Geometry Effects on Light ‐Harvesting Complex's Light Absorption and Energy Transfer in Purple Bacteria

Light ‐harvesting complexes (LHC) in photosynthetic organisms perform the major function of light absorption and energy transportation. We construct a geometric model ofRs. Molischianumin in which the geometric parameters such as ring diameter, fold symmetry order and dipole directions can be modified. We study how the absorption spectrum and energy transfer rate of the LHC depend on different geometric parameters. Our results here may find applications in designing highly efficient photovoltaic cell and other artificial photosynthetic systems. AbstractLight ‐harvesting complexes (LHC) in photosynthetic organisms perform the major function of light absorption and energy transportation. Optical spectrum of LHC provides a detailed understanding of the molecular mechanisms involved in the excitation energy transfer (EET) processes, which has been widely studied. Here, we study how the geometric property of LHC inRhodospirillum (Rs.) molischianum would affect its spectral characteristics and energy transfer process. By adopting the effective Hamiltonian and the dipole –dipole approximation, we calculate the exciton level structures for the LH2 ring and LH1 ring and the energy transfer time between different LHCs under various structural parameters and different rotational symmetries. Our numerical results show that the LHC's absorption peaks and the energy tran sfer time between different LHCs can be modified by changing the geometric configurations. Our study may be benefi...

Source: Photochemistry and Photobiology - July 16, 2019 Category: Science Authors: Lingyu Zeng, Zeyang Liao, Xue ‐hua Wang Tags: Research Article Source Type: research