Flexible Mn(II)‐Based Halide Scintillation Screen for High‐Resolution X‐Ray Imaging of Nonplanar Objects

Abstract X‐ray imaging and detection technologies based on scintillators are extensively utilized in both medical diagnosis and industrial nondestructive inspection. However, traditional rigid planar scintillation screens are susceptible to vignetting and distortion problems because of the inhomogeneity of X‐ray dose distribution. Flexible scintillation screens based on highly efficient metal‐based halides can effectively solve the above‐mentioned problems. In this work, a series of novel 0D Mn(II)‐based halides ((C 5 H 5 N) 2 MnBr 4 , (C 7 H 10 N) 2 MnBr 4 , (C 8 H 12 N) 2 MnBr 4 and (C 9 H 14 N) 2 MnBr 4 ) are designed and synthesized with small‐sized pyridine derivatives. Increasing the Mn–Mn distances through an alkyl chain modification strategy can effectively suppress the nonradiative transition and enhance exciton utilization, and thus their photoluminescence quantum yields (PLQYs) are significantly enhanced from 58.76% to 99.64%. (C 9 H 14 N) 2 MnBr 4 crystals with the highest PLQYs demonstrate superior X‐ray scintillation properties with a high relative light yield of 57739 photons MeV −1 , which is 2.6 times higher than the commercial scintillators (LuAG: Ce). Moreover, the flexible scintillation screen composed of (C 9 H 14 N) 2 MnBr 4 and thermoplastic polyurethane achieves a high resolution of 17.8 lp mm −1 and is successfully applied for nonplanar objects to reduce image distortion. This work not only provides a strategy for improving PLQYs of Mn(II)‐based halides but also demonstrates their practical applications for X‐ray imaging of non‐planar objects.