Organic Surface Doping for High‐Performance Perovskite Transistors

Abstract Quasi‐2D perovskites have attracted significant attention because of their environmental robustness and superior long‐term stability compared with their 3D counterparts. However, they typically consist of a mixture of multiple quantum wells with different optoelectrical properties, which degrades the electronic properties and hinders further electronic applications. Here, to challenge this issue, a surface p‐doping strategy involving the introduction of a thiophene‐containing polymer onto the surface of quasi‐2D tin perovskites is reported. The tin ions in the perovskites effectively interact with the sulfur atoms in the thiophene moieties, thereby generating hole carriers and inducing p‐doping. The resulting doped quasi‐2D perovskites exhibit excellent surface crystallinity, lower trap density, and enhanced charge carrier transport capability along the perovskite semiconductor channels. Consequently, the doped quasi‐2D tin perovskite‐based transistors exhibit a high field‐effect mobility of 53 cm²V⁻¹s⁻¹ (7 cm²V⁻¹s⁻¹ for the control device) and an outstanding on/off ratio (>10⁷), together with superior operational stability.