Question

Which of the following statements is true for an $N$-type semiconductor?

• A. The donor level lies closely below the bottom of the conduction band
• B. The donor level lies closely above the top of the valence band.
• C. The donor level lies at the halfway mark of the forbidden energy gap
• D. None of above

Answer 1

The correct option is A The donor level lies closely below the bottom of the conduction band

Due to addition of pentavalent impurity, there is one extra electron left, after completing the octet. This electron has very small ionisation energy and so, it lies very close to the conduction band.

Hence, $\left(A\right)$ is the correct answer.