Explain with the help of a diagram, how a depletion layer and barrier potential are formed in a junction diode.

Explanation

Due to the diffusion of electrons and the holes, from their majority zone to minority zone, a layer of positive and negative space charge region on either side on the junction is formed. This is called the depletion region. The loss of electrons, from n-region and gain of electrons by the p-region, causes a difference of potential across the junction. This tends to prevent the movement of charge carrier across the junction and is, therefore, termed as barrier potential.