Sökning: "ultrafast transient absorption spectroscopy"
Visar resultat 6 - 10 av 16 avhandlingar innehållade orden ultrafast transient absorption spectroscopy.
6. Fingerprints of light-induced molecular transients : from quantum chemical models of ultrafast x-ray spectroscopy
Sammanfattning : Absorption of sunlight generates renewable electricity and powers the growth of plants, but also causes severe damage both to synthetic materials and biological tissue. The wildly varying outcomes of these light-induced processes are ultimately determined by much slighter differences in their underlying reaction pathways, induced by the transient properties of short-lived and miniscule molecules; a powerful approach to their detection and characterization is offered by ultrafast x-ray spectroscopy, with identification of spectral fingerprints and further guidance from quantum chemical models. LÄS MER
7. Ultrafast Dynamics in Ground and Excited States of Porphyrin Molecules
Sammanfattning : This thesis describes inter and intramolecular dynamics in porphyrin molecules. To create a basis for understanding the energy and electron transfer processes in photosynthesis, the ultrafast dynamics of monomeric chlorophyll a, chlorophyll b and bacteriochlorophyll a were studied with ultrashort laser pulses. LÄS MER
8. Ultrafast Probing of CO Reactions on Metal Surfaces : Changes in the molecular orbitals during the catalysis process
Sammanfattning : This thesis presents experimental studies of three different chemical reaction steps relevant for heterogeneous catalysis: dissociation, desorption, and oxidation. CO on single-crystal metal surfaces was chosen as the model systems. LÄS MER
9. Charge carrier dynamics in colloidal quantum dots: Tracking the dance of electrons and holes by ultrashort laser pulses
Sammanfattning : Quantum dots (QDs) are semiconductor nanocrystals with quantum confinement. This thesis uses various time-resolved spectroscopic techniques to study ultrafast charge carrier dynamics in colloidal CdSe quantum dots that are important both from a theoretical point of view and for their relevance for solar cell applications. LÄS MER
10. Electronic and Vibrational Coherence in Photosynthetic and Model Systems
Sammanfattning : Ultrafast optical response and excitation energy dynamics in light harvesting pigment-protein complexes and in a few model systems have been studied both experimentally and theoretically. Femtosecond light pulses were employed to excite the system and monitor the subsequent time evolution of the transient absorption kinetics and anisotropy. LÄS MER
