Thomas Alva Edison had plenty of help when he invented the first practical incandescent lightbulb more than 125 years ago. By contrast, Shuji Nakamura was working virtually alone at a small, obscure Japanese company in 1992 when he developed the bright blue light-emitting diode, or LED, that now promises to supplant that bulb in many applications. Since then, Nakamura has become a celebrity in Japan, a litigant in a high-profile lawsuit, a California resident, the winner of the 2006 Millennium Technology Prize, and a wealthy man.
This is clearly a great subject for an engaging book, and author Bob Johnstone does not disappoint. In Brilliant! Shuji Nakamura and the Revolution in Lighting Technology , he weaves a lucid, captivating narrative around Nakamura's struggles to achieve his luminous dream. This was no easy task for a product development engineer at Nichia Chemical Industries, a tiny company in Anan on Japan's southern, and quite rural, island of Shikoku. Were it not for an owner and chief executive at Nichia with enough patience and wisdom to invest more than US $1 million in Nakamura's research, the world might still be waiting for the solid-state lighting revolution to begin.
Nakamura was working with indium-gallium-nitride, a compound-semiconductor alloy most other researchers had dismissed as useless for LED manufacturing because of its many defects. But Nakamura's isolation from the major academic and industrial R&D communities proved a blessing in disguise. He plodded stubbornly ahead on his own, modifying industry-standard chemical vapor-deposition equipment to achieve the uniform, nanometers-thin layers needed to emit copious blue light. Even a new Nichia chief executive adamantly opposed to this research could not prevent--but only delay--Nakamura's signal achievement: a device, as Johnstone says, that is "100 times brighter than commercial silicon-carbide blue LEDs, bright enough to be seen in broad daylight." In a word, brilliant!
Jaws dropped when Nichia announced his breakthrough a year later, and overnight, Nakamura became a celebrity in Japan. Two days after they learned about it, top executives of Cree Research, a Durham, N.C., firm that was the market leader in silicon-carbide blue LEDs, rushed to Tokyo to meet their Nichia counterparts and propose an industry alliance. But the Japanese phosphor maker was interested only in selling blue diodes to these gaijin customers. So, according to Johnstone, Cree plotted its counterattack, ramping up its own gallium-nitride production line and repeatedly trying to lure Nakamura away.
Instead, the loyal Nichia engineer, not understanding stock options or their value, remained at his lab bench, turning out ever brighter and more versatile diodes and staying giant steps ahead of the astonished competition. By increasing the indium content, for example, he achieved bright green LEDs. And in 1996 he again stunned the compound-semiconductor industry with his announcement of the world's first blue-violet laser diode, something others had thought impossible.
Why all the excitement over bright blue diodes? Simply because they are the crucial key--the sine qua non--to generating bright white light. Red and green light combined in the proper proportions with blue yields white. The red and green can come either from other LEDs or from the blue LED itself, using phosphors to convert part of its output to lower-frequency light. Bright blue LEDs made it possible to take dead aim at the multibillion-dollar lighting industry, which still had its feet firmly planted in Edison's more-than-century-old technology.
Already LEDs have surpassed incandescent and halogen bulbs in lumens per watt, the key figure of merit reflecting how much electrical power is converted into emitted light. With lifetimes ranging from 50 000 to 100 000 hours, they are more economical over the long run, too. During the past year, LEDs have exceeded 100 lumens per watt in the laboratory, a level that only the best fluorescent tubes can attain.
Industry watchers expect that such high-efficiency LEDs will hit the general illumination market later this year. Once that happens, the revolution will begin in earnest--helped along, as it now appears, by government initiatives to curtail incan descent lighting as a way of reducing fossil-fuel consumption.
Johnstone offers readers much more than a Nakamura biography, for this is also an insightful first look at several key players in a solid-state lighting industry that is already grossing more than $4 billion annually. Besides chip makers like Cree and Nichia, there are brash new start-up firms, such as Color Kinetics of Boston and Permlight Products of Tustin, Calif., which package LEDs into complete lighting systems for architectural and residential uses. Another company, Carmanah Technologies Corp., in Victoria, B.C., Canada, marries LEDs with photovoltaic cells to produce stand-alone systems for solar-powered, off-grid applications.
The founders of these small firms are all serial entrepreneurs who have finally found their lives' callings and who embrace them with near-religious zeal. Johnstone obviously shares their evangelical spirit, but it can get in the way of his reporting. There will be losers as well as winners in this high-stakes game, and he does not help his readers determine which companies will survive the inevitable shakeouts.
Also missing from Johnstone's account is the 400-kilogram gorilla: Royal Philips Electronics, in Amsterdam, which in 2005 bought up the rest of San Jose-based Lumileds Lighting, the joint venture it established in 1999 with Agilent Technologies, of Palo Alto, Calif. This team boasts some of the best researchers in the LED lighting industry, together with the systems integration abilities and marketing savvy of one of the biggest electronics manufacturers in the world. It will be hard to beat.
Near the end of the book, Johnstone returns to the topic he knows and relates best, the saga of Shuji, the name by which Nakamura is recognized throughout the industry. Finally succumbing to U.S. blandishments in 1999, Nakamura accepts a tenured position as the Cree Professor of Solid State Lighting and Display at the University of California, Santa Barbara.
But before he can resume his research there, he gets slapped with a lawsuit by Nichia for purportedly leaking trade secrets to its archrival, Cree. Shuji fires back with a countersuit against his old employer for a decent share of the profits that all his inventions and patents have generated. The parties carry their highly publicized case to the Tokyo High Court but then settle in early 2005, allowing Nakamura to concentrate again on his beloved gallium-nitride research.
The next chapter comes after you close the book's final page. In early 2007, Nakamura announced yet another breakthrough, this time in blue-violet laser diodes [see "A New Blue Laser" at http://spectrum.ieee.org/mar07/4988]. This advance promises to do for semiconductor lasers what his blue LEDs have already done for lighting. Johnstone's Brilliant! is a superb introduction to this dramatic story of high technology in action, which continues to this day.
About the Author
Contributing Editor MICHAEL RIORDAN teaches the history of physics and technology at Stanford University and the University of California, Santa Cruz.