Inorganic CsPbI3 Perovskites toward High-Efficiency Photovoltaics

The organic-inorganic hybrid perovskite solar cells (PSCs) have demonstrated their unprecedented high efficiency and potential for commercialization. The volatile organic components in the hybrid perovskite crystal structure are still a big challenge for long-term stabilities. Recently, inorganic CsPbI3 perovskite has attracted much attention because of its superior chemical stability over the prevailing hybrid organic-inorganic perovskite and the most suitable band gap among all-inorganic perovskites. Nevertheless, CsPbI3 suffers from phase instability and low photovoltaic (PV) performance due to its undesirable tolerant factor. Much research effort has been devoted into stabilization of CsPbI3. In this perspective, we review the recent progress on chemical engineering processes for the stabilization of inorganic CsPbI3 perovskite for high-efficiency PVs. We also discuss the importance of understanding mechanism behind stabilization of CsPbI3 perovskite film and the development of inorganic CsPbI3-based highly efficient and stable PSCs.