Ghosh Pulak Kumar, Smirnov Anatoly Yu, Nori Franco
Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198, Japan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2011 Dec;84(6 Pt 1):061138. doi: 10.1103/PhysRevE.84.061138. Epub 2011 Dec 22.
We analyze a theoretical model for energy and electron transfer in an artificial photosynthetic system. The photosystem consists of a molecular triad (i.e., with a donor, a photosensitive unit, and an acceptor) coupled to four accessory light-harvesting-antenna pigments. The resonant energy transfer from the antennas to the artificial reaction center (the molecular triad) is described here by the Förster mechanism. We consider two different kinds of arrangements of the accessory light-harvesting pigments around the reaction center. The first arrangement allows direct excitation transfer to the reaction center from all the surrounding pigments. The second configuration transmits energy via a cascade mechanism along a chain of light-harvesting chromophores, where only one chromophore is connected to the reaction center. We show that the artificial photosynthetic system using the cascade energy transfer absorbs photons in a broader wavelength range and converts their energy into electricity with a higher efficiency than the system based on direct couplings between all the antenna chromophores and the reaction center.
我们分析了一个人工光合作用系统中能量和电子转移的理论模型。该光系统由一个分子三联体（即具有一个供体、一个光敏单元和一个受体）与四个辅助光捕获天线色素耦合而成。此处通过Förster机制描述了从天线到人工反应中心（分子三联体）的共振能量转移。我们考虑了反应中心周围辅助光捕获色素的两种不同排列方式。第一种排列方式允许所有周围色素直接将激发转移到反应中心。第二种构型通过级联机制沿着一系列光捕获发色团传递能量，其中只有一个发色团与反应中心相连。我们表明，与基于所有天线发色团和反应中心之间直接耦合的系统相比，使用级联能量转移的人工光合作用系统在更宽的波长范围内吸收光子，并以更高的效率将其能量转化为电能。
