Low-Temperature Reactively Sputtered Tungsten Oxide Films for Solar-Powered Water Splitting Applications

Abstract

Tungsten oxide semiconductor films for photoelectrochemical water-splitting applications, reactively sputtered at low temperatures , have demonstrated photocurrents of under AM 1.5 illumination in 0.33M , exceeding published results for material pyrolytically fabricated at higher temperature, and approaching the theoretical maximum for tungsten trioxide based on optical absorption limits. The microstructural form of the reactively sputtered films, which is sensitive to the sputter process parameters, critically affects the photoconversion efficiency. It has also been determined that the sputtered films form true compact photoelectrodes in solution, with active charge generation and separation over the material's optical width.