| Abstract [eng] |
In the dissertation, excitation energy transfer was studied in an excitonic dimer under various conditions of inter-chromophore resonance interaction and in different regimes of the system-bath coupling. We examine the manifestation of quantum coherence in the energy transfer in molecular dimer, within the hierarchy of the relaxation processes: vibrational relaxation, energy redistribution within single exciton manifold and relaxation to the ground state. In order to capture the coherence effects in the limit of weak resonance interaction a novel technique has been presented. We are able to reproduce the coherence effects in the simulation of static and dynamic spectroscopic experiments. The study of an excitonic heterodimer under various system-bath coupling conditions revealed both coherent and incoherent excitation evolutions. In the situation of different reorganization energies, in the case of strong excitonic mixing, the vibrationally relaxed excited state energy levels may become swapped with respect to the monomeric counterparts. The study of the relaxation of the excitonic dimer to the ground state revealed that the resonant coupling strength and the energy gap between the states control the rate of the process but not the character. We have explained the dissipation mechanism in the artificial carotenoid-pthalocyanine dyads, and the results may be helpful in determining the mechanism of energy dissipation during photosynthesis, known as the non-photochemical quenching. |
