Sökning: "NATURAL SCIENCES Physics Condensed matter physics Semiconductor physics"

Visar resultat 6 - 10 av 185 avhandlingar innehållade orden NATURAL SCIENCES Physics Condensed matter physics Semiconductor physics.

1. 6. First Principles Calculations of Electron Transport and Structural Damage by Intense Irradiation

   Författare :Carlos Ortiz; Olle Eriksson; Mattias Klintenberg; Richard A. London; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Condense matter theory; electronic structure; quasiparticles; GW theory; molecular dynamics; Boltzmann transport; electron transport; impact ionization; structural damage; dielectric response; structural biology; radiation detectors; scintillators; positron emission tommography; Electronic structure; Elektronstruktur; Semiconductor physics; Halvledarfysik; Biological physics; Biologisk fysik; Critical phenomena phase transitions ; Kritiska fenomen fasövergångar ; Functional materials; Funktionella material; Materiefysik; Physics of Matter;

   Sammanfattning : First principle electronic structure theory is used to describe the effect of crystal binding on radiation detectors, electron transport properties, and structural damage induced by intense irradiation. A large database containing general electronic structure results to which data mining algorithms can be applied in the search for new functional materials, a case study is presented for scintillator detector materials. LÄS MER

3. 7. Scanning tunneling microscopy and photoemission studies of Ag films on metal/semiconductor surfaces

   Författare :Samuel Starfelt; Hanmin Zhang; Lars Johansson; Anders Mikkelsen; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum well states; thin films; semiconductor; STM; STS; ARPES; Physics; Fysik;

   Sammanfattning : The research presented in this thesis has been focused on the study of thin Ag films, grown on metal-reconstructed Si(111) and Ge(111) surfaces.The films have been grown at room temperature, and the morphologiesand electronic structures of the films have been investigated using scanning tunneling microscopy and spectroscopy (STM/STS), low-energy electron diffraction (LEED) and angle-resolved photoelectron spectroscopy(ARPES). LÄS MER

4. 8. Effect of Substrate on Bottom-Up Fabrication and Electronic Properties of Graphene Nanoribbons

   Författare :Konstantin Simonov; Olof Karis; Nils Mårtensson; Alexei Preobrajenski; Alessandro Baraldi; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; graphene nanoribbons; bottom-up; substrate; metal contact; electronic structure; electron doping; PES; ARPES; NEXAFS; STM; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : Taking into account the technological demand for the controlled preparation of atomically precise graphene nanoribbons (GNRs) with well-defined properties, the present thesis is focused on the investigation of the role of the underlying metal substrate in the process of building GNRs using bottom-up strategy and on the changes in the electronic structure of GNRs induced by the GNR-metal interaction. The combination of surface sensitive synchrotron-radiation-based spectroscopic techniques and scanning tunneling microscopy with in situ sample preparation allowed to trace evolution of the structural and electronic properties of the investigated systems. LÄS MER

5. 9. Resonant Tunneling in Laterally Confined Quantum Structures

   Författare :Boel Gustafson; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gravitation; relativity; quantum mechanics; classical mechanics; Mathematical and general theoretical physics; Fysik; Physics; High peak-to-valley ratio; Lateral confinement; Quantum dots; Resonant tunneling; Self-assembled quantum dots; Schottky depletion; Buried metal gate; Electron transport; Magnetic-field dependence; Energy level width; Tunneling transistors; Mode coupling; statistical physics; thermodynamics; Matematisk och allmän teoretisk fysik; klassisk mekanik; kvantmekanik; relativitet; statistisk fysik; termodynamik; Technological sciences; Teknik; Fysicumarkivet A:2001:Gustafson;

   Sammanfattning : In the thesis, three-dimensionally confined resonant tunneling structures were studied experimentally. Two approaches were used for obtaining quantum confinement: gate-defined lateral constriction of double barrier structures, and epitaxial growth of self-assembled quantum dots. LÄS MER

7. 10. Novel Layered and 2D Materials for Functionality Enhancement of Contacts and Gas Sensors

   Författare :Hossein Fashandi; Per Eklund; Anita Lloyd Spetz; Mike Andersson; Lars Hultman; Ganpati Ramanath; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Chemical gas sensors are widely-used electronic devices for detecting or measuring the density levels of desired gas species. In this study, materials with established or potential applications for gas sensors are treated. LÄS MER