NEET2021PhysicsSemiconductorsActual
The electron concentration in an undefined n -type semiconductor is the same as hole concentration in a undefined p -type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.
Options
- Acurrent in n - type = current in p - type
- Bcurrent in n - type < current in p - type.
- Ccurrent in n - type > current in p - type.
- DNo current will flow in p - type, current will only flow in n - type.
Correct answer
C. current in n - type > current in p - type.
Step-by-step solution
Electron's effective mass is smaller than holes therefore mobility of electrons is higher than holes and for equal electric field drift velocity of the electron will be greater compared to holes. I = n e A v d I = n e A μ E ∵   μ e > μ h o l e       so ,   v d e > v d hole ∴ I e > I h o l e