(Current flow in a pn-junction diode under forward bias.)

Under the forward bias (p-side is more positive w.r.t. n-side, or n-side is more negative w.r.t. p-side), holes are injected from the p-side (red), across the depletion region (around the junction, a region depleted of mobile carriers) into the n-side (blue). The holes injected into the n-side are minority carriers. Near the depletion region boundary, the minority-carrier hole concentration is above the thermal equilibrium concentration because of these electrically injected holes. In the neutral region (red-region) there are two processes going on for the injected minority holes: (1) diffusion and (2) recombination.

The same argument applies to the injected minority electrons.

Introduction | Mathematical Analysis | Applet Tutorial | Applet Worksheet | Quiz | SPICE/CAD | References | Feedback