# What is the reason for diffusion current?

## What is the reason for diffusion current?

Diffusion current Density is a current in a semiconductor caused by the diffusion of charge carriers (holes and/or electrons). This is the current which is due to the transport of charges occurring because of non-uniform concentration of charged particles in a semiconductor.

What causes diffusion current in pn junction?

When a p-n junction is formed, holes diffuse from the p-side to the n-side while electrons diffuse from the n-side to the p-side. This result due to the concentration gradient across p and n sides, which gives rise to a diffusion current across the junction.

What is drift and diffusion current in diodes answer?

Drift current is electric current due to the motion of charge carriers under the influence of an external electric field while diffusion current is electric current due to the diffusion of carriers leading to a change in carrier concentration.

### What is diffusion current in diode?

Diffusion current is holes and electrons moving from areas of high concentration, where they are the majority carrier, to areas of low concentration, where they become minority carriers. This occurs until they are uniformly distributed. Unlike drift, diffusion takes place without an electric field being present.

What is the direction of diffusion current in a function diode?

In junction diode, the direction of diffusing current is from P-region to N-region.

What is diffusion in pn junction diode?

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. Similarly, holes diffuse from p-side to n-side.

#### Why hole diffusion current is negative?

The concentration of holes is decreasing as you go from the -x to +x direction. Therefore, holes will diffuse to the +x direction where there’s a lower concentration of holes. This is why the negative sign is needed in the equation for the hole diffusion current.

What is the direction of diffusion current?

Solution : In junction diode, the direction of diffusing current is from P-region to N-region.

How diffusion current is different from drift current?

Hint: Drift current is the electric current due to the movement of charge carriers under the impact of an outer electric field, while diffusion current is the electric current due to the distribution of carriers, pointing to a change in carrier collection.

## In which direction is the diffusion and drift of current in a diode?

The direction of charge carriers in the semiconductor is reverse to each other. For charge carriers, the densities of diffusion are reverse in symbol to each other. The direction of the drift current, as well as the electric field, will be the same.

What is meant by diffusion in diode?

Why does diffusion current increase when the diode is forward biased?

When the diode is forward biased, V A > 0, the potential hill is still present, but is is less steep. A smaller potential hill means electrons from the n-side and holes from the p-side need less energy to climb the hill, therefore diffusion current increases.

### When does a diffusion current occur what happens?

This occurs as long as there are carriers available. Diffusion current is holes and electrons moving from areas of high concentration, where they are the majority carrier, to areas of low concentration, where they become minority carriers. This occurs until they are uniformly distributed.

Which is the only value of voltage across a diode?

The difference is that forward biased voltage across the complete circuit provided by the external voltage source. While forward voltage (VF) is the only value of voltage across the diode in a circuit. Lets start. The current flows when the diode is forward is called forward current.

Why is the flow of charge carriers referred to as diffusion?

In order to achieve uniformity, the flow of charge carriers takes place from higher concentration area to lower concentration area. It is referred to as diffusion. This process generally doesn’t occur in conductors. Fick’s law well describes the diffusion of flux from that the thesis is derived for the diffusion of electrons as well as for holes.