Ion Migration Induced Unusual Charge Transport in Tin Halide Perovskites

Metal halide perovskites are considered next-generation semiconductors for various optoelectronic devices owing to their low-cost processability and superior optoelectronic properties. However, the performance and reliability of perovskite-based devices depend on electric-field-driven ion migration, whose mechanism remains unclear. Tin (Sn2+)-based perovskites are attracting particular interest owing to their unique charge-transport properties and eco-friendly characteristics. Here, we explore the effect of ion migration on the charge-transport properties of the Sn2+ perovskite using the transistor as the test platform. To supply mobile ions, we added copper iodide to the Sn2+ perovskite film. The ion migration and accumulation-induced electrochemical doping of the perovskite channel resulted in abnormal transitions in the electrical characteristics with the abnormally high transient field-effect mobility. We expect this study provides a hint for the decipherment of ion migration effect on the charge-transport properties of Sn2+ perovskites and the design of novel perovskite-based electronics.