High-Resolution Flexible X-ray Imaging in a Two-Dimensional Mn2+-Doped Perovskite Scintillator

Flexible scintillator screens characterized by high spatial resolution, low cost, and a simple fabrication process are in significant demand for applications in medical diagnosis and industrial detection. Here, we have demonstrated a new Mn2+-doped two-dimensional (2D) Ruddlesden-Popper type perovskite, (4-tert-butylbenzylamine)(2)PbBr4:Mn, serving as a highly efficient scintillator candidate. Doping with Mn2+ induces a spin-forbidden internal transition (T-4(1g) -> (6)A(1g)) that enhances the energy-transfer efficiency from the strongly bound excitons of the host material to the d electrons of the Mn2+ ions, ultimately leading to intense orange-red emission. This process enhances the photoluminescence quantum yield of (4-tert-butylbenzylamine)(2)PbBr4 (1) and decreases its self-absorption. Therefore, at the optimal Mn2+-doping concentration, 1:8.4%Mn2+ demonstrates a high light yield of 21,532 Ph/MeV and a low detection limit of 198.19 nGy(air) s(-1), exceeding the performance of a commercial bismuth germanium oxide (BGO) scintillator. Furthermore, we combined ultrafine powders of 1:8.4%Mn2+ with poly(dimethylsiloxane) to fabricate flexible scintillator films. With the optimal film thickness and mass percentage of 1:8.4%Mn2+, the scintillator films achieve their maximum spatial resolution of 17.3 lp mm(-1). The above results indicate that the exceptional flexible scintillation imaging performance of 1:8.4%Mn2+ effectively addresses the shortcomings of current commercial scintillators, thereby providing a new option for the scintillator family.