A Photovoltaic Device Using an Electrolyte Containing Photosynthetic Reaction Centers

The performance of bio-photovoltaic devices with a monolayer of the immobilized photosynthetic reaction center (RC) is generally low because of weak light absorption and poor charge transfer between the RC and the electrode. In this paper, a new bio-photovoltaic device is described in which the RC is dissolved in the electrolyte of an electrochemical cell. The charges generated by the illuminated RC are transferred to electrodes via mediators. The difference between the reaction rates of two types of mediator at the electrode surfaces determines the direction of the photocurrent in the device. Experimental results show that the magnitude of the photocurrent is proportional to the incident light intensity, and the current increases nonlinearly with an increase in the RC concentration in the electrolyte. With further optimization this approach should lead to devices with improved light absorption.