Radiation stability and defect characteristics of CsPbBr3 perovskite crystals for room temperature radiation detection

Abstract

The radiation stability of CsPbBr3 perovskite crystals is essential for their utilization in radiation detection at room temperature. This study investigates the impact of high dose 60Co γ-ray irradiation on defect characteristics in CsPbBr3 perovskite crystals and highlights their radiation stability. An emphasis is placed on the origins of defects and mechanisms of charge transport. Radiative recombination due to free and trapped/bound excitons, as well as band tailing associated with point defects and structural disorder, were determined based on (PL) analysis. Thermally stimulated current (TSC) spectroscopy revealed a range of trap levels between 0.14 and 0.64 eV (in the temperature range of 77–300 K) in both the reference and irradiated samples. In addition, the TSC analysis revealed good retention of the low concentrations of cesium and bromine vacancies, as well as lead interstitials, with total concentrations of ∼9.09 × 1012 per cm3 for the reference sample and a slightly lower value of ∼7.27 × 1012 per cm3 for the 60Co γ-irradiated sample. Despite the presence of these defects, no significant changes were observed in energy resolution or the hole mobility-lifetime product. The apparent stability of trap concentrations following 1 Mrad 60Co γ-irradiation is indicative of the material’s radiation hardness. The findings demonstrate that the intrinsically low defect concentrations in CsPbBr3 are not severely affected by high dose 60Co γ-ray irradiation, positioning it as a compelling candidate for advanced radiation detectors and other optoelectronic applications.