Sökning: "bandgap engineering"

Visar resultat 1 - 5 av 93 avhandlingar innehållade orden bandgap engineering.

1. 1. 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

3. 2. Processing, Characterization and Modeling of AlGaN/GaN HEMTs

   Författare :Vincent Desmaris; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GaN; HEMT; III-Nitride processing; microwave modeling; AlGaN GaN; HFET; heterojunction field effect transistor; microwave devices; III-Nitride; Schottky diodes; Gallium nitride; resistive mixer; high electron mobility transistor; wide bandgap;

   Sammanfattning : III-Nitrides electronic properties make them currently the materials of choice for high-power high-frequency applications. Their wide bandgaps, high breakdown fields, the high electron peak and saturation velocities combined with the large conduction band offset and the high electron mobility observed in AlGaN/GaN heterostructures enable excellent microwave power performance of AlGaN/GaN high electron mobility transistors (HEMTs). LÄS MER

4. 3. Window Layer Structures for Chalcopyrite Thin-Film Solar Cells

   Författare :Fredrik Larsson; Tobias Törndahl; Jan Keller; Marika Edoff; Daniel Lincot; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CIGS; atomic layer deposition; ALD; thin-film technology; window layer structures; buffer layers; front contacts; metal oxides; ternary compounds; CIGS; tunnfilmssolceller; ALD; tunnfilmsteknik; fönsterlager; buffertlager; framkontakter; metalloxider; ternära föreningar; Teknisk fysik med inriktning mot elektronik; Engineering Science with specialization in Electronics;

   Sammanfattning : This thesis aims to contribute to the development of improved window layer structures for chalcopyrite thin-film solar cells, with an emphasis on the buffer layer, to assist future reductions of the levelized cost of energy. This is realized by exploring the potential of existing materials and deposition processes, as well as developing new buffer layer processes based on atomic layer deposition (ALD). LÄS MER

5. 4. Charge carrier traffic at interfaces in nanoeletronic structures

   Författare :Bahman Raeissi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; HfO2; oxide traps; High-k; interface states;

   Sammanfattning : This thesis describes investigations in relation to the search for materials with high dielectric constant, k, for future CMOS transistors. The most elementary quantities to be considered are k-value and energy band offsets between the dielectric and the silicon crystal on which it is deposited. LÄS MER

7. 5. Wide Bandgap MMIC Technology

   Författare :Mattias Sudow; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wide bandgap; AlGaN GaN; SiC MMIC; SiC MESFET; SiC Schottky; Microwave;

   Sammanfattning : Wide bandgap technology for microwave electronics has been an intense area of research during the last decade. With reas of application ranging from base station amplifiers to radar transceivers, this technology has the resources to be the basis for the next generation of high power microwave electronics. LÄS MER