Working of L.E.D.?

LED is known as Light Emitting Diode is a heavily doped forward biased p-n junction diode. This device can convert the electrical energy into light energy. Working of LED As LED is a forward biased diode, thus there is the flow of holes and electrons towards the opposite side of the depletion layer due to which the concentration of minority carriers increases on either side of the depletion layer and the concentration of majority carriers increases near the depletion layer. And when these holes and electrons get combined they releases energy in the form of heat and light.

The holes lie in the valence band, while the free electrons are in the conduction band. When there is a forward bias in the p-n junction, the electron which is a part of the n-type semiconductor material would overrun the p-n junction and join with the holes in the p-type semiconductor material. Therefore regarding the holes, the free electrons would be at the higher energy bands.
When this movement of free electron and hole takes place, there is a change in the energy level as the voltage drops from the conduction band to the valance band. There is a release of energy due to the motion of the electron. In standard diodes, the release of energy in the manner of heat. But in LED the release of energy in the form of photons that would emit the light energy. The entire process is known as electroluminescence, and the diodes are known as a light-emitting diode.

 

In LED, energy discharged in light form hinges on the forbidden energy gap. One could manipulate the wavelength of the light produced. Therefore, from its wavelength, the light colour and its visibility or cannot be controlled. The colour and wavelength of the light emitted can be determined by doping it with several impurities.

Its a type of Diode , which converts electrical energy into light energy . Thatswhy LED stands for Light Emitting Diode . !