An aerosol-liquid-solid process for the general synthesis of halide perovskite thick films for direct-conversion X-ray detectors

Medical X-ray computed tomography requires imaging at a low dose rate and in a large area. Halide perovskites have shown high potential for X-ray detection, but a pressing challenge is the current lack of low-cost methods for large-scale fabrication of high-quality thick perovskite films. Here we demonstrate and elucidate an aerosol-liquid-solid process to enable continuous growth of uniform halide perovskite films at low temperature over a large area of 100 cm 2 , which are vertically monolithic, and thus beneficial to carrier transport. Direct-conversion X-ray detectors based on the representative CsPbI 2 Br films in conjunction with a deliberated, interface-engineered C-electrode have realized an unprecedented sensitivity (≥1.48 × 10 5 μC Gy air −1 cm −2 ) and a low limit of detection (280 nGy air s −1 ). We have further demonstrated the high-resolution radiographic imaging capability of these films. These results lay the groundwork for large-scale application of halide perovskites in radiation detectors.