Influence of Dipolar Fields on the Photochemical Reactivity of Thin Titania Films on BaTiO ₃ Substrates

Abstract

The photochemical properties of TiO 2 films supported on BaTiO 3 were investigated to test the hypothesis that dipolar fields from a ferroelectric substrate would affect the reactivity of the supported film. Photochemical reaction products were formed on the TiO 2 surface in patterns that correspond to the underlying domain structure of BaTiO 3 . As the film thickness increases from 10 to 100 nm, the titania more effectively screens the ferroelectric field, and the pattern of reaction products is obscured. It is concluded that dipolar fields from the ferroelectric substrate influence charge carrier transport in the film and spatially localize the reaction products.