• Diode is a device that acts as one-way gate to control electron flow à only allows
current to pass in only one direction
• To get rid of the depletion zone, you have to let electrons moving from the N-type
area to the P-type area and holes moving in the reverse direction.
• When a diode is connected to a battery, electrons from the n-side and holes from
the p-side are forced toward the center by the electrical field. The electrons and
holes combine causing the current to pass through the diode. When a diode is
arranged in this way, we call it forward- biased.
In a forward-biased diode current is allowed electrons to flow through the device.
• When potential at anode is smaller than the potential at cathode, the diode is said
to be reverse biased. In a reverse-biased, diode current is blocked.