The use of green phosphor and yellow phosphor with blue LED chips can make high-brightness white LED; if use green phosphors with blue LED chips, can access green color directly; if use green and yellow phosphor with blue LED chips, can access cool white colors directly; also green phosphor can tie in red phosphor and blue LED chips to access white color. The color-rendering index (CRI) of white LEDs are relate with the blue chips, YAG phosphor, correlated color temperature and other relevant, the most important is the YAG phosphor. LED in different color temperature is because different phosphor and blue LED chips were used. The lower color temperature of the LED, the longer emission peak value of phosphor and chip are used. If under color temperature of 4000K, the red phosphor also need to be added to compensate the red color deficiencies, and improve the CRI purposes. In the conditions of the same LED chips and phosphor, the higher of the color temperature the higher of color-rendering index.
Summe up in production experience, the best Blue and YAG matching relation are as follows:
| YAG emission peaks / nm | blue peak wavelength / nm |
| 530 ± 5 | 450-455 |
| 540 ± 5 | 455-460 |
| 550 ± 5 | 460-465 |
| 555 ± 5 | 465-470 |
If produce as per this instruction, the white color will be much more pure. generally chip manufacturers provide the main wavelength, and the peak wavelength need to test by using specialized equipment, usually the peak wavelength is about 5nm shorter than the main wavelength. The wavelength of phosphor and LED chip determine the color coordinate in a straight line, when confirm the wavelength of the phosphor and chips, we can regulate the color coordinates in a straight line just by adjusting the ratio of phosphor and chips.
Common LED Particle are as follows:
| Materials | wavelength | Materials | wavelength |
| InGaN | 475-485nm | InGaN | InGaN 525nm |
| InGaN | 465-475nm | InGaN | 505nm |
| InGaN | 455-465nm | InGaN | 515nm |
| InGaAlP | 620-640nm | GaAlAs / GaAs | 660nm |
| InGaAlP | 610-620nm | GaAlAs / GaAlAs | 660nm |
| InGaAlP | 600-610nm | GaP | 700nm |
| InGaAlP | 592-600nm | GaP | 570-575nm |
| InGaAlP | 580-593nm | GaP | 565-570nm |
| InGaAlP | 567-577nm | GaP | 550-565nm |
| InGaAlP | 550-565nm | PY --- GaAlAs | 585nm |
Because there are inorganic phosphors and organic phosphors. In conditions of no organic phosphor, the ratio for YAG phosphor and AB glue usually is 1:6 ~ 10 (weight ratio). As for the value of AB glue should between 6 ~ 10g, and the exact value depends on the power of the blue LED chip. In conditions of higher power of LED Chip and the same phosphor, the AB glue should be relatively smaller amount (such as: 1:6). On the contrary, the number of smaller power LED chip, the AB glue should be relatively bigger amount, (such as: 1:10).
