不同形貌特征的YAG荧光粉的白光LED封装研究

Different morphologies of YAG phosphors in white LED packaging

采用蓝光芯片配合黄色的YAG荧光粉封装制成白光LED,详细研究了荧光粉的主波长对白光LED色坐标的影响,同时考量荧光粉混合浓度对光效、显色指数的影响。结果表明,随着荧光粉混合浓度的增加制得白光LED灯珠的X,Y色坐标可以回归成一条直线,主波长越短的荧光粉其回归直线斜率越大,回归直线相交于蓝光芯片的X,Y色坐标点。光效和显色指数均是随着荧光粉混合浓度的增加先增加再减少。

White LED was prepared by the blue LED chip coated with yellow YAG phosphors. The influences of pho- sphors dominating wavelength on the color coordinate of white LED was clearly discussed. The influence of the coating concentration on luminous efficacy and color rendering index were studied too. It was shown that the white LED was prepared by different coating concentration of YAG phosphors. The color coordinate X and Y of white LED returned to a straight line. The decreasing of phosphors dominating wavelength resulted in the rake ratio of the straight line got greater. These straight lines met the color coordinate of blue LED chip. The increasing of coating concentration result- ed in the luminous efficacy and color rendering index rose initially and decreased afterwards.