Isamu Akasaki

nihongo|Isamu Akasaki|赤崎 勇|"Akasaki Isamu"| born January 30 1929, is a Japanese scientist, best known for inventing p-n junction blue LEDs using gallium nitride (GaN) in as early as 1989, first in the world.Hiroshi Amano, Masahiro Kito, Kazumasa Hiramatsu and Isamu Akasaki, "P-Type Conduction in Mg-Doped GaN Treated with Low-Energy Electron Beam Irradiation (LEEBI)", Jpn. J. Appl. Phys. Vol. 28 (1989) L2112-L2114, doi|10.1143/JJAP.28.L2112]

Born in Kagoshima Prefecture in 1929, Akasaki graduated with a Bachelor of Science degree in 1952 from Kyoto University. He received PhD degree in Electronics from Nagoya University. He started his research on blue LEDs from late 1960’s .Isamu Akasaki1 and Hiroshi Amano, "Breakthroughs in Improving Crystal Quality of GaN and Invention of the p–n Junction Blue-Light-Emitting Diode", Jpn. J. Appl. Phys. Vol. 45 (2006) 9001-9010, doi|10.1143/JJAP.45.9001] and continued his efforts persistently, improving step by step the quality of GaN crystals and device structures at Matsushita, where he decided to adopt metalorganic vapor phase epitaxy(MOVPE) as the preferred growth method for GaN. In 1981 he started afresh growth of GaN by MOVPE at Nagoya University, and in 1985 he and his group succeeded in growing a high quality single crystal GaN on sapphire substrate by a low-temperature buffer layer technology. [Applied Physics Letters, Volume 48, Issue 5, pp. 353-355 [http://link.aip.org/link/?APL/48/353] ] . This high quality GaN enabled them to discover p-type GaN doping with magnesium (Mg) by MOVPE, to control n-type conductivity by silicon (Si) doping, and then to realize p-n junction blue LEDs in 1989., p-n junction blue/UV-LEDs
He and his group achieved stimulated emission in the ultra-violet(UV)region with optical excitation from GaN at room-temperature in 1990 Hiroshi Amano, Tsunemori Asahi and Isamu Akasaki, "Stimulated Emission Near Ultraviolet at Room Temperature from a GaN Film Grown on Sapphire by MOVPE Using an AlN Buffer Layer", Jpn. J. Appl. Phys. Vol. 29 (1990) L205-L206 doi|10.1143/JJAP.29.L205] and stimulated emission by current injection from nitride-based quantum well diode at room-temperature in 1995.Isamu Akasaki, Hiroshi Amano, Shigetoshi Sota, Hiromitsu Sakai, Toshiyuki Tanaka and Masayoshi Koike, "Stimulated Emission by Current Injection from an AlGaN/GaN/GaInN Quantum Well Device", Jpn. J. Appl. Phys. Vol.34(1995) L1517-L1519 doi|10.1143/JJAP.34.L1517]
They also verified quantum size effect and quantum confined Stark effect in nitride system, respectively,in 1991Kenji Itoh, Takeshi Kawamoto, Hiroshi Amano, Kazumasa Hiramatsu and Isamu Akasaki, "Metalorganic Vapor Phase Epitaxial Growth and Properties of GaN/Al0.1Ga0.9N Layered Structures", Jpn. J. Appl. Phys. Vol. 30 (1991) 1924-1927 doi|10.1143/JJAP.30.1924] and 1997 Tetsuya Takeuchi, Shigetoshi Sota, Maki Katsuragawa, Miho Komori, Hideo Takeuchi, Hiroshi Amano and Isamu Akasaki, "Quantum-Confined Stark Effect due to Piezoelectric Fields in GaInN Strained Quantum Wells", Jpn. J. Appl. Phys. Vol. 36 (1997) L382-L385 doi|10.1143/JJAP.36.L382] .
Their inventions; high quality GaN, p-type doping, conductivity control of n-type nitrides , p-n junction LEDs and stimulated emission in the UV region by current injection are epoch-making and all other researches and developments of nitride-based blue/green/white LEDs, violet lasers, optoelectronic devices in the UV region and high-speed and high-power electronic devices are based on these inventions.Isamu Akasaki and Hiroshi Amano, "Crystal Growth and Conductivity Control of Group III Nitride Semiconductors and Their Application to Short Wavelength Light Emitters", Jpn. J. Appl. Phys. Vol.36(1997) 5393-5408 doi|10.1143/JJAP.36.5393] Those devices opened up a huge market and Professor Akasaki’s patents have been rewarded as royalties.
Nagoya University Akasaki Institute was founded in 2006 based on the royalty income to Nagoya University. The Institute consists of an LED gallery to display the history of blue LED research/developments and applications, an office for research collaboration, laboratories for innovative research, and Professor Akasaki’s office on the top 6th floor. The Institute situates in the center of the collaborative research zone in Nagoya University Higashiyama campus.

Biography

1952 Bachelor of Science, Kyoto University
1952 Research Scientist at Kobe Kogyo Corporation
1959 Research Associate, Assistant Professor and Associate Professor, Nagoya University
1964 Doctor of Engineering, Nagoya University
1964 Head of Basic Research Laboratory 4, Matsushita Research Institute Tokyo, Inc.
1974 General Manager of Semiconductor Department, Matsushita Research Institute Tokyo, Inc.
1981 Professor, Nagoya University
1987-90 JST Project Leader of Research and Development of “GaN-based Blue Light–Emitting Diode” (JST: Japan Science and Technology Agency)
1992-Present Professor Emeritus, Nagoya University, Professor, Meijo University
1993-2001 JST Project Leader of Research and Development of ” GaN-based Short- Wavelength Semiconductor Laser Diode”.
1996-2001 Project Leader of the Japan Society for the Promotion of Science(JSPS)’ｓ”Research for the Future Program”
1996- Project Leader at High-Tech Research Center for Nitride Semiconductors, Meijo University
2001- Research Fellow at the Akasaki Research Center in Nagoya University

Honors (Selected list)

1989 The Japanese Association for Crystal Growth (JACG) Award (Japan)
1991 The Chu-nichi Cultural Prize (Japan)
1995 The Heinrich Welker Gold Medal (International)
1997 The Medal with Purple Ribbon(The Japanese Emperor)
1998 The Inoue Harushige Award (The Japan Science and Technology Agency, the Japanese Government)
1998 The Laudise Prize (The International Organization for Crystal Growth)
1999 The IEEE Jack A. Morton Award (USA)
1999 The Rank Prize (UK)
2000 Honoris Causa Title (University of Montpellier) (France)
2001 The Toray Science and Technology Prize (Japan)
2001 The Asahi Prize (Japan)
2002 Honoris Causa Title of Linkoping University (Sweden)
2002 Outstanding Achievement Award (The Japan Society of Applied Physics(JSAP)) (Japan)
2002 The Fujihara Prize (Japan)
2002 The Order of the Rising Sun (the Japanese Government)
2003 The Science Council of Japan President's Award (Japan)
2004 The Person of Cultural Metrits (the Japanese Government)
2006 TMS John Bardeen Award (USA）
2006 The Outstanding Achievement Award (JACG) (Japan)

References