High-Resolution Flexible X-ray Imaging in a Two-Dimensional Mn<sup>2+</sup>-Doped Perovskite Scintillator
Hao Rong, Xinqi Xu, Jia-Yu Yao, Qingshun Fan, Haoyu Zhang, Haojie Xu, Junhua Luo, Qiushui Chen, Zhihua Sun
Abstract
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 Mn 2+ -doped two-dimensional (2D) Ruddlesden–Popper type perovskite, (4- tert -butylbenzylamine) 2 PbBr 4:Mn, serving as a highly efficient scintillator candidate. Doping with Mn 2+ induces a spin-forbidden internal transition ( 4 T 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 Mn 2+ ions, ultimately leading to intense orange-red emission. This process enhances the photoluminescence quantum yield of (4- tert -butylbenzylamine) 2 PbBr 4 ( 1 ) and decreases its self-absorption. Therefore, at the optimal Mn 2+ -doping concentration, 1:8.4%Mn 2+ 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%Mn 2+ with poly(dimethylsiloxane) to fabricate flexible scintillator films. With the optimal film thickness and mass percentage of 1:8.4%Mn 2+, 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%Mn 2+ effectively addresses the shortcomings of current commercial scintillators, thereby providing a new option for the scintillator family.