Antiperovskites with Exceptional Functionalities.

ABX3 perovskites, as the largest family of crystalline materials, have attracted tremendous research interest worldwide due to their versatile multifunctionalities and the intriguing scientific principles underlying them. Their counterparts, antiperovskites (X3 BA), are actually electronically inverted perovskite derivatives, but they are not an ignorable family of functional materials. In fact, inheriting the flexible structural features of perovskites while being rich in cations at X sites, antiperovskites exhibit a diverse array of unconventional physical and chemical properties. However, rather less attention has been paid to these "inverse" analogs, and therefore, a comprehensive review is urgently needed to arouse general concern. Recent advances in novel antiperovskite materials and their exceptional functionalities are summarized, including superionic conductivity, superconductivity, giant magnetoresistance, negative thermal expansion, luminescence, and electrochemical energy conversion. In particular, considering the feasibility of the perovskite structure, a universal strategy for enhancing the performance of or generating new phenomena in antiperovskites is discussed from the perspective of solid-state chemistry. With more research enthusiasm, antiperovskites are highly anticipated to become a rising star family of functional materials.