Question

Which of the following statement is correct regarding band theory?

• A. For semiconductors, small energy gap is there between conduction band and valence band
• B. For conductors, no energy gap is there between conduction band and valence band
• C. For insulators, large energy gap is there between conduction band and valence band
• D. All of the above.

Answer 1

The correct option is D All of the above.

Conductors are mostly metals, they do not have any energy gap between conduction band and valence band since they overlap.
Semiconductors have small energy gap between the conduction and valence band and hence, the electron can jump to conduction band but not so easily as in conductors.
In insulators, the energy gap between valence band and conduction band is large and hence, electron cannot jump from valence band to conduction band