Large‐Area Stable Flexible X‐Ray Scintillation Screens with Group IIB Ions Doped CsMnCl₃ Microcrystals

Abstract Lead‐free metal halide perovskites and derivatives microcrystals (MCs) have become emerging candidates for X‐ray scintillation imaging applications. However, the luminescent properties of micrometric crystals need to be further improved, and the development of flexible scintillation screens utilizing large‐scale MCs remains a significant challenge. Here, all‐inorganic manganese (Mn)‐based perovskite CsMnCl 3 MCs are reported by room‐temperature solution‐synthesized co‐precipitation method. Introducing an amount of Group IIB divalent metal cations (i.e., Zn and Cd in this work) into CsMnCl 3 MCs greatly increases the photoluminescence quantum yield (PLQY) from 48.2% to 92.3% for CsMnCl 3 :1.5% Zn MCs (82.5% for CsMnCl 3 :1%Cd MCs). The CsMnCl 3 :1.5% Zn MCs feature excellent scintillation performance and achieve a low detection limit of 22.53 nGy air s −1 . Furthermore, solvent engineering by adding n‐hexane to the mixture of doped CsMnCl 3 MCs and polydimethylsiloxane (PDMS) assists in fabricating 100 cm 2 large‐area uniform scintillation screens. As a result, the spatial resolution of CsMnCl 3 :1.5%Zn@PDMS achieves 7.6 line pairs (lp) mm −1 , which is among the best values of CsMnCl 3 @PDMS scintillation screens. In addition, high‐resolution flexible imaging applications of non‐planar objects are achieved. The work offers a promising approach to develop high‐performance large‐area flexible scintillation screens based on large‐size MCs for high‐resolution X‐ray imaging.