Electrochemical Photovoltaic Cells Based on n ‐ GaAs and the Triiodide/Iodide Redox Couple in Acetonitrile

Abstract

The electrochemical photovoltaic cell (EPC) based on and a , redox electrolyte was evaluated. Greater than was necessary to avoid concentration polarization at the photoanode above moderate illumination intensities. The charge separation at the illuminated interface was enhanced by adsorption of Se= and Ru+3 or by complexing polymers such as polyvinyl pyrrolidone. In practical cells, a compromise is necessary between light absorption by , and having sufficient to depolarize the counterelectrode. Best "solar cell" efficiency in the quiescent electrolyte under 53 mW/cm2 irradiation was about 3.4% with , and fill factor 0.34 with no corrections for solution absorbance or cell reflectance.