Abstract
Aqueous electrolyte contacts do not form Schottky barriers with amorphous silicon electrodes. In the dark, silicon oxidation and electrolyte reduction at a counter electrode produce a battery voltage in series with the depletion-region potential. Illuminating the cell substantially decreases the amorphous silicon electrode series resistance and increases the hole concentration at the surface. This enhances the battery reaction rate and increases the current through the cell. Interpreting this current as a traditional photocurrent (due solely to a Schottky junction) overestimates the magnitude of the barrier height.