What happens when a forward bias is applied to a p-n junction?
In forward biasing, the applied voltage mostly drops across the depletion region, and the voltage drop across the p-side and n-side of the junction is negligible. The direction of the applied voltage (V) is opposite to the built-in potential Vo. As a result, the depletion layer width decreases and the barrier height is reduced. The effective barrier height under forward bias is (Vo − V).