In-situ Crystallization of Ag Clusters in Polymer Matrices for X-ray Imaging.

We report the preparation of flexible scintillation films based on AgNSCH (Ag-R-4PTT) clusters formed by in-situ crystallization within a polymer matrix. The Ag-R-4PTT clusters exhibit thermally activated delayed fluorescence with a high photoluminescence quantum yield of 93.1%. Controlled crystallization yields microcrystalline clusters in poly(vinylpyrrolidone)/thermoplastic polyurethane matrices with excellent radioluminescence performance and high structural stability, leading to a light yield of 33 400 photons MeV and an X-ray detection limit down to 231 nGy s. The scintillation films retain high mechanical flexibility, optical transmittance, and water-resistance, achieving a spatial resolution of 21 lp mm for X-ray imaging. This study introduces a general strategy to stabilize Ag clusters via coordination engineering as well as in-situ crystallization, offering a promising platform for flexible radiation detection and high-resolution imaging.