Metal halide scintillators are promising for radiation detection, but their detection performance is limited by inadequate crystal quality and defect-mediated nonradiative recombination. Herein, we report an efficient strategy to overcome the existing limitations by incorporating trace Li+ into low-dimensional Rb2CuBr3 crystals. This approach modulates the crystallization kinetics and simultaneously induces lattice contraction and effectively suppresses grain-boundary defects, enabling a controllable crystal growth of Li-doped Rb2CuBr3 crystals from the micrometer to centimeter scale. X-ray-excited Li-doped Rb2CuBr3 crystals exhibited an ultrahigh light yield of 120,871 photons MeV-1, an excellent imaging resolution of 20 lp mm-1, and a favorable detection limit of 30 μGyair s-1. The breakthrough in luminescence efficiency originates from the unique kinetics of defects under high-energy irradiation; namely, a sharp increase in the exciton concentration effectively passivates nonradiative recombination channels. This study presents a method for preparing large-sized scintillation crystals and reveals a universal mechanism for surpassing intrinsic limits in the performance of Rb2CuBr3 scintillating materials via the regulation of defect states, offering promising pathways toward efficient materials for radiation detection.
Ding et al. (Thu,) studied this question.