Дисертації з теми "Wide bandgap device"
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Sathyanarayanan, Arvind Shanmuganaathan. "Analysis of Reflected Wave Phenomenon on Wide Bandgap Device Switching Performance." The Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu149273424426787.
Повний текст джерелаShao, Ye. "Study of wide bandgap semiconductor nanowire field effect transistor and resonant tunneling device." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1448230793.
Повний текст джерелаMahadik, Nadeemullah A. "Non-destructive x-ray characterization of wide-bandgap semiconductor materials and device structures." Fairfax, VA : George Mason University, 2008. http://hdl.handle.net/1920/3404.
Повний текст джерелаVita: p. 104. Thesis director: Mulpuri V. Rao. Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Electrical and Computer Engineering. Title from PDF t.p. (viewed Mar. 17, 2009). Includes bibliographical references (p. 99-103). Also issued in print.
Deshpande, Amol Rajendrakumar. "Design of A Silicon and Wide-Bandgap Device Based Hybrid Switch for Power Electronics Converter." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461238625.
Повний текст джерелаHontz, Michael Robert. "Next Generation Integrated Behavioral and Physics-based Modeling of Wide Bandgap Semiconductor Devices for Power Electronics." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1556718365514067.
Повний текст джерелаSwenberg, Johanes F. N. McGill T. C. McGill T. C. "Development of wide-bandgap II-VI semiconductor light-emitting device technology based on the graded injector design /." Diss., Pasadena, Calif. : California Institute of Technology, 1995. http://resolver.caltech.edu/CaltechETD:etd-10122007-142152.
Повний текст джерелаRafique, Subrina. "Growth, Characterization and Device Demonstration of Ultra-Wide Bandgap ß-Ga2O3 by Low Pressure Chemical Vapor Deposition." Case Western Reserve University School of Graduate Studies / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=case1512652677980762.
Повний текст джерелаAllen, Noah Patrick. "Electrical Characterization of Gallium Nitride Drift Layers and Schottky Diodes." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/102924.
Повний текст джерелаDoctor of Philosophy
Allen, Noah P. "Electrical Characterization of Gallium Nitride Drift Layers and Schottky Diodes." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/102924.
Повний текст джерелаDoctor of Philosophy
Xia, Zhanbo. "Materials and Device Engineering for High Performance β-Ga2O3-based Electronics". The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587688595358557.
Повний текст джерелаElf, Patric. "Radiation effects on wide bandgap semiconductor devices." Thesis, KTH, Tillämpad fysik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-283320.
Повний текст джерелаGallium Nitrid (GaN) baserade high electron mobility transistors (HEMTs) används inom många olika områden, såsom 5G, bil-industrin, yg/rymd och i sensorer fö kemiska, mekaniska, biologiska och optiska applikationer. Tack vare dess goda materialegenskaper GaN baserade HEMTs särskilt användbara i harda miljöer, som till exempel i förbränningsmotorer, avgaser, i rymden, samt till medicinska instrument där pålitlighet och tålighet är eftersträvat. I det här examensarbetet sa undersöks e ekten av protonbestrålning pa GaN HEMTs samt möjligheten till användning av dem inom biomedicin och diagnostik. Arbetet är uppdelat i två delar: den ena behandlar den teoretiska bakgrunden av GaN HEMTs och den andra presenterar de experiment/simuleringar som utförts för att se efekterna på komponenterna före och efter protonbestrålning. I bakgrunds-sektionen så beskrivs hur HEMTs fungerar, tillverkningstekniker och mekanismerna för hur defekter uppkommer under olika former av protonbestrålning. Därefter sa karaktäriseras HEMT komponenterna och relaterade teststrukturer före och efter protonbestralning, med ett fokus på doser mellan 1011 to 1015 protoner=cm2, samt en jämförelse med resultat som fatts fran simuleringar med SRIM/TRIM-program. Utöver detta sa beskrivs och diskuteras även biokompatibiliteten och applikationer inom biomedicin av GaN komponenter vid protonbestralnings-scenarion i arbetet.
Grummel, Brian. "HIGH TEMPERATURE PACKAGING FOR WIDE BANDGAP SEMICONDUCTOR DEVICES." Master's thesis, University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3200.
Повний текст джерелаM.S.E.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering MSEE
Buzzo, Marco. "Dopant imaging and profiling of wide bandgap semiconductor devices /." Konstanz : Hartung-Gorre, 2007. http://www.loc.gov/catdir/toc/fy0715/2007427206.html.
Повний текст джерелаDhakal, Shankar. "Circuit Level Reliability Considerations in Wide Bandgap Semiconductor Devices." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1532703747534188.
Повний текст джерелаKozak, Joseph Peter. "Hard Switched Robustness of Wide Bandgap Power Semiconductor Devices." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/104874.
Повний текст джерелаDoctor of Philosophy
Power conversion technology is being integrated into industrial and commercial applications with the increased use of laptops, server centers, electric vehicles, and solar and wind energy generation. Each of these converters requires the power semiconductor devices to convert energy reliably and safely. textcolor{black}{Silicon has been the primary material for these devices; however,} new devices have been commercialized from both silicon carbide (SiC) and gallium nitride (GaN) materials. Although these devices are required to undergo qualification testing, the standards were developed for silicon technology. The performance of these new devices offers many additional benefits such as physically smaller dimensions, greater power conversion efficiency, and higher thermal operating capabilities. To facilitate the increased integration of these devices into industrial applications, greater robustness and reliability analyses are required to supplement the traditional tests. The work presented here provides two new experimental methodologies to test the robustness of both SiC and GaN power transistors. These methodologies are oriented around hard-switching environments where both high voltage biases and high conduction current exist and stress the intrinsic semiconductor properties. Experimental evaluations were conducted of both material technologies where the electrical properties were monitored over time to identify any degradation effects. Additional analyses were conducted to determine the physics-oriented failure mechanisms. This work provides insight into the limitations of these semiconductor devices for both device designers and manufacturers as well as power electronic system designers.
Rashid, Suhail Jeremy. "High voltage packaging technology for wide bandgap power semiconductor devices." Thesis, University of Cambridge, 2008. https://www.repository.cam.ac.uk/handle/1810/252098.
Повний текст джерелаAlexakis, Petros. "Reliability of wide bandgap semiconductor devices under unconventional mode conduction." Thesis, University of Warwick, 2017. http://wrap.warwick.ac.uk/105611/.
Повний текст джерелаWei, Yu. "A Novel Auxiliary Resonant Snubber Inverter Using Wide Bandgap Devices." Thesis, Virginia Tech, 2018. http://hdl.handle.net/10919/83238.
Повний текст джерелаMaster of Science
Ghin, Raymond. "Avalanche multiplication and breakdown in wide bandgap semiconductors." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301673.
Повний текст джерелаLades, Martin. "Modeling and simulation of wide bandgap semiconductor devices 4H/6H-SiC /." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=962057827.
Повний текст джерелаRazzak, Towhidur. "Design and Fabrication of High Performance Ultra-Wide Bandgap AlGaN Devices." The Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1619031091410235.
Повний текст джерелаKoganti, Naga Babu. "Modeling and Characterization of Circuit Level Transients in Wide Bandgap Devices." University of Toledo / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=toledo153311831687909.
Повний текст джерелаGrummel, Brian. "Design and Characterization of High Temperature Packaging for Wide-Bandgap Semiconductor Devices." Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5231.
Повний текст джерелаPh.D.
Doctorate
Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering
Montañez, Huamán Liz Margarita. "Synthesis and characterization of wide bandgap semiconductors doped with terbium for electroluminescent devices." Master's thesis, Pontificia Universidad Católica del Perú, 2016. http://tesis.pucp.edu.pe/repositorio/handle/123456789/6999.
Повний текст джерелаEn el presente trabajo de investigación se ha estudiado propiedades estequiometrias, estructurales y de emisión de luz de semiconductor de amplio ancho de banda dopados con terbio. La difracción de rayos-X en ángulo rasante confirma el estado amorfo de las películas. Los espectros de absorción infrarroja muestran la formación de óxidos en las películas y la espectroscopia de foto-electrones de rayos-X revela la formación de oxinitruro de aluminio y oxicarburo de silicio. Las películas han sido calentadas a temperaturas en el rango de 300 °C a 1000 °C en un horno de rápido procesamiento térmico. De acuerdo con el análisis de las medidas de fotoluminiscencia, la intensidad más alta de emisión de luz del terbio es para películas que tengan concentraciones de terbio mayores al 1at% y a una temperatura de tratamiento térmico de alrededor de 400 °C. Adicionalmente, las películas analizadas han sido usado como capas activas para el diseño de dispositivos electroluminiscentes
Tesis
Li, Ke. "Wide bandgap (SiC/GaN) power devices characterization and modeling : application to HF power converters." Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10080/document.
Повний текст джерелаCompared to traditional silicon (Si) semiconductor material, wide bandgap (WBG) materials like silicon carbide (SiC) and gallium nitride are gradually applied to fabricate power semiconductor devices, which are used in power converters to achieve high power efficiency, high operation temperature and high switching frequency. As those power devices are relatively new, their characterization and modeling are important to better understand their characteristics for better use. This dissertation is mainly focused on those WBG power semiconductor devices characterization, modeling and fast switching currents measurement. In order to measure their static characteristics, a single-pulse method is presented. A SiC diode and a "normally-off" SiC JFET is characterized by this method from ambient temperature to their maximal junction temperature with the maximal power dissipation around kilowatt. Afterwards, in order to determine power device inter-electrode capacitances, a measurement method based on the use of multiple current probes is proposed and validated by measuring inter-electrode capacitances of power devices of different technologies. Behavioral models of a Si diode and the SiC JFET are built by using the results of the above characterization methods, by which the evolution of the inter-electrode capacitances for different operating conditions are included in the models. Power diode models are validated with the measurements, in which the current is measured by a proposed current surface probe
Devarapally, Rahul Reddy. "Survey of applications of WBG devices in power electronics." Kansas State University, 2016. http://hdl.handle.net/2097/32665.
Повний текст джерелаDepartment of Electrical and Computer Engineering
Behrooz Mirafzal
Wide bandgap devices have gained increasing attention in the market of power electronics for their ability to perform even in harsh environments. The high voltage blocking and high temperature withstanding capabilities make them outperform existing Silicon devices. They are expected to find places in future traction systems, electric vehicles, LED lightning and renewable energy engineering systems. In spite of several other advantages later mentioned in this paper, WBG devices also face a few challenges which need to be addressed before they can be applied in large scale in industries. Electromagnetic interference and new requirements in packaging methods are some of the challenges being faced by WBG devices. After the commercialization of these devices, many experiments are being carried out to understand and validate their abilities and drawbacks. This paper summarizes the experimental results of various applications of mainly Silicon Carbide (SiC) and Gallium Nitride (GaN) power devices and also includes a section explaining the current challenges for their employment and improvements being made to overcome them.
Lyu, Xintong. "Power Module Design and Protection for Medium Voltage Silicon Carbide Devices." The Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu160856011259485.
Повний текст джерелаLi, Cong. "High Frequency High Boost Ratio Dc-dc Converters with Wide Bandgap Devices for PV System Applications." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1411858489.
Повний текст джерелаNakagawara, Tanner A. "Optical Spectroscopy of Wide Bandgap Semiconductor Heterostructures and Group-IV Alloy Quantum Dots." VCU Scholars Compass, 2017. https://scholarscompass.vcu.edu/etd/5195.
Повний текст джерелаAlsolami, Mohammed Faham. "Wide Bandgap (WBG) Devices Based Switched Capacitor Multiport Multilevel SinglePhase AC/DC/AC Converter for UPS Applications." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1461327268.
Повний текст джерелаZhao, Xiaonan. "High-Efficiency and High-Power Density DC-DC Power Conversion Using Wide Bandgap Devices for Modular Photovoltaic Applications." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/89025.
Повний текст джерелаDoctor of Philosophy
Solar energy is one of the most promising renewable energies to replace the conventional fossils. Power electronics converters are necessary to transfer power from solar panels to dc or ac grid. Since the output of solar panel is low voltage with a wide range and the grid side is high voltage, this power converter should meet the basic requirements of high step up and wide range regulation. Additionally, high power conversion efficiency is an important design purpose in order to save energy. The existing solutions have limitations of narrow regulating range, low efficiency or complicated circuit structure. Recently, the third-generation power semiconductors attract more and more attentions who can help to reduce the power loss. They are named as wide band gap devices. This dissertation proposed a wide band gap devices based power converter with ability of wide regulating range, high power conversion efficiency and simple circuit structure. Moreover, this proposed converter is further designed for high power density, which reduces more than 70% of volume. In this way, small power converter can merge into the junction box of solar panel, which can reduce cost and be convenient for installations.
Koné, Sodjan. "Développement de briques technologiques pour la réalisation des composants de puissance en diamant monocristallin." Thesis, Toulouse, INPT, 2011. http://www.theses.fr/2011INPT0048/document.
Повний текст джерелаAs applications in the field of power electronics tend toward more extreme conditions (high power density, high frequency, high temperature ...), evolution of electric power treatment systems comes up against physical limits of silicon, the main semiconductor material used in electronic industry for over 50 years. A new approach based on the use of wide bandgap semiconductor materials will permit to overcome those limits. Among these materials, diamond is a very attractive material for power electronics switch devices due to its exceptional properties: high electric breakdown field, high carriers mobilities, exceptional thermal conductivity, high temperature operating possibility... However, the use of diamond as an electronic material is still very problematic due to the difficulty in the synthesis of high electronic grade CVD diamond and to find suitable dopants (in particular donors) in diamond. Besides, some of the unique properties of diamond, such as its extreme hardness and chemical inertness that make it an attractive material also cause difficulties in its application. Nevertheless, recent progress in the field of chemical vapor deposition (CVD) synthesis of diamond allow the study of the technological steps (RIE etching, ohmic and Schottky contacts, passivation,...) necessary for future diamond power devices processing. This is the aim of this thesis. In a first section, the uniqueness of diamond, the promise it bears as a potential material for specific electronic devices and the difficulties related to its application were reviewed. Then, the different technological steps required for power switching devices processing were studied: RIE etching, Ohmic and Schottky contacts. Finally, these works were illustrated by carrying out and electrical characterizations of Schottky Barrier Diodes. The achieved results allow us to make a summary of scientific and technological locks that remain for an industrial exploitation of diamond in power electronic switch devices field
Chmielewski, Daniel Joseph. "III-V Metamorphic Materials and Devices for Multijunction Solar Cells Grown via MBE and MOCVD." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1534707692114982.
Повний текст джерелаGabrysch, Markus. "Charge Transport in Single-crystalline CVD Diamond." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-122794.
Повний текст джерелаParedes, Camacho Alejandro. "Active gate drivers for high-frequency application of SiC MOSFETs." Doctoral thesis, Universitat Politècnica de Catalunya, 2020. http://hdl.handle.net/10803/669291.
Повний текст джерелаLa tendencia en el diseño y desarrollo de convertidores de potencia está enfocada en realizar sistemas eficientes con alta densidad de potencia, fiabilidad y bajo costo. Los retos para cubrir esta tendencia están centrados principalmente en el uso de nuevas tecnologías de dispositivos de conmutación tales como, MOSFETs de carburo de silicio (SiC). Los MOSFETs de SiC presentan mejores características que sus homólogos de silicio; tienen baja resistencia de conducción, pueden trabajar a mayores velocidades de conmutación y pueden operar a mayores niveles de temperatura y tensión. A pesar de las ventajas de los transistores de SiC, existen problemas que se manifiestan cuando estos dispositivos operan a altas frecuencias de conmutación. Las rápidas velocidades de conmutación de los MOSFETs de SiC pueden provocar sobre-voltajes y sobre-corrientes que conllevan a problemas de interferencia electromagnética (EMI). Por tal motivo, el desarrollo de controladores de puertas es una etapa fundamental en los MOSFETs de SiC para eliminar los problemas a altas frecuencias de conmutación y aumentar su rendimiento. En consecuencia, aprovechar las ventajas de estos dispositivos y lograr sistemas más eficientes y con alta densidad de potencia. En esta tesis, se realiza un estudio, diseño y desarrollo de controladores activos de puerta para mejorar el rendimiento de conmutación de los MOSFETs de SiC aplicados a convertidores de potencia de alta frecuencia. Los controladores son validados a través de pruebas y estudios experimentales. Además, los controladores de puerta desarrollados son aplicados en convertidores para sistemas de carga inalámbrica de baterías de vehículos eléctricos. Los resultados muestran la importancia de los controladores de compuerta propuestos y su viabilidad en convertidores de potencia basados en carburo de silicio.
Lashway, Christopher R. "Resilient and Real-time Control for the Optimum Management of Hybrid Energy Storage Systems with Distributed Dynamic Demands." FIU Digital Commons, 2017. https://digitalcommons.fiu.edu/etd/3515.
Повний текст джерела"Robust Control of Wide Bandgap Power Electronics Device Enabled Smart Grid." Doctoral diss., 2017. http://hdl.handle.net/2286/R.I.46215.
Повний текст джерелаDissertation/Thesis
Doctoral Dissertation Electrical Engineering 2017
Wang, Yi-An, and 王翊安. "Design and Implementation of Analog Controlled Power Factor Corrector with Wide Bandgap Device." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/6wsfv7.
Повний текст джерела國立臺北科技大學
電力電子產業研發碩士專班
105
The objective of this thesis is to design and implement an analog controlled power factor corrector with wide bandgap devices. By employing the benefits of wide gap devices, including high carrier mobility, high saturation velocity, and low turn-on resistance, the whole system can operate in high frequency, which means the volume of passive elements can be reduced, and the power density can be improved. The prototype of this thesis is designed to work in discontinuous conduction mode even under full load condition. Due to the special feature of discontinuous conduction mode, the current sensor is not required, so, the traces of the PCB board can be shortened. This topology is suitable for the low-power application of the power factor corrector. The specification of this thesis is described as follow: input voltage is 110 Vac/60Hz, output voltage is 400V, switching frequency is 300 kHz, and the controller is TI UC3525A. According to the experimental results, when the input voltage is 110 Vac, full load, the efficiency is 88.9%, and the PF is 0.98.
Chiu, Ya-chi, and 邱雅琦. "Realization of a High-Efficiency Phase-Shift Full-Bridge DC-DC Converter with Wide-Bandgap Device." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/60722524739664418591.
Повний текст джерела國立臺灣科技大學
電子工程系
101
A phase-shift full-bridge converter with zero-voltage-switching (ZVS) features can reduce the switching losses and high-frequency noises. Thus, the conversion efficiency can be effectively improved and the switching frequency can be raised to reduce the sizes of magnetic components. Since the output specifications of the studied converter are low voltage and high current, synchronous rectifiers are used instead of the Schottky diodes on the secondary side to reduce the conduction losses. In addition, the effects of the primary-side clamp diodes are analyzed. And wide-bandgap GaN FETs are applied for the lagging leg to achieve ZVS at light load. The operating principles and design considerations of the proposed converter are discussed in detail. A prototype phase-shift full-bridge converter has been implemented. The input voltage is 390 V, the output voltage is 12 V and the output current is 54 A. Theoretical analyses are verified with the experimental results.
Ou, Jehn, and 歐震. "Growths and Characterizations of Wide-Bandgap III-Antimonide and III-Nitride Epilayers and Their Device Structures." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/74590427695931909661.
Повний текст джерела國立交通大學
電子物理系
87
We have carried out systematic studies on the epitaxial growth of AlAs1-xSbx, GaN and InxGa1-xN compounds using metalorganic vapor phase epitaxy technique. Experimental data indicate that the solid composition of AlAsSb depends strongly on the input reactant flow rates and the growth temperature. A high Sb concentration of AlAsSb alloy can only be obtained at a V/III ratio close to 1, whereas too high the Sb flow rates and too low the V/III ratio will lead to the formation of Sb droplets and Al metal platelets, respectively. For AlAsSb prepared at high growth temperatures, the side reaction of TBAs, b-elimination, is believed to response for the result in a decrease of the As solid concentration. By employing a thermodynamic analysis, a novel phase diagram for AlAsSb with simpler solid-vapor distribution relationship was obtained, according to which the As solid concentration can be directly determined by the input As/Al mole flow rate ratio. The AlAs1-xSbx alloy was also used to fabricate two novel diodes, the enhanced InP Schottky diode and the In0.53Ga0.47As/AlAs0.44Sb0.56/In0.53Ga0.47As single barrier tunneling diode. By introducing AlAsSb into the conventional Schottky structure, the InP Schottky barrier height was improved greatly from 0.45eV to 0.76eV. For single-barrier tunneling diode, a negative differential resistance characteristic was successfully observed at 100 and 300K. A high peak-to-valley current ratio of 4.2 is obtained at 100K, which is the best value ever reported for such type of device. For GaN, the film quality appears to be very sensitive to the buffer layer property and the growth temperature. The optimized buffer layer thickness, temperature ramping rate and growth temperature are found to be around 100~300A, 75~100℃/min, and 1,000~1,050℃, respectively. A phase transition from hexagonal to cubic structure for GaN has been evidenced at a growth temperature around 750℃. The best quality of our GaN films in terms of FWHMs of x-ray and 300K-PL are as narrow as only 160 arcsec and 28meV, respectively. The corresponding electron mobility and carrier concentration also exhibit superior values of 330 cm^2/V and 1.1x10^17 cm^-3, respectively. Regarding to the InGaN growth, our experimental results indicate that the solid composition and characteristic of InGaN are determined not only by the growth temperature, but also by the TMGa and TMIn flow rates. The films with the good structural and optical properties can only be obtained at temperatures above 750℃. For the solid distribution, we found that too high the TMIn flow rate and too low the TMGa flow rate will both bring a decrease of In concentration solid, unfavorable to the high-In content InGaN growth. Besides, the thermodynamic analysis was also performed in our InGaN study. By introducing an empirical high-temperature factor in our modified InGaN growth model, we can successfully predict the solid-vapor distribution in InGaN and the appearance of In-droplets during growth. Based on thermodynamic arguments, the maximum allowed In solid concentration for a single phase InGaN is constrained primarily by the high temperature effect, such as In desorption, and the In saturation vapor pressure. By optimizing the growth conditions, we can obtain high quality InGaN epilayers with the narrow FWHMs of 150 arcsec and 92 meV for (0002) x-ray diffraction and 300K-PL peaks, respectively.
Swenberg, Johanes F. N. "Development of wide-bandgap II-VI semiconductor light-emitting device technology based on the graded injector design." Thesis, 1995. https://thesis.library.caltech.edu/4058/1/Swenberg_jfn_1995.pdf.
Повний текст джерелаParvez, Mohammad. "Analysis, Modelling, Design, and Control of DC-DC Converter for Renewable Power Generation Systems." Thesis, 2021. https://hdl.handle.net/2440/135635.
Повний текст джерелаThesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronic Engineering, 2022
Lai, Ying-Yu, and 賴映佑. "Study of wide-bandgap semiconductor planar microcavity laser devices." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/73068859300140660100.
Повний текст джерела國立交通大學
光電工程研究所
103
In planar microcavities (MCs), beside the vertical-cavity surface-emitting laser (VCSEL) action, another low threshold laser could be generated by the Bose-Einstein condensation of cavity-polaritons, named polariton laser. Wide-bandgap materials including ZnO and GaN have a high potential on making VCSELs and polariton lasers due to their high exciton binding energies. In this thesis, we report an electrically injected GaN-based VCSEL and an optically pumped ZnO polariton laser. Through simulation, we found that transparent conducting layer and lateral confinement aperture play important roles on reducing lasing threshold of the GaN VCSEL. We also proposed a new low index aperture design for GaN VCSEL and observed a transverse mode lasing behavior by an optical pumping experiment. For the electrically pumped VCSELs, the proposed low-index SiO2 aperture can confine both the current and optical mode simultaneously, which reveals its confinement capability. For the ZnO-based MC, a clear formation of cavity polariton has been observed. And the corresponding poalriton relaxation and bottleneck effect were also verified. A low threshold polariton laser can be achieved by polariton self-interaction at room temperature. Besides, the polariton laser with a lower threshold can be achieved by assistant of longitudinal optical phonon-polariton scattering. These results provide a clear map for future designing of low threshold ZnO MC polarton lasers.
Kao, Chi-Joe, and 高治舟. "The application of surface insulating layer on wide-bandgap semiconductor devices." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/26482128824848849878.
Повний текст джерела國立中央大學
物理研究所
93
Abstracts In this dissertation, the applications of insulators/oxides on GaN-based MSM photodectors or GaN-, ZnO-based FETs are performed. Several application cases and theories of insulator on GaN- and ZnO-based devices are introduced here: GaN-based MSM UV photodetectors with a low-temperature grown GaN (LT-GaN) layer is demonstrated first. It was found that we could achieve a two-order of magnitude smaller, dark-current of GaN MSM photodetector by employing a LT-GaN surface insulating layer. This result could be attributed to the larger Schottky-barrier height between the Ni/Au metal contact and the LT-GaN surface insulating layer. It was also found that photodetectors with the LT-GaN layer could provide a larger photocurrent to dark-current contrast ratio and a larger UV-to-visible rejection ratio. The maximum responsivity was found to be 3.3 A/W and 0.13 A/W when the biases were at 5 V and 1 V, respectively. The performance of AlGaN/GaN heterostructure field-effect transistors (HFETs) with either uncapped free surface or with LT-GaN, SiO2, Si3N4 as gate insulators is examined second. LT-GaN, SiO2 and Si3N4 surface high-resistivity layer disposed on the AlGaN/GaN heterostructures resulted in an increase of sheet carrier concentrations. These observations could be attributed from the passivation effect to passivate the surface states, thereby having a different, maybe lower, electronic density of states compared to the AlGaN free surface. To clarify the effect of these surface insulating layers on the AlGaN/GaN HFET structures, Hall measurement were performed here. The sheet carrier concentrations of AlGaN/GaN HFETs with any of these surface insulating layers are similar to each other and about 100% higher than that in an AlGaN/GaN HFET structure with a free surface. Due to the better lattice match with the AlGaN surface layer, the HFET with a LT-GaN layer as the gate insulating layer shows the best DC and RF device performance, demonstrating that this material is an effective insulator for nitrides. Comparison of ZnO MOSFETs and MESFETs fabricated on the same wafers using either sapphire or glass substrate is report finally. ZnO thin film field effect transistors with 1.5-20um gate width were fabricated using either a metal gate (metal-semiconductor field-effect transistor, MESFET) or a metal-oxide-semiconductor (MOS) gate. In both cases we found that use of a thick (around 0.8~0.9µm) ZnO buffer was necessary on the sapphire or glass substrate prior to growing the active layers in order to reduce gate leakage current. The MOS structure with a 50-nm-(Ce,Tb)MgAl11O19 gate dielectric showed an order of magnitude lower gate leakage current than the MESFET, due to the relatively high barrier height of MOS structure. Good drain-source current characteristics were obtained from MOS gate structures using phosphorus-doped ZnO channels, whereas the metal structures showed very poor modulation. For the general speaking form this dissertation, surface insulating layer could provide device high Schottky barrier height, low metal/semiconductor leakage current, low surface state density and highly stable device performance. One may use surface insulating layer to achieve more stable, even higher, performance of semiconductor device easily.
Bandić, Zvonimir Z. "Novel devices employing epitaxial wide bandgap semiconductors : physics, electronics and materials characterization." Thesis, 2000. https://thesis.library.caltech.edu/6096/2/Bandic_zz_2000.pdf.
Повний текст джерелаLades, Martin [Verfasser]. "Modeling and simulation of wide bandgap semiconductor devices : 4H/6H-SiC / Martin Lades." 2000. http://d-nb.info/962057827/34.
Повний текст джерелаLi-ChiPeng and 彭立琪. "Wide Bandgap III-Nitride-based Optoelectronic Devices Grown by Metalorganic Vapor Phase Epitaxy." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/84978359794927842251.
Повний текст джерела國立成功大學
光電科學與工程學系
100
In this dissertation, growth and fabrication of III-nitride-based optoelectronic devices by MOVPE have been studied. Several methods used to improve output power efficiency of GaN-based blue light emitting diodes (LEDs) have been studied. GaN-based blue LEDs with textured sidewalls and micro-scale pillars around mesa region could enhance light efficiency about 26% by reducing the total internal reflection of light inside the LED structure. Furthermore, comparison of conventional LEDs, the LEDs combining with textured sidewalls, GaN micro-pillars around the mesa region, patterned sapphire substrate (PSS), and highly reflective p-/n-type Ag/Cr/Au electrode pads could further improve around 80% in wall-plug efficiency (WPE). The embedded multilayers of GaN/AlxGa1-xN microlens-like structure on GaN template with micro-pillars pattern could enhance the LEDs output power by more than 30% due to the enhanced guided-light scattering efficiency, resulting from the difference in refractive index of GaN and AlGaN layer. Moreover, owing to the difference in lateral and vertical growth rate of homoepitaxial GaN grown on GaN template with micro-pillars pattern, the similar epitaxial lateral overgrowth model have be demonstrated and could further improve the crystal quality of epilayer. A single AlGaN layer with two different Al contents by grown on the GaN template with micro-pillars structure has been demonstrated. The strains-induced Al incorporation efficiency and difference in lateral and vertical growth rate of AlGaN grown on the sidewalls, top and valley surfaces of the pillars lead to form the different Al contents in the single AlGaN layer. The Schottky-type photodetectors (PDs) were also demonstrated for double Al contents of deposited AlGaN on GaN μ-pillar templates, exhibiting the three steps of responses occurred at about 326, 346, and 356 nm. The cutoff wavelength of the Schottky PDs at 326 and 346 nm should be contributed by the AlGaN layer on the sidewall of cone shaped pillars and the rest of the area of the AlGaN, respectively.
Liao, Long-De, and 廖隆德. "Design and Implementation of Digital Controlled Interleaved Power Factor Corrector with Wide Bandgap Devices." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/6a8ms2.
Повний текст джерела國立臺北科技大學
電機工程系電力電子產業研發碩士專班
105
The objective of this thesis is to design and implement an interleaved power factor corrector with wide bandgap devices. Compared with traditional silicon power devices, the gallium nitride power devices have the advantages of high electron mobility, high saturable velocity, high electrical field strength and low on-resistance. The switching frequency can be increased without increasing the excessive switching loss in order to reduce the magnetic components size and increase power density. The design specifications include: output power rating of 750 W, input AC voltage 115 Vac and 230 Vac, output DC voltage of 400 Vdc and switching frequency of 300 kHz. Experimental results show that the efficiency is up to 93%, power factor is greater than 0.996 in low line voltage and full load condition. The efficiency is up to 95%, power factor is greater than 0.94 in high line voltage and full load condition.
Lin, Jia-Hong, and 林佳鴻. "Design and Implementation of a Semi-Bridgeless Power Factor Corrector with Wide Bandgap Devices." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/dmvb8n.
Повний текст джерела國立臺北科技大學
電機工程系電力電子產業碩士專班
107
The main purpose of this thesis is to design and implement a semi-bridgeless power factor corrector (PFC) by using wide bandgap device. The characteristics of wide bandgap device is utilized to increase the switching frequency and the volume of the required inductor is reduced. This thesis uses the average current control method to make the source current can trace source voltage to improve the power factor and stabilize the output voltage. Compared to the traditional power factor correctors, the number of the semiconductor components in the current path of the semi-bridgeless PFC is less, therefore the circuit efficiency can be improved, and it is more suitable for high power applications. In addition, the semi-bridgeless PFC has lower common mode noise feature. In this thesis, the microcontroller TMS320F28035 produced by Texas Instruments is used as the control core to achieve power factor correction by the average current control method, and associated with the implemented power stage circuit to verify the proposed circuit design theory. The experimental specifications include the input source voltage range changes from AC 110V to AC 220V, the output voltage is DC 400V, the maximum output power is 600W and the switching frequency is 200kHz. In experiments, the maximum efficiency is up to 98.6%, the power factor is up to 0.99 at full load condition, and the harmonic currents meet IEC61000-3-2 Class D standard.
Liao, Bo-Wei, and 廖博偉. "Design and Implementation of Digital Controlled Bridgeless Power Factor Corrector with Wide Bandgap Devices." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/dqb44m.
Повний текст джерела國立臺北科技大學
電機工程系電力電子產業碩士專班
106
The objective of this thesis is to design and implement a bridgeless power factor corrector with wide bandgap devices. Compared with traditional silicon power devices, the gallium nitride power devices have the advantages of low on-resistance, high electron mobility, high saturable velocity and high electrical field strength. The switching frequency can be increased without increasing the excessive switching loss in order to reduce the magnetic component sizes and increase power density. The implemented bridgeless power factor corrector has specifications that the output power is 500 W, the input voltage is 110 Vac/ 60 Hz, and the switching frequency is 200 kHz. The experimental results show that under full load, the efficiency can reach 96.6% and the power factor can reach 0.997.