White LEDs are already illuminating handheld devices’ display backlighting and camera flashes. Within 5 years, the majority of lights within the U.S. and much of the rest of the world will have shifted over from incandescent and fluorescent technology to solid-state: light-emirting diodes simply do a much better job of converting electrons to photons than incandescent lights and are longer-lasting than fluorescents.
LED lighting in general illumination applications has the potential in the U.S. alone to reduce lighting energy consumption by nearly one half. Over the next twenty years, the DoE estimates cumulative energy savings to total $250 billion at today’s energy prices and reduce greenhouse gas emissions by 1,800 million metric tons of carbon. This historic shift would not be possible without the development of a manufacturable intense blue LED light source.
In the fast moving and ever-evolving world of electronics, LEDs have been around for a long time, dating back to the ‘70s when the first red LED watches and displays were sold. These low-power LEDs, initially red but soon including yellow, were indicator or display lights: they imparted information rather than illumination. The goal of a blue LED had stubbornly eluded the top research organizations in the field.
Shuji Nakamura, a young engineer with a master’s degree in engineering at Nichia, a relatively small Japanese company that made phosphors for fluorescent lights and CRT displays, was becoming increasingly frustrated with his lack of ability to create new products that his company could sell. He obediently developed the new products his salespeople told him the market needed, only to be blamed when they failed to sell.
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Very well, he decided, if need be he would quit, but in the meantime he would work on projects that he personally believed to be important. And clearly being a proponent of finding a Big, Hairy, Audacious Goal, Nakamura decided to set as his goal the invention of the blue LED which had so far bedeviled researchers at companies and universities alike.
He got no support from his immediate boss: When he mentioned his goal, his boss’s reply was, “Are you stupid? The big companies have all tried and failed – what makes you think you could do it here, at a small company, with no budget and without proper equipment?” Deciding that he would have to go straight to the head of his company to get support, he walked into the founder of Nichia’s office one morning and said, “I want to develop a blue LED.”* To his surprise, he received permission to go ahead.
His lone quest to make a manufacturable gallium-nitride-based blue LED was ultimately successful. With the addition of a phosphor coating, Nakamura’s blue LED achieved the Holy Grail of solid state lighting – an intense solid-state white light source. Other companies, like Lumileds, Osram, and Cree also participated in the race to the new technology, and like Nichia, remain leaders today. Virtually single-handedly, Shuji Nakamura invented a manufacturable intense blue LED while working in a society where the lone-wolf entrepreneur is not a cultural icon.
*Quotes are from the book, “Brilliant” by Bob Johnstone.
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In the 2008 Beijing Olympics, the exterior of the Bird's Nest stadium and Water Cube aquatic center were lit by 750,000 red, blue and green LED chips manufactured by Cree (Durham, NC).