Sökning: "Oscar Tjernberg"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden Oscar Tjernberg.

  1. 1. Photoelectron spectroscopy on strongly correlated systems

    Författare :Oscar Tjernberg; KTH; []
    Nyckelord :;

    Sammanfattning : This work presents photoelectron spectroscopy data on somestrongly correlated systems. The electronic structure of the3dtransition metal oxides NiO and CoO have been studiedwith angle resolved and resonant photoemission. In the lattercase, both NiO and CoO show strong resonance effects at themetal absorption edges. LÄS MER

  3. 2. Structure-dependent charge transfer at the interafce between organic thin films, and metals and metal oxides

    Författare :Sareh Ahmadi; Oscar Tjernberg; Guy Le Lay; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; photoelectric spectroscopy; X-ray absorption spectroscopy; organic semiconductors; phthalocyanine; charge transfer; electronic structure; dye sensitization;

    Sammanfattning : The purpose of the research work, presented in this thesis is to offer a detailed atomic level study of interfaces created by adsorption of organic molecules on metals and metal oxides to point out significant impact of substrate, dye structure as well as different mediators on the charge transfer at these interfaces, which is proven to influence the device performance to a great extent.Adsorption of organic photosensitive molecules on metals and metal-oxides is the main focus of this thesis. LÄS MER

  4. 3. Consequences of a non-trivial band-structure topology in solids : Investigations of topological surface and interface states

    Författare :Magnus H. Berntsen; Oscar Tjernberg; Philip Hofmann; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; spin- and angle-resolved photoelectron spectroscopy; time-of-flight analyzer; laser based light source; topological insulator; topological crystalline insulator; thin films; surface state; interface state; Bi2Se3; Pb1-xSnxSe;

    Sammanfattning : The development and characterization of experimental setups for angle-resolved photoelectron spectroscopy (ARPES) and spin- and angle-resolved photoelectron spectroscopy (SARPES) is described. Subsequently, the two techniques are applied to studies of the electronic band structure in topologically non-trivial materials. LÄS MER

  5. 4. Investigations of Transition Metal Systems : Angle-Resolved Photoelectron Spectroscopy at Low and High Energy

    Författare :Thomas Claesson; Oscar Tjernberg; Kevin Smith; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; angle-resolved photoelectron spectroscopy; electronic structure; oxides; high-temperature superconductors; Material physics with surface physics; Materialfysik med ytfysik;

    Sammanfattning : The work presented in this thesis aims at achieving an increased understanding of the electronic structure of materials whose properties are to a large extent governed by transition metals. All studies are based on data from angle-resolved photoelectron spectroscopy (ARPES) employed on the valence band of the studied systems. LÄS MER

  7. 5. Angle-resolved photoemission study of unconventional cuprate superconductors

    Författare :Qinda Guo; Oscar Tjernberg; Andrea Damascelli; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Unconventional superconductivity; cuprate; high harmonic generation; narrow bandwidth light source; spherical grating based monochromator; time- and angle-resolved photoemission spectroscopy; Okonventionell supraledning; kuprat; hög övertonsgenerering; ljuskälla med smal bandbredd; sfäriskt gitterbaserad monokromator; tids- och vinkelupplöst fotoemissionsspektroskopi;

    Sammanfattning : Understanding unconventional superconductivity remains one of the most important unsolved problems in physics. A particularly noteworthy case is the copper-based high-temperature superconductor, which stands out due to its remarkably high transition temperature and relatively simple structure. LÄS MER