Influence of Mechanical Polishing on the Photoelectrochemical Properties of SrTiO3 Polycrystalline Anodes

Abstract

The influence of lattice defects produced by mechanical polishing of the surface upon the photoelectrochemical properties of polycrystalline anodes was investigated. The lattice defects were correlated to various subbandgap energy levels. Part of them were attributed to local Ti‒O bond weakening; they should lie close to the bandedges thus causing a tailing of the bandgap absorption and a shift of the flatband potential towards more positive values. Deeper subbandgap states resulting from Ti‒O bond breaking should render the semiconductor strongly sensitive to visible light. However, these lattice defects should also act as recombination centers causing a decrease of the hole diffusion length and therefore a decrease of the photocurrent efficiency.