Sökning: "negative-U"

Hittade 5 avhandlingar innehållade ordet negative-U.

1. 1. Electronic Structure Calculations of Point Defects in Semiconductors

   Författare :Andreas Höglund; Susanne Mirbt; Alison Mainwood; Uppsala universitet; []
   Nyckelord :Physics; electronic structure calculations; point defects; semiconductor; formation energy; equilibrium solubility limit; thermodynamic equilibrium concentration; transfer levels; negative-U; 110 surface; diffusion; activation energy; solar cells; Fysik;

   Sammanfattning : In this thesis point defects in semiconductors are studied by electronic structure calculations. Results are presented for the stability and equilibrium concentrations of native defects in GaP, InP, InAs, and InSb, for the entire range of doping conditions and stoichiometry. LÄS MER

3. 2. Electron Paramagnetic Resonance studies of negative-U centers in AlGaN and SiC

   Författare :Xuan Thang Trinh; Nguyen Tien Son; Erik Janzén; Jan Stehr; Linköpings universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

   Sammanfattning : Silicon (Si) is the most commonly used n-type dopant in AlGaN, but the conductivity of Si-doped AlxGa1-xN was often reported to drop abruptly at high Al content (x>0.7) and the reason was often speculated to be due to either compensation by deep levels or self-compensation of the so-called DX (or negative-U) center. LÄS MER

4. 3. Deep Levels in Electron-Irradiated and As-Grown SiC Power Device Material

   Författare :Carl Hemmingsson; Gerhard Pensl; Linköpings universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Silicon Carbide (SiC) has several favorable physical properties for the fabrication of highpower, high-temperature and high-frequency devices. Devices in SiC can operate at high temperatures due to the wide band gap and the high thermal stability of the material. LÄS MER

5. 4. Theory of Electron Transport in Superconducting Heterostructures

   Författare :Magnus Hurd; Chalmers University of Technology; []
   Nyckelord :;

   Sammanfattning : This thesis deals theoretically with electron transport in superconducting heterostructures. Depending on the system I use different theoretical approaches. The thesis contains an introduction followed by four research papers (Papers I-IV). The introduction gives the background of the work in Papers I-IV. LÄS MER

7. 5. Electron Paramagnetic Resonance Studies of Point Defects in AlGaN and SiC

   Författare :Xuan Thang Trinh; Nguyen Tien Son; Erik Janzén; Mary Ellen Zvanut; Linköpings universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

   Sammanfattning : Point defects in semiconductor materials are known to have important influence on the performance of electronic devices. For defect control, knowledge on the model of defects and their properties is required. LÄS MER