Sökning: "NATURAL SCIENCES Physics Condensed matter physics Surfaces and interfaces"

Visar resultat 11 - 15 av 28 avhandlingar innehållade orden NATURAL SCIENCES Physics Condensed matter physics Surfaces and interfaces.

  1. 11. The life and death of perovskites : Interfacial function and degradation of lead halide perovskites studied by photoelectron spectroscopy

    Författare :Sebastian Svanström; Ute B Cappel; Håkan Rensmo; Erik Johansson; Selina Olthof; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; lead halide perovskite solar cells; interfacial degradation; heterojunction interfaces; photoelectron spectroscopy; operando; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Lead halide perovskite solar cells are a promising new technology which could soon see widespread commercial application but is partly held back by poor long-term stability. In this thesis, photoelectron spectroscopy (PES) is used to study the dynamical processes at the surface or interfaces of lead halide perovskite materials. LÄS MER

  3. 12. Influence of Self-trapping, Clamping and Confinement on Hydrogen Absorption

    Författare :Gunnar Karl Pálsson; Björgvin Hjörvarsson; Keith Ross; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; hydrogen diffusion; thin films; superlattices; phase transitions; confinement; clamping; self-trapping; finite-size effect; Surfaces and interfaces; Ytor och mellanytor; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : The dissociation of hydrogen molecules at surfaces is the first step in the absorption process. If the absorbing material is covered by an oxide, this layer will determine the effective uptake rate of an underlying absorbing material. LÄS MER

  4. 13. Electronic structure of clean and adsorbate-covered InAs surfaces

    Författare :Karolina Szamota-Leandersson; Ulf Otto Karlsson; Vladimir Chab; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; angle-resolved photoemission; electronic structure; accumulation layer; adatoms; reconstruction; Surfaces and interfaces; Ytor och mellanytor;

    Sammanfattning : This thesis is the result of investigations regarding the processes in InAs III-V semiconductor surfaces induced by additional charge incorporated by adsorbates. The aim of the project is to study the development of the accumulation layer on the metal/InAs(111)A/B surfaces and its electronic structure. LÄS MER

  5. 14. Insights into Materials Properties from Ab Initio Theory : Diffusion, Adsorption, Catalysis & Structure

    Författare :Andreas Blomqvist; Rajeev Ahuja; Christopher Wolverton; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Density functional theory; Molecular dynamics; Diffusion; Catalysis; Adsorption; Random structure search; Hydrogen-storage materials; Phase-change materials; Defects and diffusion; Defekter och diffusion; Surfaces and interfaces; Ytor och mellanytor; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : In this thesis, density functional theory (DFT) calculations and DFT based ab initio molecular dynamics simulations have been employed in order to gain insights into materials properties like diffusion, adsorption, catalysis, and structure. In transition metals, absorbed hydrogen atoms self-trap due to localization of metal d-electrons. LÄS MER

  7. 15. Connected by voids: Interactions and screening in sparse matter

    Författare :Kristian Berland; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Using theory and computations, we study structural and electronic properties of nanoscale systems where regions of low density are important for response and function. Materials with such properties are called sparse matter. Examples include assemblies of organic molecules and layered structures like graphite. LÄS MER