Question

The current through any p-n junction is due to
a) drift of charge carriers.
b) diffusion of charge carriers.
c) different concentrations of same type of charge carriers in different regions.
d) same concentrations of same type of charge carriers in different regions.

• A. a, b and c
• B. a and b only
• C. only d
• D. a, b, c, d

Answer 1

The correct option is A a, b and c

In a p-n junction diode, the doping (impurity atoms) differs the concentrations of same type of charge carriers in different regions. In a semiconductor material, the charge carriers have the tendency to move from the region of higher concentration to that of lower concentration of the same type of charge carriers. Thus, the diffusion current flows through it. Also, holes move towards the negative terminal of the battery and electrons move towards the positive terminal of the battery under the influence of electric field due to externally applied potential. Thus, the drift current flows through it.