Ultra-stable CsPbBr3 Perovskite Nanosheets for X-Ray Imaging Screen

HighlightsA gram-scale CsPbBr3 perovskite nanosheet colloid was synthesized by a green method at room temperature.The perovskite nanosheet colloid shows uncompromised photoluminescence quantum yield upon storage for over 8months.A self-assembly crack-free thin film of the colloidal nanosheets demonstrated an efficient X-ray imaging screen. AbstractWet chemistry methods, including hot-injection and precipitation methods, have emerged as major synthetic routes for high-quality perovskite nanocrystals in backlit display and scintillation applications. However, low chemical yield hinders their upscale production for practical use. Meanwhile, the labile nature of halide-based perovskite poses a major challenge for long-term storage of perovskite nanocrystals. Herein, we report a green synthesis at room temperature for gram-scale production of CsPbBr3 nanosheets with minimum use of solvent, saving over 95% of the solvent for the unity mass nanocrystal production. The perovskite colloid exhibits record stability upon long-term storage for up to 8months, preserving a photoluminescence quantum yield of 63% in solid state. Importantly, the colloidal nanosheets show self-assembly behavior upon slow solidification, generating a crack-free thin film in a large area. The uniform film was then demonstrated as an efficient scintillation screen for X-ray imaging. Our findings bring a scalable tool for synthesis of high-quality perovskite nanocrystals, which may inspire the industrial optoelectronic application of large-area perovskite film.