During the formation of the p-n junction, two processes occur: Diffusion and drift. ... This space-charge region on either side of the junction together is known as the depletion region as the electrons and holes taking part in the initial movement across the junction depleted the region of its free charges.

What happens to the depletion region for a pn junction?

A depletion region forms instantaneously across a p–n junction. ... In a N-side region near to the junction interface, free electrons in the conduction band are gone due to (1) the diffusion of electrons to the P-side and (2) recombination of electrons to holes that are diffused from the P-side.

Why there is a depletion region at the pn junction?

Depletion Region Details

Filling a hole makes a negative ion and leaves behind a positive ion on the n-side. A space charge builds up, creating a depletion region which inhibits any further electron transfer unless it is helped by putting a forward bias on the junction.

How depletion region is formed in a junction diode?

Depletion region is formed in a junction diode because depletion region is created around the p-n junction which is devoid of free charge carriers and has immobile ions. It is created due to diffusion of majority carriers across the junction when p-n junction is formed.

What is depletion region of a diode?

Depletion region or depletion layer is a region in a P-N junction diode where no mobile charge carriers are present. Depletion layer acts like a barrier that opposes the flow of electrons from n-side and holes from p-side.

Formation and Properties of Junction Diode - Physics

What is depletion region?

A region in a semiconductor device, usually at the juncture of P-type and N-type materials, in which there is neither an excess of electrons nor of holes. Large depletion regions inhibit current flow.

What is pn junction diode?

A p-n junction diode is two-terminal or two-electrode semiconductor device, which allows the electric current in only one direction while blocks the electric current in opposite or reverse direction. ... The p-n junction diode is made from the semiconductor materials such as silicon, germanium, and gallium arsenide.

What is depletion region in pn junction Class 12?

This space-charge region on either side of the junction together is known as the depletion region as the electrons and holes taking part in the initial movement across the junction depleted the region of its free charges.

What is a PN junction explain the formation of potential barrier in a PN junction?

p–n junction is a junction formed by joining p-type and n-type semiconductors together in very close contact. ... As electrons diffuse across the junction a point is reached where the negative charge repels any further diffusion of electrons. The depletion region now acts as a Barrier. Barrier Potential.

How does the PN junction work?

A diode (PN junction) in an electrical circuit allows current to flow more easily in one direction than another. Forward biasing means putting a voltage across a diode that allows current to flow easily, while reverse biasing means putting a voltage across a diode in the opposite direction.

What is a depletion region explain its significance?

The word depletion in English refers to the decrease in the quantity of something. Similarly, in semiconductors, the depletion region is the layer where the flow of charges decreases. This region acts as the barrier that opposes the flow of electrons from the n-side to the p-side of the semiconductor diode.

What is the purpose of depletion region?

The depletion region acts like a wall between p-type and n-type semiconductor and prevents further flow of free electrons and holes.

What causes depletion region?

The depletion region is caused by the diffusion of charges. Because of the concentration gradient holes diffuse from p-side to the n-side across the junction while electrons diffuse from the n-side to the p-side. The holes and the electrons diffusing towards each other combine near the junction.

What do you mean by depletion region in a PN junction?

Depletion region or depletion layer is a region in a P-N junction diode where no mobile charge carriers are present. Depletion layer acts like a barrier that opposes the flow of electrons from n-side and holes from p-side.

What is depletion layer Class 12?

Depletion layer is the region created around the p-n junction which is devoid of free charge carriers and has immobile ions.It is created due to diffusion of majority carriers across the junction when p-n junction is formed.

How does depletion region decrease forward bias?

In a P-N junction diode, the width of the depletion region decreases in forward bias. This is due to the electrons being attracted by the positive terminal of the battery, and hence the negative ions disappear. Thus, the forward bias narrows the depletion region, due to the carriers from the battery terminals.

Which process causes depletion in a PN junction?

The depletion layer in the p-n junction region is caused by diffusion of charge carriers.

What is junction barrier?

Noun. 1. junction barrier - a junction unit for connecting 2 cables without the need for plugs. barrier strip. junction, conjunction - something that joins or connects.

What is a PN junction explain VI characteristics of a pn junction?

Volt-ampere (V-I) characteristics of a pn junction or semiconductor diode is the curve between voltage across the junction and the current through the circuit. Normally the voltage is taken along the x-axis and current along y-axis.

How is a depletion region formed in P-N junction Class 12?

Movement of electrons to the p-type side exposes positive ion cores in the n-type side while movement of holes to the n-type side exposes negative ion cores in the p-type side, resulting in an electron field at the junction and forming the depletion region.

Is depletion region neutral?

There isn't any neutral region in the depletion region.

What is depletion layer and barrier potential?

Deplection region is a region created around the p-n junction which is devoid of free charge carriers and has immobile ions. ... Potential barrier is a potential difference or junction voltage developed across the junction due to migration of majority carriers across it when p-n junction is formed.

What is junction in pn junction?

A p–n junction is a boundary or interface between two types of semiconductor materials, p-type and n-type, inside a single crystal of semiconductor. ... A Schottky junction is a special case of a p–n junction, where metal serves the role of the n-type semiconductor.

What is the use of PN junction?

Applications of PN Junction Diode

p-n junction diode can be used as a photodiode as the diode is sensitive to the light when the configuration of the diode is reverse-biased. It can be used as a solar cell. When the diode is forward-biased, it can be used in LED lighting applications.

What is the main function of a pn junction?

A p-n junction represents an electrical component with the function to allow an electric current in one direction (called the forward biased condition) and to block the current in the opposite direction (the reverse biased condition): a diode.