A highly efficient Na-doped Cs3Cu2I5 scintillator for γ-ray detection and flexible X-ray imaging

As a novel lead-free perovskite derivative material, zero-dimensional Cs3Cu2I5 crystals exhibit remarkable optical properties and hold great application prospects in the field of radiation detection. To further enhance the scintillation performance and detection efficiency, we fabricated high-quality, centimeter-level Cs3Cu2I5:Na+ single crystals using a low-cost anti-solvent method. Na+ doping in the Cs3Cu2I5 lattice optimizes the photoluminescence quantum yield (PLQY) to 95%, which can be attributed to enhanced exciton–phonon coupling and boosted self-trapped exciton fraction. Compared to the intrinsic crystal, the energy resolution and light yield of Cs3Cu2I5:5%Na+ under 137Cs γ-rays are improved by 22% and 10.5%, respectively. Under X-ray excitation, Cs3Cu2I5:5%Na+ crystals exhibit stronger RL intensity, faster response speed, lower afterglow and lower detection limit. Based on excellent X-ray detection capability, a breakthrough spatial resolution of 25.6 LP per mm@MTF = 0.2 is achieved for the Cs3Cu2I5:5%Na+@PMMA flexible film. Cs3Cu2I5:Na+ crystals boast superior optical performance, exceptional detection capabilities, cost-effectiveness and eco-friendliness, rendering them a highly competitive candidate for high-resolution γ-ray detection and flexible X-ray imaging.