Differentiate between 'diffusion current' and 'drift current'. Explain their role in the formation of p-n junction.

Differentiating between diffusion & drift current Explaining their role in p-n junction Diffusion current: It is due to the flow of majority charge carriers. Drift current: It is due to the flow of minority charge carriers. Due to the concentration gradient across p- , and n- sides, holes diffuse from p- side to n- side & electrons diffuse from n-side to p- side. This motion of charge carriers gives rise to diffusion current across the junction. Due to the positive space- charge region on n-side and negative spacecharge region on p-side, an electric field directed from positive charge towards negative charge develops. Due to this field, motion of charge carriers comes into play giving rise to drift current.