Competition between Trapping and Annihilation in Rps. Viridis Probed by Fast Photovoltage Measurements
The study of exciton transfer, exciton-exciton interaction, and primary charge separation in the photosynthetic membrane requires excitation by picosecond flashes. If a significant fraction of the reaction centers (RCs) is closed by a single flash, the excitation density reaches a level where several excitons reside in the pool of antenna pigments at the same time. Then excitons can be lost by singlet-singlet annihilation before they are trapped by the primary photochemistry in the RC. Furthermore, annihilation leads to an apparent acceleration of all other reactions connected with the exciton dynamics. As will be shown, the quantitative treatment of this competitive deactivation path allows to determine molecular parameters that characterize a given antenna system.
KeywordsEntropy Recombination Pseudomonas Convolution Quinone
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