Sökning: "acceptor doping"

Visar resultat 1 - 5 av 33 avhandlingar innehållade orden acceptor doping.

  1. 1. Molecular Doping of Epigraphene for Device Applications

    Författare :Hans He; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Molecular Doping; Graphene; epitaxial graphene; THz; Metrology; Hall Effect;

    Sammanfattning : Epitaxial graphene grown on silicon carbide, or epigraphene, offers in principle a suitable platform for electronic applications of graphene which require scalable, reproducible, and high-quality material. However, one of the main drawbacks of epigraphene lies in the difficulty in controlling its carrier density, which hinders its usefulness in future applications. LÄS MER

  3. 2. Point defects and ion conduction in solid oxides: a first-principles case study of La2Zr2O7

    Författare :Joakim Nyman; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; proton; self compensation; hydrogen economy; DFT; La2Zr2O7; acceptor doping; lanthanum zirconate; oxygen vacancy; SOFC; pyrochlore; point defect; trapping; computational methods; solid oxide; charge compensation; first principles; ion conduction; solid oxide fuel cell; ceramic electrolyte; defect cluster; fuel cell; hydrogen;

    Sammanfattning : In the endeavor to attain a clean environment and sustainable energy consumption, the notion of a future hydrogen economy stands out as one of the grandest visions. Striving for this vision, a critical task lies in optimizing the performance of the fuel-cell devices responsible for extracting electric power from the energy stored in hydrogen molecules. LÄS MER

  4. 3. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis

    Författare :Joakim Nyman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; first principles; trapping; conductivity; grain boundary; segregation; pyrochlore; space charge; solid oxide fuel cell; depletion; electrolyte; La2Zr2O7; oxygen vacancy; BaZrO3; proton; DFT; point defect; perovskite; acceptor;

    Sammanfattning : Fuel cells are devices which convert chemical energy into electrical energy cleanly and efficiently. Development of fuel cells compatible with hydrocarbon fuels would make more efficient use of present fossil and renewable fuels, and also enable progress towards a future hydrogen economy. LÄS MER

  5. 4. Epitaxy, analysis and application of semi-insulating III-V materials

    Författare :David Söderström; KTH; []
    Nyckelord :InP; GaInP; semi-insulating materials; iron doping; ruthenium doping; HVPE; diffusion; deep levels; capture cross sections; resistivity analysis; buried heterostructure laser;

    Sammanfattning : Semi-insulating (SI) III-V materials can provide electricalisolation for integration and capacitance minimisation for highspeed operation. Compared to the polyimides, these can offerbetter thermal conduction. Ever since the fabrication of thefirst SI III-V materials, transition metals have been utilisedas deep impurities to impart SI properties. LÄS MER

  7. 5. Acceptor-Doped BaZrO3 Perovskite: Synthesis, Structure and Proton Conductivity

    Författare :Istaq Ahmed; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Impedance spectroscopy; Perovskite; Neutron diffraction; Rietveld refinement; BaZrO3.; Proton conductor;

    Sammanfattning : Acceptor-doped perovskite oxides exhibit significant proton conductivity in hydrogen containing atmospheres. Therefore, they have potential for use as separator materials for various electrochemical devices including gas sensors, electrolysers and fuel cells. LÄS MER