Sökning: "impurities"

Visar resultat 1 - 5 av 260 avhandlingar innehållade ordet impurities.

  1. 1. Effects of impurities on charge transport in graphene field-effect transistors

    Författare :Marlene Bonmann; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; carrier transport; electron and hole mobility; impurities; traps; graphene; field-effect transistors; microwave devices; saturation velocity; remote phonons;

    Sammanfattning : In order to push the upper frequency limit of high speed electronics further, thereby extending the range of applications, new device technologies and materials are continuously investigated. The 2D material graphene, with its intrinsically extremely high room temperature charge carrier velocity, is regarded as a promising candidate to push the frequency limit even further. LÄS MER

  3. 2. Multiscale modeling of atomic transport phenomena in ferritic steels

    Författare :Luca Messina; Pär Olsson; Nils Sandberg; Pål Efsing; Pascal Bellon; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diffusion; impurities; iron; metals; kinetic Monte Carlo; ab initio; mean field; defects; embrittlement; reactor pressure vessel; neural networks; Fysik; Physics;

    Sammanfattning : Defect-driven transport of impurities plays a key role in the microstructure evolution of alloys, and has a great impact on the mechanical properties at the macroscopic scale. This phenomenon is greatly enhanced in irradiated materials because of the large amount of radiation-induced crystal defects (vacancies and interstitials). LÄS MER

  4. 3. Gyrokinetic simulations of turbulent particle and heat transport in tokamaks

    Författare :Daniel Tegnered; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; tokamak; plasma physics; turbulence; transport; gyrokinetics; TEM; ITG; impurities; fusion; Joint European Torus;

    Sammanfattning : Fusion power is one of few viable sustainable means of energy production. The tokamak is arguable the most mature technology to magnetically confine fusion plasmas. In these devices, heat and particle transport is dominated by small-scale turbulent fluctuations. LÄS MER

  5. 4. Gyrokinetic simulations of microturbulence and transport in tokamak plasmas

    Författare :Daniel Tegnered; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ITG; Joint European Torus; impurities; transport; fusion; TEM; tokamak; turbulence; plasma physics; gyrokinetics;

    Sammanfattning : Fusion power is one of few viable and sustainable means of energy production. The tokamak is arguable the most mature technology to magnetically confine fusion plasmas. In these devices, heat and particle transport is dominated by small-scale turbulent fluctuations. LÄS MER

  7. 5. Out of the Dark and into the Light - Microscopic Analysis of Bright, Dark and Trapped Excitons

    Författare :Maja Feierabend; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; density matrix formalism; localized states; impurities; dark excitons; strain; transition metal dichalcogenides; Bloch equations;

    Sammanfattning : Atomically thin transition metal dichalcogenides (TMDs) have been in the focus of current research due to their efficient light-matter interaction, as well as the remarkably strong Coulomb interaction that leads to tightly bound excitons. Due to their unique band structure, TMDs show a variety of optically accessible bright and inaccessible dark excitons. LÄS MER