Recent progress on cesium lead/tin halide-based inorganic perovskites for stable and efficient solar cells: A review

A comparable power conversion efficiency (PCE) to that of commercial Si solar cells (over 23%) has been achieved by organic-inorganic hybrid perovskite solar cells (OIH-PSCs) within several years. As OIH-PSC materials have hygroscopic organic cations that limit their thermal and long-term stability (i.e. operational lifetime of about 1 year, much shorter than commercial Si of 20-25 years), significant research efforts have been directed to the development of all-inorganic PSCs to overcome this limitation. These studies have demonstrated that cesium lead halide (CsPbX3) and Pb-free cesium tin halide (CsSnX3) perovskites are promising materials for the fabrication of thermally stable and efficient solar cells. This work reviews recent progress on versatile CsPbX3 and CsSnX3 inorganic PSCs. Remarkable PCE values over 17% and 4% have been achieved by employing CsPbX3 and CsSnX3 perovskites, respectively, in a short development time. In addition, we evaluate the materials engineering methods and film deposition techniques for producing such inorganic perovskite materials. Several strategies including surface and interfacial passivation are discussed to alleviate hysteresis and instability of inorganic PSCs. Furthermore, future research directions including device engineering using inorganic metal oxide charge transport layers are suggested to further reinforce this innovative advances in the inorganic PSCs.