P-n junction, in electronics, the
interface within diodes
, transistors, and other semiconductor devices between two different types of materials called p-type and n-type semiconductors. These materials are formed by the deliberate addition of impurities to pure semiconductor materials, such as silicon.
How does a PN junction works?
When a p-n junction is formed,
some of the free electrons in the n-region diffuse across the junction and combine with holes to form negative ions
. In so doing they leave behind positive ions at the donor impurity sites. Show more detail of depletion region.
What is meant by 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.
What is pn junction semiconductor 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. … When the n-type semiconductor is joined with the p-type semiconductor, a p-n junction is formed.
Under what conditions will a silicon pn junction diode turn on?
For silicon diodes, the built-in potential is approximately 0.7 V (0.3 V for germanium and 0.2 V for Schottky). Thus,
if an external voltage greater than and opposite to the built-in voltage is applied
, a current will flow and the diode is said to be “turned on” as it has been given an external forward bias.
Why is PN junction used?
The junction which is the p-n junction diode can be
used as a photodiode
, the diode which 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 then it can be used in LED lighting applications.
What is the symbol of Zener diode?
| Pin configuration Anode and cathode | Electronic symbol |
|---|
Is zener a diode?
A Zener diode is
a silicon semiconductor device that permits current to flow in
either a forward or reverse direction. The diode consists of a special, heavily doped p-n junction, designed to conduct in the reverse direction when a certain specified voltage is reached.
Why it is called depletion region?
The depletion region is so named because
it is formed from a conducting region by removal of all free charge carriers, leaving none to carry a current
.
What causes the 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.
What is the main function of PN diode?
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 are the types of diode?
- Light Emitting Diode.
- Laser diode.
- Avalanche diode.
- Zener diode.
- Schottky diode.
- Photodiode.
- PN junction diode.
Why PN junction is called diode?
A diode is called a diode
because it has two distinct electrodes (i.e. terminals)
, called the anode and the cathode. A diode is electrically asymmetric because current can flow freely from the anode to the cathode, but not in the other direction.
What are the special diode types?
Some of the more common special-purpose diodes are
(i) Zener diode (ii)Light-emitting diode (LED)(iii)Photo-diode(iv)Tunnel diode (v)Varactor diode and (vi) Shockley diode
. A zener diode is a special type of diode that is designed to operate in the reverse breakdown region.
How do you tell if a diode is on or off?
If
the voltage across a diode
is negative, no current can flow*, and the ideal diode looks like an open circuit. In such a situation, the diode is said to be off or reverse biased. As long as the voltage across the diode isn’t negative, it’ll “turn on” and conduct current.
When would you use a diode?
Despite being nothing more than a simple two-pin semiconductor devices, diodes are vital to modern electronics. Some of their most common applications include
turning AC to DC, isolating signals from a supply, and mixing signals.
