Question

What causes drift current in a p-n junction diode?

(a) Electric field

(b) Charge carriers density

(c) Collision of electrons

(d) Electric potential

This question was posed to me during an internship interview.

This is a very interesting question from Semiconductor Electronics topic in chapter Semiconductor Electronics : Materials, Devices and Simple Circuits of Physics – Class 12

Answer 1

The correct choice is (b) Charge carriers density

The explanation: Drift current is due to the high concentration of holes in the p-region and the high concentration of electrons in the n-region of the junction diode. The combined effect of the movement of minority charge carriers results in drift current.