "abstract": "This paper proposes a Six Sigma based framework to deploy high product reliability commitment in distributed subcontractor manufacturing processes. The study aims to expand the Six Sigma tools in applications, where products are designed and developed under the fast time to market requirement. The reliability deployment is driven by two incentives: the customer satisfaction and the reduction of the warranty cost. A closed loop control mechanism is created between the upper and the lower manufacturing streams to identify and remove the early life failures occurred during the initial system installation. A cross functional team is formed to implement Six Sigma tools for resolving critical failures arising in the upper manufacturing stream. The ultimate goal is to achieve high product reliability in the shortest time when the product time to market is essential for gaining the market share. Finally, the proposed control mechanism is demonstrated on the system designs drawn from the semiconductor testing industry. 2010 Elsevier B.V. All rights reserved.", "author_names": [ "Tongdan Jin", "Balaji Janamanchi", "Qianmei Feng" ], "corpus_id": 15004716, "doc_id": "15004716", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Reliability deployment in distributedmanufacturing chains via closed loop Six Sigma methodology", "venue": "", "year": 2015 }, { "abstract": "The purpose of this paper is to discuss new product development (NPD) based on a traditional stage gate process and to examine how NPD tools, such as Lean design for Six Sigma, can accelerate the achievement of the main goals of NPD: reliable product quality, cost effective implementation, and desired time to market. These new tools must be incorporated into a new approach to NPD based on the Advanced Product and Quality Planning methodology. This research paper is based on the theoretical background presented in peer reviewed scientific research papers during the period 1990 2012. In the second section of this study, the author provides examples of the proposed tools and of advanced techniques to show evidence that validates the hypothesis. This study presented the theoretical background on the NPD process and related functions in today's organizations as it relates to competition. NPD was identified as one of the top priorities of every firm, which is why the NPD process must be optimized and oriented toward customers to ensure the quality and reliability of products while minimizing manufacturing costs. The effect on timing and cost is greatly appreciated by top management, and it is well known throughout the firm when a strong, reliable product is launched that it is flawless. To fully deploy all NPD tools requires basic steps such as the following: marketing and planning, design, process, product process validation and the integration of operations from a concurrent engineering standpoint. This research paper provides step by step guidance in order to apply Lean Sigma tool in NPD process in order to achieve Six Sigma quality level in manufacturing. Promoting the practice of Lean design for Six Sigma and its tool enables firms to increase their competitiveness since they will make more reliable products delivered to its consumers. The approach of this research paper combines proven statistical tools to be applied in an original sequence in order to design robust product to match manufacturing capabilities.", "author_names": [ "Jesus Gerardo Cruz Alvarez" ], "corpus_id": 109823592, "doc_id": "109823592", "n_citations": 12, "n_key_citations": 0, "score": 0, "title": "Lean design for Six Sigma: An integrated approach to achieving product reliability and low cost manufacturing", "venue": "", "year": 2015 }, { "abstract": "Purpose The purpose of this paper is to assess and benchmark Six Sigma strategies in services sector, namely, the telecom field, by establishing tables of fallouts of non conforming services and their associated costs along with a custom data envelopment model for benchmarking the different strategic alternatives. Design/methodology/approach Under normality assumption, process fallout in Six Sigma is around 0.002/3.4 part per million for a centered/shifted process. By introducing Six Sigma to applications in services sector, normality assumption may no longer be valid; hence, fallouts of non normal attributes are computed for different one sided quality levels. The associated costs of strategy deployment, fallout and transaction completion are all considered. Data envelopment analysis model is also established to benchmark the Six Sigma strategic plans. The strategies are detailed down to processes and to quality characteristics which constitute the decision making units. The efficiency of each service unit is computed using both CCR and super efficiency models. Findings The amount of efforts/costs needed to reduce the variation in a service may differ according to the targeted quality level. For the same Six Sigma quality level, services demonstrate different performance/efficiencies and hence different returns. In some scenarios, moderate quality levels could present high efficiencies as compared to services of higher levels. It was also found that the required improvement is less in the case of Log normal as compared to normal distributions at some quality levels. This observation is also noted across the presented distributions of this study (Normal, Log normal, Exponential, Gamma and Weibull) Social implications The deployment of Six Sigma in services is mostly found in time related concepts such as timeliness of billing, lifetimes in reliability engineering, queueing theory, healthcare and telecommunication. Originality/value The paper contributes to the existing research by presenting an assessment model of Six Sigma strategies in services of non normal distributions. Strategies of different quality levels present diverse efficiencies; hence, higher quality levels may not be the best alternatives in terms of the returns on investment. The computed fallout rates of the different distributions can serve as palm lines for further deployment of Six Sigma in services. Besides, the combination of optimization and Six Sigma analysis provides additional benchmarking tool of strategic plans in both manufacturing and services sector.", "author_names": [ "Doraid M Dalalah" ], "corpus_id": 198598095, "doc_id": "198598095", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Benchmarking of Six Sigma in telecom services", "venue": "Benchmarking: An International Journal", "year": 2019 }, { "abstract": "In today's ultra competitive business environment, product life cycles have become shorter. Freeing markets and globalization have increased competition. The reliability, timeliness, accuracy, and perceived value of the products or services have become the keys to company success. The business environment has become turbulent, complex, and even chaotic. To maintain and extend competitive advantages in all dimensions and markets, companies shift increasingly from defining quality as a task that can be run by a quality department, to seeing it as the overall long term umbrella objective of their business. In this era, all manufacturing concerns across the globe are facing new challenges of competitiveness in the emerging markets and struggling hard to improve their financial performances by deploying new quality improvement initiatives. New methods to improve process capabilities and effectiveness are emerging and being applied. This seems to become increasingly important in operational level processes. In their quest to enhance operational level efficiency, market leaders in any segment of business continue to search for the latest quality tools and techniques which can enable them to improve their bottom lines and help them to stay ahead with their global competitors. Undoubtedly, Six Sigma breakthrough methodology coupled with lean practices has had helped world's leading corporations to achieve their aggressive objectives. This paper will address not only basic concepts of Six Sigma but also how this emerging breakthrough methodology has revolutionized the world's leading multinational companies. Subsequently, critical factors to ensure successful implementation of Six Sigma and the key barriers, issues and implementation concerns that lead companies to gain no benefit of its deployment will also be addressed. Further, key imperatives that can ensure successful deployment Pakistan's 9 International Convention on Quality Improvement (ICQI`2005) (c) Pakistan Institute of Quality Control 3 within a SME context will also be part of this endeavor.", "author_names": [ "Mr Shafiq Ahmad", "Mr Shahid Qureshi" ], "corpus_id": 34924368, "doc_id": "34924368", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "HOW TO ACHIEVE AND SUSTAIN OPERATIONAL EXCELLENCE BY IMPLEMENTING SIX SIGMA BREAKTHROUGH METHODOLOGY", "venue": "", "year": 2005 }, { "abstract": "Six Sigma is a known methodology for Process and Quality Improvement. It is also a philosophy, and a set of tools. It is based on the methodology DMAIC (Define, Measure, Analyze, Improve, Control) There are other business process management methodologies related to Six Sigma, such as DFSS (Design For Six Sigma) or Lean Manufacturing (Lean Six Sigma) Six Sigma is notable for using the Scientific Method, and Statistical Techniques. Some of the statistical tools that are used in Six Sigma projects are: Graphic Analysis: Pareto Charts, Histograms, Scatterplots, Box Whisker Charts, Group Charts, Location Charts, Control Charts, Multivari Charts Design of Experiments Regression and Analysis of Variance (ANOVA) Confidence Intervals, Hypothesis Testing Gage R&R Studies Acceptance Sampling, Capability Analysis, Reliability Analysis Commercial statistical software usually includes specific options for Quality Management, for example control charts. There are also a couple of contribution packages in R regarding control charts (qcc, IQCC) but there is no a complete set of tools for Six Sigma. We are currently working in several initiatives aimed at explain and facilitate Six Sigma practitioners to carry on their Six Sigma projects with R, such as a SixSigma package (already at CRAN repositories) with some functions deployed and many others in mind, as well as an on line training course within the EC Lifelong Learning Programme VRTUOSI project, and several publications in preparation.", "author_names": [ "Emilio Lopez", "R Advantages", "Andres Redchuk", "Javier M Moguerza" ], "corpus_id": 62452784, "doc_id": "62452784", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Six Sigma Quality Using R Tools and Training", "venue": "", "year": 2011 }, { "abstract": "Despite being an advanced technology, wire bonding in an actual manufacturing setting can greatly affect bond reliability. Many engineering parameters in upstream processes, if not controlled properly, may propagate downstream and limit the bond strength achievable during wire bonding. In this study, the DMAIC approach of Six Sigma methodology was used to improve the wire bonding quality of an opto coupler device developed by an electronic manufacturing firm in Malaysia. Using the five distinctive phases of the DMAIC, the problem was methodologically defined and its contributors identified, which include the improper material handling procedure, the tilted pad, and the un optimised bonding parameters. Corrective actions were deployed and the bond shear force of the device improved using the response surface methodology. The result is an in increase of the average bond shear force of the emitter and detector die from 57.2 g to 77.7 g and from 55.8 g to 66.5 g, respectively.", "author_names": [ "Chee Kuang Kok", "V S H Yeo", "H K Sim" ], "corpus_id": 110398161, "doc_id": "110398161", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Quality improvement for wire bond strength within the semiconductor manufacturing environment", "venue": "", "year": 2012 }, { "abstract": "Six Sigma Implementation at Dow Chemical Company: A Comprehensive Review Introduction The Dow Chemical Company The Six Sigma Program at Dow Preamble and Preparation The Six Sigma Journey Dow's Six Sigma Methodology at Variance The Staircase of Change Leadership Model for Six Sigma Implementation Six Sigma Project Organisational Structure Six Sigma tools, Techniques, Software and Information technology Tools and Techniques used by Dow for Six Sigma projects Six Sigma Software IT and Six Sigma at Dow Where is Dow on its Six Sigma Journey? Selected Case Studies Energy Conservation Studies Polycarbonate Unit Energy Reduction Project System Unit Energy Envelopment Project An Ergonomic Case Study (DMAIC Approach) Lessons and Insights from Dow's Six Sigma program Concluding Remarks Manufacturing Waste Reduction Using Six Sigma Methodology Introduction Project Selection Six Sigma Project: Re winder Performance Define Phase Measure Phase Analyse Phase Improve Phase Sub system CTQ sigma level Gap's Transfer Function Control Phase Temporary Solution Sustained solution Process Capability Control Plan Conclusions Process Improvement at TATA STEEL using the ASPIRE DMAIC approach Tata Steel Company ASPIRE and Six Sigma at TATA STEEL Project Selection Introduction to the project Purpose of Coke Quenching Quenching process ASPIRE DMAIC Approach The Define Phase The Measure Phase The Analyse Phase The Improve Phase The Control Phase Conclusion Improving Product Reliability Using Six Sigma Introduction Six Sigma in the Collaborative Company DMAIC Case Study Define Phase Define the Problem Define the Advocacy team Potential Financial Benefits Project Charter Measure Phase Process Mapping Identify potential causal factors Identify stakeholders' issues Measurement System Analysis Analysis Phase Improve Phase Control Phase Financial confirmation of process capability Stakeholder's issues revisited Agree line inspection frequency Conclusion Reducing the Engine Overheating problem in an Automotive Company using Six Sigma Introduction Case Study Define Phase Measure Phase Analysis Phase Improve Phase Control Phase Key results and financial savings generated from the project Key ingredients of Six Sigma project implementation Conclusion An Application of Six Sigma Methodology to the manufacture of Coal Products Introduction Company background Define Phase Product, Customers and CTQs Project Charter Business Case Statement of the Problem Project Goal Project Scope Team formation Milestones and Communications plan Business process mapping Measure Phase Measurement System Analysis Process Baseline Process Description Analyse Phase Improve Phase Control Phase Economic Benefits obtained Conclusions, comments and lessons learned Six Sigma in Healthcare: A Case Study with Commonwealth Health Corporation (CHC) Introduction to CHC Why Six Sigma in CHC? Six Sigma structure at CHC Six Sigma Methodology Benefits of Six Sigma Critical Success Factors of Six Sigma in Healthcare Clinical Project Example using DMAIC Define Measure Analyse Improve Control Conclusion Six Sigma within Doosan Heavy Industries and Construction Company Introduction Background to Doosan Heavy Industry Doosan's Six Sigma Framework Top level management commitment Stakeholder involvement Training scheme and project team activities Measurement system How to select project themes in Doosan? Doosan's Black Belt Course Case Study Define Measure Analyze Improve Control Doosan's Future Plans in Six Sigma Lean Manufacturing and Six Sigma Differences between Lean and Six Sigma Synergy effect Conclusion Application of Six Sigma in Banking Industry Introduction Why Six Sigma in the Banking Industry? Adoption of Six Sigma in the Banking Industry Introduction to JP Morgan Chase and its use of Six Sigma Introduction to JPMC Investors Services Define Measure Analyze Improve/Implement Control and Project Results Conclusion Some Challenges of Six Sigma in the Banking Industry Future Trends of Six Sigma in Banking Six Sigma Approach to reducing fall hazards among cargo handlers working on top of cargo containers: a case study Introduction and Background Problem Statement Details of cargo handling activities Objectives and overview Define Past statistics on fall accidents in the cargo handling industry in Hong Kong Interview surveys to establish the Working procedures Measure Preliminary interview Measurement tree Questionnaire development Reliability of the questionnaire Measurement I Measurement II Measurement III Analyse Critical factor I Critical factor II Critical factor III Most critical procedure Improve Solution I Solution II Solution III Solution IV Control Conclusion Six Sigma for Government IT: Strategy Tactics for Washington, DC Introduction Motivations Six Sigma and Quality Concepts Information Technology Infrastructure Library Information Technology Infrastructure Library Maturity Assessment and Improvement of Service Level Management Assessment and Improvement of Capacity Management Assessment and Improvement of Financial Management Assessment and Improvement of Availability Management Availability management Define and Measure Phases Availability Management Analyse Phase and Benchmarking Availability Management Conclusions Assessment and Improvement of Service Continuity Define, Measure and Analyse Phases for Service Continuity Continuity Design Phase Continuity Verify Phase Conclusion Increasing Newspaper Accuracy A Case Study Introduction Define Phase Measure Phase Analyse Phase Improve Phase Control Phase Results Success Factors and lessons Learned Deploying Six Sigma Company wide An Application of Six Sigma in Human Resources Alan Harrison Introduction Before Improvements Define Phase People Processes Definition of customer needs and objectives Measure Key Performance Indicators Cost of Poor Quality Analyse Improve Control Achieved Benefits Conclusion", "author_names": [ "Jiju Antony", "Ricardo Banuelas", "Ashok Kumar" ], "corpus_id": 108186923, "doc_id": "108186923", "n_citations": 35, "n_key_citations": 0, "score": 0, "title": "World class applications of six sigma", "venue": "", "year": 2006 }, { "abstract": "The initial predicted MTBF with four hours MTTR, for a base transceiver system (BTS) is 4.0/5.65 years (MIL217/Bellcore standards) With the first 12 months of commercial operation, with actual field data, the MTBF is calculated to be 8.26 years (Bellcore) which is almost double the initial predicted reliability level. The improved manufacturing techniques with (six sigma quality) advanced system test methods, removal of all defective units in early stages of deployment resulted in tremendous reliability growth which exceeded the initial expected reliability. The downtime per year has decreased from 42 min/yr. to 29 min/yr. and the BTS availability has increased from 99.993% to 99.995% or 5.39 sigma. Further refinement in the reliability is possible by introducing the following steps: (1) establish a minimum qualifying MTBF level for each component of each board; (2) validate the MTBF calculation methodology of vendor of each component; (3) improve MTBF of all weak FRUs by introducing redundancy schemes within each board; (4) introduce individual execution paths for each sector within a BTS; (5) continuous quality improvement techniques to eliminate escaping defects; (6) and establish BTS (HW and SW) stability level with an established release criteria.", "author_names": [ "Robert Bothwell", "R Donthamsetty", "Z Kania", "R Wesoloski" ], "corpus_id": 61097232, "doc_id": "61097232", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Reliability evaluation: a field experience from Motorola's cellular base transceiver systems", "venue": "Proceedings of 1996 Annual Reliability and Maintainability Symposium", "year": 1996 }, { "abstract": "GE remains a leader in the development, deployment and advancement of Six Sigma techniques to minimize manufacturing cycle time, reduce process variability, and optimize product quality. Recently GE Medical Systems Information Technologies collaborated with Plexus to develop a completely revamped version of its Transport Pro Display. The Transport Pro Display enables continuous display of vital signs in transit and captures an unbroken monitoring history both critical requirements for vital signs monitoring. The need to be highly reliable during transport of the patient among varied environments within the hospital (operating room, emergency department, ICU, procedure room, etc. further drove requirements for the design. By applying Design For Six Sigma methodologies the joint team set reliability objectives early in the design process aimed at realizing a robust product with high manufacturing yields, minimal process variation, and high availability in the field. Through a combination of clearly defined product and lower level design requirements, rigorous design analysis, milestone driven, in depth design reviews, and relentless testing, the joint team successfully met its six sigma objectives enabling GEMS IT to launch a highly accepted product that continues to exceed market forecasts. This paper details the tools and techniques used to implement a successful Design For High Reliability medical device development project. It additionally focuses on the unique requirements when collaborating with an outside supplier who must adapt to the OEM's internal processes, culture, and development environment to serve as an effective extension of the OEM's internal team. Manufacturing process yield and field failure data are presented to quantitatively demonstrate the effectiveness of the approach.", "author_names": [ "Chris M Rozewski", "Michael Tendick", "" ], "corpus_id": 15939047, "doc_id": "15939047", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "FOR HIGH RELIABILITY MEETING THE GOALS OF HIGH YIELD AND REDUCED FIELD FAILURES DURING THE MEDICAL PRODUCT DEVELOPMENT PROCESS", "venue": "", "year": 2004 } ]

[ { "abstract": "We report the unexpected temperature dependence of electron tunneling from the two dimensional electron gas (2DEG) to the Si dot in a Si dots floating gate metal oxide semiconductor (MOS) capacitor. We indicate that this temperature dependence of the electron tunneling cannot be explained by the conventional one dimensional tunneling model, and show that it is necessary for a new model which includes the geometrical factor of the system. To extract a mechanism of the electron injection process from the 2DEG to the nano structure, we have employed the numerical simulation, which includes both the geometrical condition of the system and the experimental setup. We suggest in our new tunneling model that the main contribution to the electron tunneling is induced by the wave packet like state of the electron below the Si dots. We successfully show that the temperature dependence of the electron injection voltage in the Si dots floating gate MOS capacitor fits our model. This indicates that the spatial distribution of electron density in the two dimensional electron gas would play a crucial role in the electron tunneling.", "author_names": [ "Masakazu Muraguchi", "Tetsuo Endoh", "Yukihiro Takada", "Yoko Sakurai", "Shintaro Nomura", "Kenji Shiraishi", "Mitsuhisa Ikeda", "Katsunori Makihara", "Seiichi Miyazaki", "Yasuteru Shigeta" ], "corpus_id": 121804625, "doc_id": "121804625", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Importance of electronic state of two dimensional electron gas for electron injection process in nano electronic devices", "venue": "", "year": 2010 }, { "abstract": "ABSTRACT Introduction: Cardiac implantable electronic devices (CIEDs) integrate numerous automatic and monitor functions. Nowadays, most CIEDs are connected to the Internet (via Wi Fi, Bluetooth or smartphone) to ensure remote monitoring of technical and clinical data: despite the importance of such a monitoring, especially from a clinical point of view, concerns have been raised about information (IT) security in terms of both privacy and security for CIEDs' carriers. Areas covered: This review will provide an outline of remote monitoring of CIEDs, main IT security issues that have affected them so far, main cybervulnerabilities and possible solutions. Expert opinion: Although there is no evidence that cyber attacks have been carried out against any CIED so far, they may occur in the future. Cyber attacks are usually aimed at stealing sensitive information or granting access to the IT systems to which CIEDs are connected; the possibility of an active reprogramming of CIEDs by cyber attacks is extremely low. Political, regulatory, scientific, and clinical integration is essential to provide not only effective IT solutions for CIEDs and their carriers, but also for the development of educational programs; it should also promote cooperation between stakeholders in order to reduce the risk of CIEDs' cybervulnerability and increase patient safety.", "author_names": [ "Cristian Martignani" ], "corpus_id": 148568776, "doc_id": "148568776", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Cybersecurity in cardiac implantable electronic devices", "venue": "Expert review of medical devices", "year": 2019 }, { "abstract": "The article represents a short conceptual overview of biofuel cell applications, rather than their design and operation. Special attention is given to interfacing enzyme based biofuel cells with power consuming microelectronic devices. Importance of electronic management of the power extracted from biological sources is emphasized. In addition to several briefly explained examples collected from recent publications, one system demonstrating powering of a standard glucometer with an implantable or wearable biofuel cell is described in details. The opinion on the biofuel cell applications and limitations represents the personal vision of the authors and might be not fully in accordance with the opinions of other experts.", "author_names": [ "Maria Gamella", "Ashkan Koushanpour", "Evgeny Katz" ], "corpus_id": 206006298, "doc_id": "206006298", "n_citations": 59, "n_key_citations": 0, "score": 0, "title": "Biofuel cells Activation of micro and macro electronic devices.", "venue": "Bioelectrochemistry", "year": 2018 }, { "abstract": "The chiral induced spin selectivity (CISS) effect, which describes the spin filtering ability of diamagnetic structures like DNA or peptides having chiral symmetry, has emerged in the past years as the central mechanism behind a number of important phenomena, like long range biological electron transfer, enantiospecific electrocatalysis, and molecular recognition. Also, CISS induced spin polarization has a considerable promise for new spintronic devices and the design of quantum materials. The CISS effect is attributed to spin orbit coupling, but a sound theoretical understanding of the surprising magnitude of this effect in molecules without heavy atoms is currently lacking. We are taking an essential step into this direction by analyzing the importance of imaginary terms in the Hamiltonian as a necessary condition for non vanishing spin polarization in helical structures. Based on first principles calculations and analytical considerations, we perform a symmetry analysis of the key quantities determining transport probabilities of electrons of different spin orientations. These imaginary terms originate from the spin orbit coupling, and they preserve the Hermitian nature of the Hamiltonian. Hence, they are not related to the breaking of time reversal symmetry resulting from the fact that molecules are open systems in a junction. Our symmetry analysis helps to identify essential constraints in the theoretical description of the CISS effect. We further draw an analogy with the appearance of imaginary terms in simple models of barrier scattering, which may help understanding the unusually effective long range electron transfer in biological systems.", "author_names": [ "Martin Sebastian Zollner", "Solmar Varela", "Ernesto Medina", "Vladimiro Mujica", "Carmen Herrmann" ], "corpus_id": 215726973, "doc_id": "215726973", "n_citations": 22, "n_key_citations": 1, "score": 0, "title": "Insight into the Origin of Chiral Induced Spin Selectivity from a Symmetry Analysis of Electronic Transmission.", "venue": "Journal of chemical theory and computation", "year": 2020 }, { "abstract": "Introduction In the last two decades, the increased number of implants of cardiac implantable electronic devices has been accompanied by an increase in complications, especially infection. Current recommendations for the appropriate treatment of cardiac implantable electronic devices related infections consist of prolonged antibiotic therapy associated with complete device extraction. The purpose of this study was to analyze the importance of percutaneous extraction in the treatment of these devices infections. Methods A systematic review search was performed in the PubMed, BVS, Cochrane CENTRAL, CAPES, SciELO and ScienceDirect databases. A total of 1,717 studies were identified and subsequently selected according to the eligibility criteria defined by relevance tests by two authors working independently. Results Sixteen studies, describing a total of 3,354 patients, were selected. Percutaneous extraction was performed in 3,081 patients. The average success rate for the complete percutaneous removal of infected devices was 92.4% Regarding the procedure, the incidence of major complications was 2.9% and the incidence of minor complications was 8.4% The average in hospital mortality of the patients was 5.4% and the mortality related to the procedure ranged from 0.4 to 3.6% The mean mortality was 20% after 6 months and 14% after a one year follow up. Conclusion Percutaneous extraction is the main technique for the removal of infected cardiac implantable electronic devices, and it presents low rates of complications and mortality related to the procedure.", "author_names": [ "Antonio da Silva Menezes Junior", "Thais Rodrigues Magalhaes", "Alana de Oliveira Alarcao Morais" ], "corpus_id": 46945286, "doc_id": "46945286", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Percutaneous Lead Extraction in Infection of Cardiac Implantable Electronic Devices: a Systematic Review", "venue": "Brazilian journal of cardiovascular surgery", "year": 2018 }, { "abstract": "Heart disease is a leading cause of maternal mortality and morbidity. Pregnant women with structural, conduction or degenerative cardiac disease who require rhythm control or who are at high risk of sudden cardiac death may carry a cardiac implantable electronic device or may occasionally require the insertion of one during their pregnancy. These women are now encountered more frequently in clinical practice, and it is essential that a multidisciplinary approach, beginning from the early antenatal phase, be adopted in their counselling and management. Contemporary cardiac rhythm control devices are a constantly evolving technology with increasingly sophisticated features; anaesthetists should therefore have an adequate understanding of the principles of their operation and the special considerations for their use, in order to enable their safe management in the peripartum period. Of particular importance is the potential adverse effect of electromagnetic interference, which may cause device malfunction or damage, and the precautions required to reduce this risk. The ultimate goal in the management of this patient subgroup is to minimise the disruption to cardiovascular physiology that may occur near the time of labour and delivery and to control the factors that impact on device integrity and function. We present the ante and peripartum management of two pregnant women with an implantable cardioverter defibrillator, followed by a review and update of the anaesthetic management of parturients with cardiac implantable electronic devices.", "author_names": [ "M M Salman", "Harriet Kemp", "Matthew Cauldwell", "Daryl P Dob", "Richard Sutton" ], "corpus_id": 205304268, "doc_id": "205304268", "n_citations": 5, "n_key_citations": 1, "score": 0, "title": "Anaesthetic management of pregnant patients with cardiac implantable electronic devices: case reports and review.", "venue": "International journal of obstetric anesthesia", "year": 2018 }, { "abstract": "Recent progress in electronic skin or e skin research is broadly reviewed, focusing on technologies needed in three main applications: skin attachable electronics, robotics, and prosthetics. First, since e skin will be exposed to prolonged stresses of various kinds and needs to be conformally adhered to irregularly shaped surfaces, materials with intrinsic stretchability and self healing properties are of great importance. Second, tactile sensing capability such as the detection of pressure, strain, slip, force vector, and temperature are important for health monitoring in skin attachable devices, and to enable object manipulation and detection of surrounding environment for robotics and prosthetics. For skin attachable devices, chemical and electrophysiological sensing and wireless signal communication are of high significance to fully gauge the state of health of users and to ensure user comfort. For robotics and prosthetics, large area integration on 3D surfaces in a facile and scalable manner is critical. Furthermore, new signal processing strategies using neuromorphic devices are needed to efficiently process tactile information in a parallel and low power manner. For prosthetics, neural interfacing electrodes are of high importance. These topics are discussed, focusing on progress, current challenges, and future prospects.", "author_names": [ "Jun Yang", "Jaewan Mun", "Se Young Kwon", "Seongjun Park", "Zhenan Bao", "Steve Park" ], "corpus_id": 202701758, "doc_id": "202701758", "n_citations": 266, "n_key_citations": 0, "score": 0, "title": "Electronic Skin: Recent Progress and Future Prospects for Skin Attachable Devices for Health Monitoring, Robotics, and Prosthetics.", "venue": "Advanced materials", "year": 2019 }, { "abstract": "Development of novel van der Waals (vdW) heterostructures from various two dimensional (2D) materials shows unprecedented possibilities by combining the advantageous properties of their building layers. In particular, transforming the vdW heterostructures from type I to type II is of great interest and importance to achieve efficient charge separation in photocatalytic, photovoltaic, and optoelectronic devices. In this work, by means of ab initio calculations, we have systematically investigated the electronic structures, optical properties, and mechanical properties of MXene/Blue Phosphorene (BlueP) vdW heterostructures under various deformations. We highlight that, under strain, the type I heterostructures can be transformed to type II with their conduction band minimum (CBM) and valence band maximum (VBM) separated in different layers. Interestingly, the locations of the CBM or VBM in MXene/BlueP vdW heterostructures can also be reversed by compressive or tensile strain between the building layers, which indicates that either layer can be utilized as an electron donor or acceptor by varying its deformation conditions. Meanwhile, this compressive (tensile) strain can also induce a red (blue) shift in the optical absorption spectra of MXene/BlueP vdW heterostructures. Finally, our results on the mechanical flexibility and deformation mechanism of MXene/BlueP vdW heterostructures suggest their great long term stability as well as promising applications in flexible devices. We believe that our findings will open a new way for the modulation and development of vdW heterostructures in flexible optical/electronic devices.", "author_names": [ "Zhonglu Guo", "Naihua Miao", "Jian Zhou", "Baisheng Sa", "Zhimei Sun" ], "corpus_id": 138815756, "doc_id": "138815756", "n_citations": 88, "n_key_citations": 0, "score": 0, "title": "Strain mediated type I/type II transition in MXene/Blue phosphorene van der Waals heterostructures for flexible optical/electronic devices", "venue": "", "year": 2017 }, { "abstract": "Abstract The impact of seeding of the diamond growth on the microstructural properties of GaN on diamond wafers was studied using in situ focused ion beam cross sectioning and scanning electron microscopy imaging. Microstructural studies revealed that the seeding conditions are a critical parameter to obtain an optimal material, allowing the manufacture of GaN on diamond wafers with no microscopic defects and with structural stability under thermal annealing at 825 degC. The use of the right seeding conditions also results in homogeneous thermal properties across four inch GaN on diamond wafers, which is of critical importance for their use for ultra high power microwave electronic devices.", "author_names": [ "Dong Liu", "Daniel Francis", "Firooz N Faili", "C Middleton", "Julian Anaya", "James W Pomeroy", "Daniel J Twitchen", "Martin Kuball" ], "corpus_id": 54900686, "doc_id": "54900686", "n_citations": 32, "n_key_citations": 0, "score": 0, "title": "Impact of diamond seeding on the microstructural properties and thermal stability of GaN on diamond wafers for high power electronic devices", "venue": "", "year": 2017 }, { "abstract": "The creation of molecular electronic switches by using smart molecules is of great importance to the field of molecular electronics. This requires a fundamental understanding of the intrinsic electron transport mechanisms, which depend on several factors including the charge transport pathway, the molecule electrode coupling strength, the energy of the molecular frontier orbitals, and the electron spin state. On the basis of significant progresses achieved in both experiments and theory over the past decade, in this review article we focus on new insights into the design and fabrication of different molecular switches and the corresponding switching effects, which is crucial to the development of molecular electronics. We summarize the strategies developed for single molecule device fabrication and the mechanism of these switching effects. These analyses should be valuable for deeply understanding the switching effects in molecular electronic devices.", "author_names": [ "Zihao Liu", "Shizhao Ren", "Xuefeng Guo" ], "corpus_id": 20212231, "doc_id": "20212231", "n_citations": 30, "n_key_citations": 0, "score": 0, "title": "Switching Effects in Molecular Electronic Devices", "venue": "Topics in Current Chemistry", "year": 2017 } ]

[ { "abstract": "Currently, a lot of efforts have been applied to diagnosis and treat tumors through the fabrication of highly efficient and multi functional nanomaterials. Superior to other methods, photothermal therapy (PTT) has been demonstrated as a noninvasive, controllable, and targeted strategy to eliminate tumor cells. The use of functional biomedical and bioactive nanomaterials can enhance the photothermal performances and meanwhile integrate with favorable functions, by taking into account their risk assessments. In this review, novel engineered photothermal nanomaterials, such as noble metal carbon semiconductor and organic molecule based PTT agents, as well as their targeted biomedical applications were summarized and discussed comprehensively. Particularly, the latest advances of not only the conventional nanomaterials, but also the newly discovered alternatives, like Au Ag, graphdiyne, and selenides, were introduced. Besides the benefits, the risks and other implications of novel PTT agents were recorded and evaluated. Moreover, the potential applications of nanomaterials in targeted and multi functional PTT treatments, which served as foundations and directions for future PTT approaches developments, were stated. Depending on the urgency and boosting demands for tumor treatments, novel engineering advancements of techniques, not limited to PTT and nanomaterials, are prerequisites in the history of medical development.", "author_names": [ "Wenfeng Wei", "Xiaoyuan Zhang", "Shan Zhang", "Gang Wei", "Zhiqiang Su" ], "corpus_id": 197305888, "doc_id": "197305888", "n_citations": 72, "n_key_citations": 0, "score": 0, "title": "Biomedical and bioactive engineered nanomaterials for targeted tumor photothermal therapy: A review.", "venue": "Materials science engineering. C, Materials for biological applications", "year": 2019 }, { "abstract": "Functional carbon based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e. thermal and electrical conductivity, high mechanical strength, and optical properties) and extensive research efforts are being made to utilize these materials for various industrial applications, such as high strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineering. This Perspective highlights different types of carbon based nanomaterials currently used in biomedical applications.", "author_names": [ "Chaenyung Cha", "Su Ryon Shin", "Nasim Annabi", "Mehmet Remzi Dokmeci", "Ali Khademhosseini" ], "corpus_id": 30111144, "doc_id": "30111144", "n_citations": 500, "n_key_citations": 2, "score": 1, "title": "Carbon based nanomaterials: multifunctional materials for biomedical engineering.", "venue": "ACS nano", "year": 2013 }, { "abstract": "After hydrogen and oxygen, carbon is the third most abundant component present in the cosmos with excellent characteristic features of binding to itself and nearly all elements. Since ancient times, carbon based materials such as graphite, charcoal, and carbon black have been utilized for writing and drawing materials. As these materials possess excellent chemical, mechanical, electrical, and thermal features, they have been readily engineered into carbon based nanomaterials (CNMs) such as carbon nanotubes, graphene oxide, graphene quantum dots, nanodiamonds, fullerenes, carbon nano onions, and so forth. These materials are now widely explored in biomedical applications. Thus, the emergence of CNMs has opened up a gateway for the detection, delivery, and treatment of a multitude of diseases. They are being actively researched for applications within tissue engineering, as vaccine vectors, and for the delivery of therapeutics to the immune system. This review focuses on the recent advances in various types of CNMs, their fabrication techniques, and their application in the delivery of therapeutics both in vitro and in vivo. The review also focuses on the toxicity concern of the CNMs and the possible remedies to tackle the toxicity issues. Concluding remarks emphasize all the CNMs discussed in the review over their possible biomedical applications, while the future perspectives section discusses the approaches to bring CNMs into the mainstream of clinical trials and their therapeutic applications.", "author_names": [ "Alok Mahor", "Prem Prakash Singh", "Peeyush Bharadwaj", "N Sharma", "Surabhi Yadav", "Jessica M Rosenholm", "Kuldeep K Bansal" ], "corpus_id": 234062800, "doc_id": "234062800", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Carbon Based Nanomaterials for Delivery of Biologicals and Therapeutics: A Cutting Edge Technology", "venue": "", "year": 2021 }, { "abstract": "Surface functionalization of nanomaterials to combine different material's properties together opens up unlimited possibilities for both academic research and industrial applications. In this thesis, flexible and scalable chemical approaches to functionalize carbon nanomaterials (CNMs) are developed for different applications, including electronics, composite and biomedical applications. According to the bonding difference between CNMs and functional components, these approaches can be divided into two groups, including covalent functionalization and non covalent functionalization. Covalent functionalization of CNMs surface is based on reactions of different components with the oxygen containing groups of CNMs. The first part in this section introduced the covalent functionalization of carbon nanotubes for biomedical application. The surface of CNTs was modify by a multi oxidation process and coated by silver nanoparticles to improve CNT's antibacterial property. The developed silver/CNT composites show strong antibacterial property to bacteria. The second part presents covalent functionalization of graphene oxide for cement reinforcement. The developed surface functionalized GO (FGO) can improve both the early and ultimate strength of the Portland cement mortar efficiently. The key benefit of FGO lies in its ability to form covalent bonds with C S H whilst having minimum effect on the workability of mortar paste. The third part introduced the covalent functionalization of graphene based films (GBFs) that act as heat spreaders for hotspot cooling. The applied covalent bonding between GBF and the substrate can significantly reduce the thermal interface resistance, showing great advantages on cooling of high power density devices. Non covalent functionalization utilizes various functional molecules or active species as assembly mediators to functionalize the surface of CNMs via non covalent interactions. The first part of this section presents a method of non covalent self assembly of high thermal conductivity of graphene films (GFs) The fabricated smooth, large grain and turbostratic stacking GFs shows excellent thermal and mechanical properties, which is superior to most of currently existing thermally conductive materials. The second part introduced the non covalent functionalization of graphene for high thermal conductive adhesive. Liquid exfoliated few layer graphene was utilized as fillers to improve the thermal conductivity of the thermal conductive adhesive which showed an improvement of 400 The third part presents a non covalent functionalization process for synthesizing intrinsically flexible multi functionalized CNT based hybrid nanowires. The synthesized multi functionalized CNT based hybrid nanowires possess many excellent properties, such as good dispersability and stability in various polar solvents, large flexibility and high electrical conductivity. These extraordinary properties facilitate the application of hybrid nanowires in the fabrication of flexible and stretchable circuits (FSCs) with high resolution.", "author_names": [ "Nan Wang" ], "corpus_id": 136433258, "doc_id": "136433258", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Functionalization and Characterization of Carbon Based Nanomaterials for Electronics, Composite and Biomedical Applications", "venue": "", "year": 2017 }, { "abstract": "Carbon nanofibers (CNFs) not only retain a similar one dimensional nanostructure, similar special properties, and similar multi functionality to carbon nanotubes, but they also exhibit a few advantages, like easier production, lower cost, lower crystallinity, and more defects. Therefore, CNF based nanomaterials have been widely used for applications relating to energy conversion/storage, catalysis, sensors, adsorption/separation, and biomedical engineering. Due to their high specific surface area, interconnected porous structure, light weight, and high mechanical strength, CNF based three dimensional (3D) nanomaterials have attracted more and more attention in many fields, especially in energy production/storage and environmental science. In this work, we demonstrate the development of CNF based 3D nanomaterials for applications relating to energy and environmental science. To achieve this aim, typical design strategies for the production of CNF based 3D nanomaterials, including electrospinning, chemical vapor deposition, templated synthesis, hydrothermal synthesis, and other combined techniques are introduced and summarized, and then cases involving fabricated CNF 3D nanomaterials for supercapacitors, fuel cells, electrochemical batteries, water purification, air cleaning, and microwave/radiation adsorption are presented and discussed. This study will be helpful for readers to understand the production of CNFs, and the subsequent design and fabrication of functional CNF based 3D nanostructures and nanomaterials; meanwhile it will be valuable for promoting the advanced applications of CNF based nanomaterials in different fields.", "author_names": [ "Xinxiao Zhou", "Bin Liu", "Yun Chen", "Lei Guo", "Gang Wei" ], "corpus_id": 225424304, "doc_id": "225424304", "n_citations": 10, "n_key_citations": 1, "score": 0, "title": "Carbon nanofiber based three dimensional nanomaterials for energy and environmental applications", "venue": "", "year": 2020 }, { "abstract": "Abstract Nanotechnology is a multidisciplinary area that requires an understanding of various fields such as chemistry, electronics, physics, biology, and engineering. It is one of the fastest emerging research areas; therefore, it would not be wrong to call this period as \"Nano era.\" Furthermore, Nanotechnology is the study of materials that are characterized by at least one dimension in the nanometer range. These materials include carbon based nanomaterials such as carbon nanotubes, metal based nanomaterials (metal oxides, nanogold, and nanosilver) micelles, liposomes, and polymeric nanoparticles to name a few. In general, the main function of nanomaterials is the vectorization of insoluble drugs. Hence, drug delivery can be achieved by targeting biomolecules such as receptors both on the cell surface and inside the cells. This can enhance the biodistribution of the drug while providing targeted delivery to diseased tissue only. Although nanomaterials have a good impact on medical science, military technology, and space programs, the size and shape of these nanosized materials pose a danger as they can interact with other living systems by crossing the skin and blood/brain barrier. Therefore, this chapter highlights the different carrier platforms, clinical applications, and challenges in the use of these nanomaterials.", "author_names": [ "Jyoti Ahlawat", "Mahesh Narayan" ], "corpus_id": 218918410, "doc_id": "218918410", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Introduction to Active, Smart, and Intelligent Nanomaterials for Biomedical Application", "venue": "", "year": 2020 }, { "abstract": "Carbon based materials (CBMs) such as graphene, nanodiamonds, carbon fibers, and carbon dots, have attracted much scientific attention as promising biomedical tools. Following exposure, particularly intravenous injection, these nanomaterials can be recognized by immune cells. Such interactions could be modulated by the different physicochemical properties of the materials (e.g. structure, size, and chemical functions) by either stimulating or suppressing the immune response. However, a harmonized cutting edge approach for the classification of these materials based not only on their physicochemical parameters but also their immune properties was missing. The European Commission funded G IMMUNOMICS and CARBO IMmap projects aimed to fill this gap, developing a functional pipeline for the qualitative and quantitative immune characterization of graphene, graphene related materials (GRMs) and other CBMs. The goal was to open breakthrough perspectives for the definition of the immune profiles of these materials. Here we summarize our methodological approach, key results, and the necessary multidisciplinary expertise ranging across various fields, from material chemistry to engineering, immunology, toxicology, and systems biology. G IMMUNOMICS, as a partnering project of the Graphene Flagship, the largest scientific research initiative on graphene worldwide, also complemented the studies performed in the Flagship on health and environmental impact of GRMs. Finally, we present the nanoimmunity by design concept, developed within the projects, which can be readily applied to other 2D materials. Overall, the G IMMUNOMICS and CARBO IMmap projects have provided new insights on the immune impact of GRMs and CBMs thus laying the foundation for their safe use and future translation in medicine.", "author_names": [ "Arianna Gazzi", "Laura Fusco", "Marco Orecchioni", "Silvia Ferrari", "Giulia Franzoni", "J Stephen Yan", "Matthias Rieckher", "Guotao Peng", "Matteo Andrea Lucherelli", "Isabella Anna Vacchi", "Ngoc Do Quyen Chau", "Alejandro Criado", "Akcan Istif", "Donato Mancino", "A Dominguez", "Hagen Eckert", "Ester Vazquez", "Tatiana Da Ros", "Paola Nicolussi", "Vincenzo Palermo", "Bjorn Schumacher", "Gianaurelio Cuniberti", "Yiyong Mai", "Cecilia Clementi", "Matteo Pasquali", "Xinliang Feng", "Kostas Kostarelos", "Acelya Yilmazer", "Davide Bedognetti", "Bengt Fadeel", "Maurizio Prato", "Alberto Bianco", "Lucia Gemma Delogu" ], "corpus_id": 219411627, "doc_id": "219411627", "n_citations": 9, "n_key_citations": 0, "score": 0, "title": "Graphene, other carbon nanomaterials and the immune system: toward nanoimmunity by design", "venue": "", "year": 2020 }, { "abstract": "Carbon based nanomaterials are gaining more and more interest because of their wide range of applications. Carbon dots (CDs) have shown exclusive interest due to unique and novel physicochemical, optical, electrical, and biological properties. Since their discovery, CDs became a promising material for wide range of research applications from energy to biomedical and tissue engineering applications. At same time several new methods have been developed for the synthesis of CDs. Compared to many of these methods, the sonochemical preparation is a green method with advantages such as facile, mild experimental conditions, green energy sources, and feasibility to formulate CDs and doped CDs with controlled physicochemical properties and lower toxicity. In the last five years, the sonochemically synthesized CDs were extensively studied in a wide range of applications. In this review, we discussed the sonochemical assisted synthesis of CDs, doped CDs and their nanocomposites. In addition to the synthetic route, we will discuss the effect of various experimental parameters on the physicochemical properties of CDs; and their applications in different research areas such as bioimaging, drug delivery, catalysis, antibacterial, polymerization, neural tissue engineering, dye absorption, ointments, electronic devices, lithium ion batteries, and supercapacitors. This review concludes with further research directions to be explored for the applications of sonochemical synthesized CDs.", "author_names": [ "Rajesh Kumar", "Vijay Bhooshan Kumar", "Aharon Gedanken" ], "corpus_id": 211555846, "doc_id": "211555846", "n_citations": 35, "n_key_citations": 0, "score": 0, "title": "Sonochemical synthesis of carbon dots, mechanism, effect of parameters, and catalytic, energy, biomedical and tissue engineering applications.", "venue": "Ultrasonics sonochemistry", "year": 2020 }, { "abstract": "Abstract One of the pillars of nanotechnology is the study of materials whose nanoscale properties allow developing technologies for several fields. Carbon nanomaterials, such as fullerene, carbon nanotubes (CNTs) and graphene, with applications in engineering and medical fields are highlighted. This chapter provides a brief review on these nanomaterials and emphasizes their relevance to nanotechnology. The main properties and synthesis methods will be discussed, as well as the research fields that benefit from their use. Our emphasis is on the use of C60 fullerene in organic solar cells, CNTs in sensors and biosensors, and graphene in batteries and supercapacitors. Other areas of interest that are shared by the three types of materials, such as engineering and biomedical applications, are also mentioned.", "author_names": [ "Jose R Siqueira", "Osvaldo N Oliveira" ], "corpus_id": 138170180, "doc_id": "138170180", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Carbon Based Nanomaterials", "venue": "", "year": 2017 }, { "abstract": "s for Posters 1. Innervation of an engineered muscle graft for reconstruction of muscle defects Ben Kaplan* c,d Tal Kaufman* a,b Luba Perry d,e Yulia Shandalov c Itay Srugo f Dean Ad El a,b and Shulamit Levenberg +c a Department of Plastic Surgery, Rabin Medical Center, Petach Tikva, Israel. b Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel. c Department of Biomedical Engineering, Technion Israel Institute of Technology, Haifa, Israel. d Bruce Rapaport Faculty of Medicine, TechnionIsrael Institute of Technology, Haifa, Israel. e Interdepartmental Program in Biotechnology, TechnionIsrael Institute of Technology, Haifa, Israel. f Vetneuro, Beit berel Israel. Autologous muscle flaps are commonly used to reconstruct defects that involve muscle impairment. In order to maintain viability and functionality of these flaps, they must be properly vascularized and innervated. Tissue engineered muscles could potentially replace autologous muscle tissue, but still require establishment of sufficient innervation to ensure functionality. In this study, we explored the possibility of innervating engineered muscle grafts transplanted to an abdominal wall defect in mice, by transferring the native femoral nerve to the graft. Six weeks post transplantation, nerve conduction studies and electromyography demonstrated increased innervation in engineered grafts that were neurotized with the femoral nerve, as compared to non neurotized grafts. Histological assessments revealed axonal penetration and formation of neuromuscular junctions within the grafts. The innervation process described in this study may advance the fabrication of a fully functional engineered muscle graft that will be of utility in clinical settings. 2. Single layer graphene promotes neuronal activity by regulating potassium ion channels in interfaced neural networks Niccolo Paolo Pampaloni, Martin Lottner, Michele Giugliano, Alessia Matruglio, Francesco D'Amico, Maurizio Prato, Jose Antonio Garrido, Laura Ballerini, Denis Scaini Graphene, with its peculiar bi dimensional crystal arrangement of pure carbon atoms, is catching the eye of the research community with its extraordinary physicochemical properties. In particular, single layer graphene (SLG) potential applications in biology and (nano)medicine have being deeply investigated during last years. Although preliminary reports have shown that graphene based materials can be safely interfaced with neuronal cells, to date an exhaustive functional study of neuronal networks developed interfaced with SLG is missing. For the first time, we show that uncoated SLG is not only fully biocompatible but, surprisingly, induces in cultured neurons an increased network synaptic activity, presumably by altering the availability of extracellular K ions. The homeostatic changes observed in SLG interfaced cells, as well as the increased network activity, were not observed when neurons were interfaced neither on a many layers graphene (MLG) nor onto conductive thin gold substrates, suggesting a highly material specificity of this adaptive interaction. In particular, combining material characterization, electrophysiological patch clamp recordings and neuronal network simulations, we propose a model in which the peculiar interaction of SLG with the ionic species present in solution shifts a significant fraction of phasically firing neurons towards a tonic phenotype, and these changes ultimately reflect as an increase in firing activity of the entire network. 3. A Quest for the Cortical Representation of Subjective Surprise With a Virtual Reality Neurofeedback Platform Hadar Levi Aharoni 1* Oren Alkoby 2 Naftali Tishby 1,3 Oren Shriki 2 1 The Edmond Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Israel; 2 Dept. of Cognitive and Brain Sciences, Ben Gurion University, Israel; 3 The School of Computer Science and Engineering, The Hebrew University of Jerusalem, Israel ELSC, The Edmond J. Safra Campus, The Hebrew University, Jerusalem 91904, Israel. E mail: [email protected] It is well known that responses to external stimuli are context dependent. Specifically, when a rare event occurs, it elicits the P300 event related potential (ERP) while when a stimulus repeats itself responses are attenuated. Context dependency can be modelled by conditional probabilities of future events. Arguably, these are the measures that give rise to the experience of expectation and surprise. These expectations, or conditional probabilities, should depend on both the memory capacity of subjects and on their goals. Using the Information Bottleneck method developed by Tishby et al. a trial by trial subjective surprise signal can be calculated, taking into account the subject's memory resources and goals. This calculated surprise signal can then be tested against physiological data. We examine the above hypothesis in the framework of an auditory oddball experiment. Our results indicate a correlation between the trial by trial measure of subjective surprise and an EEG metric based on the P300 component. Moreover, a platform we developed containing a virtual reality game combined with EEG measurements, allows us to have an ERP based neurofeedback in which the subject is getting feedback within the game on his current surprise related EEG feature. 4. Extended LFP study reveals the dorsal STN as the source of Beta", "author_names": [ "Liav Leiboviz", "Valentina Borgil", "Mirit Eynan", "Rivka Efrat", "", "Ben Aviner" ], "corpus_id": 141059201, "doc_id": "141059201", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Neural Interfaces Abstracts March 5 7 2018 Carbon based nanomaterials for active neuronal interfacing impact on signaling and regrowth", "venue": "", "year": 2018 } ]