Sökning: "Ohmic"

Visar resultat 21 - 25 av 78 avhandlingar innehållade ordet Ohmic.

1. 21. Nanostructured materials for gas sensing applications

   Författare :Kristina Buchholt; Per Eklund; Lars Hultman; Anita Lloyd Spetz; Harry L. Tuller; Linköpings universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

   Sammanfattning : In this Thesis I have investigated the use of nanostructured films as sensing and contact layers for field effect gas sensors in order to achieve high sensitivity, selectivity, and long term stability of the devices in corrosive environments at elevated temperatures. Electrochemically synthesized Pd and Au nanoparticles deposited as sensing layers on capacitive field effect devices were found to give a significant response to NOx with small, or no responses to H2, NH3, and C3H6. LÄS MER

3. 22. Modelling of Terahertz Planar Schottky Diodes

   Författare :Aik-Yean Tang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; S-parameter extraction; Electro-thermal; Schottky diodes; Skin effect; Electromagnetic; Frequency multipliers; High-power frequency multiplier; Current crowding; Proximity effect; Submillimetre wave generation and detection; Geometric modelling; Gallium Arsenide;

   Sammanfattning : This thesis deals with the modelling of THz planar Schottky diodes, focusing on analyses of the geometry- dependent parasitics and the diode chip thermal management. Moving towards higher operating frequencies, the electromagnetic couplings pose significant limitations on the diode performance. LÄS MER

4. 23. Design Optimization and Realization of 4H-SiC Bipolar Junction Transistors

   Författare :Hossein Elahipanah; Mikael Östling; Carl-Mikael Zetterling; Anders Hallèn; Adolf Schöner; Tsunenobu Kimoto; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 4H-SiC; BJT; high-voltage and ultra-high-voltage; high-temperature; self-aligned Ni-silicide Ni-SALICIDE ; lift-off-free; wafer-scale; current gain; Darlington; Electrical Engineering; Elektro- och systemteknik; Informations- och kommunikationsteknik; Information and Communication Technology;

   Sammanfattning : 4H-SiC-based bipolar junction transistors (BJTs) are attractive devices for high-voltage and high-temperature operations due to their high current capability, low specific on-resistance, and process simplicity. To extend the potential of SiC BJTs to power electronic industrial applications, it is essential to realize high-efficient devices with high-current and low-loss by a reliable and wafer-scale fabrication process. LÄS MER

5. 24. Development and Characterisation of SiC Based Sensors for Harsh Environments

   Författare :Lars Unéus; Jacobus H. Visser; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : The introduction of chemical gas sensors in our environment is a process that started many years ago. However, although the process has been rather slow over the years, the interest for chemical gas sensors is rising due to the growing environmental awareness. LÄS MER

7. 25. Dielectric Relaxation in Dielectric Mixtures

   Författare :Enis Tuncer; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : In this thesis dielectric properties of both ideal composite structures and polymeric composite materials were investigated. Numerical calculations were performed to simulate frequency response of interfacial polarization using the finite element method in two dimensions. LÄS MER