Search for dissertations about: "heterojunction"

Showing result 11 - 15 of 76 swedish dissertations containing the word heterojunction.

2. 11. Ultra High Speed InP Heterojunction Bipolar Transistors

   Author : Mattias Dahlström; KTH; []
   Keywords : InP HBT carbon high-speed;

   Abstract : This thesis deals with the development of high speed InPmesa HBT’s with power gain cut—off frequencies up toand above 300 GHz, with high current density and low collectordischarging times.Key developments are Pd—based base ohmics yielding basecontact resistances as low as 10 Ωµm2, base—collector grades to enable to use ofInP in the collector, and an increase in the maximum currentdensity through collector design and thermal optimization. READ MORE

4. 12. InGaAs/AlGaAs Heterojunction Phototransistors for Optical Signal Processing Applications

   Author : Ola Sjölund; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : This thesis deals with InGaAs/AlGaAs heterojunction phototransistors (HPTs) operating in the wavelength region where the GaAs substrate is transparent. Vertical integration of such a current amplifying detector with emitters or modulators will facilitate the fabrication of two dimensional arrays of components for parallel optical signal processing and transmission applications. READ MORE

5. 13. Modelling of Silicon Germanium heterojunction bipolar transistors and its applications

   Author : S Bruce; Uppsala universitet; []
   Keywords : ;

   Abstract : .... READ MORE

6. 14. Materials aspects in spin-coated films for polymer photovoltaics

   Author : Ana Sofia Anselmo; Ellen Moons; Krister Svensson; Jan van Stam; Paul Dastoor; Karlstads universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; materials science; photovoltaics; conjugated polymer; polymer solar cell; bulk heterojunction; coating; morphology; fullerene; photostability; degradation; X-ray absorption spectroscopy; synchroton-based techniques; Materialvetenskap; Materialvetenskap;

   Abstract : Polymer-based photovoltaics have the potential to contribute to boosting photovoltaic energy conversion overall. Besides allowing large-area inexpensive processing, polymeric materials have the added benefit of opening new market applications for photovoltaics due to their low-weight and interesting mechanical properties. READ MORE

7. 15. The life and death of perovskites : Interfacial function and degradation of lead halide perovskites studied by photoelectron spectroscopy

   Author : Sebastian Svanström; Ute B Cappel; Håkan Rensmo; Erik Johansson; Selina Olthof; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; lead halide perovskite solar cells; interfacial degradation; heterojunction interfaces; photoelectron spectroscopy; operando; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Abstract : Lead halide perovskite solar cells are a promising new technology which could soon see widespread commercial application but is partly held back by poor long-term stability. In this thesis, photoelectron spectroscopy (PES) is used to study the dynamical processes at the surface or interfaces of lead halide perovskite materials. READ MORE