涂敷红、绿荧光粉的白光LED显色性研究

Research of Color Rendering of White LED Based on Red and Green Phosphors

通过蓝光发光二极管（LED）芯片激发红、绿两种荧光粉制作白光LED，首先保持两种荧光粉的配比不变，依次从2700-13000K改变相关色温，发现在某一色温段时，显色指数达到最高。然后依次改变两种荧光粉的配比，重复试验，发现不同的荧光粉配比，达到最高显色指数所对应的色温段不同。试验结果表明，通过合理匹配红、绿荧光粉和硅胶三者之间的比例，可以实现在2700～13000K之间的任一色温区，显色指数均能达到90以上，在4000K以下的低色温区，显色指数可达到96。基于此，通过选择和匹配LED蓝光芯片、荧光粉的激发、发射波长，以及它们之间的比例关系，可以实现在任意色温段使显色指数最大化的白光LED光谱设计。

White light emitting diodes （LED） are packaged based on blue LED dies surrounded by two different phosphors that emit red and green light respectively. First, the ratio of two phosphors maintains invariable, color rendering index achieves the maximal value in some color temperature, when it increases from 2700 K to 13000 K by degrees. Then, the ratio of two phosphors is changed gradually, by repeating above test, it is found that the color temperature corresponding to the maximal color rendering index is different at different phosphors ratio. The experimental results indicate that color rendering index can reach above 90 in any color temperature region from 2700 to 13000 K by matching the ratio of red, green phosphors and silica gel. Especially, color rendering index can achieve about 96 in the color temperature below 4000 K. Therefore, the maximal color rendering index in any color temperature can be obtained by the choice and match between blue LED dies, excitating and emitting wavelength, and the scale between them.