Luminescence and energy transfer of color-tunable Tb3+/Sm3+co-doped BaZn2(PO4)2 glass-ceramic phosphors

Abstract

The color-tunable phosphors can be obtained by co-doping strategy and energy transfer regulation. In this work, Tb3+ and Sm3+ co-doped BaZn2(PO4)2 glass-ceramic (GC) phosphors are prepared and their structural, optical and luminescent properties are characterized. By adjusting the doping concentration of Sm3+, The luminescent color of BaZn2(PO4)2 GC: Tb3+/Sm3+ Phosphors ranges from green to light green to yellow-green and finally to yellow. The photoluminescence (PL) spectra and fluorescence decay curves confirmed the energy transfer from Tb3+ to Sm3+, and the energy transfer efficiency (η) increased monotonically with the increase of Sm3+ concentration. Moreover, the energy transfer mechanism from Tb3+ to Sm3+ in BaZn2(PO4)2 GC is a dipole-dipole interaction. The typical BaZn2(PO4)2 GC: 0.75 Tb3+/0.75Sm3+ phosphor has a high thermal stability with an activation energy determined to be 0.29525 eV. Coupling BaZn2(PO4)2 GC: 0.75 Tb3+/0.75Sm3+ Phosphors with commercially available ultraviolet light-emitting diodes (UV-LEDs) chips yields luminescent color coordinates of (0.3965, 0.4253) and a color correlation temperature of 3927 K, close to warm white light emission. These results indicated that the Tb3+ and Sm3+ co-doped BaZn2(PO4)2 GC achieved luminescence color modulation, which has potential applications in UV-converted LEDs and other optical devices.