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

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)2SnBr6, is synthesized for UV-photodetector application. The material shows anisotropic photoconductivity with conductivity values of 8.4 x 10-5 and 4.0 x 10-5 cm2 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 mu s in the crystalline form and 57 mu s 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 x 1011 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. A lead-free, 0D Sn-halide perovskite featuring N-(2-aminoethyl)-2-hydroxybenzamide as a spacer cation is synthesized and characterized. It exhibits a quantum-well-like structure and type-IIb band alignment, contributing to its high charge carrier lifetime. Using this material, a photodetector device is constructed, demonstrating deep-UV photoresponse and good device characteristics.image