Question

In a semiconductor diode, the barrier offer resistance to
1. Holes in P region only
2. Free electrons in N region only
3. Majority carriers in both the regions
4. Majority as well as minority carriers in both the regions

Answer 1

Correct Answer - Option 3 : Majority carriers in both the regions

Explanation:

• In forward biasing, the applied voltage V of the battery mostly drops across the depletion region and the voltage drops across the p-side and n-side of the p-n junction is negligibly small.
• It is due to the fact that the resistance of the depletion region is very high as it has no free charge carriers.
• The barrier potential restricts the flow of majority charge carriers. 
• In forward biasing the forward voltage opposes the potential barrier Vb. As a result of it, the potential barrier height is reduced and the width of the depletion layer decreases.
• As forward voltage is increased, at a particular value the depletion region becomes very much narrow such that a large number of majority charge carriers can cross the junction.