Question

A semiconductor becomes an insulator at

• A. $0^{\circ }C$
• B. $-{100}^{\circ }C$
• C. $300K$
• D. $0K$

Answer 1

The correct option is D $0K$

Semiconductors are solids with conductivity that is intermediate between conductors and insulators which lies in the range ${10}^{-6}\text{to}{10}^{4}oh{m}^{-1}{m}^{-1}$.

Conductivity of a solid depends on the band gap between the valence and conduction band.
The conduction of electricity for semiconductors depends on the temperature.
If a semidonductor is cooled to absolute zero $\left(0K\right)$ the electrons occupy their lowest possible energy levels. The conduction band is empty because at very low temperature electrons cannot jump from the valence band to conduction band.
Hence, the material will become a perfect insulator.