Routes to energy conversion with functional oxide films and nanostructures, a short review

•Ferroelectric materials for energy conversion•Piezoelectric materials for kinetic energy harvesting•Function materials used in spatial selective photocatalysis•Piezoelectric influence on photovoltaic performance

In the last 10 years there has been growing interest to investigate the impact of non-centrosymmetry of piezo or ferroelectric materials for energy harvesting devices and systems. There are a large range of devices being investigated including those that convert kinetic energy into electrical energy or convert sunlight into fuels, known as solar fuels, or produce electrical energy such as in a photovoltaic device. The fundamental principle and area of interest in these materials are related to the breaking of crystal symmetry found in a piezo or ferroelectric material. This breaking of crystal symmetry intimately influences the physical properties within the material and leads to some specific behaviour. We know that the domain structure of a ferroelectric material separates photoinduced carriers that lead to regio-specific photochemistry.