There are mainly 3 categories of phosphors for lamps. The first category is used for ordinary fluorescent lamps and low-pressure mercury lamps, the second category is used for high-pressure mercury lamps and self-ballasted fluorescent lamps, and the third category is used for ultraviolet light sources, etc. There are many types of phosphors, and the price is different, phosphors have good thermal stability, safety and environmental protection, for a variety of white light, can be adjusted to different red, blue, yellow and so on the color.