How depletion region is formed in pn junction?
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.
When depletion region is formed?
A depletion region is also formed when only the anode electrode is connected to the high-voltage power supply, relying on the air to provide the negative charge to create a field and cause cation migration in the glass [2].
How does the depletion region behave?
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.
Why there are no charge carriers in depletion region?
The region depleted of mobile charge carriers is called the 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.
What is the width of depletion region?
The physical width of the depletion region in a typical Si diode ranges from a fraction of a micrometer to tens of micrometers depending on device geometry, doping profile, and external bias. Figure 11.4.
What is difference between potential barrier and depletion region?
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 the potential barrier in pn junction?
Definition: The potential barrier in the PN-junction diode is the barrier in which the charge requires additional force for crossing the region. In other words, the barrier in which the charge carrier stopped by the obstructive force is known as the potential barrier.
What is a barrier potential voltage?
The negative charge formed at the p-side of the p-n junction is called negative barrier voltage while the positive charge formed at the n-side of the p-n junction is called positive barrier voltage. The total charge formed at the p-n junction is called barrier voltage, barrier potential or junction barrier.
What is potential barrier in depletion region?
Potential barrier is the potential difference or junction voltage developed across the junction due to migration of majority charge carriers across it when p-n junction is formed. It opposes further migration of majority carriers across the junction due to this junction voltage.
How does the depletion region work?
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 potential barrier is created?
Barrier Potential: The electric field formed in the depletion region acts as a barrier. External energy must be applied to get the electrons to move across the barrier of the electric field. The potential difference required to move the electrons through the electric field is called the barrier potential.
Do you mean by depletion layer?
In semiconductor physics, the depletion region, also called depletion layer, depletion zone, junction region, space charge region or space charge layer, is an insulating region within a conductive, doped semiconductor material where the mobile charge carriers have been diffused away, or have been forced away by an …
What does depletion mean?
Depletion is an accrual accounting technique used to allocate the cost of extracting natural resources such as timber, minerals, and oil from the earth. Like depreciation and amortization, depletion is a non-cash expense that lowers the cost value of an asset incrementally through scheduled charges to income.
What is there in depletion region?
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.
Why is the depletion region important?
The depletion region acts like a wall between p-type and n-type semiconductor and prevents further flow of free electrons and holes.
Why an electric field is produced in a depletion region of a pn junction?
Hence, the regions nearby the p-n interfaces lose their neutrality and become charged, with positive charge on n-side and negative charge on p-type. Thus, the electric field in the depletion layer of an unbiased p-n junction is from n-side to p-side.
What is the barrier voltage of germanium?
The barrier potential of germanium is approximately 0.3 V, and of silicon is 0.7 V. These values cannot be measured directly and appears across the space charge region of the junction. In order to produce current conduction, the barrier potential of a P-N junction must be overcome by an external voltage source.
When a pn junction is formed diffusion current causes?
Right Answer is: D When a PN diode is forward biased then diffusion takes place, which will reduce the depletion width and results in the lowering of barrier potential. Hence, we can say that the diffusion current causes the barrier potential.