以NH4H2PO4、SrCO3、Na2CO3、Li2CO3、ZnO、H3BO3和Sb2O3为原料,采用熔融淬冷和后续球磨制备磷酸盐玻璃粉体.将玻璃粉与 YAG: Ce 荧光粉均匀混合,利用二次熔融制得 YAG:Ce 块体荧光玻璃陶瓷.利用XRD、SEM、荧光光谱仪等研究玻璃陶瓷的相组成、显微结构和发光性能.结果表明:荧光粉均匀分布于玻璃基体中并得到很好地保存,没有发生化学分解反应.激发光谱在340 nm和460 nm处有两个激发峰.发射光谱在530 nm左右有一宽峰,属于Ce3+的5d→4f 特征跃迁发射.通过对不同熔融温度、不同荧光粉浓度和不同厚度的荧光玻璃陶瓷进行发光性能表征,发现最佳荧光粉掺杂浓度、最佳熔融温度和最佳样品厚度分别为8%(质量分数), 900 ℃和1.5 mm.该玻璃陶瓷封装蓝光芯片所得白光LED器件在540 mA 驱动下的发光效率为93.4 lm/W,色坐标为(0.306,0.331),色温为6867 K,显色指数为72.研制的玻璃陶瓷是一种可用于白光LED 的新型荧光材料.%The phosphate glass powders were synthesized by melting-quenching and subsequent ball milling method using NH4H2PO4, SrCO3, Na2CO3, Li2CO3, ZnO, H3BO3 and Sb2O3 as raw materials. After mixing the YAG:Ce phosphor with glass powder, bulk YAG:Ce fluorescence glass ceramics were obtained by melting again. The phase composition, microstructure and photoluminescence properties of glass ceramics were investigated by XRD, SEM and fluorescence spectrophotometer. The results show that the Ce:YAG phosphor particles are uniformly distributed and well preserved in glass matrix without any decomposition reaction. The excitation spectra have two excitation bands at 340 nm and 460 nm. The broad emission peaks at about 530 nm can be attributed to 5d→4f transition of Ce3+ ion. The photoluminescence properties of glass ceramics with different melting temperatures, various Ce:YAG concentration and different thickness were characterized, indicating that the optimal Ce:YAG phosphor concentration, melting temperature and thickness is 8% (mass fraction), 900 C and 1.5 mm, respectively. Under driving current of 540 mA, the luminous efficiency of the white LED packaged by the as-prepared glass ceramic and blue LED chip is 93.4 lm/W, and its color coordinate (CIE), color temperature (CCT) and color rendering index (CRI) are (0.306, 0.331), 6867 K and 72, respectively. These results show that the as-prepared glass ceramic is a new fluorescent material for white LEDs.
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