Sökning: "excited-state relaxation"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden excited-state relaxation.

  1. 1. Chiral Ruthenium Dipyrodiphenazine Complexes: DNA Binding and Excited State Relaxation

    Författare :Björn Önfelt; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; polarization spectroscopy; DNA-probe; dppz; excited-state relaxation; intercalation; solvent relaxation; DNA-threading;

    Sammanfattning : Ruthenium complexes with aromatic ligands have been extensively studied due to their interesting photophysical properties, including photophysics and electron transfer upon interaction with nucleic acids. For example, the broad absorption spectrum makes them suitable as antenna molecules in photochemical reaction systems and their ability to accept or donate electrons in their excited state could have potential in opto-electronical devices. LÄS MER

  3. 2. Excited state dynamics in low-dimensional perovskite nanocrystals

    Författare :Weihua Lin; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Two-dimensional perovskite; Ultrafast spectroscopy; Single crystal; Nanocrystals; Hot carrier cooling;

    Sammanfattning : Two-dimensional (2D) perovskites have emerged as promising building blocks for optoelectronic applications. To fabricate high-performance devices, the relation between the material structures and their function in terms of excited state and charge carrier dynamics need to be well understood. LÄS MER

  4. 3. Understanding the interactions between vibrational modes and excited state relaxation in garnet structured phosphors

    Författare :Yuan-Chih Lin; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; free electron laser; thermal quenching.; luminescence; garnet; vibrational spectroscopy; neutron scattering; phosphor; light emitting diode;

    Sammanfattning : This thesis concerns investigations of the local structural environments and vibrational dynamics of the three garnet type oxide phosphors Ce3+-doped Y3Al5O12 (YAG:Ce3+), Ca3Sc2Si3O12 (CSS:Ce3+), and Sr3Y2Ge3O12 (SYG:Ce3+), which show promising optical properties as luminescent materials used in solid state white lighting technologies. The study focuses on a comprehensive analysis of the nature of the long-range vibrations (phonons) in terms of local atomic and molecular motions of the garnet structure, as well as their dependence on the nature of the garnet chemical composition, Ce3+ concentration and temperature. LÄS MER

  5. 4. Life of Excitons in Artificial Photosynthetic Antennas

    Författare :Johan Andersson; Kemisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Zn-porphyrin; Osmium; Ruthenium; Polypyridine; Inter Ligand Energy Transfer; Inter System Crossing; Excited state dynamics; Transition metal complexes; Photosynthetic Antennas; Solar energy conversion; Artificial photosynthesis; Physical chemistry; Fysikalisk kemi; Transient Absorption Anisotropy.; Reaction Center; Dendrimer; Energy Transfer;

    Sammanfattning : Due to the predicted energy crisis when fossil fuels will be exhausted it is important to search for alternative energy sources. Utilizing sunlight via artificial photosynthesis is an interesting possibility. LÄS MER

  7. 5. Porphyrin-Based Donor-Bridge-Acceptor Systems: Intrinsic Excited State Deactivation and Intramolecular Energy/Electron Transfer Reactions

    Författare :Joakim Andreasson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spectroscopy; superexchange; mediation; energy transfer; porphyrins; conformational gating; conformational distortions; electron transfer;

    Sammanfattning : Intramolecular energy and electron transfer reactions have been studied between porphyrin donor and acceptor moieties. The porphyrin units are covalently linked together by one of three different bridging chromophores to constitute the series of D-B-A systems. LÄS MER