what is drift current and diffusion current plz explain
Drift current :-
When charges(holes or electrons) move under external electric field to produce current is called drift current.
It is produced due minority carriers( holes in n–type move from right to left and electrons in P–type move from
left to right) under the external electric field developed in depletion layer.
Drift current is directed from N type to P type material.
The current that is observed when the excess holes diffuse to other side(N type) and the excess electrons diffuse to P type due carrier concentration is called diffusion current.
Diffusion current is directed from P type to N type material.
If there is no biasing drift current is equal to diffusion current.
Drift and diffusion currents :-
→ The flow of charge (ie) current through a semiconductor material are of two types namely drift & diffusion.
→ (ie) The net current that flows through a (PN junction diode) semiconductor material has two components
(i) Drift current
(ii) Diffusion current
the drift current is defined as the flow of electric current due to the motion of the charge carriers under the influence of an external electric field.
the movement of charge carriers takes place resulting in a current called diffusion current.
Diagram of the diffusion across a pn junction, with the resultant uncovered space charges, the electric field and the drift currents.