Question

In extrinsic $P$ and $N$ type semiconductor materials , the ratio of the impurity atom to the pure semiconductor atoms is about

• A. $1$
• B. ${10}^{-1}$
• C. ${10}^{-4}$
• D. ${10}^{-7}$

Answer 1

Answer: (D)

${10}^{-7}$

The ratio of the pure atoms to impure atoms in extrinsic semiconductors is ${10}^{-7}$. When pure or intrinsic semiconductors are doped with trivalent or pentavalent impurities then it results in the formation of n-type and p-type semiconductors.

This drastically affects the conduction of these semiconductors and provides free charge carriers to conduct electricity through the crystal.