MHT CET Medical202626 April 2026Morning ShiftPhysicsSemiconductorsActual
For an n-type semiconductor, the relation between the number density ' n_h ' and ' n_e ' is
Options
- An_e = n_h
- Bn_h << n_e
- Cn_h >> n_e
- Dn_h = n_e = 0
Correct answer
B. n_h << n_e
Step-by-step solution
In an n-type semiconductor, pentavalent impurity atoms are added to the intrinsic semiconductor. Each impurity atom donates one free electron, significantly increasing the number density of electrons. As a result, electrons become the majority charge carriers and holes become the minority charge carriers. Therefore, the number density of electrons ( n_e ) is much greater than the number density of holes ( n_h ), which can be written as n_h Answer: n_h << n_e