What is depletion layer in BJT?

In the depletion region, an electric field exists that quickly sweeps out electron-hole pairs that may be thermally generated and reduces the equilibrium concentration of the charge carriers to exceedingly low levels. This region, called the depletion layer, behaves as an insulator.

How many depletion regions does a transistor have?

two depletion regions
The device in Figure below (a) has a pair of junctions, emitter to base and base to collector, and two depletion regions. (a) NPN junction bipolar transistor.

Why is depletion region important?

Free charge carriers cannot be present in a region where there is a potential barrier. This creates the depletion region. Hence, the formation of a depletion layer across the junction is important to limit the number of majority carriers crossing the junction.

What is depletion region in semiconductor diode?

[ dĭ-plē′shən ] 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. See also semiconductor diode.

How is the depletion region formed?

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.

Is depletion region is created by ionization?

The depletion region is a region void of any charges. So obviously ionization is ruled out because ionization creates charges. Diffusion is a process where charges move from higher concentration to lower concentration with or without the influence of field. They are responsible for charge movement through the junction.

What is depletion region in a semiconductor 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.

How depletion region is formed?

What is depletion region 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 depletion region in semiconductor physics?

Similarly, in semiconductor physics, the depletion region refers to a region where flow of charge carriers are decreased over a given time and finally results in empty mobile charge carriers or full of immobile charge carriers.

What is the depletion region?

The depletion region is also called as depletion zone, depletion layer, space charge region, or space charge layer. The depletion region acts like a wall between p-type and n-type semiconductor and prevents further flow of free electrons and holes.

What is the depletion region of a diode?

Depletion Region: 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 depletion mode transistor with example?

Example: A transistor that is closed (on), which allows current to pass, but is triggered to open (off) and resist the current is called depletion-mode transistor. Depletion mode transistors are always passing current until they are turned off.