Anti-perovskites with long carrier lifetime for ultralow dose and stable X-ray detection

Halide perovskites have shown promising potential for direct X-ray detection due to their high X-ray absorption coefficient, low trap states and convenient fabrication process. However, it is still a challenge to achieve high sensitivity, low dark current and low detection limit in a single material. The deep reason for this is the trade-off between the material’s μτ product and resistivity. Here we report the construction of an organic–inorganic hybrid anti-perovskite ((2-Habch)₃Cl(PtI₆)) with indirect transition and low orbital symmetry at the band edge to achieve an ultralong intrinsic lifetime and thus break the trade-off. (2-Habch)₃Cl(PtI₆) achieves an unprecedented long carrier lifetime of >3 ms, leading to a large μτ product of 6.25 × 10⁻³ cm² V⁻¹ and high resistivity of 10¹² Ω cm, outperforming most X-ray detection materials. These properties enabled the development of X-ray detectors that simultaneously achieve an ultralow dark current of 0.21 nA cm⁻², high sensitivity of 1.0 × 10⁴ µC Gy_air⁻¹ cm⁻², ultralow detection limit of 2.4 nGy_air s⁻¹ and excellent operational stability with no observable baseline drift, outperforming state-of-the-art perovskite single-crystal detectors. The rare combination of high performance in almost every figure of merit in the anti-perovskite-based X-ray detector could enable new-generation X-ray detection systems.