Tailoring tin-based perovskite crystallization via large cations and pseudo-halide anions for high mobility and high stable transistors
Yanqiu Wu, Yuan Feng, Shuzhang Yang, Enlong Li, Wunan Wang, Yu Liu, Xiaomin Yang, Jincheng Wen, Lina Hua, Yingguo Yang, Yusheng Lei, Junhao Chu, Wenwu Li
Abstract
Tin-based perovskites, renowned for their eco-friendliness, intrinsic high hole mobility, and low effective mass, hold great potential for p-type thin-film transistors (TFTs). However, their propensity for rapid crystallization and oxidation severely limits stability and carrier mobility. Here, we strategically enhance perovskite TFT performance by incorporating 2-thiopheneethylamine thiocyanate (TEASCN) into 3D tin-based perovskites. The induction of the pseudo-halide SCN − into a bilayer quasi-2D perovskite intermediate phase, combined with the strong interaction between sulfur-bearing thiophene rings (TEA + ) and Sn-I octahedra, effectively reorients perovskite crystallization while inhibiting Sn 2+ oxidation and reducing trap density. Consequently, TEASCN-based TFTs achieve an average hole mobility of more than 60 square centimeters per volt per second and an on/off current ratio surpassing 10 8 , standing out among state-of-the-art p-type perovskite TFTs. Furthermore, unencapsulated devices preserve 84% of their initial mobility after 30 days in an N 2 atmosphere, underscoring their remarkable stability. This work opens a straightforward path toward high-mobility and highly stable tin-based perovskite transistors.