Sökning: "Exciton dynamics"

Visar resultat 1 - 5 av 34 avhandlingar innehållade orden Exciton dynamics.

  1. 1. Electron-Lattice Dynamics in pi-Conjugated Systems

    Författare :Magnus Hultell (Andersson); Sven Stafström; Alexander Onipko; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polaron dynamics; Exciton dynamics; pi-conjugated systems; Su-Schrieffer-Heeger SSH model; Adiabaticity; Charge carrier transport; Organic electronics.; Computational physics; Beräkningsfysik;

    Sammanfattning : In this thesis we explore in particular the dynamics of a special type of quasi-particle in pi-conjugated materials termed polaron, the origin of which is intimately related to the strong interactions between the electronic and the vibrational degrees of freedom within these systems. In order to conduct such studies with the particular focus of each appended paper, we simultaneously solve the time-dependent Schrödinger equation and the lattice equation of motion with a three-dimensional extension of the famous Su-Schrieffer-Heeger (SSH) model Hamiltonian. LÄS MER

  3. 2. 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

  4. 3. Collective Excitation Dynamics in Molecular Aggregates

    Författare :Mats Dahlbom; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Fysik; Physics; computational methods; photosynthesis; femtosecond spectroscopy; Exciton; Polaron;

    Sammanfattning : The aim of this thesis is to study collective excitation dynamics in molecular aggregates. Half of the work presented here is method development and the remainder is application of these methods to several di.erent molecular aggregates. LÄS MER

  5. 4. Strong exciton-photon and exciton-exciton coupling and its effects on molecular photophysics

    Författare :Yi Yu; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Strong coupling; triplet transition dynamics; TADFs; aggregate states;

    Sammanfattning : The energy of molecular states and their transition dynamics form the key properties to understand the photophysics of organic molecules. Strong exciton-photon and exciton-exciton couplings enable the possibility to manipulate these properties without changing the chemical structures. This is due to the formation of new energy states. LÄS MER

  7. 5. Microscopic Modeling of Exciton Propagation and Dissociation in Two-Dimensional Materials

    Författare :Raul Perea Causin; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; 2D materials; excitons; dissociation; many-particle physics; propagation; dynamics;

    Sammanfattning : Atomically thin materials have been in the spotlight of research during the last decade due to their exceptional properties, providing a platform for the study of novel physical phenomena. In particular, transition metal dichalcogenides (TMDs) have emerged as promising atomically thin materials for future optoelectronic applications owing to their strong light-matter interaction and their high tunability. LÄS MER