APbI₃-A₂AgBiI₆ Double-Layer Perovskite Film for a Self-Powered and High-Stability X-ray Detector

The development of lead halide perovskite X-ray detectors has promising applications in medical imaging and security inspection but is hindered by poor long-term stability and drift of the dark current and photocurrent. Herein, we design a (Cs_0.05MA_0.65FA_0.3)PbI₃-(Cs_0.1MA_1.3FA_0.6)AgBiI₆ double-layer perovskite film to assemble a self-powered flat-panel X-ray detector. The demonstrated X-ray detector achieves an outstanding self-powered sensitivity of 80 μC Gy_air^-1 cm^-2 under a 0 V bias. More importantly, owing to the inhibition of the phase transition process and ion migration of (Cs_0.05MA_0.65FA_0.3)PbI₃ by the (Cs_0.1MA_1.3FA_0.6)AgBiI₆ layer, the device exhibits excellent continuous operating stability with a retention rate of 99% dark current and photocurrent over X-ray pulses of up to 4000 s and excellent long-term stability without a loss of the original response current after 150 days in an air environment. The strategy of double-layer perovskites improves the stability and sensitivity of devices, which paves a path for the industrial application of lead halide perovskite X-ray detectors.