Investigation on luminescence of bifunctional Y4.67(SiO4)3O:Ce3+/Tb3+/Eu3+ phosphors

To develop new luminescent materials for bitifunctional applications, a series of Ce3+/Tb3+/Eu3+ doped Y-4.67(SiO4)(3)O (YSO) phosphors were designed, and their morphology and spectra characteristics were studied in detail. The phase purity of the as-prepared samples was examined by Rietveld refinement and XRD patterns. Smooth surface of the particles was found although the particles are somewhat aggregated. Upon 355 nm excitation, the broad and intense emission of Ce3+ appeared, and the optimal Ce3+ doping concentration was determined to be 1 mol%. Two Ce3+ emission centers were analyzed by using Gaussian fitting. To tune the emission-color, the Ce3+-Tb3+ codoped samples were prepared, and white emission can be achieved when the Tb3+ concentration reaches 2% and 3% with the help of the energy transfer from Ce3+ to Tb3+. To obtain red emission, the Eu3+ activated YSO was designed, and the integrated intensity of YSO:25%Eu3+ is about 3.5 times as strong as that of the commercial Y2O3:Eu3+ phosphor. The above results demonstrate the potential applications of the phosphors in white LEDs. On the other hand, in the YSO:1%Ce3+,4%Tb3+ and YSO:6%Eu3+ samples, the fluorescence intensity ratio (FIR) technique was used to realize the temperature sensing performance. High sensitivities have been gained in these phosphors, and the corresponding mechanism was discussed in detail.