Sökning: "Photon migration"
Visar resultat 21 - 25 av 27 avhandlingar innehållade orden Photon migration.
21. Metal distribution and mobility under alkaline conditions
Sammanfattning : The adsorption of an element, expressed as its distribution between liquid (aquatic) and solid phases in the biogeosphere, largely determines its mobility and transport properties. This is of fundamental importance in the assessment of the performance of e.g. geologic repositories for hazardous elements like radionuclides. LÄS MER
22. Structure-Property Relationships in Chromophore-Organogel Assemblies: Consequences for Triplet-Triplet Annihilation and Singlet Fission
Sammanfattning : Better utilization of the solar spectrum by absorbing photons that are currently wasted by solar cells, due to the bandgap mismatch with the semiconductor, will help to improve the device efficiency. Two low energy photons can be upconverted to one high energy photon through triplet-triplet annihilation (TTA-UC); one high energy photon can be down converted to form two charge carriers through singlet fission (SF). LÄS MER
23. Ionic impacts on solids and sputtering phenomena : experiments in the low-keV region, using optical and collector methods
Sammanfattning : Energetic ions bombarding the surface of a solid result in a manifold of processes. An ion with sufficient energy can penetrate into the solid. The slowing-down process represents a transfer of energy to the lattice atoms. Part of this energy is deposited on the target surface and may result in sputtering, the release of particles from the target. LÄS MER
24. Ultra-fast dynamics in atoms and molecules during photoionization: from attoseconds to femtoseconds
Sammanfattning : Treating the correlated behaviour of multiple particles is challenging for both theory and experiment. This thesis reports on a variety of experimental investigations aiming to advance the understanding of fundamental processes in atoms and molecules: double ionization, isomerization and dissociation. LÄS MER
25. Excited-state dynamics of small organic molecules studied by time-resolved photoelectron spectroscopy
Sammanfattning : Ultra-violet and visible light induced processes in small organic molecules play very important roles in many fields, e.g., environmental sciences, biology, material development, chemistry, astrophysics and many others. Thus it is of great importance to better understand the mechanisms behind these processes. LÄS MER
