Official Correct Choice:
Option C: Depleted of mobile charge carriers, high electrical resistivity, and immobile space-charge ions
Concept:The depletion region is formed by the diffusion and recombination of free carriers near the metallurgical junction, leaving behind fixed ionic charges.
Formula:$$\rho = e(N_D - N_A) \quad (\text{space-charge density})$$
Solution:- The region is depleted of mobile electrons and holes.
- It consists of immobile positive donor ions on the N-side and immobile negative acceptor ions on the P-side.
- Because there are no free carriers, the region exhibits high electrical resistivity and maintains an internal electric field.
Why other options are incorrect:- Option A: The depletion region has a very low mobile carrier density and a strong internal electric field.
- Option B: The depletion layer is depleted of free holes and acts as a resistive barrier rather than a conductor.
- Option D: Semiconductors do not exhibit superconducting behavior at room temperature.
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