Forward Bias

Forward Bias

The process by which a p – n junction diode allows the electric current in the presence of applied voltage is called forward biased p – n junction diode. In forward biased p – n junction diode, the positive terminal of the battery is connected to the semiconductor material and the negative terminal of the battery is connected to the n – type semiconductor material.

Unbiased Diode and Forward Biased Diode: Under no voltage or unbiased condition, the p – n junction diode does not allow the electric current. If the external forward voltage applied on the p – n junction diode is increased from zero to 0.1 volts, the depletion region slightly decreases. Hence, very small electric current flows in the p – n junction diode. However, this small electric current ion the p – n junction diode is considered as negligible. Hence, they do not used for any practical applications.

Forward Bias

If the voltage applied on the p – n junction diode is further increased, then even more number of free electron and holes are generated in the p – n junction diode. This large number of free electron and holes further reduces the depletion region. Hence, the electric current in the p – n junction diode increase. Thus, the depletion region of a p – n junction diode decreased with increase in voltage.  In other words, the electric current in the p – n junction diode increases with the increase in voltage.

Forward Bias