A Potted History of LED Lighting
Today's LEDs are incredibly energy-efficient and have a much longer lifespan than any other light source that’s currently on the market. But this wasn't always the case as you'll discover when you delve into LED Monkey's potted history of LEDs…
Way Back When
In 1907, Henry Joseph Round (Pictured below), a British engineer at Marconi Laboratories, discovered that passing 10 volts of electricity through Carborundum (Silicon Carbide) crystal made it emit a faint yellowish light.
The first person to thoroughly investigate the phenomenon and to propose a working theory, however, was Oleg Vladimirovich Losev a Russian scientist.
In 1927, Losev published a 1044-page paper entitled Luminous Carborundum Detector and Detection Effect and Oscillations with Crystals. This described his experiments and observations at great length.
For a great many years, no further progress was made. Then, in 1955, Rubin Braunstein of the Radio Corporation of America, observed infrared emissions being generated by simple diode structures using Gallium Antimonide, Indium Phosphide and Silicon-Germanium alloys at room temperature and also at 77° Kelvin.
In 1957, Braunstein further demonstrated that it was possible to use the simple LED devices for non-radio communication across a short distance. This foreshadowed their use in optical communication applications.
The First LED Patent
In 1961, Gary Pittman and Bob Baird from Texas Instruments, discovered that Gallium Arsenide diodes emit infrared light when they’re connected to an electrical current.
And, in the same year, they achieved the world's first infrared LED patent, too.
The next year, Nick Holonyak Jr. (pictured below), an engineer at General Electric, developed the first LED capable of emitting visible light.
Holonyak's was the very first red LED. However, just a decade later, his student was to surpass his achievements!
That's right, M. George Craford, a student of Holonyak’s, invented not only the first yellow LED but also a brighter red one!
In 1976, Thomas P. Pearsall developed a high brightness LED, for use in telecommunications fibre optics. Then, in 1979, Shuji Nakamura of Nichia Corporation created the first blue LED.
Nakamura, who's pictured below, won the Nobel Prize in Physics for his blue LED. However, it was too expensive for commercial applications until 1994, some 15 years later. Indeed, in that year, the revolutionary invention started being produced more cost-effectively thanks to technological improvements.
As a direct result of all these developments, LEDs are now available in a variety of different colours and colour temperatures.
Initially, LEDs were unbelievably expensive, some changing hands at up to $200 each! This meant that they were only useful as indicator lights in specialised laboratory equipment.
Fairchild Semiconductors succeeded in reducing the cost of individual LEDs to just 5 cents in the 1970s. They achieved this by using the "Planar" manufacturing process in the production of its semiconductor chips.
By exploiting innovative packaging techniques, combined with the Planar process, Fairchild Semiconductors made LED into a commercially viable product with a wide variety of applications and uses.
The Many Benefits Of LED Lighting
LEDs are now being used as replacements for incandescent, halogen, fluorescent and neon light sources.
Incredibly energy-efficient, they’re capable of generating many more lumens of brightness-per-watt of electricity. This means that people can significantly reduce their lighting energy bills simply by replacing their light bulbs.
Their switching is also a great improvement on that of their slow-to-light CFL contemporaries, and means they need no warming-up time whatsoever.
Modern LED technology has also come on in leaps and bounds with regard to bulb longevity.
One of the reasons for this is that they’re made of plastic and not thin glass. So, they’re a lot more robust than other types of bulb.
LEDs also generate very little heat, and what heat they do create is effectively dissipated by an aluminium heat-sink.
Extra Long Life!
This enables them to have a long and productive lifespan of up to 50,000 hours. This is around 8 times as long as a CFL and around 20 times that of an incandescent!
Take a look at the tongue-in-cheek video below, and you'll see just how little heat an LED bulb produces compared with an incandescent. And spare a thought for the chocolate bunny that died during the making of this movie!
Talk To The Experts
If you’d like to know more about switching to LED lighting, please don’t hesitate to contact us. You can get in contact with us on 0800 999 7797, or you can send us an e-mail enquiry to: email@example.com.