Electronic structure of bismuth titanates thin films and their application in solar energy conversion

摘要

There is a growing interest in the use of coloured complex metal oxides as visible light-active photocatalysts and photoelectrodes. In contrast to simple oxides (AOx), complex oxides (ABOx) possess two ordered metal sub lattices for the large A and smaller B cations. In order to afford visible light activity, elements other than d~0 and d~(10) metals must be incorporated. Conventional doping of simple oxides like TiO2 or WO3 for inducing visible light activity often leads to the formation of localised defects that detrimentally affect the charge mobility. On the other hand, incorporation of an extended and ordered lattice facilitates the formation of energy bands that extend throughout the structure, rather than localised defect sites, and thus does not hinder charge migration through the semiconductor particle.