Long lasting yellow phosphorescence and photostimulated luminescence in Sr₃SiO₅: Eu²⁺ and Sr₃SiO ₅: Eu²⁺, Dy³⁺ phosphors

We report the observation of long lasting yellow phosphorescence and photostimulated luminescence (PSL) in Sr₃SiO₅ : Eu ²⁺ and Sr₃SiO₅ : Eu²⁺, Dy ³⁺ phosphors. The decay patterns of phosphorescence and thermoluminescence curves demonstrate that introduction of Dy³⁺ into Sr₃SiO₅ : Eu²⁺ can generate a large number of shallow traps and deep traps. The generated deep traps prolong the phosphorescence up to 6 h after UV irradiation. The PSL is studied under 808 nm excitation. Slow rising and falling edges of the emission in Sr ₃SiO₅ : Eu²⁺, Dy³⁺ are observed, showing a retrapping process by the generated shallow traps due to co-doping Dy³⁺.