Sökning: "Defects and impurities in crystals"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Defects and impurities in crystals.

  1. 1. Growth and characterization of SiC and GaN

    Författare :Rafal Ciechonski; Erik Janzén; Sebastian Lourdudoss; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SiC; GaN; Deep level transient spectroscopy; Minority Carrier Transient Spectroscopy; Hall effect; Cathodoluminescence; Scanning electron microscopy; Atomic Force microscopy; sublimation growth; MOCVD; heterostructures; High Electron Mobility transistor; point defects; Material physics with surface physics; Materialfysik med ytfysik;

    Sammanfattning : At present, focus of the SiC crystal growth development is on improving the crystalline quality without polytype inclusions, micropipes and the occurrence of extended defects. The purity of the grown material, as well as intentional doping must be well controlled and the processes understood. LÄS MER

  3. 2. Ab initio based modeling of defects and disorder in industrial materials

    Författare :Yunguo Li; Pavel Korzhavyi; Tony Paxton; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : The study of defects and disorder in condensed matter remains a central subject of materials science. Newly emerging experimental and theoretical techniques promote our understanding in this field, and reveal many interesting phenomena in which the atomic picture plays a crucial role. LÄS MER

  4. 3. Structured MFI film catalysts and adsorbents

    Författare :Olov Öhrman; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical Technology; Kemisk teknologi;

    Sammanfattning : A method originally developed at the division of Chemical Technology, Luleå University of Technology was tailored for the preparation of well-defined ZSM-5 films and zoned MFI films on supports suitable for catalysis and adsorption applications. Films were grown on monoliths, ceramic foams, alumina beads, soda glass beads and quartz glass. LÄS MER

  5. 4. 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

  7. 5. Molecular sieve film catalysts

    Författare :Olov Öhrman; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Chemical Technology; Kemisk teknologi;

    Sammanfattning : In this study, well defined ZSM-5 films were prepared on monoliths, ceramic foams, alumina beads, glass beads and crushed quartz glass by further refinement of a method originally developed at the division of Chemical Technology, Luleå University of Technology. The supports were seeded with silicalite-1 seeds and hydrothermally treated, either at 75 °C or at 150 °C in a single or several steps. LÄS MER