Sökning: "bonding energy"

Visar resultat 21 - 25 av 147 avhandlingar innehållade orden bonding energy.

  1. 21. Electronic Structures and Energy Level Alignment in Mesoscopic Solar Cells : A Hard and Soft X-ray Photoelectron Spectroscopy Study

    Författare :Rebecka Lindblad; Håkan Rensmo; Hans Seigbahn; Anders Hagfeldt; Erik Johansson; Marcus Bär; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photoelectron spectroscopy; HAXPES; PES; XPS; electronic structure; energy level alignment; mesoscopic solar cell; hole conductor; perovskite; dye-sensitized; semiconductor-sensitized; TiO2; ZnO; spiro-OMeTAD; P3HT; DEH; metal sulfide; Li-TFSI; Co III complex; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Photoelectron spectroscopy is an experimental method to study the electronic structure in matter. In this thesis, a combination of soft and hard X-ray based photoelectron spectroscopy has been used to obtain atomic level understanding of electronic structures and energy level alignments in mesoscopic solar cells. LÄS MER

  2. 22. A Theoretical Perspective on the Chemical Bonding and Structure of Transition Metal Carbides and Multilayers

    Författare :Mikael Råsander; Olle Eriksson; Biplab Sanyal; Risto Nieminen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electronic structure; transition metal carbides; density functional theory; disorder; multilayers; chemical bonding; materials science; Condensed matter physics; Kondenserade materiens fysik; Materialvetenskap; Materials Science;

    Sammanfattning : The present thesis deals with a theoretical description of issues regarding chemical bonding, structure and stability of transition metal carbides and multilayered structures. First principles density functional theory has been used extensively to investigate the properties of alloyed solutions of transition metal carbides. LÄS MER

  3. 23. The silicon nitride reaction-bonding process

    Författare :Bingqiang Lei; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

    Sammanfattning : The so called Reaction-Bonded Silicon Nitride (RBSN) materials are usually produced through the chemical reaction of silicon powder compacts in a nitriding atmosphere. This nitriding reaction is strongly exothermic and much heat is generated, which may cause to overheating, even melting of the powder compacts so to hinder the further reaction due to the reduction of specific area of the powder compacts, especially when the nitridation involves a rather large mass of silicon. LÄS MER

  4. 24. Influence of Fluid Shear on Primary  Nucleation of Organic Compounds in Solution  Jin Liu  Doctoral Thesis

    Författare :Jin Liu; Åke Rasmuson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Agitation; Primary nucleation; Induction time; Fluid shear; Energy dissipation; Mass transfer; Molecular alignment; Cluster coalescence; Butyl paraben; Curcumin; m-Hydroxybenzoic acid; Solid-liquid interfacial energy; Nuclei critical radius.; Chemical Engineering; Kemiteknik;

    Sammanfattning : In this work, three experimental systems have been used to study the influence of agitation/ fluid shear on primary nucleation. Three organic compounds have been used with different solvents, i.e. butyl paraben in ethanol solution, curcumin in ethanol solution and m-hydroxybenzoic acid in 1-propanol solution. LÄS MER

  5. 25. Chemical Bonding of Hydrocarbons to Metal Surfaces

    Författare :Henrik Öström; Anders Nilsson; Phil Woodruff; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Adsorption; hydrocarbon; core-level; spectroscopy; Physics; Fysik;

    Sammanfattning : Using x-ray absorption spectroscopy (XAS), x-ray emission spectroscopy (XES) and x-ray photoelectron spectroscopy (XPS) in combination with density functional theory (DFT) the changes in electronic and geometric structure of hydrocarbons upon adsorption are determined. The chemical bonding is analyzed and the results provide new insights in the mechanisms responsible for dehydrogenation in heterogeneous catalysis. LÄS MER