Synthesis and Luminescent Properties of Tb/Eu Co-doped Zinc Borophosphate Glasses for White Light Generation

Tb /Eu co-doped zinc borophosphate glasses were successfully synthesized by melt quenching method.The effect of glass matrix composition and rare erath ions concentration were discussed.The structural and luminescent properties were characterized by Fourier transform infrared(FT-IR) spectra,absorption spectra,photoluminescence(PL) spectra,fluorescence lifetimes and colorimetric analysis.Eu3+ ions were partly reduced to Eu2+ during the synthesization in air.Under380 nm excitation,white light emission was observed composited by emission at 612 nm and 590 nm for Eu3+,544 nm and 488 nm for Tb3+,and 430 nm for Eu2+.The FT-IR spectra showed that the structure of glass matrix changed when B2O3 content increased,which affected the Eu2+/Eu3+ ratio in glass samples.The spectra results show that Eu2+ ions are donors which can transfer energy to Eu3+ and Tb3+.Lifetime analysis proved that Tb3+ions can transfer energy to Eu3+through nonradiative transition.The luminescence intensity and emission color can be efficiently controlled by changing glass composition and rare earth ion concentration.Optimized white light with CIE(0.318 7,0.286 1) and correlated color temperature at 6 480 K was obtained when the mole fractions of Eu and Tb were both 1.5%.