Shuji Nakamura

Shuji Nakamura (Japanese: 中村 修二, romanized: Nakamura Shūji; born May 22, 1954) is a Japanese–American electronic engineer and co-inventor of the blue LED, a major breakthrough in lighting technology.^[3] He specializes in the field of semiconductor technology. He is Professor of Materials and of Electrical and Computer Engineering at the University of California, Santa Barbara (UCSB) since 1999.^[4]

Together with Isamu Akasaki and Hiroshi Amano, Nakamura received the 2014 Nobel Prize in Physics "for the invention of efficient blue light-emitting diodes, which has enabled bright and energy-saving white light sources."^[5]

Nakamura graduated from the University of Tokushima in 1977 with a B.Eng. in Electronic Engineering, and obtained an M.Eng. in the same subject in 1979, after which he joined the Nichia Corporation, also based in Tokushima. It was while working for Nichia that Nakamura invented the method for producing the first commercial high brightness gallium nitride (GaN) LED whose brilliant blue light, when partially converted to yellow by a phosphor coating, is the key to white LED lighting, which went into production in 1993.

Previously, J. I. Pankove and co-workers at RCA put in considerable effort but did not make a marketable GaN LED in the 1960s. The principal problem was the difficulty of making strongly p-type GaN.^[6] Nakamura drew on the work of another Japanese group led by Professor Isamu Akasaki, who published their method to make strongly p-type GaN by electron-beam irradiation of magnesium-doped GaN; however, this method was not suitable for mass production. Nakamura developed a thermal annealing method much more suitable for mass production.^[7] In addition, he and his co-workers worked out the physics and pointed out the culprit was hydrogen, which passivated acceptors in GaN.^[8]

At the time, many considered creating a GaN LED too difficult to produce; therefore, Nakamura was fortunate that the founder of Nichia, Nobuo Ogawa (1912–2002), was willing to support and fund his GaN project.^[9][10] However, the senior Ogawa ceded the presidency to his son-in-law Eiji Ogawa (in 1989). The company under Eiji's direction ordered him to suspend work on GaN, claiming it was consuming too much time and money.^[11][12] Nakamura continued to develop the blue LED on his own and in 1993 succeeded in making the device.^[13][12]

Despite these circumstances, once Nakamura succeeded in creating a commercially viable prototype, 3 orders of magnitude (1000 times) brighter than previously successful blue LEDs, Nichia pursued developing the marketable product.^[9][14] The company's gross receipt surged from just over ¥20 billion (≈US$200 million) in 1993 to ¥80 billion (≈US$800 million) by 2001, 60 percent of which was accounted for by sales of blue LED products.^[12] The company's workforce doubled between 1994 and 1999 from 640 to 1300 employees.^[15]

In 1994, Nakamura was conferred a D.Eng. degree by the University of Tokushima, earned through a doctoral thesis submitted by publication.^[16]

Nakamura left Nichia Corporation in 1999 to join the faculty at the University of California, Santa Barbara at the personal invitation of the university's chancellor, Henry T. Yang. Yang flew three times from California to Japan to recruit Nakamura, with promises to build new research facilities and having a Japanese-speaking research staff team already assembled for him.^[17][18]

In 2001, Nakamura sued his former employer Nichia over his bonus for the discovery as a part of a series of lawsuits between Nichia and Nakamura with Nichia's US competitor Cree Inc.; they agreed in 2000 to jointly sue Nichia at the expense of Cree and Nakamura received stock options from Cree. Nakamura claimed that he received only ¥20,000 (≈US$180) for his discovery of "404 patent," though Nichia's president Eiji Ogawa's side of the story was that he was shocked beyond belief that the court would award Nakamura ¥20 billion, and downplaying the significance of the "404 patent," opined that the company had adequately compensated him for the innovation through promotions and bonuses amounting to ¥62 million over 11 years and annual salary which was raised to ¥20 million by the time Nakamura quit Nichia.^[19]

Nakamura sued for ¥2 billion (<US$20 million) as his fair share for the invention, and the district court awarded him ten times the amount, ¥20 billion (<US$200 million). However, Nichia appealed the award and the parties settled in 2005 for ¥840 million (≈US$8.1 million, less than 5% of the award amount), which was still the largest payment ever paid by a Japanese company to an employee for an invention,^[20][21] an amount only enough to cover legal expenses incurred by Nakamura.^[22] In line with the lawsuit, Nakamura has repeatedly criticized Japanese companies for not giving their researchers the salaries and recognition they deserve.^[23]

Nakamura has also worked on green LEDs and is responsible for creating the white LED and blue laser diodes used in Blu-ray Discs and HD DVDs.^[24]

Nakamura is a professor of Materials at the UCSB.^[25] In 2008, Nakamura, along with fellow UCSB professors Dr. Steven P. DenBaars and Dr. James Speck, founded Soraa, a developer of solid-state lighting technology built on pure gallium nitride substrates.^[26] Nakamura holds 208 US utility patents as of 5 May 2020.^[27]

In November 2022, Nakamura co-founded Blue Laser Fusion, a commercial fusion company, with Hiroaki Ohta, a former president of Tokyo-based drone maker ACSL.^[28] In July 2023, Blue Laser Fusion raised $25 million from venture capital firm JAFCO Group and the Mirai Creation Fund, which is backed by Toyota Motor and other investors and managed by the SPARX Group.^[28]

Nakamura is married to Yuki Nakamura.^[29]

• List of Japanese Nobel laureates and nominees

Citations

Bibliography

• Shuji Nakamura, Gerhard Fasol, Stephen J. Pearton, The Blue Laser Diode : The Complete Story, Springer; 2nd edition, October 2, 2000, (ISBN 3-540-66505-6)

• Professor Nakamura's home page at UCSB
• The Solid State Lighting and Energy Center at UCSB
• Shuji Nakamura Wins $188.7 Million Settlement from Former Employer Nichia for Blue Spectrum Breakthrough Technology
• New York Times article on Nakamura's settlement with Nichia
• U.S. patent 6,900,465 — Nitride semiconductor light-emitting device
• Shuji Nakamura wins the 2006 Millennium Technology Prize
• Nichia's Shuji Nakamura: Dream of the Blue Laser Diode
• 2008 Prince of Asturias Award For Technical and Scientific Research Archived 2022-01-13 at the Wayback Machine
• Harvey Prize
• Shuji Nakamura SPIE Photonics West plenary presentation: Future and present technologies of solid state lighting
• Shuji Nakamura on Nobelprize.org