Inorganic lead-based halide perovskites: From fundamental properties to photovoltaic applications

Compared with organic–inorganic hybrid halide perovskites (OIHPs), inorganic cesium lead halide perovskites (CsPbX3) possess superior intrinsic stability for high temperatures and are considered one of the most attractive research hotspots in the perovskite photovoltaic (PV) field in the past several years. The PCE of CsPbX3 inorganic perovskite solar cells (IPSCs) has increased from 2.9% in 2015 to more than 20% with excellent stability. There are still many on-going studies on the properties of perovskite materials and their applications in PV technology, thereby needing a thorough understanding. Here, the progress of inorganic perovskites is systematically introduced, including the fundamental properties of CsPbX3 materials and CsPbX3-based PV devices. The origins of stability and instability of CsPbX3 and defects in CsPbX3 are discussed. CsPbI3-, CsPbI2Br-, CsPbIBr2- and CsPbBr3-based PV devices and performance are comprehensively reviewed. The stabilization methods and mechanism for the photoactive phases of inorganic perovskites with low bandgap are emphasized. Reported strategies to boost the performance of CsPbX3-based IPSCs are summarized. In the end, the potential of inorganic perovskites is evaluated, which opens up new prospects for the commercialization of IPSCs.