Why is there an electric field in the depletion region of an unbiased junction?

Why does an electric field generate in a depletion region?

Light travels in packets of energy called photons. The generation of electric current happens inside the depletion zone of the PN junction. … The hole created by the dislodged electron is attracted to the negative charge of N-type material and migrates to the back electrical contact.

Why electric field is maximum at the center of the depletion region in the pn junction?

The Electric Field gets stronger as you move past more space charge progressing towards the junction, reaching a maximum at that point because of accumulating the same sign charge.

What happens in depletion region?

The depletion region is caused by the diffusion of charges. … The holes and the electrons diffusing towards each other combine near the junction. In doing so positive and negative ions are formed. The pair of positive and negative ions at the junction forms the dipole.

Why does depletion region increases in reverse bias?

A P-N junction diode is formed by joining one P-type and one N-type diode. … This happens because when we apply reverse bias voltage the electrons are drifted away from the junction and hence, conduction is not possible. So, the width of the depletion region in a P-N junction diode is increased by reverse bias.

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What depletion region contains?

Note: The depletion layer consists of both electrons and protons but they are immobile in nature therefore the correct answer would be immobile ions. The donor and acceptor atom get a positive and negative charge due to which the PN junction forms.

Why charge carriers are not present in depletion region?

The depletion region has only positive ions and negative forms due to the diffusion of carriers across the junction of the pn diode. …

When PN junction is unbiased the junction current?

In an unbiased PN-junction the junction current at equilibrium is zero, because equal but opposite carriers crossing the junction.

What is an unbiased junction?

Unbiased p-n junction

Unbiased conditions mean that there is no external energy source (no voltage). In an unbiased diode, an electric field is set up across the depletion layer between the n-type and the p-type material.