Inorganic CsPbI2 Br Perovskite Solar Cells: The Progress and Perspective

Cesium-based all-inorganic perovskite solar cells (PSCs), especially for CsPbI2Br component-based devices, have attracted increasing attention due to its advantage of superior thermal and phase stability. Since the pioneering study reported in 2016, more than 30 papers have been published, reporting the rapid boost in the power conversion efficiency (PCE) of PSCs to 14.81%. The CsPbI2Br PSC is one of the most remarkable research hotspots in the field of perovskite photovoltaics. In this progress report, the recent advances in CsPbI2Br PSCs are systematically reviewed, which in turn introduces the basic property and stability of active layers, and the performance improvements in these devices. The challenges as well as the possible solutions toward better-performing CsPbI2Br PSCs are also discussed. The theoretical calculation results point out that there is much room for further device performance enhancement, particularly in open-circuit voltages. This progress report focuses on CsPbI2Br material properties and summarizes recent strategies to improve the corresponding device's PCE, in order to open new perspectives toward commercial utility of PSCs.