Pn Junction

August 31, 2024 Post a Comment

Pn junction

Definition: A P-N junction is an interface or a boundary between two semiconductor material types, namely the p-type and the n-type, inside a semiconductor. In a semiconductor, the P-N junction is created by the method of doping.

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.

Why is it called a PN junction?

They called the regions n-type (for negative) and p-type (positive); the surface or "barrier" where these regions met became known as a "p-n junction." Light striking this junction stimulated electrons to flow from the n-side to the p-side, resulting in an electric current.

What is PN junction or diode?

A p-n junction diode is a basic semiconductor device that controls the flow of electric current in a circuit. It has a positive (p) side and a negative (n) side created by adding impurities to each side of a silicon semiconductor. The symbol for a p-n junction diode is a triangle pointing to a line.

What is formula of pn junction?

In a p-n junction diode, the current I can be expressed as I=I0(exp(eVKBT)−1), where I0 is called the reverse saturation current, V is the voltage across the diode and is positive for forward bias and negative for reverse bias, and I is the current through the diode, KB is the Boltzmann constant (8.6×10−5eV/K) and T is

What is PN type of semiconductor?

p-n junction diodes are made up of two adjacent pieces of p-type and n-type semiconducting materials. p-type and n-type materials are simply semiconductors, such as silicon (Si) or germanium (Ge), with atomic impurities; the type of impurity present determines the type of the semiconductor.

What is the symbol of PN junction?

Explanation:In the figure given above, first symbol represents the circuit symbol of a semiconductor pn junction diode. The 'P' side of diode is always positive terminal and is designated as anode for forward bias. Other side which is negetive is designated as cathode and is the 'N' side of diode.

What are the properties of PN junction?

It can rectify electric current, inject minority carriers, create a potential barrier, make use of its capacitance properties, accumulate space charge, create various non-linear current—voltage characteristics, transform light energy into electrical, react to various kinds of irradiation, emit light radiation when a

What is p-type diode?

A p–n diode is a type of semiconductor diode based upon the p–n junction. The diode conducts current in only one direction, and it is made by joining a p-type semiconducting layer to an n-type semiconducting layer.

How a pn junction is formed?

P-n junctions are formed by joining n-type and p-type semiconductor materials, as shown below. Since the n-type region has a high electron concentration and the p-type a high hole concentration, electrons diffuse from the n-type side to the p-type side.

Why diode 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. In this way, it functions as a one-way valve for current.

What is the depletion layer in 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 forward bias in PN junction?

A P-N junction diode is forward biased when the P side and the N side are connected to the positive and negative terminals of a battery respectively while in reverse bias, they are connected to the opposite terminals.

What is pn junction explain forward bias?

A P-N junction diode is said to be forward biased when the positive terminal of a cell or battery is connected to the p-side of the junction and the negative terminal to the n side. When diode is forward-biased the depletion region narrows and consequently, the potential barrier is lowered.

What is pn junction diode diagram?

The symbol of the PN junction diode is depicted as a triangle pointing towards a line or running through one vertex. This arrangement shows the direction of current flow in the circuit from the positive anode terminal to the negative cathode terminal.

Is pn junction neutral?

The one-dimensional device is divided into three regions with or without an electric field. In a P-N junction, 2 regions having no electric field are on the ends of the device and are termed quasi-neutral regions.

What devices use pn junction?

p-n diodes are the basis for solar cells, photodiodes, light-emitting diodes (LEDs), and laser diodes. Solar cells are illuminated p-n junctions. They convert sunlight into electricity. Photodiodes are p-n junctions held in reverse bias used to detect light.

What are the types of diode?

Types of Diodes

Light Emitting Diode.
Laser diode.
Avalanche diode.
Zener diode.
Schottky diode.
Photodiode.
PN junction diode.

What is p-type and n-type?

In a p-type semiconductor, the majority carriers are holes, and the minority carriers are electrons. But In the n-type semiconductor, electrons are the majority carriers, and holes the minority carriers.

What is p-type impurity?

A p-type semiconductor is formed by adding a III group element(such as B, Al) as a doping element. An impurity added creates a vacancy of electrons. For example in the above picture, The impurity atom is surrounded by four silicon atoms.