白光LED用YAG:Ce3+荧光粉的增红

目前白光LED在红光波段发射较弱,导致其显色指数偏低,本文在最常用的白光LED荧光粉Y3Al5O12:Ce3 (YAG:Ce3 )中掺入Gd3 、Pr3和Sm3 ,来增强红光波段的发射,从而提高显色指数.用X射线衍射仪(XRD)、分光光度计、光谱分析仪及荧光粉相对亮度测试仪对样品进行表征,研究了Gd3 、Pr3 和Sm3 对荧光粉性能的影响,并对其增红机理进行了初步的探讨.结果表明:Gd3 、Sm3 及Pr3 的加入都增强了光谱的红区发射,Gd3 使光谱发生红移;Sm3 则在光谱上增加了峰值分别位于566、600和616nm的三个弱发射峰;Pr3 在光谱的红区发射区叠加了一个峰值在610nm的尖锐发射峰;Gd3 、Sm3 及Pr3 的加入,使样品相对亮度及发光强度都下降了一定程度.

Enhancement of Red Emission on YAG:Ce3+ Phosphors for White LED

In present,the color index of white LED is low because its red emission is too weak.This paper aimed to enhance the red emission by doping Gd3 ,Sm3 ,Pr3 into the phosphor (Y3Al5O12:Ce3 ,YAG:Ce3 ) used for white LED.The samples were characterized by X-ray diffraction (XRD),fluorescence spectrophotometer,phosphor relative brightness meter and spectrophotocolorimeter.The principles of enhancement of red emission were investigated.Red shift phenomenon in the spectrum was observed after doping Gd3 into YAG; three weak emission peaks,peaked at 566 nm ,600 nm and 616 nm respectively in the red region of the spectrum,were successfully superposed by the doping of Sm3 ,also a emission peaked at 610 nm was superposed by the doping of Pr3 .The relative brightness and the luminescence intensity of the samples decreased quickly with the doping of Gd3 ,Sm3 and Pr3 .