Electrospray prepared flexible CsPbBr3 perovskite film for efficient X-ray detection

Abstract

CsPbBr₃ perovskite materials have demonstrated excellent X-ray detection performance, including high sensitivity, owing to their high absorption coefficient, high carrier mobility, and long carrier lifetime. However, the large-scale preparation of CsPbBr₃ perovskite films characterized by a flexible and large area can still hardly be accomplished, which impedes their application for X-ray imaging. Herein, an improved electrospray method is developed to successfully prepare a flexible CsPbBr₃ film with an area of 5 × 5 cm². By optimizing the solvent system and the temperature of crystal growth, a highly crystalline film is obtained without pinholes or microcracks. An assembled interdigital detector displays a resistivity of 1.14 × 10⁹ Ω cm and outstanding performance with an X-ray sensitivity of 823.12 μC Gy_air⁻¹ cm⁻² under a 20 kV_p X-ray source. Furthermore, the X-ray detection limit of the flexible CsPbBr₃ film is 14.61 nGy_air s⁻¹. The facile preparation of flexible CsPbBr₃ films and their superior X-ray detection performance exhibit their huge potential applications in the areas of X-ray imaging, non-destructive inspection and other photoelectric devices.