Graphene-Perovskite composite structure facilitates High-Performance X-ray detectors with low detection limits

Metal-halide perovskite X-ray detectors offer a low-cost platform for direct detection across a broad high-energy spectrum. However, the large thickness and the high defect density of the perovskite thick films increase recombination, resulting in performance bottlenecks. Herein, we demonstrate a high-performance X-ray detector featuring a perovskite/graphene heterostructure that synergistically combines graphene’s high carrier mobility (> 10⁴ cm²·V⁻¹·s⁻¹) with perovskite’s exceptional photophysics properties. The bulk heterojunction formed between CsPbBr₃ and graphene facilitates efficient charge transport and suppresses non-radiative recombination. Additionally, a MAPbCl₃ buffer layer reduces lattice mismatch at the perovskite/Si interface, enhancing mechanical adhesion by 10 times. The optimized device achieves a sensitivity of 4162 µC·Gyₐir⁻¹·cm⁻² (3× higher than perovskite-only devices) and a record-low detection limit of 9.6 nGyₐir·s⁻¹ (60× improvement), alongside exceptional operational stability. This work establishes a paradigm for developing high-sensitivity, high-stability, and low-cost perovskite X-ray detectors.