[SOLVED] Why do we use Semiconductor

Our teacher asked question that why do we use semiconductor why not conductors and insulators by changing their properties?
I answered that semiconductor have specific resistance and with four valence electrons they are suitable. Second they have crystalline structure which shares electrons with other elements by covalent bond.
My question is what do you think that why we use semiconductor and is it possible that other elements can be made P type and N type materials to work just like semiconductors.

"While silicon is the prevalent material for wafers used in the electronics industry, other compound III-V or II-VI materials have also been employed. Gallium arsenide (GaAs), a III-V semiconductor produced via the Czochralski process, is also a common wafer material." from Wafer (electronics) - Wikipedia, the free encyclopedia.

"Silicon still dominates the semiconductor industry as the standard material, with gallium arsenide (GaAs), indium phosphide (InP), gallium phosphide (GaP), gallium nitride (GaN), silicon carbide (SiC) and sapphire substrates currently accounting for just 1.1% of the 7504 million square inches processed annually in semiconductor foundries." from Semiconductor Today.

Quote: I answered that semiconductor have specific resistance and with four valence electrons they are suitable

Good question from your teacher.
My question to you: Do you really understand and are you happy with your answer ("specific resistance") ? And why 4 valence electrons are "suitable" ?
The answer touches a lot of basics that cannot be repeated here. But - in any case - forgot at the moment the term "resistance" as it leads you the wrong linear way. Semiconductors are strongly non-linear devices and their main application is amplification, and in this context perhaps it could be helpful if you know the operation principles of a vacuum tube. Do you?

Another hint: If you try to learn something about transistor principles, start with FET's. They are easier to understand than BJT's.

Hello Everyone.

I would like to share my thoughts about it, and then receive your feedback.
For me, the answer is simple. We use semiconductor because we wish a material that you can control easily the conductivity. And for this purpose, semiconductors are the best one. It is not so easy to control the conductivity of isolator and conductors.
The transistor works as a switch, that is close (low resistance) or open (high resistance). It is easy to do this with semiconductors. You create the channel with a gate-bulk (or gate-source, …) voltage, and then, you close the switch.

These are my thoughts.

Best regards,

hi all
that is right palmeiras , besides they non magnetic materials , so they don't generate any magnetic flux while they work unlike the conductors .
that what i think
regards

hitman1988 said:

hi all
that is right palmeiras , besides they non magnetic materials , so they don't generate any magnetic flux while they work unlike the conductors .
that what i think
regards

Click to expand...

HEY,so u r telling that current through a semiconductor will not create any magnetic field around the semiconductor??!!
Magnetic field will be generated when a charge move from one direction to other according to the right hand grip rule, and it doesn't depend on the medium like conductor or semiconductor..I think so....

palmeiras said:

Hello Everyone.

I would like to share my thoughts about it, and then receive your feedback.
For me, the answer is simple. We use semiconductor because we wish a material that you can control easily the conductivity. And for this purpose, semiconductors are the best one. It is not so easy to control the conductivity of isolator and conductors.
The transistor works as a switch, that is close (low resistance) or open (high resistance). It is easy to do this with semiconductors. You create the channel with a gate-bulk (or gate-source, …) voltage, and then, you close the switch.

These are my thoughts.

Best regards,

Click to expand...

For my opinion, this is a very simplified view that cannot explain the basic semiconductor properties (control of conductivity, ...works as a switch, close or open,..).
Have you ever heard about a p/n junction and the effects associated with it?

hitman1988 said:

hi all
that is right palmeiras , besides they non magnetic materials , so they don't generate any magnetic flux while they work unlike the conductors .
that what i think
regards

Click to expand...

HEY,so u r telling that current through a semiconductor will not create any magnetic field around the semiconductor??!!
Magnetic field will be generated when a charge move from one direction to other according to the right hand grip rule, and it doesn't depend on the medium like conductor or semiconductor..I think so....

Hello everyone!

I know that transistor as a switch is a very simple way to describe. But, even considering the transistor as a amplifier, or a current source. But the key point for me, is that possibility to control the conductivity. And why silicon? Because is cheap.
Best Regards,