Diode Working

Diode working:
Forward bias Diode
When a diode is connected to a battery as shown in the figure, electrons which are majority carrier from the n-side and holes which are majority carrier from the p-side are forced to move toward the junction by the effect of an electrical potential supplied by the battery. The electrons and holes combine causing the current to pass through the diode. This type of diode when the P side is connected to the positive terminal and N side is connected to a negative terminal, it is said to be forward biased.

Reverse Bias Diode
When a diode is connected to a battery as shown in the figure, holes in N side are forced to move to the left side while electrons in the p-side are forced to move to the right side. This results in a free area at the PN- junction that is free of charge carries creating a depletion region at the junction. This depletion region acts as an insulator preventing current from flowing through the diode. When a diode is arranged in a way that p side is connected to a negative terminal of battery and n side is connected to a positive terminal of a battery, it is said to be reverse biased.