With the help of circuit diagram, explain theV-l characteristics of p-n junction diode in forward biasing.

Explanation

Variation of current with voltage when p-n junction diode is forward biased: Circuit diagram is shown below when p-n junction diode is forward biased. In the beginning, when applied forward bias is low (less than the potential barrier), forward current is very low because potential barrier voltage opposes the applied voltage. So a small forward current flows, till the applied voltage does not become greater than the potential barrier voltage. It is represented by the portion OP of the graph. As soon as the forward bias becomes greater than the potential barrier voltage, forward current increases linearly. It is represented by portion PQ of the graph. Voltage corresponding to point P in the graph is known as knee voltage.