Improved photoluminescence properties of a new green SrB2O4:Tb3+ phosphor by charge compensation

A new green-emitting SrB2O4:Tb3+ phosphor was synthesized by solid-state reaction. X-ray powder diffraction (XRD) analysis confirmed all the samples with orthorhombic formation of SrB2O4. The excitation spectra indicate the phosphor can be effectively excited by near ultraviolet (NUV) light, making it attractive as conversion phosphor for LED applications. The phosphor exhibits a bright green emission with the highest photoluminescence (PL) intensity at 544 nm excited by 378 nm light. The critical quenching concentration of Tb3+ in SrB2O4:Tb3+ is about 10 mol%. The effects of charge compensators (Li+, Na+, and K+) on photoluminescence of SrB2O4:Tb3+ were also studied. The results show that the emission intensity can be improved by all the three charge compensators and Na+ is the optimal one for SrB2O4:Tb3+. All properties show that the phosphor is a promising green phosphor pumped by NUV InGaN chip for fabricating white light-emitting diodes (WLEDs).