Question

Explain the following term:

Drift velocity and Mobility

Answer 1

Under an applied electric field both the current carriers, i.e., electrons and holes acquire an average velocity, called drift velocity (v).
It is defined as the average velocity acquired by the charge carriers of the semiconductor under the influence of an electric field.

Drift velocity ∝ electric field.

i.e.   `v prop "E"`

`v = mu"E"`

Where µ is the constant and called the mobility of charge carriers.