LED is English abbreviation of light emitting diode, namely: light excitation diode, belonging to a kind of semiconductor component. The core of a light-emitting diode is a wafer of p-type and n-type semiconductors. Between the p-type and n-type semiconductors there is a transition layer called the p-n junction. In some PN junctions of semiconducting materials, injected minority carriers, in combination with majority carriers, release excess energy in the form of light, converting the electrical energy directly into light energy. PN junction plus the reverse voltage, a minority of carriers is difficult to inject, it does not light. The use of this principle of injection electroluminescent diodes called light-emitting diodes, commonly known as LED.
When it is in the forward working state (that is, both ends plus forward voltage), the current flows from LED anode to cathode, the semiconductor crystal emits light of different colors from ultraviolet to infrared. The intensity of light is related to the current. For example, LED is like a hamburger, the light-emitting material is the "patties" in the mezzanine, and the electrodes on the top and bottom are breads with meat. Through the study of luminescent materials, people gradually developed various light colors, LED components with higher and higher luminous efficiency, but no matter how the LED's overall luminescence principle and structure have not changed much.
