Abstract
Organic–inorganic hybrid metal-halide perovskites have emerged as potential semiconductors for high-performance X-ray detection owing to their large radiation stopping power, high sensitivity, large mobility-lifetime (μτ) product, and facile fabrication strategies. In recent times, two-dimensional (2D) layered perovskite-based X-ray detectors have attracted significant attention owing to their superior ambient and thermal stability, reduced ion migration, and low defect density. Notably, in 2D perovskites, the larger organic amine spacer integrated alternately between inorganic lead halide octahedral layers can effectively restrict ion migration even for higher bias voltages in X-ray detection. In this work, we have fabricated centimeter-sized high-quality butyl amine organic spacer-incorporated n = 1 layered Ruddlesden–Popper (RP) phase (BA)2PbI4 2D perovskite single crystals using a conventional slow cooling method and demonstrated their X-ray detection and imaging applications. The (BA)2PbI4 single crystal detector exhibits an excellent X-ray performance with a sensitivity of 148 μCGy–1 cm–2 at 10 V mm–1 applied electric field, an ultralow detection limit less than 241 nGy s–1, a very low and stable dark current (20.52 pA), and a quick response time of ∼4 ms. Moreover, the fabricated devices have shown remarkably stable responses for continuous X-ray exposure over 60 min and ultrahigh storage stability of over 4 months, confirming the material robustness and stability. Finally, high-resolution X-ray imaging is demonstrated using these (BA)2PbI4 single crystal-based detectors. The exceptional operational stability and high performance of (BA)2PbI4 X-ray detectors make them promising candidates for low-dose X-ray detection and imaging applications.