MHT CET202522 Apr 2025Evening ShiftPhysicsSemiconductorsActual
In n-type semiconductor, free electrons donated by the impurity atoms occupy energy levels in
Options
- Athe conduction band.
- Bthe valence band.
- Cthe band gap and are close to the conduction band.
- Dthe band gap and are close to the valence band.
Correct answer
C. the band gap and are close to the conduction band.
Step-by-step solution
In n-type semiconductors, pentavalent impurity atoms introduce donor levels within the forbidden energy gap. These donor levels lie close to the conduction band edge, requiring minimal thermal energy for electron excitation. The extra valence electrons from donor atoms occupy these levels before transitioning to the conduction band as free charge carriers. Therefore, the correct option is C.