Halide perovskites and high-pressure technologies: a fruitful encounter

Recent decades have witnessed significant progress in halide perovskites, a rising star in emerging optoelectronic technology. Their development appeared to have reached a ceiling, and few breakthroughs in novel properties were emerging. But there is an exception: high-pressure techniques, which offer a promising way to synthesize new halide perovskites and change the properties of the existing perovskites. This review article provides an overview of research advances in high-pressure technologies for the development of halide perovskites. It starts with an introduction to apparatus for creating high pressures. Then, the synthesis of halide perovskites is discussed to show the effects of high pressures on their composition, morphology, etc. Then, high-pressure-driven modification of halide perovskites is reviewed, including their crystal structure, bandgap, quantum yield and ionic movement. Although plenty of achievements have been made in this field, challenges still remain, such as exploring new halide perovskites and stabilization of the high-pressure phase under ambient conditions.