Search for dissertations about: "insulating"

Showing result 1 - 5 of 196 swedish dissertations containing the word insulating.

2. 1. Epitaxy, analysis and application of semi-insulating III-V materials

   Author : David Söderström; KTH; []
   Keywords : InP; GaInP; semi-insulating materials; iron doping; ruthenium doping; HVPE; diffusion; deep levels; capture cross sections; resistivity analysis; buried heterostructure laser;

   Abstract : Semi-insulating (SI) III-V materials can provide electricalisolation for integration and capacitance minimisation for highspeed operation. Compared to the polyimides, these can offerbetter thermal conduction. Ever since the fabrication of thefirst SI III-V materials, transition metals have been utilisedas deep impurities to impart SI properties. READ MORE

4. 2. Gallium arsenide based buried heterostructure laser diodes with aluminium-free semi-insulating materials regrowth

   Author : Carlos Angulo Barrios; KTH; []
   Keywords : semiconductor lasers; in-plane lasers; VCSELs; GaAs; GaInP; semi-insulating materials; hydride vapour phase epitaxy; regrowth; buried heterostructure; leakage current; simulation;

   Abstract : Semiconductor lasers based on gallium arsenide and relatedmaterials are widely used in applications such as opticalcommunication systems, sensing, compact disc players, distancemeasurement, etc. The performance of these lasers can beimproved using a buried heterostructure offering lateralcarrier and optical confinement. READ MORE

5. 3. Guiding of highly charged ions through insulating nanocapillaries

   Author : Hongqiang Zhang; Reinhold Schuch; Amine Cassimi; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Atomic physics; Atomfysik; fysik; Physics;

   Abstract : This thesis contains experimental work on guiding of highly charged ions through insulating nanocapillaries. We have studied the time evolution of angular distributions of transmitted ions under well defined initial conditions: already charged, as well as fully discharged nanocapillaries, by using a two-dimensional position sensitive Micro Channel Plate detector with a data acquisition system working in event mode. READ MORE

6. 4. Surface potential dynamics on insulating polymers for HVDC applications

   Author : Shahid Alam; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dielectric spectroscopy; silicone rubber; intrinsic conduction; surface potential decay; activation energy; electric conductivity; HVDC insulation;

   Abstract : The use of high voltage direct current (HVDC) technology in power transmission systems is continuously expanding. Nowadays, HVDC transmissions operate at voltages up to 800 kV and higher levels are being developed. READ MORE

7. 5. Characteristics of streamer discharges in air and along insulating surfaces

   Author : Lan Gao; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; Electricity; Esp The Study Of Transients and Discharges; elektricitetslära; ssk studiet av transienter och urladdning;

   Abstract : Power quality is dependent on the dielectric properties of the insulators used throughout the power generation and power transmission utilities. Knowledge of the pre-discharge stage associated with the electrical breakdown across outdoor insulators is essential if one is to improve the performance of these insulators under various electrical and environmentalconditions. READ MORE