X‐Ray‐Activated Long Afterglow Double‐Perovskite Scintillator for Detection and Extension Imaging

Abstract X‐ray flat‐panel detectors are widely used for nondestructive detection of internal information in medical radiography and industrial applications. However, a persisting challenge is the application of radiography on highly curved 3D objects to realize flexibility and information storage for the fabrication of flexible large‐area X‐ray detectors. This study demonstrates a halide‐based double perovskite Cs₂Na_0.9Ag_0.1LuCl₆:Dy³⁺ by a hydrothermal reaction. The as‐prepared crystals exhibit afterglow features through a co‐doping strategy of Dy³⁺ and Ag⁺ ions. The double perovskite material with doping modification exhibits excellent scintillation properties with high sensitivity, low detection limit, and high radiation stability. In addition, flexible scintillator detectors are fabricated with an area of 8.0 × 6.0 cm² by the blade‐coating strategy, which has a high spatial resolution of 11.2 lp mm⁻¹@MTF = 0.2. Based on the long afterglow properties, the Cs₂Na_0.9Ag_0.1LuCl₆:Dy³⁺ flexible film exhibits thermoluminescence after turning off the X‐ray, thereby having strong potential for X‐ray imaging of nonflat and irregular objects.