以Sr3N2、Eu2O3、AlN和Li3N为原料, 利用高压氮化烧结制备了系列高显色LED用红色荧光粉(Sr0.96,Eu0.04)LiAl3N4。通过XRD、SEM图像和激发发射光谱研究了不同Sr3N2用量、不同助熔剂对荧光粉颗粒和发光性能的影响。XRD及XRD Rietveld精修结果表明, 1.3倍Sr3N2原料所得的粉体具有更纯的晶相, 此时发光强度达到最大。研究了分别以氯化物和氟化物作为助熔剂对烧结粉体发光效果以及颗粒形貌的影响, 结果表明LiCl和NH4F的助熔效果较好。将LiCl和NH4F作为组合助剂, 研究了不同组合比例对荧光粉发光性能的影响, 实验确定组合比例为1∶1时可得到颗粒分散性较好的窄谱带红光荧光粉, 发光强度比未使用助熔剂时提高了近4倍。红色荧光粉(Sr0.96,Eu0.04)LiAl3N4粉体与GAG535绿粉组合进行4 000 K白光封装测试, 结果表明该器件具有较高的发光效率, 显色指数Ra高达91.9, 适用于高显色指数的封装方案。

(Sr0.96,Eu0.04)LiAl3N4 red phosphor for high color rendering LED was prepared using Sr3N2, Eu2O3, AlN and Li3N as raw materials by high pressure nitrogenize sintering method. The effects of Sr3N2 proportions and different fluxes on morphology and luminescence properties of phosphors were analyzed by scanning electron microscope(SEM), X-ray diffraction(XRD), excitation and emission spectrum. XRD patterns and XRD Rietveld refinement showed that the 1.3 times Sr3N2 material has better luminescent intensity and more pure phase state. The influence of the chlorides and fluorides fluxes on the morphology and luminescent properties was also discussed. NH4F and LiCl had better fluxing effect and they were selected as mixed fluxes. The effects of different proportions of the mixed fluxes on the luminescent properties of the phosphors were studied in detail. The experimental results showed that the phosphor had the better particle morphology and the luminescent intensity was increased by nearly 4 times when the combination ratio of NH4F and LiCl was 1∶1. White LED(4 000 K) was prepared by combining with (Sr0.96,Eu0.04)LiAl3N4 and GAG535 green phosphor and the results indicated that this LED has higher luminous efficiency and higher Ra, which was more suitable for high color rendering index white LED.