carbon is having 4 valence electron then why it is not a semiconductor?

Question

the atom having more than 4 valence electron are conductor in nature, those having less than 4 or having non are Insulator and those are having exactly 4 valence electron are called semiconductor. The best known Semiconductor are Silicon(Si) and Germanium(Ge)
having 4 valence electron in their outermost orbit. Carbon is also having 4valence electron in outemost orbit but is not a semiconductor. Why?

Answer 1

Semiconductors have a doped crystalline structure . For carbon this is diamond which is hard to make, however someone recently succeeded.

Answer 2

Dear Hansi,
The best way to understand insulators, conductors and semi-conductors is by using the idea of energy band levels. Look it up in an advanced book on Solid State Physics.

Simply:
CONDUCTOR: If the top band (the conduction band) is not full, then energy can be added to the carriers (electrons) which makes them move and hence conduct electricity.

INSULATOR: If the top band is full and there is a big energy gap to the next band then the electrons will not have enough energy to be pr emoted into the higher empty band. The material is an insulator because the electrons can not move.

SEMICONDUCTOR: If the top band (the conduction band) is full and there is a small energy gap to the next band, then thermal energy can be added to the carriers (electrons) which makes them jump into hat higher band where they are free to move and hence conduct. This is an intrinsic semi-conductor.

By adding impurities to the intrinsic semiconductor we can allow electrons to jump into intermediate energy state creating free electrons or holes which can conduct the electricity.



This theory is good at explaining the temperature dependence of conduction.
Look this up in a book!

Answer 3

As the 4 valence electrons are bound to the outermost orbit the binding force is very very less and when it comes in contact with any another matal the valence electrons are taken by them. so they don't behave as conductors.

Answer 4

the valence of carbon is four but as we know that the size of carbon is vary small so that inter nuclear attractiion is very large in case of carbon .such that carbon formed double bond whith another carbon and fill it's outer valancey.
the another most valuable thing is that due to higher inter atomicforce carbon having catination tandency to form chain with another carbon atom thats why it is not as semiconducter.

Answer 5

since carbon needs more energy to break its bond to get or donate electrons

since it has a large energy gap in between its conduction n balance band

Answer 6

It depends upon the allotrope.If it is Diamond or coke or charcoal or soot, it doesn't conduct electricity. But if it is Graphite or gas carbon it does conduct. (If Diamond contains impurities like Boron, it conducts electricity)

Answer 7

because an atom having 4 electrons is havin tetravalency nature & can form many different compoinds

Answer 8

you know