Sökning: "dark excitons"

Visar resultat 1 - 5 av 13 avhandlingar innehållade orden dark excitons.

  1. 1. 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

  3. 2. Microscopic Mechanisms of the Formation, Relaxation and Recombination of Excitons in Two-Dimensional Semiconductors

    Författare :Samuel Brem; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; relaxation dynamics; 2D materials; density matrix formalism; excitons; exciton-phonon interaction; Bloch equations;

    Sammanfattning : Monolayers of Transition Metal Dichalcogenides (TMDs) present a giant leap forward towards the realization of semiconductor devices with atomic scale thickness. As a natural consequence of their two-dimensional character TMDs exhibit a reduced dielectric screening, leading to the formation of unusually stable excitons, i.e. LÄS MER

  4. 3. Microscopic modelling of exciton-exciton interactions in atomically thin semiconductors

    Författare :Daniel Erkensten; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; transition-metal dichalcogenides; dark excitons; density matrix formalism; exciton-exciton interactions;

    Sammanfattning : The successful isolation and characterization of the technologically promising material graphene in 2004 has spurred huge interest in other two-dimensional materials. Transition-metal dichalcogenides (TMDs), being one such class of materials, display intriguing properties from both a fundamental and techno- logical point of view. LÄS MER

  5. 4. Microscopic Theory of Externally Tunable Exciton Signatures of Two-Dimensional Materials

    Författare :Maja Feierabend; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; localized states; density matrix formalism; magnetic field; transition metal dichalcogenides; Bloch equations; organic inorganic heterostructures; dark excitons; strain;

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

  7. 5. Microscopic Theory of Exciton Dynamics in Two-Dimensional Materials

    Författare :Samuel Brem; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; exciton-phonon interaction; van der Waals materials; relaxation dynamics; excitons; 2D materials; density matrix formalism;

    Sammanfattning : Transition Metal Dichalcogenides (TMDs) present a giant leap forward towards the realization of nanometer-sized quantum devices. As a direct consequence of their truly two-dimensional character, TMDs exhibit a strong Coulomb-interaction, leading to the formation of stable electron-hole pairs, so-called excitons. LÄS MER