For general lighting, the people need is mainly white light. 1998 glowing LED developed. This is the GaN LED chip and yttrium aluminum garnet (YAG) packaged together to make. GaN blue chip fat (λp = 465nm, Wd = 30nm), made of high-temperature sintering of YAG phosphors with Ce3 + excited by this blue light yellow light, peak 550nm. Blue LED substrate cavity installed in the reflective bowl, cover with thin layer of resin mixed with YAG, about 200-500nm. LED substrate phosphor emitted blue light is absorbed, and some blue and yellow light emitted phosphor mixture can be too white. Now, for the InGaN / YAG white LED, YAG phosphor by changing the chemical composition and adjust the thickness of the phosphor layer can be obtained color temperature 3500-10000K in colored white.
White light is composed of a variety of colors of light, usually sunlight, fluorescent light are all white
White light is visible light (orange, yellow, indigo, violet) and non-visible (UV-X microwave radio waves, infrared ray r ray, etc.) together a mixture of light.
