Originally used as instruments of instruction LED light source, then all kinds of light-colored LED has been widely used in traffic lights and large displays, resulting in a good economic and social benefits. 12-inch red traffic lights, for example, in the United States would have long-life, low-efficiency 140-watt incandescent lamp as a light source, it produces 2000 lumens of white light. The red filter, 90% light loss, only 200 lumens of red light. In the new design of the lamp, Lumileds company used 18 red LED light source, including circuit losses, including a total power of 14 watts to produce the same light effect. LED lights are also important areas of automotive light applications.

For general lighting purposes, people need a white light. 1998 white LED developed. This is the GaN LED chip and yttrium aluminum garnet (YAG) packaged together to make. GaN chip emits blue light (λp = 465nm, Wd = 30nm), issued a yellow YAG phosphor containing Ce3 + after high-temperature sintering of blue excitation light emitted by this peak 550nm. Blue LED substrate is mounted in the reflective cavity bowl, covered with a thin layer of resin mixed with YAG, about 200-500nm. The blue part of the LED substrate phosphor emitted absorbed, and some blue mixed with yellow light emitted by the phosphor can be too white. Now, for the InGaN / YAG white LED, the YAG phosphor by changing the chemical composition and adjust the thickness of the phosphor layer, the color temperature can be obtained 3500-10000K colored white. This white light by blue LED method, simple structure, low cost, technical maturity, and therefore use the most.

  60s of last century, scientists using the principle of light-emitting semiconductor PN junction, research has become LED light-emitting diode. Was developed by the LED, the materials used are GaASP, its luminous color is red. After nearly 30 years of development, we are now very familiar with the LED, has been able to issue a red, orange, yellow, green, blue and other colored light. However, white light LED lighting required only developed in recent years, where information about the white LED lighting to readers.