A novel long persistent luminescent material CaGeO3: Tb3+ with photo-stimulation properties

In this paper, a novel green long afterglow material CaGeO3:Tb3+ was synthesized by high temperature solid phase method. According to the experimental results, CaGeO3:Tb3+ is a green long persistent luminescent (LPL) material with excellent performance. CaGeO3:Tb3+ shows LPL emission peak at 442, 490.9, 548.7, 588.5 and 623.8 nm, corresponding to 5D3 to 7F4 and 5D4 to 7FJ (J = 6, 5, 4, 3) transitions of Tb3+. Its CIE coordinates are (0.27, 0.50), indicating that the afterglow emission is close to the light of green region. In addition, after the excitation source is turned off, the afterglow time is longer than 90 min. After an interval of 7 h, the photo-stimulation luminescence (PSL) can be observed by using 980 nm laser cyclic excitation. The thermoluminescence (ThL) results show that there are three types of traps in the material and their depths are 0.666, 0.774 and 0.892 eV respectively, which are caused by the doping of Tb3+. All the results show that CaGeO3:Tb3+ is an excellent long afterglow luminescent material.