Question

Which of the following statement is correct reagarding electrical conductivity of a semiconductor:

• A. Decreases with the rise in temperature
• B. Increases with the rise in temperature
• C. Does not change with the rise in its temperature
• D. First increases and then decreases with the rise in its temperature

Answer 1

The correct option is B Increases with the rise in temperature

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

Here, a small difference in energy is seen between the filled valence band and conduction band of electrons i.e., small band gap.
The conduction of electricity for semiconductors depends on the temperature.
At normal temperatures or higher temperature, some electrons are thermally excited from the valence band to the conduction band. So, their electrical conductivity will increase with rise in its temperature.