Enhanced afterglow performance of Zn2SiO4:Mn2+ by Pr3+ doping and mechanism

High luminescence intensity and long persistent duration is desired for practical application of long persistent materials. But it still remains challenging due to insufficient phosphors to meet the commercial request and a general lack of understanding of luminescence mechanism. In this work, green persistent luminescent phosphor Zn2SiO4:Mn2+,Pr3+ was first synthesized by traditional solid-state reaction method with self-made SiO2 submicrospheres as silicon source. The morphology, crystal structure, photoluminescence and the long afterglow performance have been investigated systematically. Interestingly, the longest persistent luminescence is observed for 0.025 Mn2+, 0.001 Pr3+ co-doped Zn2SiO4 with a persistent time of ~2640 s at (0.32 mcd/m(2)), which is 20 times longer than those of Zn2SiO4 host or single Mn2+ doped Zn2SiO4 phosphors. The possible persistent mechanism has been discussed. The finding will be beneficial for developing persistent phosphors with superior functionalities.