以硼酸和碱土氟化物作为助熔剂,调整助熔剂比例和组分,采用高温固相法合成一系列白光LED用YAG∶Ce3+发光材料.采用XRD、扫描电镜(SEM)和荧光光谱(PL)等对样品进行表征.研究表明,合适的助熔剂有助于降低样品的烧结温度,不会有杂相产生,加入不同浓度和成分的助熔剂对样品的发射、激发光谱形状和峰值波长位置无影响,但对发光强度影响较大；采用助熔剂质量分数为0.4％(0.2％H3BO3-0.2％BaF2)时.所合成样品的颗粒比较均匀,发光性能的增强最为有效.将其和蓝光Ga(In)N芯片封装成白光LED,光效也得到显著提高.封装后白光LED的色坐标为(0.3341,0.4190),色温为5470K,显色指数为67,光效可达到78.3lm/W,高于其它条件合成荧光粉封装的白光LED.%A series of YAG : Ce3+ phosphors were synthesized by the high-temperature solid-state reaction under a reduction atmosphere. The influence of flux on the optical properties of YAG : Ce3+ phosphor was investigated in details. The powder samples were characterized by X-ray powder diffraction and scanning electron microscope (SEM). The photoluminescence emission and excitation spectra were also studied. And the conclusions can be obtained from the investigation that the flux can help YAG : Ce3+ phosphors to crytallize, and no other phases are formed; 0. 2% BaF2 and 0. 2% H3BO3 added together as flux can enhance the intensity of excitation and emission spectra of YAG : Ce3+ phosphors. And it can be obtained that the particle size and size distribution of the phosphor are suitable for the application of white LEDs. Furthermore, white LEDs with high luminous efficiency can be obtained by these phosphors and the blue Ga(In)N chip. The chromaticity eoordinate(x, y), the correlated color temperature Tc, and the color rendering index R8, were calculated to be(0. 3341, 0. 4190), 5470K, and 67, respectively. The luminous efficiency of the fabricated LEDs can reach 78. 31m/W, which are higher than those of other phosphors.
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