Dual‐Heterovalent Codoping Enables Bright and Rapid X‐Ray Excited Persistent Luminescence for Noise‐Free 3D Imaging and Intelligent Detection

ABSTRACT Scintillator‐based X‐ray imaging is widely applied in medical diagnostics, security screening, and nondestructive evaluation. However, continuous irradiation inevitably generates scattered photons that degrade image quality, and it remains a major challenge to design intrinsically noise‐resistant imaging platforms. Here, we demonstrate that X‐ray‐excited persistent luminescence (XEPL) from scalable lanthanide‐doped SrFCl phosphors enables low‐dose, noise‐free delayed X‐ray imaging. Trace Ce 3+ incorporation creates an efficient trap–Ce–Tb energy transfer cascade, while Na + co‐doping increases trap density, yielding a 13.4‐fold enhancement in Tb 3+ XEPL. The system exhibits remarkable stability under repeated irradiation and after 80 days of ambient storage, outperforming the commercial SrAl 2 O 4 : Eu/Dy. Bright afterglow is achieved with only 5 s of X‐ray exposure, delivering a spatial resolution of 21.4 lp/mm. Delayed image acquisition permits extended camera integration without further irradiation, thereby eliminating scattering noise and enabling background‐free 3D reconstruction. Furthermore, we show that delayed imaging can be combined with machine learning for intelligent detection. This work addresses a fundamental limitation of real‐time X‐ray detection and offers a practical route toward high‐resolution, low‐dose, and intrinsically noise‐resistant imaging.