What is drift current and diffusion current in pn junction diode?
Diffusion current is a current in a semiconductor caused by the diffusion of charge carriers (holes and/or electrons). The drift current, by contrast, is due to the motion of charge carriers due to the force exerted on them by an electric field.
What is diffusion and drift in pn junction?
Diffusion is the process of movement of charge carriers due to concentration gradient along the semiconductor. In a p-n junction, n-side has excess of electrons and hence electrons diffuse from n-side to p-side. Drift is the process of movement of charge carriers due to the net electric field.
In which direction does the diffusion and drift current flow in the diode?
As we apply the voltage to the diode, the holes will move towards the negative terminal of the battery and the electrons will move towards the positive terminal of the battery. The direction of the drift current is opposite to the direction of the diffusion current.
What is drift current in unbiased pn diode?
Now if an electron from p-type comes in the depleton region then the electric field pushes the electron to the n-type. Similarly holes are drifted towards the p-type. Thus due to these holes and electron drift, a drifting current exists which flows from n-type to p-type.
When does the PN junction diode have a forward biased current?
When the diode is forward biased drift current is present, but because diffusion current grows exponentially, it dominates. The total current flowing through the depletion region under forward biasing is made up of mostly majority carrier diffusion. When the diode is reverse biased diffusion is negligible, but drift remains constant.
How is the drift current in a p-n junction?
Similarly holes are drifted towards the p-type. Thus due to these holes and electron drift, a drifting current exists which flows from n-type to p-type. Was this answer helpful?
How is pn-junction formed in the diffusion process?
Because both the types of semiconductors will present over a single crystal at the center so that PN-junction can be formed. When the doping of this junction diode is done non-uniformly then charge carriers movement will be an exit from high to low concentration which leads to the recombination of carriers as well as to the diffusion process.
When does the doping of a junction diode occur?
When the doping of this junction diode is done non-uniformly then charge carriers movement will be an exit from high to low concentration which leads to the recombination of carriers as well as to the diffusion process. There is an additional method is also occurs based on the applied electric field namely drift current.