Forward bias: The process in which a p-n junction diode permits the electric current in the presence of applied voltage is called forward biased p-n junction diode.
Inforward biasing, the positive region of the battery is joined to the P-type material while the negative terminal of battery is connected to the N-type material in the diode.
Due to the applied voltage, electrons from n-side cross the depletion region and reach p-side (where they are minority carries). Similarly, holes from p-side cross the junction and reach the n-side (where they are minority carries). This process under forward bias is known as minority carrier injection.
The effective potential barrier is weakened in this biasing thus permitting current to flow more easily.
The depletion width of the diode also decreases in forward bias.
Reverse bias: The process in which a p-n junction diode stops the electric current in the presence of applied voltageis called reverse biased p-n junction diode.
Inreverse biasing, the positive region of the battery is joined to the N-type material while the negative terminal of battery is connected to the P-type material in the diode.
The external voltage is applied for strengthening of the potential barrier and it prevents the flow of current through it.
The depletion layer of the diode increases in reverse biasing.
