Zero‐Dimensional Tin Halide Perovskite with Long Charge Carrier Lifetime and Anisotropic Photoconductivity for Selective Deep‐UV Photodetection

Abstract The rapid evolution of research on efficient and cost‐effective materials for UV photodetection is driven by their applications in environmental monitoring, medical diagnosis, security systems, and scientific research. In this study, a novel zero‐dimensional tin (IV) halide perovskite, (AEHB) 2 SnBr 6 , is synthesized for UV‐photodetector application. The material shows anisotropic photoconductivity with conductivity values of 8.4 × 10 −5 and 4.0 × 10 −5 cm 2 V −1 s −1 in the parallel and perpendicular directions to the long crystal axis, respectively. Its film state demonstrated photoconductivity approximately three times higher than that of its crystalline state. The material has a substantial charge carrier lifetime of 37 µs in the crystalline form and 57 µs in the film state, which can be attributed to its quantum‐well‐like structure and type‐IIb band alignment at the organic–inorganic heterojunction, as evident from single‐crystal X‐ray diffraction analysis and density functional theory calculations. A UV photodetector is fabricated with this material, demonstrating impressive device parameters, such as a high responsivity of 9.96 A W −1 , a specific detectivity of 6.8 × 10 11 Jones, and an external quantum efficiency of 49%. The device also showed a consistent photocurrent, fast photoresponse, and long‐term stability, making it a promising material for practical applications.