Sökning: "transient absorption spectroscopy"

Visar resultat 11 - 15 av 51 avhandlingar innehållade orden transient absorption spectroscopy.

  1. 11. Fundamental interactions in transition metal reactions

    Författare :Michael R. Coates; Michael Odelius; Markus Kowalewski; Abhik Ghosh; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemistry; electronic structure; multiconfigurational; density functional theory; molecular dynamics; excited state molecular dynamics; non-adiabatic dynamics; solvation; organometallic complexes; x-ray absorption spectroscopy; photoelectron spectroscopy; time-resolved spectroscopy; femtosecond; picosecond; kemisk fysik; Chemical Physics;

    Sammanfattning : Transition metal complexes that participate in homogeneous reactions often perform the role of a catalyst, facilitating novel reaction pathways. When these complexes are pushed away from their equilibrium, the arrangement of the coordinating ligands around the metal center is perturbed and new reaction pathways are opened. LÄS MER

  3. 12. Non-linear Spectroscopy of Conical Intersections with XUV and X-ray Photons

    Författare :Deependra Jadoun; Markus Kowalewski; Faris Gelmukhanov; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Conical Intersections; Non-linear Spectroscopy; Quantum Dynamics; Perturbation Theory; Ultrafast Spectroscopy; X-ray; XUV; Theoretical Physics; teoretisk fysik;

    Sammanfattning : Conical intersections (CIs) appear in a molecule due to the breakdown of the Born-Oppenheimer approximation when the energy difference between two or more electronic states decreases. CIs are known to play a crucial role in processes such as photosynthesis and vision in the human eye, and therefore it is important to probe the existence of such entities in molecules. LÄS MER

  4. 13. Exploring Organic Dyes for Grätzel Cells Using Time-Resolved Spectroscopy

    Författare :Ahmed M. El-Zohry; Burkhard Zietz; Ana Morandeira; Leif Hammarström; Eric Vauthey; Uppsala universitet; []
    Nyckelord :Laser spectroscopy; DSSCs; DSC; Electron dynamics; Deactivation processes; Isomerization; Twisting; TICT; Quenching by protons; Semiconductor; Electrolyte; Electron injection; Regeneration; Recombination; Chemistry with specialization in Physical Chemistry; Kemi med inriktning mot fysikalisk kemi; Kemi med inriktning mot kemisk fysik; Chemistry with specialization in Chemical Physics;

    Sammanfattning : Grätzel cells or Dye-Sensitized Solar Cells (DSSCs) are considered one of the most promising methods to convert the sun's energy into electricity due to their low cost and simple technology of production. The Grätzel cell is based on a photosensitizer adsorbed on a low band gap semiconductor. LÄS MER

  5. 14. Dynamics of Excitation Transfer and Charge Separation in Polymeric Semiconductors

    Författare :Arvydas Ruseckas; Kemisk fysik; []
    Nyckelord :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

  7. 15. Photoinduced Electron and Energy Transfer in Π-Conjugated Systems

    Författare :Melina Gilbert Gatty; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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