Preparation of Lead-free Two-Dimensional-Layered (CHNH)SnBr Perovskite Scintillators and Their Application in X-ray Imaging.

Scintillators, as spectral and energy transformers, are essential for X-ray imaging applications. However, their current disadvantages, including high-temperature sintering and generation of agglomerated powders or large bulk crystals, may not meet the increasing demands of low cost, nontoxicity, and flexible radiation detection. Thus, improved perovskite scintillators are developed in this research. A hybrid perovskite ((CHNH)SnBr), which is nontoxic, lead-free, and organic-inorganic, is developed as a scintillator with good emission performance and radioluminescence intensity. These perovskite scintillators are synthesized at low temperatures in an aqueous acid solution, through which they generate a near-unity photoluminescence quantum yield of 98% with the excitation of ultraviolet light. As far as we know, this work is the first to show that the two-dimensional (2D) (CHNH)SnBr perovskite scintillator films prepared by coating a polymer layer can be applied to an X-ray imaging system. The results demonstrate that the low cost X-ray imaging device with good resolution and performance benefits dramatically from this lead-free organic-inorganic hybrid perovskite film. Therefore, this 2D-layered (CHNH)SnBr perovskite scintillator may be a high potential candidate for scintillating material for X-ray imaging techniques.