What is an LED (Light Emitting Diode)?


LED is basically a semiconductor device like GaAs (Gallium arsenide) and GaP (Gallium phosphide) which emits visible light when an electric current is passed through it. Generally it is monochromatic and mostly used in indoor & outdoor lighting and electronic displays. Proper combination of RGB i.e red, green and blue produce a white light, such technology in lighting is more efficient in energy saving and has longer life span than ordinary incandescent bulbs.

The idea is to create bright white light by using combination of RGB diode. The green and red diodes were invented past five decades back in 1962, and blue diode was developed by three Japanese scientists Isamu Akasaki, Hiroshi Amano and Shuji Nakamura in 1990s. In year 2014, The Royal Swedish Academy of Sciences has awarded the noble prize in physics to these three scientists. With their invention, soon incandescent light bulbs are replaced by the LED’s as its more efficient and environment friendly. They produce more light and require 30% low power compared to ordinary bulbs. Thus the invention of blue LEDs has created huge impact in power consumption.

The mechanism behind traditional, incandescent and fluorescent lamps is they use electricity to heat the filament to produce light. However, LED is based on PN junction diode that uses two lead semiconductors which directly converts the applied electric power into photons of light. They consume very less power compared to ordinary bulbs.

Today LED has not only replaced the ordinary bulbs but also the technology is being used in making LCD (liquid crystal display) screens for computers, TVs and smartphones. LCD screens use cold cathode fluorescent lamps (CCFL) to provide back lighting whereas LED uses an array of smaller LED lights. LEDs provide better backlighting and have more contrast with better color accuracy when compared to LCDs.

Advantages of Blue LEDs

Automobile Industry
As LEDs are brighter and durable than traditional filament bulbs they are used in headlights and tail lights. They have quicker response when turned on and provide more visibility while driving in fog. LED is not only used for lighting but also used in styling LED strips & LED logos.

Electronic Industry
In electronic industry, LED provides backlight for screen. Without blue light there will not be good quality display in smartphones, TVs and computers. Apart from that, blue ray players in DVDs use blue LED to read data from digital optical disk. The change of disk technology from infrared laser to blue LED laser made it possible to store 5 times more data.

Blue LEDs are also used in communication for transmitting data which is similar to Wi-Fi called Li-Fi (light fidelity). They have high capability of transmitting data with speeds of 224 Gbps.