Luminescence of SrGdGa3O7:RE3+(RE = Eu, Tb) phosphors and energy transfer from Gd3+ to RE3+

Eu3+- and Tb3+-activated SrGdGa3O7 phosphors were synthesized by the solid-state reaction and their luminescence properties were investigated. Sr(Gd1 − xEux)Ga3O7 and Sr(Gd1 − xTbx)Ga3O7 formed continuous solid solution in the range of x = 0–1.0. Unactivated SrGdGa3O7 exhibited a typical characteristic excitation and emission of Gd ion. The SrGdGa3O7:xEu3+ and SrGdGa3O7:xTb3+ phosphors also showed the well-known Eu3+ and Tb3+ excitation and emission. The energy transfer from Gd3+ to Eu3+ and Tb3+ were verified by photoluminescence spectra. The dependence of photoluminescence intensity on Eu3+ and Tb3+ concentration were also studied in detail and the photoluminescence (PL) intensity of SrGdGa3O7:Eu and SrGdGa3O7:Tb were compared with commercial phosphors, Y2O3:Eu and LaPO4:Ce,Tb. The luminescence decay measurements showed that the lifetimes of Eu3+ and Tb3+ were in the range of microsecond. The energy transfer from Gd3+ to Tb3+ was also observed in decay curve.