Voltage dependence of the dark and photocurrents in semiconductor-electrolyte junctions

Expressions for the dark and photocurrent of a semiconductor-electrolyte junction are derived. Charge transfer kinetics, surface recombination, recombination in the space-charge region, and series resistance are discussed in our model. A measurement of the I-V characteristics, both in the dark and under illumination, aids in the estimation of the parameters of the device. The model agrees with the general observed quantum efficiency variation with voltage.