Did you know that the LED or light-emitting diodes that illuminate most of our lives today were discovered only in the 60s? The most energy-efficient and durable lighting solution available for residential and commercial usage, LEDs lights are based on the principle of electroluminescence, wherein a semiconductor converts electricity into light, across visible, ultraviolet and infrared spectres, without producing much heat. The history of LEDs is as illustrious as the journey of the earliest fire lit from a flintstone to modern industrial lighting. Let us take a sneak peek into the discovery of LED lights and the experimentation involved in their making.
In 1907, Henry Joseph Round, an Englishman, first told the world of his observation that electrical currents, when applied to silicon carbide crystals, emit a pale yellow light.
A Russian gentleman Oleg Vladimirovich Losev investigated this observation further and, in 1927, published his theory in the paper “Luminous carborundum detector and detection effect and oscillations with crystals“.
Later in 1935, Georges Destriau – a French physicist, cemented Round and Losev’s theory of light created by inorganic materials when an electric current passes through them. Known as the Father of Electroluminescence for coining the term, he discovered that zinc sulphide emits light.
The story of infrared
In 1955, Rubin Braunstein, an employee of Radio Corporation of America, revealed that some diodes emit infrared light when connected to electrical current. Gary Pittman and Bob Biard of Texas Instruments, while experimenting with a laser diode in 1961, accidentally discovered that gallium-arsenide diode emitted infrared light and got their discovery patented.
The first practical application of LED
Nick Holonyak of GE first developed a visible red light emitting-LED in 1962. Later, in 1972, M. George Craford of Monsanto Company made a yellow one that was 10-times brighter than what Holonyak had made. Seven years later, Shuji Nakamura of Nichia Corporation made the blue light. In between the making of LEDs in the various shades of the visible spectre, Thomas P. Pearsall had in 1976, developed very bright LED for use in telecommunications with fibre optics.
Monsanto Company first ventured into the production of LED-lights on a large scale for mass consumption. In the late 70s, Fairchild Optoelectronics further popularised LEDs by producing low-cost devices.
Present-day cost-efficient super-bright LEDs
The super-bright LEDs that we use now, both indoors and outdoors, have come a long way since Round first made his observation. Shuji Nakamura used Gallium Nitride to make ultra-bright blue LEDs in 1994, and soon after, Indium Gallium Nitride was used to develop intense green and blue LEDs that paved the way for the in-vogue, cost-efficient white LED lights. The journey of LED technology is dotted with consistently intense R&D for better and brighter illumination. In a nod to the exciting history and evolution of LED lights, leading home lighting experts like Oz Lighting offer a range of lighting solutions — from designer lights for sophisticated indoors to practical bollard lights for landscapes and pathways.