Synthesis and luminescence properties of Dy3+ and Tb3+ doped Y2Mg3Ge3O12 phosphors with excellent thermal stability and color tunable emission

A series of Y2-x-yMg3Ge3O12: xDy(3+), yTb(3+) samples were manufactured by high temperature solid phase method. XRD test and Rietveld refinement clarified the phase purity of the samples. When the excitation wavelength is 352 nm, the energy transfer efficiency is 57.74%, and q-q interaction is the main energy transfer mechanism of Dy3+-Tb3+ co-doped samples. In addition, we tested the thermal stability of Y1.94Mg3Ge3O12:0.05Dy(3+), 0.01 Tb3+ sample, and found that its luminous intensity at 423 K could still reach 93.86% of that at 303 K. By changing the concentrations of Tb3+, the luminescent color of the samples could also be changed from blue-white light to yellow-green light. These results indicate that Y2Mg3Ge3O12 co-doped with Dy3+ and Tb3+ is expected to be applied in the field of white light LEDs.