白光LED用Phosphor-on-Glass(PoG)材料的制备与表征

采用商业Ce^3+∶YAG荧光粉包埋钇铝硅酸盐玻璃并在该体系玻璃转变温度附近进行烧结的方法,成功制备了荧光粉粘附在玻璃表面上的复合材料(Phosphor-on-Glass,PoG)。利用XRD、SEM和荧光光谱仪等研究了PoG材料的物相、显微结构和变温发光性能。研究结果表明:PoG材料结构为荧光粉/玻璃/荧光粉复合体,Ce^3+∶YAG荧光粉粘附在玻璃上下表面且均匀分布,其形貌与颗粒大小未发生明显变化。固定烧结时间为10h,PoG材料的荧光强度随着烧结温度的增加先增强后减弱;PoG材料的发光抗热淬灭性能较好(热激活能为0.22eV),这说明Ce^3+∶YAG荧光粉的优良发光性能在PoG材料中得到了很好地保存。以PoG材料封装的白光LED样品在100mA电流驱动下,获得白光输出,其中最接近纯白光(0.33,0.33)的LED光效为69.8lm/W,相关色温为5873K,显色指数72.3。由于Ce^3+∶YAG荧光粉缺乏红色发光,尝试在钇铝硅酸盐玻璃基质中掺杂Eu3+以增加红色发光部分,获得光效为52.1lm/W,相关色温为3910K,显色指数75.8的暖白光输出。

Preparation and Characterization of Phosphor-on-Glass(PoG) Materials for White LEDs

The Phosphor-on-Glass(PoG)composite materials were successfully prepared by embedding yttrium aluminosilicate glasses with commercial Ce^3+∶YAG phosphor and sintering near the glass transition temperature.The phase,microstructure and temperature-dependent luminescence properties of PoG materials were studied by XRD,SEM and fluorescence spectrometer.The results show that the structure of PoG is phosphor/glass/phosphor composite.The distributed Ce^3+∶YAG phosphor adhere to the upper and lower surfaces of the glasses.The morphology and particle size of the Ce^3+∶YAG phosphor maintain original.The fluorescence intensity of PoG material increases first and then decreases with the increase of sintering temperature with 10 h sintering time.The luminescence thermal resistance of PoG material is good(the thermal activation energy is 0.22 eV),which indicates that the excellent luminescent properties of Ce^3+∶YAG phosphors are well preserved in PoG materials.The white LED sample packaged in this PoG material is driven by a 100 mA current to obtain a white light output.The closest LED light with pure white light(0.33,0.33)is 69.8 lm/W,the correlated color temperature is 5873 K,and the color rendering index is 72.3.Due to the lack of red luminescence of Ce^3+∶YAG phosphor,Eu^3+doped yttrium aluminosilicate glass were utilized for PoG materials.This result in warm white light output,the light efficiency is 52.1 lm/W,the correlated color temperature is 3910 K,and the color rendering index is 75.8.