When a pentavalent impurity is added to a pure semiconductor; it becomes?

A. a p-type semiconductor
B. an n-type semiconductor
C. an insulator
D. an intrinsic semi-conductor

Correct Answer:

Option B – an n-type semiconductor

Explanation

When a pentavalent (5 outer electron)atom is added to a pure semiconductor, there is extra electrons that do not take part in the covalent bonding resulting in an n-type semiconductor.