Sökning: "Electron self energy"

Visar resultat 1 - 5 av 100 avhandlingar innehållade orden Electron self energy.

1. 1. Self-consistency and the GW-approximation

   Författare :Bengt Holm; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Matematisk och allmän teoretisk fysik; thermodynamics; Spectral Function; Greens functions; Self-energy; classical mechanics; Mathematical and general theoretical physics; Quasiparticle.; quantum mechanics; relativity; statistical physics; gravitation; klassisk mekanik; kvantmekanik; relativitet; statistisk fysik; termodynamik; Fysicumarkivet A:1997:Holm;

   Sammanfattning : The effects of self-consistency in the GW-approximation are studied. The $GWA$ is known to describe the electronic properties of a wide range of materials very well. However, the calculations made so far have not taken into account the issue of self-consistency, which is implied in the original formulation of the $GWA$. LÄS MER

3. 2. Electron-lattice dynamics in π-conjugated systems

   Författare :Magnus Hultell (Andersson); Sven Stafström; Alessandro Troisi; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; charge transport; electron-lattice dynamics; polaron; adiabatic transport; electron localization; internal conversion; Computational physics; Beräkningsfysik;

   Sammanfattning : The work presented in this thesis concerns the dynamics in π-conjugated hydrocarbon systems. Due to the molecular bonding structure of these systems there exists a coupling between the electronic system and the phonons of the lattice. LÄS MER

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

   Författare :Mattias P Eng; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 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

5. 4. Building crystals out of crystals : Synthesis, structure and magnetic properties of iron oxide nanoparticles and self-assembled mesocrystals

   Författare :Erik Wetterskog; Lennart Bergström; Markus Niederberger; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; iron oxide; nanoparticle; synthesis; self-assembly; characterization; electron microscopy; scattering; magnetic properties; Materials Chemistry; materialkemi;

   Sammanfattning : This thesis is focused on the fabrication and characterization of self-assembled arrays of magnetic iron oxide (Fe3O4, γ-Fe2O3 and Fe1-xO) nanoparticles. The synthesis of spherical and cubic iron oxide nanocrystals, with sizes between 5 and 30 nm and narrow size distributions, is demonstrated, along with a rigorous morphological characterization of the cubic nanoparticles. LÄS MER

7. 5. Shining Light on Molecules : Electron Transfer Processes in Model Systems for Solar Energy Conversion Investigated by Transient Absorption Spectroscopy

   Författare :Jens Föhlinger; Leif Hammarström; Davidsson Jan; Benjamin Dietzek; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; photophysics; photoinduced electron transfer; transient absorption spectroscopy; laser spectroscopy; solar energy conversion; p-type DSSCs; Charge separation; recombination; mesoporous NiO;

   Sammanfattning : In the recent years, solar energy conversion has attracted a huge research interest due to the potential application for limiting the greenhouse effect. In many solar cells and solar fuel cells, understanding of charge transfer (CT) and recombination is important for future improvement of the overall efficiency. LÄS MER