Luminescent Properties Of NaLaBB’O₆ Phosphor For WLED

As new light sources for next generation illumination, white light-emitting diodes are commercially available and have been extensively developed due to its energy-saving, high luminous efficiency, compactness and long operational lifetime. The phosphors with AA’BB’O6 perovskite structure can be excited by365 nm ultraviolet chip and exhibit broad emission band in visible light region due to their excellent advantages.Rare earth ion doped complex perovskite-type Na La BB’O6(B= Mg, Zr; B’=W, Te, Zr) phosphors have been synthesized by solid state method and launch visible light emission. Their crystal structure, microstructure, CCT, CRI,excitation spectrum, emission spectrum and other performance parameters were investigated by X-ray diffraction(XRD), scanning electron microscope(SEM)and photoluminescence spectrum analysis system. Furthermore, the energy transfer probability in the host was discussed. The main work and results are as follows:(1) The Na La Mg WO6 phosphors were synthesized by solid-state method,their luminescent properties are discussed below. The results showed that setting sintering temperature at 1000 degree Celsius and three hours holding time makes excellent crystalline phase. The Na La Mg WO6: RE3+ phosphor can be excited effectively by NUV light. Doping rare earth ion has no influence on the structure of host. Average diameter of the powder vary from 2μm to 5μm. Na La Mg WO6:Eu3+, Na La Mg WO6: Dy3+ and Na La Mg WO6: Tb3+ phosphors exhibited red,yellow and green light emission separately at 615 nm, 575 nm and 544 nm.(2) The effect of activator concentration was investigated in this article.Quenching occurred when the concentration of activator in Na La Mg Te O6: Eu3+,Na La Mg Te O6: Dy3+ and Na La Mg Te O6: Sm3+ beyond specific value, The optimal doping concentration was 7%, 7%, 5%. The Na La Mg Te O6: 0.09Tb3+phosphor has high intensity and quantum efficiency. When the concentration of Dy3+ was coordinated to 0.01, we got the white devices with CIE coordinated at(0.3226, 0.3405), which was very close to the required ideal white color chromaticity coordinates(0.3333, 0.3333). The results indicated that phosphor Na La Mg Te O6: 0.01Dy3+ can be potentially matching with commercial UV-based LED chips.(3) Phosphors Na La Zr2O6: Tb3+ were synthesized by solid state reaction and the technical index and performance parameter were discussed in detail. The phosphor Na La Zr2O6: 0.03Tb3+ can exhibit broad emission band from 490 nm to625nm monitored at 365 nm, phosphors show intense emission predominated at545 nm and exhibited green light emission through optical lens effect.The perovskite-type phosphors in this article not only have excellent luminescent properties but got a good match with commercial LED chips.Therefore, it has great potential to applying these phosphors to WLEDs.