Which of the following statements is/are correct for a p-n junction diode?

(a) During forward bias, the width of the depletion region decreases, and the barrier height is reduced.

(b) During reverse bias, the width of the depletion region increases, and the barrier height increases.

Concept:

P-N junction diode:

• A P-N junction is an interface or a boundary between two semiconductor material types, namely the p-type and the n-type, inside a semiconductor.
• A P-N junction diode is a two-terminal semiconductor device that is used for allowing electric current in one direction.

There are two operating regions in the P-N junction diode: ​

1. P-type 
2. N-type

There are three biasing conditions for the P-N junction diode, and this is based on the voltage applied:

• Zero bias: No external voltage is applied to the P-N junction diode.
• Forward bias:
  • The positive terminal of the voltage potential is connected to the p-type while the negative terminal is connected to the n-type.
  • During forward bias, the width of the depletion region decreases, and the barrier height is reduced.

Reverse bias:

• The negative terminal of the voltage potential is connected to the p-type and the positive is connected to the n-type.
• During reverse bias, the width of the depletion region increases, and the barrier height increases.

Explanation:

In forward biased, the width of the depletion region decreases and the barrier height decreases while in reverse biased, the width of the depletion region increases and the barrier height increases.

Additional Information

• V-I characteristics of P-N junction diode: VI characteristics of P-N junction diodes is a curve between the voltage and current through the circuit