Storage effect in LiRESiO4:Ce3+, Sm3+, RE=Y,Lu phosphor

Good storage properties after irradiation have been observed in doubly rare-earth-doped LiRESiO4:Ce3+,Sm3+, RE=Y,Lu powders. We present strong arguments that in the studied materials Ce3+ ions play a role of hole trapping and Sm3+ ions of electron trapping centres. Additionally, oxygen vacancies are also involved in electron trapping, however they can be removed by appropriate thermal treatment. During thermal stimulation of irradiated LiRESiO4:Ce3+,Sm3+, RE=Y,Lu an electron from Sm2+ is released into the conduction band formed by SiO4 and further migrates to Ce4+ centers. This causes the TL peak at 340 K in LiLuSiO4:Ce3+,Sm3+ and at 400 K in LiYSiO4:Ce3+,Sm3+ upon heating rate of 1 Ks. Very fast and efficient photo-stimulated luminescence (PSL) have been observed upon stimulation with an IR laser (λ=830nm). The presented materials can be utilized in Image Plates for X-ray or neutron position sensitive detection.