The P-N junction can convert absorbed light energy into a proportional electric current. The same process is reversed here (i.e. the P-N junction emits light when electrical energy is applied to it). This phenomenon is generally called, which can be defined as the emission of light from a under the influence of an . The charge carriers recombine in a forward-biased P-N junction as the electrons cross from the N-region and recombine with the holes existing in the P-region.
Free electrons are in theof energy levels, while holes are in the valence . Thus the energy level of the holes will be lesser than the energy levels of the electrons. Some portion of the energy must be dissipated in order to recombine the electrons and the holes. This energy is emitted in the form of heat and light.
The electrons dissipate energy in the form of heat for silicon and germanium diodes but in(GaAsP) and (GaP) semiconductors, the electrons dissipate energy by emitting . If the semiconductor is translucent, the junction becomes the source of light as it is emitted, thus becoming a light-emitting diode, but when the junction is reverse biased no light will be produced by the LED and, on the contrary, the device may also be damaged.
Advantages Of LED-
There are many advantages of using a LED as :
- It helps in saving energy.
- Reduction in costs.
- Self Ambience Adjustment.
- Soothes & Energizes the environment & People.
- Enhances the brand with its gorgeous lighting.
- Environment Transformation.
Disadvantages Of LED-