Question

Which of the following is the consequence of doping an intrinsic semiconductor?

• A. Will increase band gap
• B. Electrical conduction will decrease
• C. Impurity band will lie between valence and conduction band
• D. Impurity band will lie above conduction band

Answer 1

The correct option is C Impurity band will lie between valence and conduction band

Doping is the intentional introduction of impurities into an intrinsic semiconductor for the purpose of modulating its electrical, optical and structural properties.

After doping, the band from the impurity lies in between the valence and conduction bands. It will act as a bridge and electrons can be excited to this bridge easily from filled valence band to conduction band.
Thus, option (c) is correct.