The Effects of Mn²⁺ Doping on the Luminescence Properties of 12CaO·7Al₂O₃:Eu²⁺ Nanocrystal Phosphor

The long lasting blue phosphorescence (LLP) and photostimulated luminescence (PSL) after ultraviolet light irradiation at room temperature in 12CaO·7Al₂O₃:xEu²⁺, yMn²⁺ (x = 0, 0.001; y = 0, 0.01) prepared by the chemical co-precipitation method were observed. It was shown that novel oxide 12CaO·7Al₂O₃:Eu²⁺, Mn²⁺ (C12A7:Eu²⁺, Mn²⁺) with unique nanocage structure can store energy when irradiated with 365 nm photons. And photon energy can be subsequently released by exposed to 980 nm light. The codopant Mn²⁺ enhances the intensity of the persistent phosphorescence and PSL due to the existence of more shallow and new deeper electron traps in C12A7: Eu²⁺, Mn²⁺. A model for energy storing and recovering and the detailed mechanism of PSL are presented through comparing with the luminescence properties of the co-doped C12A7:Eu²⁺, Mn²⁺ and C12A7:Eu²⁺.