Physics - Semiconductors Question with Solution | TestHub

In a p-n junction, there is a higher concentration of holes in the p-region and a higher concentration of electrons in the n-region.

Due to this concentration gradient, holes diffuse from the p-side to the n-side, and electrons diffuse from the n-side to the p-side.

As these charge carriers diffuse across the junction, they leave behind immobile ionized dopant atoms (negative ions on the p-side and positive ions on the n-side).

This creates a region near the junction that is depleted of mobile charge carriers, which is known as the depletion layer.

Therefore, the depletion layer is caused by the diffusion of charge carriers.

Answer: diffusion of charge carries.