Question

Explain the formation of the barrier potential in a p-n junction.

Answer 1

A p-n junction is formed by bringing p-type and n-type semiconductors together in very close proximity.

At the instant of p-n-junction, movement of free electrons from the n-side and free holes from the p-side diffuse across the junction and combine and thus leave -ve ions on the p-side and +ve ions inn-side.

These two layers of +ve and -ve ions form the depletion region and the potential difference thus sets up is called the potential barrier.