The pn Junction under Forward Bias Condition

pn junction is get excited by a constant current source that supplying a current I in forward direction. The depletion layer narrows & barrier voltage drop by V volts, which appear as an external voltage in the forward direction.

1. This current causes majority carriers to be supplied to both sides of the junction by the external circuit. Holes to the p material & electrons to the n material.
2. These majority carriers shall neutralize some uncovered, causing less charge to be hold in the depletion region. Therefore the depletion layer narrows and the depletion barrier voltage dropped.
3. This decrease in voltage cause more holes to move from p side to n side and more electrons to move from n side to p side. In order that diffusion currents enhance until equilibrium is attained.