Sökning: "defect states"

Visar resultat 1 - 5 av 67 avhandlingar innehållade orden defect states.

  1. 1. Electronic states of adsorbates and insulating overlayers on metal surfaces

    Författare :Fredrik Olsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Shockley surface states; local density of states; scanning tunneling microscope; chemisorption; sodium chloride; noble metals; image states; electronic states; density functional theory;

    Sammanfattning : Electronic states of adsorbates and insulating overlayers provide a wealth of scientifically interesting phenomena with great technological importance. Interesting phenomena arise, for example, from the interaction of electronic states of an adsorbate with the continuum of metal electron states, both propagating bulk states and surface states. LÄS MER

  3. 2. Reactivity of Transition-Metal Compounds from Electronic Structure

    Författare :Aleksandra Vojvodic; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; magnetic edge states; electronic structure; density-functional theory; growth; surface states and resonances; nitrides; density of states; hydrodesulphurisation; sulphides; steam reforming; transition-metal carbides; Bronsted-Evans Polanyi relation; scaling relations; adsorption; descriptor; reactivity; catalysis;

    Sammanfattning : Transition-metal carbides (TMC's), nitrides, and sulfides belong to the class of materials known as transition-metal compounds (TMX's). Besides having intriguing properties, these materials are relevant for, e.g., growth and catalysis. LÄS MER

  4. 3. Microscopic Theory of Externally Tunable Exciton Signatures of Two-Dimensional Materials

    Författare :Maja Feierabend; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; localized states; density matrix formalism; magnetic field; transition metal dichalcogenides; Bloch equations; organic inorganic heterostructures; dark excitons; strain;

    Sammanfattning : Atomically thin transition metal dichalcogenides (TMDs) are in the focus of current research due to their efficient light-matter interaction and the remarkably strong Coulomb interaction that leads to tightly bound excitons. Due to their unique band structure, TMDs show a variety of bright and optically inaccessible dark excitonic states. LÄS MER

  5. 4. Optical properties of some complex defects in silicon

    Författare :Johan Svensson; G. D Watkins; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : lnfrared absorption spectroscopy has been used study transitions between electronic states related to some complex defects in silicon. Three different defects have been studied: a complex defect involving carbon as one of its constituents, a divacancy, and a defect found in silicon containing tin. LÄS MER

  7. 5. Photoluminescence Studies of Single Quantum Dots

    Författare :Nikolay Panev; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Stranski-Krastanow; photoluminescence; laser spectroscopy; antibunching; random telegraph noise; blinking; Physics; Fysik; Fysicumarkivet A:2004:Panev; solid immersion lens; quantum dots; low-dimensional structures;

    Sammanfattning : This thesis presents photoluminescence (PL) spectroscopy studies of single III-V semiconductor quantum dots (QDs). The electronic properties of the QDs, as well as, the dynamics of the processes taking part inside and in the surroundings of the QDs have been studied by single quantum dot photoluminescence spectroscopy, time resolved spectroscopy, and correlation spectroscopy. LÄS MER