Explain, with the help of suitable diagram, the two important processes that occur during the formation of p-n junction. Hence define the terms: depletion region and barrier potential.

Question

Philoid · Accepted Answer

In a p-n junction diode, the important processes that occur are

(i)Diffusion of charges: Diffusion refers to the process of the movement of the majority charge carriers cross the junction. Depletion region is formed as a result of diffusion.

(ii)Drift: Drift refers the movement of the minority charge carriers within the junction.

Depletion region: Due to diffusion of carriers, a layer of positive charge occurs near the n-type region and a layer of negative charge forms near the p-type region. This space charge region around the junction is called depletion region.

Barrier Potential: Due to the formation of a depletion region, there exists a resisting potential in the depletion lanes which restricts the flow of majority charge carriers. This potential developed across the depletion layer is called barrier potential.