Question

Why is there no current in reverse bias condition?

Answer 1

Hint :Inside a semiconductor, a p-n junction is an interface or a border between two semiconductor material types, namely the p-type and the n-type. The semiconductor's p-side, or positive side, has an excess of holes, whereas the n-side, or negative side, has an excess of electrons. The doping process is used to produce the p-n junction in a semiconductor.

Complete Step By Step Answer:
When the voltage is increased, electrons move from the n-side to the p-side of the junction. The migration of holes from the p-side to the n-side of the junction occurs in a similar manner as the voltage rises. As a result, a concentration gradient exists between the terminals on both sides. There will be a movement of charge carriers from higher concentration regions to lower concentration regions as a result of the development of the concentration gradient. The current flow in the circuit is caused by the movement of charge carriers inside the pn junction.
The p-n junction is said to be reverse biased when the p-type is linked to the negative terminal of the battery and the n-type is attached to the positive side. The applied electric field and the built-in electric field are both in the same direction in this situation. The resultant electric field is in the same direction as the built-in electric field, resulting in a more resistive, thicker depletion zone. If the applied voltage is increased, the depletion area gets more resistant and thicker.
The charge carriers are pushed away from the p-n junction in reverse bias conditions, causing the p-n junction to widen. The larger the depletion area, the more difficult it is for charge carriers to get through, resulting in very limited current flow.

Note :
When the p-n junction diode's arrangement is reverse-biased, the diode may be utilised as a photodiode since it is sensitive to light.
It has the potential to be utilised as a solar cell. The diode can be utilised in LED lighting applications when it is forward-biased. Many electric circuits use it as a rectifier, while varactors employ it as a voltage-controlled oscillator.