Effects of YAG: Ce phosphor particle size on optical performance of white LEDs

YAG:Ce phosphor is widely used in LED industry with powder form to mix with silicone. The phosphor particle size is important by affecting optical performance of white LEDs in terms of luminous flux and angular color uniformity. This paper constructed a white LED optical model referring to CREE white LEDs. The optical simulation reveals that 2 μm phosphor particle presents the lowest luminous flux and the best angular color uniformity. Particle size larger than 10 μm has the ability to generate the highest luminous flux, but its angular color uniformity is deteriorated seriously. To obtain high luminous flux and moderate angular color uniformity, it is suggested to apply particle size with its range from 6 μm to 8 μm.