Comprehensive Summary

Perovskite solar cells (PSCs) have achieved significant progress in the past decade and a certified power conversion efficiency (PCE) of 26.0% has been achieved. The widely used organic hole transport materials (HTMs) in PSCs are typically sensitive to the moisture environment and continuous light exposure. In contrast, the inorganic HTMs benefiting from their outstanding merits, such as excellent environmental stability, are considered as alternatives and have attracted much attention in PSCs. In this review, we provide a comprehensive summary of the fundamental properties and recent progress of inorganic HTMs in n-i-p and p-i-n structured PSCs. Additionally, we emphasize the importance of inorganic HTMs in the development of highly efficient and stable PSCs.