Fluorinated Organic A‐Cation Enabling High‐Performance Hysteresis‐Free 2D/3D Hybrid Tin Perovskite Transistors

Abstract 2D tin‐based perovskites have gained considerable attention for use in diverse optoelectronic applications, such as solar cells, lasers, and thin‐film transistors (TFTs), owing to their good stability and optoelectronic properties. However, their intrinsic charge‐transport properties are limited, and the insulating bulky organic ligands hinder the achievement of high‐mobility electronics. Blending 3D counterparts into 2D perovskites to form 2D/3D hybrid structures is a synergistic approach that combine the high mobility and stability of 3D and 2D perovskites, respectively. In this study, reliable p‐channel 2D/3D tin‐based hybrid perovskite TFTs comprising 3D formamidinium tin iodide (FASnI₃) and 2D fluorinated 4‐fluoro‐phenethylammonium tin iodide ((4‐FPEA)₂SnI₄) are reported. The optimized FPEA‐incorporated TFTs show a high hole mobility of 12 cm² V⁻¹ s⁻¹, an on/off current ratio of over 10⁸, and a subthreshold swing of 0.09 V dec⁻¹ with negligible hysteresis. This excellent p‐type characteristic is compatible with n‐type metal‐oxide TFT for constructing complementary electronics. Two procedures of antisolvent engineering and device patterning are further proposed to address the key concern of low‐performance reproducibility of perovskite TFTs. This study provides an alternative A‐cation engineering method for achieving high‐performance and reliable tin‐halide perovskite electronics.