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LEDs are light-emitting diodes (LEDs)

 - LEDs are light-emitting diodes (LEDs)

A light-emitting diode is a semiconductor light source with two leads. Nick Holoniac, who worked for a general electric company, invented the light diode in 1962.

LEDs are special types of diodes with the same electrical characteristics as P N junction diodes. They allow current to flow through the lead and prevent the current from flowing backwards. The LED occupies a small area less than 1 mm2.

 - LEDs are light-emitting diodes (LEDs)

How does a Light Emitting Diode work?


LEDs are p-n junction diodes that operate on the principle of electro-luminance. In a material called electro-luminance, electrical energy is converted into light energy, which is used to propagate light energy. When light is emitted in front bias, it is called a light-emitting diode.

LED construction

A LED is usually constructed from gallium arsenide (GAS), gallium phosphide (GAP), or gallium arsenide phosphide (GASP). Any of these materials can be used, but the color of the light depends on the material.
The table below shows the name of the material and the corresponding color of the light it emits.
MATERIALS IN CONSTRUCTIONCOLOURFORWARD VOLTAGE (IN VOLTS)
GaPGreen/Red2.2
GaAsPYellow2.2
GaAsPRed1.8
GaNWhite4.1
GaNBlue5.0
AllnGaPAmber2.1
AllnGaPYellow2.1

How does a Light Emitting Diode work?

Light-emitting diodes are what we know as forms of diodes, and when they are forward biased, electrons are moving rapidly at the hole junction and continuously joining, making the entire atom more stable and releasing a small amount of energy in the form of a photon of light when the diode is forward biased.

 - LEDs are light-emitting diodes (LEDs)
The workings of a light-emitting diode

According to the figure, N-type silicon has a red color and contains electrons, whereas P-type silicon has a blue color and has holes. The power supply to the p-n junction biases the diode forward, pushing the electrons from n-type to p-type. Electrons and holes are connected at the junction, and photons are closed as electrons and holes are rearranged.

LEDs: Their Working Principle

The working principle of LEDs is based on the quantum principle. According to quantum theory, electrons move from high energy levels to low energy levels. When photon energy is released, the distance between the two levels of energy remains the same. In semiconductors, current flows through a PN-junction diode when it is in forward bias. The flow of current in semiconductors is caused by two opposite currents and the flow of electrons in the current direction.
 - LEDs are light-emitting diodes (LEDs)
Due to the flow of these charge carriers, recombination occurs, which indicates that electrons in the conduction band jump below the valence band. When electrons jump from one band to another, they emit electromagnetic energy as photons, and their energy equals the forbidden energy interval.

The applications of light-emitting diodes

There are many uses for light emitting diodes, but some of them are listed below.
LED screens are commonly used as billboards or entertainment backgrounds.

Household LED lamps use LEDs.

Industrial lights are made from LED fluid.
Street lights and traffic signals use roads.
Calculators and digital clocks use them.

LED’s advantages

It operates in a wide range of temperatures from 00C to 700C
The LED switching time is in the range of 1ns. As a result, they are useful in dynamic operations involving many arrays.

It uses very little power and can run even at low power levels.
The LED’s radiant power is determined by the current flowing through it. As a result, the LED’s light intensity can be easily controlled.

Economical and reliable-LEDs are cheap and reliable.

They can be stacked together to form an alphanumeric display due to their small size and portability.
LED’s disadvantages

When the power exceeds a certain limit, there is a risk of loss. Even when the power is low, the same can be achieved.
An excessive increase in radiant power causes it to overheat. LEDs can be damaged by this.
Screens made of LEDs

Rental panel for indoors and outdoors – Climber

Rental panel for indoors and outdoors – SPad Pro
LED display for outdoor use – Ares
LED video wall hiLux Pro – Indoor

LED’s advantages

  1. It operates in a wide range of temperatures from 00C to 700C
  2. LED switching time is in the order of 1ns. As a result, they are useful in dynamic operations with many arrays.
  3. Low power consumption- It consumes very little power and can run with a low power supply.

4.The radiant power of the LED is determined by the current flowing through it. As a result, LED light intensity can be easily controlled.

  1. Cheap and reliable LEDs have a high degree of reliability and are economical in price.
  2. They are small and can be stacked together to form an alphanumeric display.

LED’s disadvantages

1.If the power exceeds a certain limit, there is a possibility of loss. When the power is low, the same is possible.

2.Overheating due to radiant power – It overheats when radiant power is excessively increased. LEDs can be damaged by this.

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