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A dogged inventor whose drive and determination led him to invent a vital optoelectronic component has been rewarded with Finland’s €1m Millennium Technology Prize. The previous winner was Sir Tim Berners-Lee, inventor of the world-wide web.
Professor Shuji Nakamura invented the blue light-emitting diode (LED), which makes new products, such as alternative display technologies, possible. In the longer term his work may lead to high-efficiency lighting systems that could have a significant impact on global energy consumption.
Dr Tech Tapio Alvesalo, secretary general of the Millennium Prize Foundation, said: “Seeing his enthusiasm and drive for his research, it’s clear that the money isn’t the main thing for him.”
Professor Nakamura received his master’s degree in 1979 at the University of Tokushima in rural Japan. He then started his scientific and technological career outside the mainstream of Japanese technology, working as an engineer at Nichia Chemical, a small phosphor company in the countryside.
According to Alvesalo, Nakamura had only modest support from his company, which didn’t feel it could afford to support his work.
“Nakamura started doing his research outside the mainstream, but it was something he believed he could do, so he worked his way through to solve the problems. He overcame some really difficult issues to create the gallium nitride (GaN) LED,” said Alvesalo.
Nakamura patented his work, and later won a €138m (¥20bn) settlement against Nichia, after they paid him a bonus of just €138 (¥20 000) for his invention. The company had earned royalties of €820m (¥120bn) from Nakamura's work by the time the case was decided in January 2004. The judgement was seen as a breakthrough for the rights of the individual inventor within Japanese companies.
Blue LEDs have been difficult to produce because of problems finding materials with the electronic properties to emit the right wavelengths. Nakamura stunned the opto-electronics community in 1993 by announcing very bright blue LEDs based on GaN, followed by a green GaN LED, a blue laser diode, and a white LED. Other researchers had spent decades trying to create such devices.
Blue laser diodes, another Nakamura invention, are now reaching the market in the pick-up heads of next-generation DVD players. Alvesalo says the Millennium Technology Prize was awarded, in part, to help see Nakamura’s technology out of its cradle into wider use. One of the most exciting applications of the technology could be in the development of a white LED, which is already being adopted in some traffic light systems. Alvesalo says today’s white LEDs are ten times as efficient as incandescent lighting, and even greater efficiency may be possible.
“White LEDs may eventually replace today’s illumination, which would have a real impact on global power consumption,” he added, since buildings would also need less air conditioning to take away the energy emitted as heat in incandescent lighting. White LEDs also have a longer working life than conventional light bulbs.
Professor Nakamura received his doctorate in engineering at the University of Tokushima in 1994, after his GaN breakthrough. Five years later he left Japan and joined the faculty of the University of California, Santa Barbara, where he is working on new devices including full-colour LEDs, an efficient white-LED light bulb, laser diodes and high-power, microwave communication devices.
doi:eiq-2006-008-0033
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