Physics - Semiconductors Question with Solution | TestHub

When a p-n junction is formed, electrons from the n-region diffuse into the p-region and holes from the p-region diffuse into the n-region.

This diffusion of majority charge carriers leaves behind immobile positive donor ions on the n-side and immobile negative acceptor ions on the p-side near the junction.

The accumulation of these positive and negative charges near the junction creates an electric field directed from the n-side to the p-side, which gives rise to the potential barrier.

Answer: accumulation of positive and negative charges near the junction.