Non-Hygroscopic, Self-Absorption Free, and Efficient 1D CsCuI Perovskite Single Crystal for Radiation Detection.

A novel all-inorganic CsCuI single-crystalline perovskite as a nonhygroscopic and efficient X-ray and γ-ray scintillator is described herein. It is featured by a one-dimensional (1D) perovskite structure with an orthorhombic system and a space group of . The CsCuI crystal emits yellow light peaking at 570 nm originated from strongly localized 1D exciton emission. It appears self-absorption free because of the large Stokes shift of 1.54 eV. The photophysics process of the self-trapped exciton was studied using temperature dependent photoluminescene spectra and decay kinetics measurements. The CsCuI crystal exhibits an extremely low afterglow level of 0.008% at 10 ms under X-ray excitation. Under Cs γ-ray irradiation, its light yield is 16 000 photons/MeV with an energy resolution of 7.8% at 662 keV.