ABSTRACT Lead‐free perovskites are emerging as eco‐friendly alternatives for X‐ray detection, yet achieving high sensitivity, stability, and self‐powered operation remains a challenge. Here, we present a 0D chiral organic‐inorganic hybrid bismuth perovskite single crystal, (R/S‐NEA) 4 Bi 2 Cl 10 (NEA = (2‐naphthyl)ethylamine), that enables a bulk photovoltaic effect (BPVE) for efficient, self‐powered X‐ray detection. Its unique structure, featuring isolated Bi 2 Cl 10 4 − dimers within a hydrogen‐bonded chiral lattice, facilitates asymmetric charge transport, enhancing intrinsic carrier separation. The resulting detector achieves a record sensitivity of 10 200 µC·Gy −1 cm −2 at 1000 V bias and maintains self‐powered operation (0 V) with a low detection limit of 510 nGy s −1 , outperforming existing bismuth‐based perovskite detectors. Notably, these crystals retain structural integrity for over a year in ambient conditions, while the device exhibits stable operation for over 4000 s under continuous X‐ray exposure. This work advances chiral perovskite engineering as a powerful strategy for developing next‐generation lead‐free X‐ray detectors with high performance and long‐term durability, making them attractive for portable medical imaging and radiation monitoring.
Huang et al. (Tue,) studied this question.