Boosting up color tunability of Sr2Ga2GeO7 by energy transfer between Dy3+ and Eu3+ ions

A series of Sr2Ga2GeO7 (SGGO) phosphors doped with Dy3+ and/or Eu3+ were synthesized using solid-phase reaction. The structure and luminescence properties of phosphors were studied. The XRD, FT-IR, SEM and XPS analysis show that the doping with trivalent Dy and Eu have no effect on the structure of the phosphor, and the feature emission of Dy3+ or Eu3+ was observed by photoluminescence investigation. Based on the spectral overlapping of the Dy3+ emission and Eu3+ excitation, there is an energy transfer from Dy3+ to Eu3+ in the Sr2Ga2GeO7. Under excitation at 344 nm, with the increment of Eu3+ concentration, the Dy3+ emission intensity was decreased and the emission lifetime was shortened, whereas the lifetime of Eu3+ was increased, confirming the energy transfer from Dy3+ to Eu3+. The resulting tunable orange emission has potential applications in plant growth.