Nobel Physics Laureate Shuji Nakamura Sheds Light on How He Invented the Blue LED
Dr. Shuji Nakamura, along with two other Japanese researchers, Dr. Isamu Akasaki and Dr. Hiroshi Amano, received the 2014 Nobel Prize in Physics in recognition of their major breakthrough in lighting technology with the invention of efficient blue light- emitting diodes (LED), which has enabled bright, energy-saving white light sources. Dr. Nakamura is a physicist and inventor specializing in semiconductor technology. He is a professor at the University of California, Santa Barbara College of Engineering. Tokyo Journal’s Executive Editor Anthony Al-Jamie spoke with Dr. Nakamura about his career, the intellectual property legal battle he faced with his former company, Nichia Corp., and the impact of his invention on the world.
TJ: Did you ever imagine that you might receive the Nobel Prize someday?
NAKAMURA: When I was a child, no. I was born in a remote village on Shikoku Island. There were no high schools or universities. But since 1993 when I invented the high-efficiency blue LED, the mass media has come to my house every year on October 7 at midnight, [waiting for the Nobel Prize announcement] and hoping for an interview.
TJ: How was your experience at the University of Tokushima?
NAKAMURA: I was bored by general education. I only wanted to study math and science, and for the first half of the year I didn’t go to class at all. I stayed in my apartment studying math and science. My grades were terrible until my mother called me and begged me to please graduate. That six-month period of staying in my apartment was the most important period in my life. I started thinking about life. In high school, I followed what my teachers told me. During those six months, I realized everything they said was totally wrong and that I have to follow what I believe in. I became a totally independent person.
TJ: After you left Nichia, why did you go to the University of California, Santa Barbara (UCSB) instead of a Japanese university?
NAKAMURA: I got zero offers from Japanese universities and companies, but a lot from the U.S., including Stanford, MIT and UCSB, and UCSB was the top-ranked in my field. UCSB works in blue LED research, but Stanford doesn’t have such facilities. Stanford is very good for LSI, silicon-based semiconductors. My field is called compound semiconductor research, and UCSB is always on top in this field.
TJ: Let’s talk about blue LED. Why is blue LED so important?
NAKAMURA:Because by using blue LED, we can make white LED. White LED is used for all kinds of lighting applications. The efficiency of white LED is 10 times higher than that of conventional incandescent light bulbs and two times higher than fluorescent. By using white LED for lighting applications, we can save a lot of energy. The United States Department of Energy estimates that by 2030, we can eliminate 30 power plants by using LED lighting. For the world it’s maybe five times that, so 150 power plants could be eliminated by 2030 all over the world. That is a huge energy reduction. So LED lighting has a positive impact when considering global warming. Also, the lifetime of white LED is 50 years. If you install this energy-efficient lighting in your house, you don’t need to change a bulb until you die (laughs)!
TJ: I understand that RCA Corp. made strong efforts to create a marketable gallium-nitride LED in the 1960s. Why were they not successful? If a big American company like RCA couldn’t do it, then why didn’t that discourage you in your efforts?
NAKAMURA: In order to make high-efficiency LEDs, we need three layers: n-type gallium nitride, p-type gallium nitride and an emitting layer. At that time, p-type gallium nitride and the emitting layers were missing, so they couldn’t make high-efficiency LED and gave up. I started working on blue LED with Nichia in 1989. In Japan, there is no big di erence between having a Ph.D. and a master’s degree, but when I was sent to the University of Florida as a visiting researcher for a year, I wasn’t treated like a scientist. I was treated like a technician because I didn’t hold a Ph.D. When I went back to Japan, I decided I needed a Ph.D. and at the time we didn’t need to go to university in order to earn a Ph.D. We simply needed to publish five scientific papers. At that time, there were two types of material available to make blue LED. One was zinc selenide-based material. The other was gallium nitride-based material. All scientists choose "zinc selenide" to develop blue LED because of the high quality of crystal. However, gallium nitride crystal quality is very poor. I never expected to be able to invent blue LED with it. I just wanted to publish five scientific papers to get a Ph.D. Basically there were tons of papers which about zin selenide, so I choose gallium nitride. However there is none about this material. Five years later, I was able to invent the blue LED.
TJ: How long did you work on the creation of blue LED?
NAKAMURA: I started LED research in April 1989. I invented the high-efficiency blue LED in October 1993 and Nichia started production in November.
TJ: What was your relationship like with Nichia and the founder, Nobuo Ogawa?
NAKAMURA: I worked for Nichia for 20 years. He supported and never interfered with my research. After I joined Nichia in 1979, I worked in the R&D [Research and Development] department. During the first 10 years, I developed three products, but the sales were very poor. Many of the bosses were complaining a lot and I became very depressed. I made the decision to quit the company because I didn’t want the company to keep losing money. But before quitting, I decided to do what I wanted to do, and that was to work on blue LED. Up until this point, I had not used a lot of money, but I went to the founder’s office and asked for $5 million to do blue LED research. I also asked him to send me to the University of Florida for one year as a visiting researcher to study MOCVD (Metal Organic Chemical Vapor Deposition) to learn about the crystal growth of gallium arsenide. He agreed to everything in just a couple of minutes. He was a great venture capitalist and backer for me.
TJ: Can you tell us about the blue LED patents? Who owns the patents?
NAKAMURA: I invented blue LED while with Nichia, and I applied for U.S. and Japanese patents — maybe 300 or 400 patents in total. At the end of 1999, I quit Nichia, and at the beginning of 2000 I moved to the United States. The problem was Nichia’s lawyer asked me to sign an NDA (Non-Disclosure Agreement). But the University of California’s lawyer said, “No, you don’t need to sign any agreement.” At the end of 2000, Nichia started an infringement of trade secret lawsuit against me in the United States because I didn’t sign an NDA. I found that, at the time, Japanese patent law said all inventions belonged to inventors, even if the person is an employee, unless an agreement is signed between the employee and the company. In my case, I had no agreement. Nichia also agreed that there are no agreements between both parties. But the local Tokyo court judge said although there was no documented agreement, there was some kind of unconscious agreement between both sides, so the patent rights belonged to the company. Japanese patent law said if the inventor gave the patent right to the company, then the company had to give reasonable compensation in return for getting the patent right. The local Tokyo court ruling said I could win about US$600 million. However, I only requested US$200 million, so the judge said I could get US$200 million then and another US$400 million later. Nichia appealed to the High Court and the High Court insisted that we settle immediately for approximately US$8 million. Finally we settled. The Japanese court system is a crazy court system. There is no discovery process, no deposition, no documents, and no evidence. Lying is no problem in court, so there is no perjury. The entire ruling is based on the judge’s feelings.
TJ: How is your relationship with Nichia now?
NAKAMURA: Very bad. After receiving the Nobel Prize, I proposed friendship with my former company, especially the current president Eiji Ogawa, through the Japanese mass media. But Nichia rejected it.
TJ: Do you think this new LED technology is going to become obsolete in the near future and be replaced with a new technology?
NAKAMURA: Yes. New technology is coming already. I won the Nobel Prize for inventing high-effi ciency blue LED, which brought about the high-efficiency white LED. White LED lighting using blue LED makes white things like white paper and white shirts become yellowish because white LED doesn’t include violet or UV emission. But recently a [U.S.] company named Soraa started a new white LED using violet LED to make white. Designers love to use Soraa’s white LED lamps.
TJ: What are you working on now at UCSB?
NAKAMURA: We are working on the next generation solid state lighting: high- efficiency laser lighting. Instead of blue LED, we are using blue laser diodes to make white lamps. Laser lighting is now used for headlamps of automobiles like BMW and Audi. The elevation distance of the LED lamp is 200 meters or 300 meters. With laser lighting, the projection distance is one kilometer. Germany has the Autobahn, so they need long-distance elevation lighting for headlamp lighting. The light coming out of laser lighting is almost 1,000 times stronger than that of LED. It’s very strong, so laser lighting is very interesting in the long term.
TJ: You said you weren’t interested in general education when you were in college, but do you think it is important for young Japanese people to speak English?
NAKAMURA: Yes, I think it is the most important thing to improve the Japanese economy. Japanese companies make very good products, but they can only sell their products in Japan, not in foreign countries. They’ve lost the semiconductor, TV and cell phone markets. Even though Japanese people study English in junior high and high school, they can’t speak English. If they could speak English like in Hong Kong or Singapore, I think Japanese companies could sell their products all over the world. tj
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