What is Diode -Light Emitting Diode-Tunnel diode -Varactor Diode explanation

what is a Diode?

        
   Mostly diodes are rectifiers that are used in power supplies to convert AC voltage into DC voltage. This is the general purpose but some other specific diodes are used to do special operations. such as Zener diode is designed to operate in the reverse breakdown region.




Light Emitting Diode (LED)

                
    A light-emitting diode is a diode that gives off visible light when forward-biased.






Usually, all semiconductors are made up of silicon and germanium, but LED is made by using elements like gallium, arsenic and phosphorus. Varying these elements produces light of different wavelengths with colours that include red, green, yellow and blue.

Red light LED      -      made by gallium arsenide 
Green light LED   -      made by gallium phosphide

Tunnel diode 



The Tunnel diode is a diode that exhibits positive resistance when it is forward-biased or reverse-biased when ti is exhibits negative resistance.

            The tunnel diode is a PN junction with heavy doping of P-type and N-type semiconductor materials. A tunnel diode is doped 1000 times as heavily as a conventional diode.
              

Varactor Diode


            A varactor diode is a junction diode that acts as a variable capacitor under changing reverse bias is known as a varactor diode. A varactor diode is specially constructed to have high capacitance under reverse bias. The values of the capacitance of varactor diodes are approximately picofarad range.




There are many other types of diodes used in electronics. Some common diodes use rectification at the same time some special operations use special diodes such as Zener diode, LED, Photo diode, Tunnel diode and Varactor diode.
What is Diode -Light Emitting Diode-Tunnel diode -Varactor Diode explanation What is Diode -Light Emitting Diode-Tunnel diode -Varactor Diode explanation Reviewed by knowledge people creators on January 01, 2019 Rating: 5
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