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 CsMnCl₃ 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 CsMnCl₃ MCs greatly increases the photoluminescence quantum yield (PLQY) from 48.2% to 92.3% for CsMnCl₃:1.5% Zn MCs (82.5% for CsMnCl₃:1%Cd MCs). The CsMnCl₃:1.5% 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 CsMnCl₃ MCs and polydimethylsiloxane (PDMS) assists in fabricating 100 cm² large-area uniform scintillation screens. As a result, the spatial resolution of CsMnCl₃:1.5%Zn@PDMS achieves 7.6 line pairs (lp) mm⁻¹, which is among the best values of CsMnCl₃@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.