Inorganic CsSnI3 Perovskite Solar Cells: The Progress and Future Prospects

Although the power conversion efficiency of Pb-based perovskite solar cells (PSCs) has increased rapidly from 3.8% to 25.2%, the concerns about the toxicity of Pb greatly hinders its large-scale application in the future. Therefore, many efforts have been made to develop environmentally benign Pb-free perovskites, and there is a growing consensus that Sn-based perovskites are by far the most promising alternative due to their ideal electric and optical properties. Among Sn-based perovskites, CsSnI3 perovskite shows great promise for developing high-efficiency Sn-based PSCs due to its high thermal stability, ideal bandgap range, and low exciton binding energy. On the basis of the device engineering, an efficiency up to 10.1% has been reported for CsSnI3 PSCs. Nevertheless, considering the theoretical efficiency of CsSnI3 PSCs to be over 30%, there is still much room for improvement in the efficiency. Herein, the properties of CsSnI3 perovskite are summarized and the origins of stumbling the efficiency improvement of CsSnI3 PSCs are provided. The device engineering toward more stable and efficient CsSnI3 PSCs is discussed in detail. Finally, the remaining challenges and future perspectives in the field of CsSnI3 PSCs are also shown to help further the development of highly efficient CsSnI3 PSCs.

Automated summary

Efforts are being made to develop lead-free perovskite solar cells (PSCs) as concerns about the toxicity of lead hinder its large-scale application. Among the alternatives, tin-based perovskites, specifically CsSnI3 perovskite, show great promise due to their ideal properties. Despite achieving an efficiency of 10.1%, there is still room for improvement considering the theoretical efficiency of over 30%. This article summarizes the properties of CsSnI3 perovskite, provides insights into the challenges hindering efficiency improvements, discusses device engineering strategies, and highlights the remaining challenges and future perspectives for highly efficient CsSnI3 PSCs.