Sökning: "Low bandgap"

Visar resultat 11 - 15 av 116 avhandlingar innehållade orden Low bandgap.

  1. 11. Thermal conductivity of wide and ultra-wide bandgap semiconductors

    Författare :Dat Tran; Plamen Paskov; Vanya Darakchieva; Martin Kuball; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; III-nitrides; β-Ga2O3; Thermal conductivity; Thermal transport;

    Sammanfattning : This PhD thesis presents experimental and theoretical studies of the thermal conductivity of wide and ultra-wide bandgap semiconductors including GaN, AlN, β-Ga2O3 binary compounds, and AlxGa1−xN, ScxAl1−xN, YxAl1−xN ternary alloys. Thermal conductivity measurements are conducted using the transient thermoreflectance (TTR) technique and the results are interpreted using analytical models based on the solution of the Boltzmann transport equation (BTE) within the relaxation time approximation (RTA). LÄS MER

  3. 12. High-Temperature Analog and Mixed-Signal Integrated Circuits in Bipolar Silicon Carbide Technology

    Författare :Raheleh Hedayati; Carl-Mikael Zetterling; H. Alan Mantooth; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; silicon carbide SiC ; bipolar junction transistor BJT ; high temperature; SiC integrated circuit; Spice Gummel-Poon SGP ; operational amplifier opamp ; negative feedback amplifier; bandgap reference; masterslave comparator; digital-to-analog converter DAC ; analog-to-digital converter ADC ; flash ADC; successive approximation register SAR ADC; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Silicon carbide (SiC) integrated circuits (ICs) can enable the emergence of robust and reliable systems, including data acquisition and on-site control for extreme environments with high temperature and high radiation such as deep earth drilling, space and aviation, electric and hybrid vehicles, and combustion engines. In particular, SiC ICs provide significant benefit by reducing power dissipation and leakage current at temperatures above 300 °C compared to the Si counterpart. LÄS MER

  4. 13. Wirelessly Powered Communications: From Signal Optimization to Antenna Design

    Författare :Boules Atef Nessim Mouris; Ragnar Thobaben; Aggelos Bletsas; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless power transfer; multi-tone signals; non-linear energy harvester; wirelessly powered sensors; joint source-channel coding; analog mappings; energy scheduling; mutual coupling reduction; electromagnetic bandgap; glide symmetry.; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Future internet-of-things (IoT) and beyond 5G communication systems are envisioned to offer large-scale wireless connectivity where the different components of life, society and industry are connected in a smart yet sustainable way. The need for continuous battery charging and/or replacement is a bottleneck for sustainability in these systems. LÄS MER

  5. 14. Microwave power device characterization

    Författare :Kristoffer Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; statistical estimation; self-heating; Silicon Carbide; Gallium Nitride; mixer; thermal resistance; wide bandgap; microwave; error-correction; small-signalmodel;

    Sammanfattning : The first part of the thesis covers work done on device characterizationmethods. A statistical method for estimating small-signal model parametersin FET-models was proposed. A maximum likelihood estimator wasderived and the new method was compared to a standard direct extractiontechnique. LÄS MER

  7. 15. Surfaces and interfaces of low dimensional III-V semiconductor devices

    Författare :Yen-Po Liu; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; III-V semiconductor; nanowires; nanosheet; nano-device fabrication; STM; AFM; SGM; OBIC; XPS; Fysicumarkivet A:2022:Liu;

    Sammanfattning : The demand for fast and energy efficient (opto-)electronic applications needs high mobility semiconductor materials, such as InAs with a very high electron mobility and GaSb with a very high hole mobility. Beyond the material itself, also an innovative device geometry is needed, for example, the gate-all-around geometry that provides higher efficiency and electrostatic control for computational units. LÄS MER