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simple question about LED

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desperado1

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we know that a LED is made up of Gallium Arsenide. Plus we also know that it is a diode having p and n junctions.
Normally a silicon is doped with born to make p type and with phosphorus to make n type.

we also know that a LED has p and n type junctions. then WHAT IS THIS JUNCTIONS MADE OFF ? IS IT THE SAME GALLIUM ARSENIDE OR OTHERS ?

thanks in advance
 

wd5gnr

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The material depends on the color and brand of the LED.

There is a table at https://en.wikipedia.org/wiki/LEDs but it didn't paste well into the message.

But for example, Blue LEDs often use Silicon Carbide or Zinc Selenide. Gallium Arsenide is used in IR LEDs, among others.
 

subharpe

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When we say GaAs LED we mean in stead of Silicon or any other basic semiconductor material GaAs is chosen for substrate where you diffuse or do anything else to make it p-type or n-type. There are many reasons why in stead of Si, in spite of availability and all virtues we associate with Si, cannot be used in LED. Mainly the wavelength and also indirectness of band-gap are the two major issues. But basic material may be GaAs or any other suitable compound material depending on the wavelength requirement
 

OMID-313

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Hi
Actually, I don't know the answer!
The only thing I know is that gramatically it's true to say " an LED " and not " a LED " !!
Do you know why!?
Because it's the first SOUND of the word that specifies " a " or " an " .
Hope I've helped your English !!
 

desperado1

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subharpe said:
When we say GaAs LED we mean in stead of Silicon or any other basic semiconductor material GaAs is chosen for substrate where you diffuse or do anything else to make it p-type or n-type. There are many reasons why in stead of Si, in spite of availability and all virtues we associate with Si, cannot be used in LED. Mainly the wavelength and also indirectness of band-gap are the two major issues. But basic material may be GaAs or any other suitable compound material depending on the wavelength requirement

But, my question is what's that SUITABLE material that is doped in GaAS to make p and n type ?
 

nitrojacob

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Ga is p type impurity, and Arsenic is n type impurity. I think it is by varying the proportion of Ga and As. Please correct me, if i am wrong.
 

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