Reactive Inorganic Vapor Deposition of Perovskite Oxynitride Films for Solar Energy Conversion

Abstract

The synthesis of perovskite oxynitrides, which are promising photoanode candidates for solar energy conversion, is normally accomplished by high-temperature ammonolysis of oxides and carbonate precursors, thus making the deposition of their planar films onto conductive substrates challenging. Here, we proposed a facile strategy to prepare a series of perovskite oxynitride films. Taking SrTaO2N as a prototype, we prepared SrTaO2N films on Ta foils under NH3 flow by utilizing the vaporized SrCl2/SrCO3 eutectic salt. The SrTaO2N films exhibit solar water-splitting photocurrents of 3.0 mA cm-2 at 1.23 V vs. RHE (reversible hydrogen electrode), which increases by 270% compared to the highest photocurrent (1.1 mA cm-2 at 1.23 V vs. RHE) of SrTaO2N reported in the literature. This strategy may also be applied to directly prepare a series of perovskite oxynitride films on conductive substrates such as ATaO2N (A=Ca,Ba) and ANbO2N (A=Sr,Ba).