Bismuth Vacancy-Induced Enhancement of Luminescence Intensity and Irradiation Resistance for Bi 4 Ge 3 O 12 .

Bi 4 Ge 3 O 12 (BGO) is a traditional scintillator, widely used in high-energy physics and nuclear medicine. However, it not only suffers from low scintillation intensity but also tends to be damaged by high-energy rays. Herein, we prepare pure-phase BGO materials enriched with Bi vacancies by rationally reduced Bi content, showing significantly enhanced luminescence intensity and irradiation resistance ability. The optimized Bi 3.6 Ge 3 O 12 shows 178% of luminescence intensity compared to BGO. After 50 h of ultraviolet irradiation, Bi 3.6 Ge 3 O 12 possesses ∼80% of original luminescence intensity, much superior to the 60% for BGO. The existence of the Bi vacancy is identified by advanced experimental and theoretical studies. The mechanism studies show the Bi vacancies could cause the symmetry destruction of the local field around the Bi 3+ ion. It enhances scintillation luminescence by increasing the probability of radiative transition while resisting nonradiative relaxation caused by irradiation damage. This study initiates vacancy-induced performance enhancement for inorganic scintillators.