An Asymmetric D–A–D' Decoupling Strategy Enables Organic Scintillator‐Photocatalyst Integration for Temperature‐Adaptive and Conformal X‐Ray Imaging

ABSTRACT

High performance X‐ray imaging in extreme environments requires scintillators with robust luminescence across a wide temperature range. To address this, we propose an asymmetric “donor‐acceptor‐donor'” (D–A–D') decoupled strategy to integrate organic temperature‐adaptive scintillator and photocatalyst functionalities into a single molecule. This approach enables precise, temperature‐dependent regulation of intersystem crossing (ISC) and reverse intersystem crossing (RISC) to achieve phosphorescence at low temperatures and thermally activated delayed fluorescence (TADF) at ambient and elevated temperatures. The resulting scintillator maintains efficient and stable luminescence from 80 to 480 K. Particularly, its photocatalytic capability drives photopolymerization to in situ encapsulate itself within the polymer matrix, enhancing the scintillation performance. The transparent photocured films achieve conformal contact with targets, showing a low detection limit of 2.11 µGy s ⁻¹ (lower than the standard dosage of 5.5 µGy s ⁻¹ for X‐ray diagnostics) and spatial resolution exceeding 25 lp mm ⁻¹ at room temperature. Finally, we demonstrate its practical potential through variable‐temperature X‐ray imaging. This study extends the temperature‐adaptive operational range of organic scintillators, thereby facilitating the advancement of X‐ray imaging technologies for extreme‐environment applications.