Question

The dominant mechanisms for motion of charge carriers in forward and reversed biased silicon p-n junctions are :

• A. Diffusion in forward bias, drift in reverse bias
• B. Diffusion in both forward and reverse bias
• C. Drift in both forward and reverse bias
• D. None of these

Answer 1

The correct option is A Diffusion in forward bias, drift in reverse bias

$\Rightarrow$ In forward bias we apply voltage in a direction opposite to that of barrier potential p-side to positive terminal, n-side to negative terminal of battery. So electrons in the n-side, holes in p side pushed towards the junction. Results in increased diffusion.

$\Rightarrow$ In reverse bias, electrons in n-side, holes in p-side pushed away from function.

Ref. image

n-side to positive terminal p-side to negative terminal.