Like ordinary diodes, light-emitting diodes consist of a PN junction. After electrification, the holes injected from the P region to the N region and the electrons injected from the N region to the P region recombine with the electrons in the N region and the holes in the P region within a few microns of the PN junction, respectively, resulting in spontaneous emission fluorescence. The energy states of electrons and holes in different semiconductor materials are different, the energy released when the holes recombine is different, and the wavelengths of the light emitted are different, thus showing different colors. Light Emitting Diode (Light Emitting Diode) is referred to as LED for short. Made of compounds containing gallium (Ga), arsenic (As), phosphorus (P), nitrogen (N), etc.

     SMD LED is also called SMDLED. Its light-emitting principle is to pass current through compound semiconductor, and through the combination of electrons and holes, excess energy will be released in the form of light to achieve the effect of light-emitting.

1. The light-emitting principle belongs to cold light-emitting, rather than heating or discharging light, so the life of the components is about 50~100 times longer than that of tungsten bulbs, about 100,000 hours.

2. Good shock resistance, high reliability and low system operating cost.

3. It is easy to be small, thin, and lightweight, without shape restrictions, and can be easily made into various applications.

4. No warm-up time is required, and the lighting response speed is faster than that of ordinary lamps (about 3~400ns).

5. High electro-optical conversion efficiency and low power consumption, saving about 1/3~1/20 of energy consumption compared to bulbs.