Which one of the following is the correct statement regarding the depletion region of an unbiased p-n junction?

Options

A. Its width does not depend upon the densities of the impurities (dopants)
B. Its width is considerably increased when it is forward biased
C. The electric field in the depletion region is produd by the electrons in the conduction band and holes in the valence band
D. The potential barrier across the junction produces a very strong electric field

Answer

D

Explanation

(a),(b) , (c ) is wrong. (d) is the corrent statement .
e.g. For Ge, dV=0.3 V and dx = `10^(-6)` m
`therefore E="dV"/"dx" = 0.3/10^(-6) = 0.3xx10^6 = 3xx10^5` V/m
Thus a strong electric field is produced.