• Poornima Mani

Light Emitting Diode

Updated: Dec 1, 2020

This article will provide you an understanding of all the basics you necessitate to grasp about Light Emitting Diodes or simply LEDs.

First of all, let us keep it simple. An LED is nothing but a semiconductor device that is capable of emitting light when electricity passes through it. In this semiconductor device, light is emitted during the recombination of electrons and holes. LEDs are widely used across the world and are replacing the conventional incandescent and tungsten halogen lamps.

LED and Lighting - Brief History

The first LED that was invented by two scientists working at Texas Instruments accidentally when one of the scientists was working on a laser diode. But this light was IR and therefore invisible to the naked eye. Later Gallium Arsenive revolutionized the very first use of practical LED and produced visible red light. Ever since there hasn't been a break and lead to the rise of various other colors such as green, blue, and white light. Right now, there is even technology that is capable of liberating "black" light.

How do LEDs emit such a wide range of colors?

As mentioned previously, LEDs are semiconductor devices that fall in the category of semiconductor devices, specifically solid-state devices. The electrons and protons are contained in energy bands; the difference determines the bandgap of the color of the light emitted by the LED. Different LEDs produce light of different colors depending on the wavelength and bandgap. A variety of materials are used to generate these colors with precision and altered according to demand. Until a few years back, only blue and white LEDs were of existence until Gallium Nitride (GaN) stepped in and opened up many new applications.

The most commonly used materials to make LEDs include Indium gallium nitride (InGaN), Aluminum gallium indium phosphide (AlGaInP), Aluminum gallium arsenide (AlGaAs), Gallium phosphide (GaP) to release colors including blue, green, yellow, orange, and high-brightness LEDs.

Colour Changing LEDs: A color-changing LED is a group of multiple LED light groups that come with a mini-computer (microcontroller) inside. Suppose we have blue, red and green colors inside, the computer can turn on or off, the desired colors and the combination of two more colors result in a new one.

Advantages of LED lights over conventional lighting.

There is an endless list of why people prefer to use LEDs and might leave you wonderstruck. Let us take a deeper look into it.

1. Lifespan: An LED has a lifespan of 50,000 to 100,000 hours which is almost 40 times the average lifespan of a traditional lightbulb. This means that the maintenance cost is really low and the bulb need not be replaced every once in a while.

2. Directional Emissions: One major property of LED is directional emission which basically means that the light emitted by the LED is only at the angle of 180 degrees while all other light bulbs release at 360 degrees. This saves a large amount of power and reduces the wastage of power to a really small level.

3. Much Safer: This is most probably the most overlooked property when it comes to LED lighting. Incandescent bulbs liberate a huge amount of heat (almost 90% of the power) whereas LEDs emit a very small amount of forward-heat. LEDs consume a much lesser amount of energy and are completely safe for use.

4. Energy Efficient: This is probably the most popular and famous reasons why people use LEDs. Statistics have proved that LEDs result in a 70% reduction in power consumption and if installed will result in a 90% savings.

Applications of LED

1. Automotive lighting: Visibility while driving is a major concern along with illumination. Dimming can be triggered easily and is also of great advantage to the pedestrians as this is quite safe.

2. LED Displays: Television has switched their displays into LED lighting. Display and billboards are common these days. Hence LED lighting is extensively used as it gives clear visibility for signs and comments on various languages.

3. Medical Applications: LED lights have already become an integral part of surgical illumination, photodynamic therapy, and reducing acne inflammation.

LEDs have taken over in almost all fields and are one of the most efficient and fast-developing technologies in today's world. They are preferred due to their durability, high quality, and energy-saving capability.

See Also:

  1. What is IoT?

  2. NOR Gate as a Universal Gate









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