Efficient Nanostructured Biophotovoltaic Cell Based on Bacteriorhodopsin as Biophotosensitizer

Here, we report on utilizing a photoactive protein, bacteriorhodopsin (bR), as a light harvester in combination with TiO2 nanoparticles in biosensitized solar cell application. Experiments have been conducted to investigate the capability of surface adsorption of bR on nanoparticular TiO(2)photoanodes. Different pretreatment processes have been done to modify the interface of TiO2 nanoparticles and bR as a biophotosensitizer. Our results indicate the feasibility of efficient immobilization and photoinduced charge transfer of bR to the nanostructured TiO2 photoelectrode. Under illumination of simulated AM1.5 sunlight, the solar-light-to-electricity conversion efficiency of the designed solar cell, composed of nanoparticular and nanofibrous layers, reached up to 0.35%, with an open circuit voltage of 533 mV and photocurrent density of 1 mA cm(-2). This optimized design of our bR-sensitized solar cell shows superior energy conversion efficiency in comparison to previously reported studies.