Zn-based oxide perovskite nanocomposites for energy and sensing applications

Lead and other heavy metals in traditional functional perovskites are detrimental for usage in devices, due to the increasing number of applications of low-powered sensors and microenergy electronics. Cubic and distorted hexagonal Zn-based perovskites are as such potential candidates for their symmetry-dependence and show enhanced ferroelectricity, nonlinear optical phenomena with unique dielectric and catalytic properties for suitable applications in energy harvesting, storage, and sensing for hazardous gas. Dimensional and compositional nanocomposite bulk and films for Zn perovskite materials furthermore show modified band gap energy through defect or strain engineering, and hence, ionic and electronic conductivities can be possibly modulated in the right order. In this short review, we collate the last five-year research results of specific Zn-based perovskites such as ZnSnO₃, ZnTiO₃, and ZnMnO₃, and their LiNbO₃-type varieties with targeted applications in energy harvesting, storage, and gas sensing. First we discuss the fundamental crystal structures of Zn-based perovskites and introduce nanocomposites in general. Then the discussion moves to the properties and functionality relationships in these materials with examples of selected recent advancements in the reviewed materials nanocomposite systems. Finally, future directions in these materials systems for multifunctional properties exploration are briefly unveiled.