World+Dog hails 50th birthday of the LED
But this now commonplace technology is much, much older
The Light Emitting Diode (LED) is 50 years old. Well, kind of...
It’s certainly 50 years since Nick Holonyak, working at GEC’s Syracuse, New York facility, developed what is considered the first LED capable of generating visible light. Holonyak’s LED was also the first to be in form ready for commercial usage. He wrote up his work and sent it off to Applied Physics Letters on 17 October 1962. The journal published the work in December 1962 under the headline ‘Coherent (visible) Light Emission from GaAs xPx Junctions’.
However, Holonyak’s work followed that of Gary Pittman and Robert Baird who, in 1961, observed the emission of infrared light by Gallium Arsenide - the GaAs in Holonyak’s headline - and, on the back of it, applied for and gained a patent - US number 3,025,589 - for the infrared LED.
Indeed, while Holonyak was working on his visible LED, so too were Robert Hall, also of GEC but employed at a different location; IBM’s Marshall Nathan; and MIT’s Robert Rediker. All four sent papers to journals; Holonyak was judged by his peers to have produced his LED first.
LED bellies: (L-R) Nick Holonyak, Henry J Round, Oleg Vladimirovich Losev
The substance’s ability to emit infrared had been previously observed by Rubin Braunstein six years earlier, in 1955. Braunstein, who was working for RCA at the time, published his findings, ‘Radiative Transitions in Semiconductors’, in Physical Review.
Follow the literature back and you end up in Britain in February 1907, with the work of Marconi assistant Henry Round, who first observed the emission of light from a crystal of silicon carbide when a current was applied to it, a phenomenon called electroluminescence. In that sense, the LED is more than 100 years old. Round, however, never wrote a report on his findings.
Twenty years later, Russian Oleg Vladimirovich Losev became the first scientist to create a semiconductor diode capable of emitting light - the first LED. Losev’s write-up was published at home, and in Britain and Germany, under the title ‘Luminous Carborundum Detector and Detection Effect and Oscillations with Crystals’. Given the terse notification of Round’s discovery 20 years previously in the English-language Electrical World, it’s highly unlikely Losev was aware of the Briton’s discovery. He was three years old when Round first observed electroluminescence.
In 1927 Losev applied for a patent to protect his finding, and the IP was granted in December 1929. However, his work was held to be of little practical value in the pre-war, pre-electronics era. He would eventually have 43 scientific papers and 16 patents under his belt, but he died in 1942, a victim of the German siege of Leningrad. He was 39 years old.
You can read more about Losev's story in Nikolay Zheludev's article in Nature Photonics April 2007 issue. ®
Thanks to Reg reader Darryl for the tip
The BBC has a lovely audio-cum-slideshow of the LED at 50, featuring an interview with Prof Nick Holonyak.
Having as a kid inadvertently connected a BY100 silicon rectifier directly across the live- and neutral-pins of a 15 amp 240V socket, I really think I should try to establish rights to having invented that little-known but fundamentally-important semiconductor device, the Noise Emitting Diode.
By standing on the shoulders of giants
some could see further.
Now we use patents to bring them to their knees and can see from about the giants navel level - into a thicket of legislation.
Shine a little light in my life...
I was wondering when ElReg would pick up on this... as the BBC has an excellent slideshow with narration on the development and evolution of LEDs by Nick Holonyak himself, on the BBC News Tech page
I recall forking out my hard earned pocket money on red, green and yellow LEDs in the late 1970's and early 80's. To the electronic hobbyist, an illuminated LED meant it was ON! However it didn't guarantee the Everyday Electronics project I painstakingly etched and soldered together worked though!
My most valued project was an LED based VU meter and the LEDs would light up to the music levels, oh such joy for a nerdy schoolboy in 1980!
Today we take the little light emitting diode for granted, it's commonplace and cheap, but it tells us things are recording, or are powered on, on-line, the channel number or sometimes if something is actually faulty. 7 segment LEDs also tell us the time and how much things cost when we shop..
My son recently bought two LED torches, these things make a thousand plus Lumens and use Cree LED technology, how things have changed over the years. These torches have an adjustable focus point and you can actually see the square shape of the LED when the adjustable lens on the torch is zoomed out.. all this from an LED? Afuckingmazing..
Yes, the LED deserves all the credit it gets for it's 50th birthday..
Wrong one. The General Electric Company or GEC was a major British-based industrial conglomerate, involved in consumer and defence electronics, communications and engineering. It became Marconi.plc, and was then sold off piecemeal.
So who is going to blow out the LEDs on the birthday cake?
OK, OK, I'm going