Tailoring High‐Temperature Co‐Precipitation Synthesis of Nanoscintillators for High‐Performance Dynamic X‐ray Imaging

The development of scintillators that combine strong X‐ray excited optical luminescence (XEOL) with minimal afterglow is pivotal for advancing dynamic X‐ray imaging applications. Herein, we report a facile strategy for the simultaneous optimization of scintillation properties in NaLuF 4 :Tb/Gd nanoscintillators (NSs) through precise control of co‐precipitation temperature. Elevating the reaction temperature from 300°C to 320°C yields a monotonic enhancement in XEOL intensity along with a significant reduction in X‐ray excited persistent luminescence (XEPL). This synergistic effect is attributed to temperature‐induced improvement in crystallinity and a substantial decrease in the number of charge‐trapping defects. The optimized NaLuF 4 :Tb/Gd NSs were fabricated into a flexible composite film, which exhibits excellent stability and enables high‐resolution (14.1 lp mm −1 ) dynamic X‐ray imaging. This work provides a scalable pathway for optimizing scintillation yield while suppressing afterglow in fluoride NSs.