Ultrathin, Transparent, and High Density Perovskite Scintillator Film for High Resolution X‐Ray Microscopic Imaging

Abstract Inorganic perovskite quantum dots CsPbX 3 (X = Cl, Br, and I) has recently received extensive attention as a new promising class of X‐ray scintillators. However, relatively low light yield (LY) of CsPbX 3 and strong optical scattering of the thick opaque scintillator film restrict their practical applications for high‐resolution X‐ray microscopic imaging. Here, the Ce 3+ ion doped CsPbBr 3 nanocrystals (NCs) with enhanced LY and stability are obtained and then the ultrathin (30 µm) and transparent scintillator films with high density are prepared by a suction filtration method. The small amount Ce 3+ dopant greatly enhances the LY of CsPbBr 3 NCs (about 33 000 photons per MeV), which is much higher than that of bare CsPbBr 3 NCs. Moreover, the scintillator films made by these NCs with high density realize a high spatial resolution of 862 nm thanks to its thin and transparent feature, which is so far a record resolution for perovskite scintillator‐based X‐ray microscopic imaging. This strategy not only provides a simple way to increase the resolution down to nanoscale but also extends the application of as‐prepared CsPbBr 3 scintillator for high resolution X‐ray microscopic imaging.