LED: A Long Road to Modern LED Development

Electroluminescence, the process that makes LED lighting possible, has its origins going way back to 1907, when British scientist H. J. Round, working out of the famous Marconi Labs, was using a sliver of silicon carbide with a cat's whisker. This started scientists on the road to LED development that has lasted most of the last century.

In 1927, Oleg Vladimirovich Losev out of Russia created the first official LED. His country, plus the scientists in Germany and England, shared the information, but nothing was really done with the new technology until Rubin Brownstein of RCA discovered infrared emissions from a conductor alloy called gallium arsenide in 1955.

Moving ahead to 1961, and America joins the development history when Texas Instruments scientists Robert Biard and Gary Pittman discovered gallium arsenide let off radiation in infrared when electricity was introduced to it. This LED to the infrared LED patent.

Red LED had its first practical use a year later when GE employee Nick Holonyak Jr put it to use. Ten years later, Holonyak's grad student, M. George Craford, invented the first yellow LED and enhanced the red's and orange-red's brightness aspect to ten times more powerful than a decade earlier. Four years after that, T.P. Pearsall developed the high-efficiency, high-bright LEDs used in fiber optics. This changed the face of telecommunications permanently.

The cost of both infrared and visible LEDs were through the roof until around 1968, so these expensive units weren't developed for practical use. Monsanto stepped in to develop mass-produced visible LEDS, with gallium arsenide phosphide in indicator lights. Hewlett Packard came next, bringing LEDs to the general market in '68. They started by using the gallium arsenide phosphide coming directly from Monsanto, and began commercial life in HP's calculators.

The 70s brought on inexpensive LEDs, thanks to Fairchild Optoelectronics, which produced them at a cost of less than five cents a unit. This opened the door to further develop and use LEDs in practical daily usage.