Effect of Pr³⁺ on Site Preferences of Eu²⁺ in NaBaScSi₂O₇ and Its Optical Properties

Abstract

NaBaScSi2O7 with Eu2+ doped phosphors are prepared by high temperature solid state reaction. It is found that there are two different sites for Eu2+ occupied, which is responsible for different emission color of NaBaScSi2O7: Eu2+ with increasing Eu2+concentration. Pr3+ ions are introduced to regulate the Eu2+ ions occupied sites. When Pr3+ ions content climbs, conversion of blue to green emitting light can be realized because of the location migration of Eu2+ ions. Meanwhile, the defect structure of NaBaScSi2O7: Eu2+ has been adjusted by introducing Pr3+ ions, the shallow and deep traps generated benefits the long persistent luminescence (LPL) and photo-stimulated luminescence (PSL) phenomenon. It is interesting to note that NaBaScSi2O7: Eu2+, Pr3+ demonstrates different LPL and PSL color compared to NaBaScSi2O7: Eu2+. The controllable optical properties are realized on the basis of Eu2+ site preferences assisted by doping Pr3+, which provides guidance for the development of electron trapping materials.