Question

What is the difference between Drift current & Diffusion current ?

Answer 1

In a pn junction , the current due to concentration difference or gradient is called Diffusion Current. Here charge carriers move from a region of high concentration of carriers to a region of low concentration.

Answer 2

Drift Current on the other hand is due to the external potential applied to pn junction. The electric field due to this potential results in a force on charge carriers , thereby making them move, which results in a current. This current is called Drift Current.

Answer 3

ohk So in my book it says "Initially, diffusion current is large and drift current is small" How is it so ?

Answer 4

When the applied potential is less, drift current is less. Diffusion current is due to the concentration gradient. So diffusion current dominates initially.
When the applied potential is large, drift current becomes large and dominates. That time diffusion current is negligible

Answer 5

Star did you understand?

Answer 6

Ok Yes i did
Thank you :)

Answer 7

welcome:)