Efficient Bio-Nano Hybrid Solar Cells via Purple Membrane as Sensitizer.

Bacteriorhodopsin is a heptahelical protein found in the purple membrane of Halobacterium salinarum. The performance of bacteriorhodopsin was evaluated as a sensitizer in dye-sensitized solar cells (DSSCs). Bacteriorhodopsin was efficiently immobilized on the titanium dioxide nanoparticles and then tested for its ability to convert solar radiation to electricity. The photovoltaic performance of DSSC based on the bacteriorhodopsin sensitizer has been examined. Under AM1.5 irradiation, a short-circuit current of 0.28 mA cm, open-circuit voltages of 0.51 V, fill factor of 0.62, and an overall energy conversion efficiency of 0.09 % are achieved employing platinum as a counter electrode. Carbon was used as a counter electrode instead of platinum to reduce costs. Based on carbon electrode, a short-circuit current of 0.21 mA cm and open-circuit voltages of 0.52 V were obtained. [ABSTRACT FROM AUTHOR]