Question

Draw and explain the band diagram of N-type semiconductor at 0 K temperature and room temperature.

Answer 1

In n-type semiconductor pentavalent impurity is added.

Each pentavalent impurity donates a free electron.

The addition of pentavalent impurity creates large number of free electrons in the conduction band.

At room temperature, the number of electrons in the conduction band is greater than the number of holes in the valence band.

Hence, the probability of occupation of energy levels by the electrons in the conduction band is greater than the probability of occupation of energy levels by the holes in the valence band.