Ce3+ luminescence, near-UV excitation enhancement of Tb3+ emission via energy transfer in Y4Zn4(SiO4)5:Ce3+,Tb3+ phosphor for white LED application

Abstract

The luminescence property of phosphors plays an important role in the performance of phosphor-converted white light-emitting-diode (pc-WLED). In this paper, we report a simple energy-transfer (ET) strategy to enhance Tb3+ emission under near-UV excitation in Y4Zn4(SiO4)5 (YZS) doped with Ce3+/Tb3+ phosphor. The luminescence properties of YZS:Ce3+ based on crystal structure of YZS were investigated. The ET mechanism from Ce3+ to Tb3+ was also discussed in detail. The color of emitted light can be adjusted from blue to green by introducing Tb3+ ions into YZS:Ce3+. More importantly, the Tb3+ emissions under near-UV excitation are enhanced evidently, and the excitation spectrum for the Ce3+,Tb3+ co-doped phosphor matches well with the emission of near-UV chip. The selected green phosphor and commercial red, blue phosphors were coated on a 365-nm chip to fabricate a WLED device. The WLED shows an outstanding performance (Ra = 93.5 and CCT = 4769 K), indicating that YZS:Ce3+,Tb3+ phosphors have potential applications in near-UV pc-WLED as a green-emitting component.