Surface modification in semiconductor liquid-junction cells

Abstract

Modification of the photoactive junction in semiconductor based photoelectrochemical cells to improve or stabilize the current–voltage characteristics under illumination has been attempted in many ways in the brief history of such energy converting devices. We discuss two such efforts with n-type gallium arsenide substrates. In one, polycrystalline films incorporating submonolayers of metal ions in the surface region show significant enhancement of power output in selenide–polyselenide cells. In the second, single crystals electroplated with noble metals and contacted by a redox solution to the resulting metal–semiconductor Schottky junction are examined for solar conversion prospects.