Blue LEDs, Joint Invention of Three Japanese-Born Researchers, Wins Physics Nobel

Tonight, when you look up at one of the city’s electronic billboards as you head towards your nearest train station, gaze out at Tokyo’s seemingly endless skyline, or squint your eyes at the screen of the computer or smartphone on which you might be reading these words, you are also looking on the results of the research and development that led to this year’s Nobel Prize in Physics: the invention of the blue LED.

Isamu Akasaki, 85, professor at Meijo University in Nagoya, Hiroshi Amano, 54, professor at Nagoya University, and Shuji Nakamura, 60, professor at the University of California, Santa Barbara, are splitting the 2014 Physics Nobel Prize “for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources,” in the words of the Nobel Prize committee. In addition to the way the invention has revolutionized the way homes and communities are illuminated around the world, blue LEDs are used for applications such as water purification, data storage, and high-speed computer networking.

The story behind the invention spans three decades, and involves considerable work done in the field of chemistry as well as physics. Although the first red LED was created in 1962, LED-generated white light would be impossible without adding green and blue light. Green light LEDs were developed in the years to come, and the price for red LEDs dropped had dropped significantly by the 1970s. However, creating an LED that would generate short-wavelength blue light proved to be a much more difficult challenge. As the Nobel announcement put it, “They succeeded where everyone else had failed.”

This success was not a singlehanded achievement, though. As explained in a New York Times article on the prize announcement, Akasaki had begun research on growing crystals of gallium nitride, a semiconducting material that was crucial for the creation of blue LEDs, in the late 1960s. It was finally his graduate student Amano who, in 1986, was able to successfully grow high-quality crystals on a layer of sapphire. Finally, it was Nakamura, working at Nichia Corporation in Tokushima Prefecture, who improved upon Amano’s method, eventually developing a practical design for blue LEDs in 1993.

It did not take long for the technology to quickly make its way into everyday life, and as manufacturers have continued to refine the invention, prices for LED lights have dropped at the same time that the lights’ illuminating power has increased. Currently, LEDs can produce light at a quarter of the cost of a fluorescent bulb and one-twentieth of the cost of an incandescent, while lasting 10 times (fluorescent) or 100 times (incandescent) as long. LEDs’ cost-effectiveness have since made them a viable possibility for being used in solar power applications in poorer parts of the world that lack electricity infrastructure.

An interesting aspect of the Nobel Committee’s decision is that, this year, the general public will have no problem understanding just what the prize is being awarded for. This can be rare for the Physics Prize: past awards went to research in “Giant Magnetoresistance” (2007), “the discovery of asymptotic freedom in the theory of the strong interaction” (2004), and the “discovery of superfluidity in helium-3” (1996). The announcement may also serve as something of a boost of confidence to science in Japan: although the STAP cell scandal that broke this year involved a different scientific discipline, it had cast a pall over the nation’s reputation for scientific achievement.

Nonetheless, the announcement is not without its bad blood: Rick Holonyak, the inventor of the red LED, was disappointed that US scientists could not be recognized among the group of awardees. And, despite the huge industry that LED illumination has become, Nichia only awarded Nakamura a ¥20,000 ($200) bonus for his discovery at the time. After moving to the US, where he is now a naturalized citizen, Nakamura sued his former employer, eventually winning approximately $8 million. He can add one-third of the $1.1 million prize that will be granted to the awardees this December to that, along with the satisfaction of being part of the illuminated landscape of the 21st century.

Correction: Shuji Nakamura’s citizenship was incorrectly reported as a permanent resident of the United States. He is a naturalized citizen of the United States.

—Alec Jordan

Main Image: zonedancer/Flickr

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