Photoluminescence and Energy Transfer Properties with Y+SiO4 Substituting Ba+PO4 in Ba3Y(PO4)3:Ce3+/Tb3+, Tb3+/Eu3+ Phosphors for w-LEDs

A series of Ce3+, Tb3+, Eu3+ doped Ba2Y2(PO4)(2)(SiO4) (BYSPO) phosphors were synthesized via the high-temperature solid-state reaction route. X-ray diffraction, high-resolution transmission electron microscopy, Fourier transform infrared, solid-state NMR, photoluminescence (PL) including temperature-dependent PL, and fluorescent decay measurements were conducted to characterize and analyze as-prepared samples. BYSPO was obtained by the substitution of Y+SiO4 for Ba+PO4 in Ba3Y(PO4)(3) (BYPO). The red shift of PL emission from 375 to 401 nm occurs by comparing BYSPO:0.14Ce(3+) with BYPO:0.14Ce(3+) under 32 nm UV excitation. More importantly, the excitation edge cap be extended from 350 to 400 nm, which makes it be excited by UV/n-UV chips (330-410 nm). Tunable emission color from blue to green can be observed under 365 nm UV excitation based on the energy transfer from Ce3+ to Tb3+ ions after codoping Tb3+ into BYSPO:0.14Ce(3+). Moreover, energy transfer from Tb3+ to Eu3+ ions also can be found in BYSPO:Tb3+, Eu3+ phosphors, resulting in the tunable color from green to orange red upon 377 nm UV excitation. Energy transfer properties were demonstrated by overlap of excitation spectra, variations of emission spectra, and decay times. In addition, energy transfer mechanisms from. Ce3+ to Tb3+ and Tb3+ to Eu3+ in BYSPO were also discussed in Quantum yields and CIE chromatic coordinates were also presented: Generally, the results suggest their potential applications in UV/n-UV pumped LEDs.