Rapid and Large-Scale Syntheses of Microcrystal Cuprous Halide Scintillators for X-ray Imaging

Zero-dimensional (0D) organic-inorganic metal halides (OIMHs), as a new frontier of solid-state photoluminescent materials, have been demonstrated to show outstanding radioluminescence (RL) properties and multiple applications originating from self-trapped excitons. Herein, two new 0D OIMHs of (DTBEDA)₂Cu₄Cl₈ and (MOPPZ)₂Cu₄Cl₈·H₂O based on [Cu₄Cl₈]^4- were successfully prepared with near-unity broadband orange and yellow light emissions, respectively. Meaningfully, the microscale crystals of both halides can be rapidly and facilely synthesized in the large scale by simply adding the CuCl in acid solution at room temperature, which greatly expand the practical application prospect of these metal halides. Benefiting from the near unity PLQY and negligible self-absorption characteristics, (DTBEDA)₂Cu₄Cl₈ achieves excellent scintillation property with a high light yield of 38,200 phonon MeV^-1 and low detection limit of 81.7 nGy_air s^-1, which provides the prerequisite for high-resolution X-ray imaging. In addition, a flexible film scintillation screen of (DTBEDA)₂Cu₄Cl₈@EVA was manufactured, which achieves an astonishing spatial resolution of 18.1 lp mm^-1. The multiple advantages of rapidly and large-scale synthesis, microscale size, and satisfactory scintillation performance not only demonstrate a new synthesis strategy for 0D OIMH-based scintillators but also expand the practical application range of 0D OIMHs.