Sökning: "Excitation transfer"

Visar resultat 1 - 5 av 117 avhandlingar innehållade orden Excitation transfer.

  1. 1. Tailing Charges on New Paths : Ultrafast intramolecular charge transfer in chromophores

    Författare :Belinda Pettersson Rimgard; Leif Hammarström; Oliver S. Wenger; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; intramolecular charge transfer; interligand electron transfer; electron transfer; proton transfer; concerted electron-proton transfer; Marcus inverted region; solvent; temperature; femtosecond spectroscopy; proton-coupled energy transfer; Chemistry with specialization in Physical Chemistry; Kemi med inriktning mot fysikalisk kemi;

    Sammanfattning : By tailing charges on their paths within a molecule, one can gain fundamental knowledge of their inherent reactivity. The charges, originally residing in their lowest energy configuration, can upon light absorption move across the system, or transfer in between them. LÄS MER

  2. 2. Dynamics of Excitation Transfer and Charge Separation in Polymeric Semiconductors

    Författare :Arvydas Ruseckas; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Anisotropy; Photoinduced absorption; Femtosecond spectroscopy; Polythiophene; Conjugated polymers; Donor-Acceptor Complexes; Carbazole; Charge separation; Excitation transfer; Recombination; Physics; Fysik;

    Sammanfattning : Dynamics of optically excited electronic states have been studied in solid films and solutions of semiconducting polymers and model compounds. Transient absorption, monitored in the spectral range from 0.9 eV to 2.5 eV with a time resolution of about 100 fs, was the main experimental technique. LÄS MER

  3. 3. Triplet Excitation Energy Transfer in Donor-Bridge-Acceptor Systems: Experimental and Theoretical Investigations

    Författare :Mattias P Eng; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; self-assembled monolayer; density functional theory; triplet excitation energy transfer; gold porphyrin; electron transfer; spectroscopy; superexchange; electronic coupling;

    Sammanfattning : This thesis is a contribution to the understanding of bridge mediation of electron exchange processes in Donor-Bridge-Acceptor (D-B-A) systems. The field of research is relevant for the development and optimization of dye-sensitized solar cells, artificial photosynthesis, and the possible future development of molecular electronic devices. LÄS MER

  4. 4. Photoinduced Electron and Energy Transfer in Π-Conjugated Systems

    Författare :Melina Gilbert Gatty; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fs spectroscopy; exciton coupling; conjugated porphyrin oligomers; ps spectroscopy; molecular wire; electron transfer; conformational analysis; self‒assembly; anthracene dendrimers; energy transfer; fluorescence anisotropy;

    Sammanfattning : Photosynthesis is a fascinating process that provides food and oxygen. In this thesis, focus is on understanding and controlling the early processes of photosynthesis, namely photoinduced energy and electron transfer. LÄS MER

  5. 5. Studies of Light Emitting Devices Based on Er-doped Si and SiGe Layered Structures

    Författare :Chun-Xia Du; Fransesco Priolo; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; electroluminescence; diode; transistor; hot electron; recombination; excitation; de-excitation; Auger effect; molecular beam epitaxy; Er; Si; SiGe;

    Sammanfattning : Doping with rare earth element erbium (Er) in Si has recently attracted a lot of research interest due to potential applications in Si-based opto-electronics. By using molecular beam epitaxy (MBE), precipitate-free Er-doping in Si has been made together with other co-dopants, e.g., oxygen (0) and fluorine (F), up to a level ∼1020 cm-3. LÄS MER