We performed the simulation and experiment to investigate the influence of Zirconium dioxide (Zirconia, ZrO2) particles on the optical properties of phosphor converted white LED (pcW-LED). An efficient optical model was developed and applied to the incorporation diffuse particle of ZrO2 into a hemisphere package containing YAG phosphors. The optical properties (chromaticity, packaging efficiency) were estimated as a function of phosphor and ZrO2 particles, through the calculation of effective radius, refractive index, and absorption and conversion efficiency, in a range of correlated color temperature 4500 K to 6500 K. In the same way, the amount of phosphor and ZrO2 can be calculated accurately to obtain a targeted optical property in a hemisphere LED design. Especially, the angular distribution of CCT was also diminished, and even almost inexistent for low CCT design. In addition, the adding of ZrO2 particles allows clearly decreasing the amount of phosphor for an identical target CCT. It is really suitable in the context of decreasing the amount of phosphor or in some applications where the color uniformity is an important parameter, like indoor down-lighting.
We performed the simulation of white LEDs packaging with different chessboard structures of white light
converting phosphor layer covered on GaN die chip. Three different types of chessboard structures are called type 1,
type 2 and type 3, respectively. The result of investigation according to the phosphor thickness show the increasing
of thickness of phosphor layer are, the decreasing of output blue light power are. Meanwhile, the changes of yellow
light are neglect. Type 3 shows highest packaging efficiency of 74.3 % compares with packaging efficiency of type
2 and type 1 (72.5 % and 71.3 %, respectively). Type 3 also shows the most effect of forward light. Attention that
the type 3 chessboard structure gets packaging efficiency of 74.3 % at color temperature of daylight as well as high
saving of phosphor amount. The color temperatures of three types of chessboard structure are higher than 5000 K, so
they are suitable for lighting purpose. The angular correlate color temperature deviation (ACCTD) of type 1, type 2
and type 3 are 6500K, 11500K and 17000K, respectively.