Explain the working of a semiconductor diode when it is forward biased. Draw the I-V characteristics for both forward bias and reverse bias of a semiconductor diode.

Explanation

When the +ve terminal of a battery is connected to the p region and the -ve terminal battery is connected to the n-region of the junction diode , then the p-n junction is said to be forward biased.
When a battery is connected across the p-n junction diode , a p.d of .v. volt is applied across the diode . The resistance of depletion region is very high as it has no free charge carriers.As a result of this , the potential barrier height is reduced and width of deplection layer is decreased.
The +ve potential of the p-region attracts the electrons from the n-regions and the -ve potential of the n-region attracts the holes from the p-region. Due to these , the diffusion of majority carriers takes place across the junction . Thus an electric current will flow due to migration of majority carriers across the p-n junction, which is called forward current.