The Voltage Loss in Tin Halide Perovskite Solar Cells: Origins and Perspectives

Abstract

Abstract Exploring stable and efficient lead‐free perovskite solar cells (PSCs) is critical to solving the environmental concerns caused by lead. Recently, tin halide perovskites (THPs) have become a promising candidate due to its low toxicity and similar electronic configuration to lead counterparts. Currently, the power conversion efficiency of tin‐based PSCs (TPSCs) has been pushed over 14%. However, there is still a considerable gap compared to lead PSCs due to the non‐negligible open‐circuit voltage loss ( V loss ). Therefore, understanding the origins and regulation strategies of V loss for TPSCs is of great importance. Herein, the nature of THPs is first reviewed from the crystal structure, electronic structure, and phase transition. Subsequently, the origins and determinants of V loss are discussed in TPSCs. Besides the intrinsic low bandgap, the bulk recombination of tin perovskite, and the non‐radiative recombination of the associated interfaces induce the V loss of the TPSCs devices. Then, some recently emerged strategies to suppress the V loss in TPSCs are introduced. Finally, a perspective on the further suppression of V loss in TPSCs including purifying the precursor solution, suppressing the oxidation Sn 2+ , and optimizing the device structure is outlined.