Realization of Passive X‐Ray Detection with a Low Detection Limit in Dion–Jacobson Halide Hybrid Perovskite

Abstract Halide hybrid perovskites are a kind of intriguing contenders for X‐ray detection, and their low detection limits (LoDs) have played a crucial part in X‐ray safety inspection and medical examination. However, there is still a significant challenge in manufacturing perovskite X‐ray detectors with low LoDs. Herein, attributed to the bulk photovoltaic effect (BPVE) of a Dion–Jacobson (DJ) type 2D halide hybrid perovskite polar structure (3‐methylaminopropylamine)PbBr 4 ( 1 ), self‐powered X‐ray detection with low detection limit is successfully realized. Specifically, the crystal‐based detector of 1 exhibits a low dark current at zero bias, which reduces the noise current (0.34 pA), leading to a low detection limit (58.3 nGy air s −1 ) which is two orders of magnitude lower than that of under external voltage bias. The combination of BPVE and LoDs of halide hybrid perovskite provides an efficient strategy to achieve passive X‐ray detection with low doses.