Write working principle of photodiode and state its two applications.

Write working principle of photodiode and state its two applications.
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1 Answer

Answer :

Working principle of photodiode:

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Working principle: A photodiode is a PN- junction diode that consumes light energy to produce electric current. Sometimes it is also called as photo-detector, a light detector, and photosensor. Photodiodes are work in reverse bias condition, it means that the P-side of the photodiode is connected to the negative terminal of the battery and n-side is connected to the positive terminal of the battery. When a photon of ample energy strikes the diode, it makes a couple of an electronhole. This mechanism is also called as the inner photoelectric effect. If the absorption arises in the depletion region junction, then the carriers are removed from the junction by the inbuilt electric field of the depletion region. Therefore, holes in the region move toward the anode, and electrons move toward the cathode, and a photocurrent will be generated.

Applications :

Fibre optic links

Optical communication

Optical remote control

Smoke detectors

Flame detectors

Intruder alert security system 

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