Fabrication of CsPbBr₃ Thick Films by Using a Mist Deposition Method for Highly Sensitive X-ray Detection

Abstract

X-ray imaging is a valuable technique used for medical imaging and non-destructive inspection of industrial products. However, the radiation may put humans at risk of developing cancer. Consequently, highly sensitive X-ray detectors, which enable X-ray imaging at a low dose rate, are required. Metal halide perovskite materials have demonstrated excellent X-ray detection performance including a high sensitivity owing to their high absorption coefficient, high carrier mobility, and long carrier lifetime. However, perovskite thick films with a large area, which is essential to realize the application of such materials to X-ray imaging devices have not been extensively investigated. To this end, in this study, a polymer is employed as a buffer layer to avoid film exfoliation, which makes it difficult to fabricate perovskite thick films, and a 110-μm-thick CsPbBr₃ film is successfully obtained using a scalable solution method. In addition, an X-ray detector based on the CsPbBr₃ thick film is fabricated, which demonstrates a sensitivity of 11, 840 μC Gyair⁻¹ cm⁻². This sensitivity is approximately 600 times higher than that of the existing commercial a-Se X-ray detectors.