19
Feb
Led Structure And Operating Principle. These PN junctions can be made from. So lets get started with Working Principle of LED. When free electrons reach the junction or depletion region some of the free electrons recombine with the holes in the positive ions. Light Emitting Diode LED works only in forward bias condition.
The LED stands for light-emitting diode and in the below figure you can see the symbol of LED. When a suitable voltage is applied to the leads electrons are able to recombine with electron holes within the device releasing energy in the form of photons. The p-type layer is made thin and is grown on the n-type substrate. Although the basic PN junction had been in use for many years it was not until 1962 that the LED was developed and its action started to be understood. The device is capable of emitting a fairly narrow bandwidth of visible or invisible light when its internal diode junction attains a forward electric current or voltage. LEDs are the opto semiconductor devices which easily converts electric current into illumination or light.
Although the basic PN junction had been in use for many years it was not until 1962 that the LED was developed and its action started to be understood.
LEDs are the opto semiconductor devices which easily converts electric current into illumination or light. Physical Structure of LED. The LED stands for light-emitting diode and in the below figure you can see the symbol of LED. A light emitting diode LED is known to be one of the best optoelectronic devices out of the lot. Working Principle of LED The holes lie in the valence band while the free electrons are in the conduction band. LED is structured in such a way so that light emitted does not get reabsorbed into the material.