Phosphorescence properties and energy transfer of red long-lasting phosphorescent (LLP) material β-Zn₃(PO₄)₂:Mn²⁺,Pr³⁺

The red long-lasting phosphorescent (LLP) of β-Zn₃(PO₄)₂:Mn²⁺,Pr³⁺ material was prepared through combustion and conventional solid-state sintering methods. The influence of Pr³⁺ ions on luminescence and LLP of Mn²⁺ in β-Zn₃(PO₄)₂:Mn²⁺,Pr³⁺ phosphor was systematically investigated. The phosphor presented a strong photoluminescence peak at 620 nm attributed to the ⁴T1g→ ⁶A1g transition of Mn²⁺ ions in octahedral coordination. Red LLP was observed in β-Zn₃(PO₄)₂:Mn²⁺,Pr³⁺ phosphors with persistence time for more than 2 h. It was found that the long persistent phosphorescent performance of Mn²⁺ such as brightness and duration was improved by the energy transfer from Pr³⁺ to Mn²⁺ when Pr³⁺ ions as sensitizers were doped into matrix. The fact that the TL peak at low temperature was largely enhanced in Mn²⁺, Pr³⁺ codoped β-Zn₃(PO₄)₂ phosphor showed the significant increase of defect concentration with suitable depth. There existed two factors working together to be responsible for the enhancement of LLP performance in β-Zn₃(PO₄)₂:Mn²⁺,Pr³⁺.