Question

How does diffusion current produce the depletion region?

(a) The diffusion causes the holes and electrons to collect at the junction

(b) The diffusion is because of the depletion region

(c) The depletion region aids diffusion

(d) The statement is not true

The question was posed to me in a job interview.

My question is based upon Drift and Diffusion Current in portion Diode Circuit of Analog Circuits

Answer 1

Correct option is (a) The diffusion causes the holes and electrons to collect at the junction

To explain: The diffusion of carriers from one side to another makes the holes and electrons to collect on either side of the junction creating the depletion region. This is further widened or shortened depending on the biasing.