Green and red long lasting phosphorescence (LLP) in γ-Zn3(PO4)2:Mn2+/Ga3+

Green and red long lasting phosphorescent (LLP) phenomenon in γ-Zn3(PO4)2:Mn2+/Ga3+was systematically investigated. Two emission bands are observed in γ-Zn3(PO4)2:Mn2+/Ga3+, which are respectively centered at 507 nm and 620 nm. The green and the red long afterglow have been observed after removing the ultraviolet light. The spectral overlap between the green emission band and the excitation band monitored at 620 nm, which supports the feasibility of the energy transfer from Mn2+ (CN = 4) to Mn2+ (CN = 6), has been studied. The distribution of Mn2+ ions in tetrahedral and octahedral lattice changes with the incorporation of Ga3+ ions. The ratio of the green to the red enhances because of the increase of Ga3+ concentration. With the introduction of Ga3+, the color of the afterglow has been regulated, and the performance has been improved.

► We have found the color-tunable long lasting phosphorescent phenomenon of γ-Zn3(PO4)2:Mn2+,Ga3+.
► The distribution of Mn2+ ions in tetrahedral and octahedral lattice changes with the incorporation of Ga3+ ions.
► Both of the red and green afterglow performances from Mn2+ are largely improved by co-doping with Ga3+ ions.
► Ga3+ not only acts the role of adjusting the ratio of the green/red luminescent center but also acts as an electron trap.