Study On Photoluminescence Properties Of White LED With Green Borate Phosphor

White LED is considered to be the21st century’s most valuable new light source due to several advantages such as high luminescence efficiency, low synthetic temperature and high stability.A series of stable green phosphor (R, Tb3+)xBa1-2xB2O4(R=Li+, Na+, K+),(R, Tb3+) xSr1-2xB2O4(R=Li+, Na+, K+),(R, Tb3+) xZn1-2xB2O4(R=Li+, Na+, K+) and BaAl2B2O7:Tb3+with high luminescence efficiency, low synthetic temperature and high stability was prepared by high-temperature solid-phase method process. XRD and SEM characterize its structure. The factors of their luminescent properties, such as concentration of Tb3+and charge-compensating agent were studied.Phosphor of BaB2O4:Tb3+was prepared by conventional solid-state reaction. With XRD and SEM to characterize its structure shows that the resulting product is the target product BaB2O4:Tb3+. Its photoluminescence properties were investigated. The emission spectrum of BaB2O4:Tb3+excited by378nm NUV light. There are four major emission peaks at488,544,587and621nm, which are attributed to the5D4â†'7F6,5D4â†'7F5,5D4â†'7F4and5D4â†'7F3typical transitions of Tb3+, respectively. The strongest emission peak appears at544nm. The excitation spectrum of BaB204:Tb3+monitored at544nm. The excitation spectrum is composed of a series of sharp lines including the peaks of318,352,370and378nm (7F6â†'5Dj,5Gj,5L10and5D3). The critical quenching concentration of Tb3+in BaB2O4:Tb3+phosphor is about4mol%. Na+is the optimal charge compensator to increase the luminescent intensity of BaB2O4:Tb3+.Phosphor of SrB2O4:Tb3+was prepared by conventional solid-state reaction. With XRD and SEM to characterize its structure shows that the resulting product is the target product SrB2O4:Tb3+. Its photoluminescence properties were investigated.The phosphor SrB2O4:Tb3+exhibits bright green emission at378nm NUV light excitation. The strongest emission peak appears at544nm. The critical quenching concentration of Tb3+in SrB2O4:Tb3+phosphor is about10mol%. Na+is the optimal charge compensator to increase the luminescent intensity of SrB2O4:Tb3+Phosphor ZnB2O4:Tb3+was prepared by conventional solid-state reaction. With XRD and SEM to characterize its structure shows that the resulting product is the target product ZnB2O4:Tb3+. Its photoluminescence properties were investigated. The phosphor ZnB2O4:Tb3+exhibits bright green emission at378nm NUV light excitation. The emission spectrum of ZnB2O4:Tb3+have four major emission peaks at488,544,587and621nm, which are attributed to the5D4â†'7F6,5D4â†'7F5,5D4â†'7F4and5D4â†'7F3typical transitions of Tb3+, respectively. The strongest emission peak appears at544nm. The charge compensations of Na+and K+increase the luminescent intensity of ZnB2O4:Tb3+. Especially, K+is the optimal charge compensator. Li+brings a negative effect.Phosphor of BaAl2B2O7:Tb3+was prepared by conventional solid-state reaction. With XRD and SEM to characterize its structure shows that the resulting product is the target product BaAl2B2O7:Tb3+. Its photoluminescence properties were investigated. The phosphor BaAl2B2O7:Tb3+exhibits bright green emission at378nm NUV light excitation. The emission spectrum of BaAl2B2O7:Tb3+have four major emission peaks at488,543,584and625nm, which are attributed to the5D4â†'7F6,5D4â†'7F5,5D4â†'7F4and5D4â†'7F3typical transitions of Tb3+, respectively. The strongest emission peak appears at544nm. The excitation spectrum of BaAl2B2O7:Tb3+monitored at544nm The excitation spectrum is composed of the peaks of318,352,370and378nm.