Ultrabright and Highly Efficient All‐Inorganic Zero‐Dimensional Perovskite Scintillators

Low-dimensional halide perovskites with excellent luminescent properties have become leading candidates for optoelectronic and radiation-detection applications. In this work, Tl cation is incorporated into 0D perovskite Cs3Cu2I5 host and an ultrabright and efficient scintillator is developed for X-ray and gamma-ray detection. The Tl-doped Cs3Cu2I5 crystals exhibit a high photoluminescence quantum efficiency of 79.2%. The radioluminescence emission of Cs3Cu2I5:Tl crystal under X-ray excitation consists of a self-trapped exciton emission at 440 nm and a Tl-related emission at 510 nm at room temperature. With optimized Tl doping, the Cs3Cu2I5 not only demonstrates about five-times enhanced steady-state scintillation yield up to 150 000 photons/MeV and an improvement of X-ray detection limit from 103.6 to 66.3 nGy s(-1), but also maintains an extremely low afterglow of 0.17% at 10 ms after X-ray cut-off. The Cs3Cu2I5:Tl also possess a remarkable energy resolution of 3.4% at 662 keV and an ultrahigh light yield of 87 000 photons/MeV under Cs-137 gamma-ray radiation.