Acceleration of exciton radiative recombination in Zn-alloyed 0D/3D heterostructure perovskite scintillators for efficient X-ray imaging

The increasing demand for more efficient and stable scintillators in X-ray imaging applications has spurred extensive research on lead-halide perovskites, particularly Cs-Pb-Br systems. Encapsulating 3D CsPbBr 3 in 0D Cs 4 PbBr 6 matrices represents a promising strategy for enhancing luminescence efficiency. However, persistent lead toxicity impedes clinical and industrial translation, while complex exciton dynamics in these heterostructures complicate scintillation optimization. Here, we develop a liquid-solid interface cation exchange (LSICE) strategy to synthesize Zn-alloyed Cs 4 PbBr 6 /CsPbBr 3 (0D/3D) heterostructures, achieving an enhanced scintillation performance with concurrent lead reduction of 60 %. Unmodified 0D/3D perovskites exhibit abundant paramagnetic Pb (III) defect states, which act as hole-trapping centers, impairing energy transfer from the 0D to 3D phase and causing delayed fluorescence, severe nonradiative recombination, persistent afterglow, and a low scintillation yield of 7423 photons/MeV. In contrast, Zn-alloyed 0D/3D perovskites substantially suppress Pb (III) defects, enabling efficient energy transfer, low afterglow emission, and accelerated excitonic radiative recombination. The optimized scintillator exhibits exceptional performance metrics, achieving a light yield of 13,326 photons/MeV, a spatial resolution of 10.3 lp/mm, and an ultra-low radiation detection limit of 22 nGy air /s. This work addresses the toxicity-performance trade-off in perovskites and establishes B-site alloying as a universal paradigm for designing eco-friendly, high-efficiency radiation detectors.