Steady state model of an illuminated liquid-junction solar cell

Abstract

We propose that the position of the semiconductor band edges relative to the electrolyte redox potential at an illuminated semiconductor-electrolyte interface is determined by the minority photocurrent at the interface and its interaction with the density of states distribution of the redox couple, rather than by a flatband potential or by Fermi level pinning. The model is demonstrated for a solar illuminated Au/n-GaAs0.6P0.4 photoanode in contact with electrolytes having redox potentials differing by 0.8 V.