Zero-dimensional cesium lead halide perovskites: Phase transformations, hybrid structures, and applications

Fabrication of materials for current energy applications is one of the most exciting areas of contemporary materials research. Over the past few years, the oldest perovskites and their related materials stay in the frontline of this research, yielding advancements to photovoltaic, optoelectronic, and laser technologies. Previously, familiar zero-dimensional (OD) all-inorganic (Cs4PbX6, X = Cl, Br, and I) perovskite materials have emerged in new forms with unusual chemical and physical properties, coupled together with strengths of traditional perovskite research. As a result of intense efforts, OD-Cs4PbX6 single crystals, thin films, micron sized crystals, powders, nanocrystals, and their hybrid structures with 3D perovskites were added to the literature. This review aims to provide an overview of OD-Cs4PbBr6 and related hybrids, and their substantial contributions to fundamental understanding and technological applications, such as photodetectors, light emitting diodes, and temperature-insensitive lasers.