Question

The potential barrier in the depletion layer is due to-
A. Ions
B. Holes
C. Electrons
D. Forbidden band

Answer 1

Hint: In this question, we need to comment on the potential barrier in the depletion layer in a transistor. For this, we will follow the properties of the depletion layer and the movement of the electrons and the holes across the different layers.

Complete step by step answer:The potential barrier in the PN- junction is the barrier which does not allow charge flow across the junction normally. As the p-type material of a semiconductor is brought in contact with the n-type material of the semiconductor then, then there starts the diffusion of the electrons from the n-type to the p-side and holes from the p-type to the n-side of the material leaving. As the result of the movement of the charges, the immobile ions are created near the depletion layer which consequently creates an electric field that opposes the flow of the current. So, the region (depletion) nearby the depletion layer loses their neutrality and becomes charged due to ions.
Hence, the potential barrier in the depletion layer is due to Ions.
Option A is correct.

Note:The region in the transistor where there is no charge present (electrically neutral region) is known as the depletion region of the transistor. After joining p-type and n-type semiconductors, electrons from the n-region near the p-n interface tend to diffuse into the p-region.