High-Performance and Stable b-PBD/Perovskite Liquid Scintillators for X-ray Imaging

Perovskite nanocrystals (PNCs) are emerging as promising scintillator materials owing to their high photoluminescence quantum yield (PLQY) and substantial X-ray absorption coefficient, among other superior properties. Nevertheless, their solid-state films encounter challenges such as limited environmental stability and nonuniform deposition over large areas. In contrast, liquid scintillators present advantages including superior radiation hardness, environmental stability, morphological flexibility, and cost-effective scalability, positioning them as a viable alternative. However, a significant limitation remains: PNCs demonstrate markedly reduced scintillation efficiency in solution. To address this issue, we propose an organic-inorganic hybridization strategy. The surface hybridization of metal halide perovskite CsPbX₃ (X: Cl, Br, I) nanocrystals (NCs) with the organic molecule b-PBD results in a new generation of efficient and low-cost liquid scintillators. This hybrid system substantially enhances the X-ray radioluminescence quantum yield, achieving a light yield that represents an 18.59-fold increase over that of pristine CsPbBr₃ solutions. The composite exhibited remarkable stability, retaining high luminescence intensity after high-dose X-ray irradiation and maintaining robust fluorescence intensity with stable emission peaks following prolonged ambient exposure. X-ray photoelectron spectroscopy (XPS) and density-functional theory (DFT) analyses confirmed N-Pb bond formation, revealing an enhancement mechanism driven by X-ray-induced directional electron transfer from the organic molecule to PNCs. We have further demonstrated a CsPbBr₃/b-PBD liquid X-ray imager showing a high spatial resolution of 4.9 lp/mm. This strategy demonstrates universal enhancement across CsPbX₃ variants and lead-based PNCs (e.g., Mn: CsPbCl₃, Ni: CsPbBr₃), facilitating low-dose radiation detection for fundamental science and diverse imaging applications.