State operating principle of LED. Write material names used to manufacture LED.

State operating principle of LED. Write material names used to manufacture LED.
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1 Answer

Answer :

Principle of Operation of LED: 

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When an LED is forward biased, the electron in the n-region will cross the junction and recombine with the holes is p-type.

When the recombination takes place, electrons from the conduction band resides these electrons return back to the valance band.

While returning back, the recombining electrons give away the excess energy in the form of light.

Semiconductor Materials Used:

Gallium Arsenide (GaAs) : Infrared (IR)

Gallium Arsenide Phosphite (GaAsP) : Red or Yellow.

Gallium Phosphite (GaP) : Red or Green.

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