Mg(II)-Doped Perovskite-like Cs<sub>3</sub>Cu<sub>2</sub>I<sub>5</sub> Single Crystals with High Quantum Yield for Efficient X-ray Detection
Tong Wu, Yun Shi, Xuzhong Zuo, Mingyue Chen, Hongbing Ran, Shuwen Zhao, Junfeng Chen, Yiwen Tang
Abstract
Cs 3 Cu 2 I 5 halide perovskites doped with luminescence activators have unique optical and electronic properties; however, they tend to combine with slow scintillation decay, which leads to ghosting or blurriness during X-ray imaging. In this study, we produced magnesium (Mg 2+ )-doped Cs 3 Cu 2 I 5 single crystals (SCs) with blue emission at 440 nm, and the photoluminescence quantum yields ranged from 72.4 to 81.7%. Moreover, enhanced radioluminescence (RL) intensity and light output were achieved without deteriorating scintillation decay compared to those of pure Cs 3 Cu 2 I 5 SCs. Mg doping can strengthen electron–phonon coupling, and the emission (2.15 eV) at a low temperature (80–290 K) showed the presence of additional carrier capture channels of Mg-related defect levels in the band gap, which can help reduce the probability of nonradiative recombination. Therefore, flexible X-ray scintillator films with excellent hydrophobicity were fabricated using Mg 2+ -doped Cs 3 Cu 2 I 5 SC powders, and their spatial resolution (2.5 Lp/mm) met the resolution requirements of commercial spiral computed tomography. This study found an effective strategy for enhancing the self-trapped exciton emission of metal copper-based halide scintillators and highlighted their applicability in low-dose flexible X-ray detection and imaging.