The Discovery of the Light Emitting Diode

Everyone knows who Thomas Edison, the inventor of the filament light bulb, is. In fact the image of a light bulb has become synonymous with 'bright ideas.' Another bright idea is LED lighting, which is set to replace Edison's creation quite soon. This is because they are over 90 per cent more energy-efficient that traditional bulbs, which, in a world that is running on limited resources, are very important. But who is the person, or persons, behind the creation of the LED? According to The Life and Times of the LED, 'many people believe that the LED was discovered by US researchers working in the 1960s.' Actually, the story of the LED begins a number of decades beforehand a lot closer to home.

The origins of the LED can actually be traced back to a British experimenter. Henry Joseph Round (sometimes shortened to H J Round) was an early pioneer of radio broadcasting and assistant to Guglielmo Marconi, the inventor of the radio. In 1907, while performing experiments with cat's whiskers detectors, he noted the emission of light from a semiconductor diode. He found that when he passed a current through certain substances they would actually give off light; a phenomenon called electroluminescence. This is the key scientific principle behind the LED and led directly to its discovery. Even though Round published his findings in a scientific journal called Electrical World, it would be several decades before a use was found for his discovery.

The invention of the LED actually goes to a little known Russian genius called Oleg Vladimirovish Losev, whose life and work remains, unfortunately, rather obscure. His independent work on solid-state electronics, which included the first solid-state semiconductor amplifier and generator, LED to the creation of the first actual LED. His findings were published in a paper entitled 'Luminous carborundum (silicon carbide) detector and detection with crystals' was published in 1927 in a journal called Wireless Telegraphy and Telephony. This paper has been constituted the discovery of the LED.

Although Losev's research was distributed in Russian, German and British scientific journals, it did not receive any attention from the scientific community for a number of decades. For a number of years American scientists experimented with semiconductors emitting infrared light, but it wasn't until the early 1960s that a practical, visible-spectrum LED was created. Nick Holonyak Jr. is widely considered 'the father of the light-emitting diode.' He developed the first practical LEDs in 1662 while working for the General Electric Company in New York. These early LEDs were all red and were used as replacements for incandescent indicators because they used less energy. They were also put to use in seven-segment displays (digital clock displays). Before long they were being used in a wide range of appliances including televisions, radios, telephones, calculators and watches.

Over a period of time the materials and technology behind the LED have become more advanced. They can now achieve a much greater light output which has made them suitable for a wider range of applications, including television screens and household lighting. Although Round and Losev don't always receive the credit they deserve, I can imagine they would be thrilled to see what their respective work has contributed to. A GU10 24 SMD would certainly be something to be proud of. They can achieve the same brightness as a 60 watt halogen at a fraction of the energy use. They also last up to 50,000 hours. That's very impressive.

Find out more about LED Lights here.