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Visar resultat 1 - 5 av 9 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. On Gate Drivers for MOS-Controlled Power Devices and dv-dt Filters for Train Traction Converters

    Författare :Erik Velander; Hans-Peter Nee; Francesco Iannuzzo; KTH; []
    Nyckelord :Power semiconductor devices; DC-AC power converters; Silicon carbide; Insulated gate bipolar transistors; P-i-n diodes; Schottky diodes; Traction motors; Power MOSFET; Krafthalvledare; DC-AC kraftomvandlare; kiselkarbid; IGBT; P-i-n dioder; Schottky dioder; traktionsmotorer; Effekt-MOSFET; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In this thesis, low-loss gate-drive solutions and a proposed dv/dt-filter have been investigated with focus on train traction converters with dv/dt constraints.By using the silicon carbide (SiC) junction field-effect transistor (JFET), the switching losses can be significantly reduced compared to the commonly used insulated-gate bipolar transistor (IGBT), but complex gate-driver solutions are required for high utilization in terms of loss reduction. LÄS MER

  3. 2. Photo diodes for machine vision : device characteristics and a-Si:H deposition and analysis

    Författare :Annika Rantzer; Marcus Böhm; Linköpings universitet; []
    Nyckelord :TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : During the last years the area of digital cameras based on CMOS technology has grown rapidly. In CMOS, signal processing circuitry and sensor elements can be combined on the same chip, which has resulted in advanced machine vision chip designs. LÄS MER

  4. 3. Electrical and Optical Properties of AlGaAs/GaAs Aperiodic Superlattices and Resonant Tunneling Diodes. Theory, Design and Applications

    Författare :Simon Mang Cao; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; exciton-assisted transport; miniband; high-speed quantum electronics; optical properties; ultrafast optoelectronics; field-induced transport; irregular superlattices; nanometer-scale heterostructures; laser diodes; resonant tunneling;

    Sammanfattning : The objective of the work presented in this thesis is to study quantum transport and optical properties of aperiodic superlattices and resonant tunneling diodes using III-V semiconductor heterostructures grown by molecular beam epitaxy. The study follows a procedure of theoretical modeling, computer-aided design and simulation, sample growth, and measurements. LÄS MER

  5. 4. Junction Engineering in Nanostructured Optoelectronic Devices

    Författare :Ali Nowzari; NanoLund: Centre for Nanoscience; []
    Nyckelord :Nanowire; Solar cell; Photodetector; Light Emitting Diode; Doping Evaluation; Fysicumarkivet A:2018:Nowzari;

    Sammanfattning : Semiconductor nanowires have proven to be promising building blocks for next-generation optoelectronic devices. The nanometric dimensions of nanowires provides strain relaxation capability, thus enabling the heteroepitaxy of III-V materials on silicon, as well as providing the possibility of realizing optoelectronic devices with lattice-mismatched material combinations. LÄS MER

  7. 5. Studies of Light Emitting Devices Based on Er-doped Si and SiGe Layered Structures

    Författare :Chun-Xia Du; Fransesco Priolo; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; electroluminescence; diode; transistor; hot electron; recombination; excitation; de-excitation; Auger effect; molecular beam epitaxy; Er; Si; SiGe;

    Sammanfattning : Doping with rare earth element erbium (Er) in Si has recently attracted a lot of research interest due to potential applications in Si-based opto-electronics. By using molecular beam epitaxy (MBE), precipitate-free Er-doping in Si has been made together with other co-dopants, e.g., oxygen (0) and fluorine (F), up to a level ∼1020 cm-3. LÄS MER