Enhancing the Performance of Amorphous-Silicon Photoanodes for Photoelectrocatalytic Water Oxidation.

Herein, hydrogenated amorphous Si (a-Si:H) covered with a thin layer of CoOx is applied as photoanode for PEC water splitting. The thin layer of CoOx effectively protects a-Si:H from the corrosive electrolyte and quantitative oxidation of water to oxygen was observed. A high applied bias photon-to-current efficiency of 2.34 % was achieved using an intrinsic absorber and an additional p-type layer. This work shows that a-Si:H with a sandwich-like structure, in which each layer has its own functionality, can be applied as an efficient and stable photoanode for PEC water oxidation.