Light Emitting Diodes (LED) is a semiconductor device that emits light when an electric current passes through it. It is a type of solid-state lighting technology that has gained immense popularity and is widely used in various applications due to its energy efficiency, longevity, and versatility.
LEDs work based on the principle of electroluminescence, where light is produced when electrons recombine with electron holes in a semiconductor material. The semiconductor material used in LEDs is typically a combination of different elements such as gallium, arsenic, phosphorus, and nitrogen, which determine the color of the emitted light.
Light Emitting Diodes (LEDs) are the most widely used semiconductor diodes among all the different types of semiconductor diodes available today. Light emitting diodes emit either visible light or invisible infrared light when forward biased. The LEDs which emit invisible infrared light are used for remote controls.
A light Emitting Diode (LED)
is an optical semiconductor device that emits light when voltageis applied. In other words, LED is an optical semiconductor device that converts electrical energy into light energy.
When Light Emitting Diode (LED) is forward biased, free electrons in the conduction band recombines with the holes in the valence band and releases energy in the form of light.
The process of emitting light in response to the strong electric field or flow of electric current is called electroluminescence.Before going into how LED works, let’s first take a brief look at light self. Since ancient times man has obtained light from various sources like sunrays, candles and lamps.
In 1879, Thomas Edison invented the incandescent light bulb. In the light bulb, an electric current is passed through a filament inside the bulb.
When sufficient current is passed through the filament, it gets heated up and emits light. The light emitted by the filament is the result of electrical energy converted into heat energy which in turn changes into light energy.In Light Emitting Diodes (LEDs), electrical energy flowing through it is directly converted into light energy.
Light Emitting Diodes
Light is a type of energy that can be released by an atom. Light is made up of many small particles called photons. Photons have energy and momentum but no mass.
Atoms are the basic building blocks of matter. Every object in the universe is made up of atoms. Atoms are made up of small particles such as electrons, protons and neutrons.
Electrons are negatively charged, protons are positively charged, and neutrons have no charge.
The attractive force between the protons and neutrons makes them stick together to form nucleus. Neutrons have no charge. Hence, the overall charge of the nucleus is positive.
The negatively charged electrons always revolve around the positively charged nucleus because of the electrostatic force of attraction between them. Electrons revolve around the nucleus in different orbits or shells. Each orbit has different energy level.