Luminescence properties and energy transfer of Eu3+/Tb3+ co-doped glass ceramics containing Na3Gd(PO4)2

Tb3+-doped and Eu3+/Tb3+ co-doped transparent glass ceramics containing Na3Gd(PO4)(2) crystal phase were prepared by melt crystallization. The types of crystals, grain size, and optical transmittance of the samples were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), and UV visible absorption spectrometer. The effect of different heat treatment time on grain size, crystal morphology, and light transmittance was also studied. The luminescence performance of transparent glass ceramics was systematically studied by the excitation spectrum, emission spectrum, and the fluorescence lifetime. The optimal doping concentration of Tb3+ doped and Eu3+/Tb3+ co-doped were determined. When the mole percent concentration of Tb4O7 was 0.4%, the strongest green light was obtained at 546 nm (D-5(4) -> F-7(5)). Meanwhile, the energy transfer process between Eu3+ and Tb3+ was discussed. Under the excitation of 374 nm, white light can be obtained by adjusting the concentration ratio of Eu3+ and Tb3+.