Concept:Forward biasing reduces the height and width of the potential barrier, allowing majority carriers from both sides to diffuse across the junction.
Formula:$$I_F = I_{\text{diff}} - I_{\text{drift}} \approx I_0 e^{\frac{qV_F}{\eta k T}}$$
Solution:- When the forward voltage \( V_F \) counteracts the barrier voltage \( V_0 \), electrons in the N-region and holes in the P-region gain enough energy to cross the junction.
- This flow of majority carriers constitutes the forward diffusion current.
Why other options are incorrect:- Option A: Drift of minority carriers constitutes the reverse saturation current, not the forward current.
- Option C: Thermionic emission occurs in vacuum tubes at high temperatures, not solid-state PN junctions.
- Option D: Atomic nuclei remain fixed and do not participate in electronic conduction.
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