Ag doped Cs3Cu2Br5 scintillator for high-resolution X-ray imaging

Abstract

Copper halide scintillation materials with self-trapped exciton (STE) photoluminescence have attracted great interest in the field of optoelectronics. However, it is challenging for Cs₃Cu₂Br₅ materials to achieve wider spectral emission and high spatial resolution X-ray imaging in applications. Herein, combining XRD and energy dispersive spectroscopy results, it is proved that Ag⁺ is doped into the Cs₃Cu₂Br₅ lattice through an ion doping process, and PL is regulated from 460 nm to 543 nm. By density functional theory calculation, the band gap is reduced from 2.25 eV of Cs₃Cu₂Br₅ to 1.99 eV of Cs₃Cu₂Br₅:Ag, which is also consistent with the spectral redshift. The gradient study of the silver ion concentration from 5% to 35% shows that the best silver ion concentration is 25%. The experimental results show that the doped silver ions can improve the PL, PLE, PLQY, XEL and other properties of the material, such as the PLQY which increased from 27.38% to 90.62%. At the same time, Cs₃Cu₂Br₅:Ag also has good stability, it can be stored in air for 30 days, and its PL intensity remains at 90.73%. The X-ray space of the Cs₃Cu₂Br₅:Ag-UV scintillation film measured in a laboratory imaging system can reach 18.3 lp mm⁻¹.