50 years ago, people have to understand semiconductor material can produce light of the basic knowledge, in 1962, General Electric Company Nick Ho Lun Yake (NickHolonyakJr.) developed the first practical application of visible light-emitting diodes. LED is the abbreviation of the English light emitting diode (light emitting diode), its basic structure is an electroluminescent semiconductor materials, placed on a wire rack, then surrounded sealed with epoxy resin, solid package, so can play to protect the role of the internal core wire, so the LED's seismic performance.

The core portion of the light emitting diode is composed of a P type semiconductor and N type semiconductor wafer, and a transition layer, called the PN junction between the P-type semiconductor and N type semiconductor. In some semiconductor materials, PN junction, the injection of minority carrier and majority carrier recombination, when will the excess energy released in the form of light, which converts electrical energy directly into light. PN junction when a reverse voltage is applied, the minority carrier injection is difficult, and therefore does not emit light. This luminescence principle of making the use of injection electroluminescent diodes called light-emitting diodes, known as LED. When it is in working condition (ie, ends with a positive voltage), current from the LED anode to the cathode, the semiconductor crystals on the issue from the ultraviolet to the infrared light of different colors, light intensity and current.