Led
LED :- Light Emitting Diode
Led is like a p-n junction diode in which p-junction consists of more holes or positive charges and n-junction contains more number electrons(e-) or negative charges.So different p-type and n-type materials combine to form leds of different colors which we will see later.
Structure:-
Working Of Led :-
Symbol :-
Before understanding the concept of working of led we should just revise the working of p-n junction diode.
Now, just think about p-type and n-type material.When we are operating p-n junction diode in forward bias so the negative charges in n-type region moves towards p-type by crossing a junction and holes or positive charges moves towards n-type region by crossing the junction.
In similar way the leds work but here when the electrons cross from conduction band to valence band that is in short when electrons moves from n-type to p-type region some energy is released in the form of light photons and this happens in band gap area.
Here is the information of leds operating with different voltages
Color Operating Voltage
Violet 2.8v - 4.0v
Blue 2.5v - 3.7v
Green 1.9v - 4.0v
Yellow 2.1v - 2.2v
Orange 2.0v - 2.1v
Red 1.6v - 2.0v
Now You would be thinking that why leds of different colors has different operating voltages?
So here is the answer of it
Violet led is made with [InGaN]
Blue Led consists of [InGaN & SiC]
Green Led consists of [GaP , AlGaInP & AlGaP]
So to make leds of different color we are using different materials as you see above due to this reason leds of different colors has different operating voltages.
Applications:- It is used as a output in various practicals like for studying gate in digital electronics,used in DJ lights for parties,you can see in day to day life in various devices like your mobile,Tv,watches,etc not only that they are used in various projects
Here are some of the projects that I had explained in detailed way
3) Dancing Leds
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