发光学报, 2013, 34 (2): 133, 网络出版: 2013-02-26
白光LED用新型MgAl2O4/Ce∶YAG透明陶瓷的发光性能
Luminescent Properties of New MgAl2O4/Ce∶YAG Transparent Ceramics for White LED Applications
摘要
采用金属醇盐法制备MgAl2O4前驱体, 通过高温煅烧2~4 h得到纯相MgAl2O4粉体, 再将其与YAG∶Ce荧光粉均匀混合, 利用热压烧结并结合热等静压处理得到MgAl2O4/Ce∶YAG透明陶瓷。 利用X射线衍射、紫外-可见分光光度计等测试手段对样品进行表征。样品由MgAl2O4和YAG两相组成, 在340 nm和475 nm有两个激发峰。发射光谱在533 nm有一宽峰, 属于Ce3+的5d→4f特征跃迁发射。该透明陶瓷封装蓝光芯片所得白光LED器件在35 mA驱动下的发光效率为133.47 lm·W-1, 其寿命及色温稳定性优于采用传统方式封装的白光LED。实验结果表明MgAl2O4/Ce∶YAG透明陶瓷是一种可用于白光LED的新型荧光材料。
Abstract
High-purity ultrafine MgAl2O4 powder was synthesized by metal-alkoxide method and calcining for 2~4 h.After mixing the YAG∶Ce phosphor with MgAl2O4 powder, MgAl2O4/Ce∶YAG transparent ceramics were obtained by hot-pressed sintering and hot isostatic pressed sintering technique. The transparent ceramics were characterized by X-ray diffraction and UV-Vis spectrometer. The crystal phase of the transparent ceramic was composed of MgAl2O4 and YAG. The excitation spectra had a weak band at 345 nm and a strong band at 475 nm. The broad emission peaks at about 533 nm can be attributed to 5d→4f transition of Ce3+ ions. The luminous efficacy of the white LED which packaged by the transparent ceramic and blue LED chip was 133.47 lm·W-1 at 35 mA, and its color temperature are not varied with the change of driving current. It had better performance in stability and lifetime than that packaged in traditional ways under the same condition. All results show that MgAl2O4/Ce∶YAG transparent ceramic may be a promising fluorescent material for white LEDs.
贺龙飞, 范广涵, 雷牧云, 娄载亮, 郑树文, 苏晨, 肖瑶, 陈志武, 张涛. 白光LED用新型MgAl2O4/Ce∶YAG透明陶瓷的发光性能[J]. 发光学报, 2013, 34(2): 133. HE Long-fei, FAN Guang-han, LEI Mu-yun, LOU Zai-liang, ZHENG Shu-wen, SU Chen, XIAO Yao, CHEN Zhi-wu, ZHANG Tao. Luminescent Properties of New MgAl2O4/Ce∶YAG Transparent Ceramics for White LED Applications[J]. Chinese Journal of Luminescence, 2013, 34(2): 133.