2009 Kyoto Prize Laureates

Advanced Technology

Electronics

Isamu Akasaki

/  Semiconductor Scientist

1929 -

University Professor, Nagoya University ; Professor, Meijo University

Commemorative Lectures

Enchanted Journeys in Blue Light

2009

11 /11 Wed

Place:Kyoto International Conference Center

Workshop

Nitride Semiconductors and Their Device Applications: Current Status and Future Prospects

2009

11 /12 Thu

13:00 – 17:25

Place:Kyoto International Conference Center

Achievement Digest

Pioneering Work on Gallium Nitride p-n Junctions and Related Contributions to the Development of Blue Light Emitting Devices

Dr. Akasaki conducted persistent research on gallium nitride (GaN) for many years toward the realization of blue LEDs. His efforts culminated in the pioneering realization of GaN-based p-n junctions, which were once believed to be practically impossible. This achievement served as the first firm step toward the eventual commercialization of blue LEDs. To this day, Dr. Akasaki has consistently played a leading role in a series of significant research endeavors. His contributions to them certainly deserve the highest recognition the world over.

Citation

Dr. Isamu Akasaki conducted persistently intensive research on gallium nitride (GaN) for many years toward the realization of blue light-emitting diodes (LEDs). His efforts culminated in the pioneering realization of GaN-based p-n junctions, which were believed to be practically impossible. This achievement has stimulated research activities on blue LEDs in Japan and elsewhere, and served as the first firm step toward their eventual commercialization. To this day, Dr. Akasaki has consistently played a leading role in a series of research endeavors. His contributions to the birth and progress of GaN-based blue LEDs deserve the highest recognition the world over.

With their high efficiency and long life, LEDs can be used in a wide range of applications. For this reason, R&D efforts in this area started early on, resulting in the development of red and green LEDs. With the addition of blue LEDs, the three primary colors of light would be complete, raising expectations that LEDs could be used to realize full-color displays and white illumination. It was hoped that the realization of blue laser diodes would allow the dramatic increase in the recording density of optical discs. These high expectations led to several attempts to realize blue LEDs around 1970, with researchers conducting intensive research on the promising material of GaN. However, it was quite difficult to prepare high-quality GaN and control their electrical properties. One could form n-type GaN, but p-type materials indispensable for LEDs remained out of reach. As a result, most researchers gave up on their attempts to develop blue LEDs and withdrew from such attempts by the end of the 1970s.

Dr. Akasaki, however, did not. He resolutely continued his research and went on to find in 1985 that the crystalline quality of GaN can be remarkably enhanced by forming a buffer layer at low temperatures on sapphire substrate before growing GaN crystals. With the cooperation of Dr. Hiroshi Amano, Dr. Akasaki made groundbreaking discoveries in 1989. His work demonstrated that p-type GaN can be formed by doping magnesium atoms into high quality GaN and irradiating them with electron beams. Using this method, he and his group realized the world’s first GaN-based p-n junctions and demonstrated their operation as blue LEDs.

These achievements shed new light on the potential of GaN as a material for blue LEDs and restimulated GaN researches. They induced intense R&D activities to establish the technological basis for the commercialization of blue LEDs. These efforts bore fruit when blue LEDs went on the market in 1993. This device is widely used in displays and lighting. Later, blue laser diodes were commercialized, and played a pivotal role in raising the recording density of optical discs. All through these developments, Dr. Akasaki has played leading roles by his pioneering work for the realization of blue light emitting devices and by his persistent research for the advancement of this field.

For these reasons, the Inamori Foundation is pleased to present the 2009 Kyoto Prize in Advanced Technology to Dr. Isamu Akasaki.

Profile

Biography
1929
Born in Chiran, Kagoshima, Japan
1952
B. Sc., Kyoto University
1964
D. Eng., Nagoya University
1952
Kobe Kogyo Corporation (currently Fujitsu Ltd.)
1959-1964
Research Associate, Assistant Professor and Associate Professor, Nagoya University
1964-1981
Head of Basic Research Laboratory 4, Matsushita Research Institute Tokyo, Inc.
1981
Professor, Nagoya University
1992
Professor Emeritus, Nagoya University
1992
Professor, Meijo University
2004
University Professor, Nagoya University
Selected Awards and Honors
1995
Heinrich Welker Gold Medal
1997
Medal with Purple Ribbon (Japan)
1998
IOCG Laudise Prize, C&C Prize, IEEE Jack A. Morton Award, Rank Prize
1999
Honoris Causa Doctorate of University of Montpellier
2001
Asahi PrizeHonoris Causa Doctorate of Linkoping University
2002
The Order of the Rising Sun, Gold Rays with Neck Ribbon JSAP Outstanding Achievement Award, Fujihara Prize
2004
Person of Cultural Merits
Members:
IEEE Fellow, Honorary Member of IEICE, Emeritus Member of JSAP, Foreign Associate of the US National Academy of Engineering
Selected Publications
1986
Metalorganic vapor phase epitaxial growth of a high quality GaN film using an AlN buffer layer (Amano, H., Sawaki, N., Akasaki, I. and Toyoda, Y.). Applied Physics Letters 48: 353-355, 1986.
1989
Effects of AlN Buffer Layer on Crystallographic Structure and on Electrical and Optical Properties of GaN and Ga1-xAlxN (0<x≤0.4) Films Grown on Sapphire Substrate by MOVPE (Akasaki, I., Amano, H., Koide, Y., Hiramatsu, K. and Sawaki, N.). Journal of Crystal Growth 98: 209-219, 1989.
1989
P-Type Conduction in Mg-Doped GaN Treated with Low-Energy Electron Beam Irradiation(LEEBI) (Amano, H., Kito, M., Hiramatsu, K. and Akasaki, I.). Japanese Journal of Applied Physics 28: L2112-L2114, 1989.
1997
Crystal Growth and Conductivity Control of Group III Nitride Semiconductors and Their Application to Short Wavelength Light Emitters (Akasaki, I. and Amano, H.). Japanese Journal of Applied Physics 36: 5393-5408, 1997.
2006
Breakthroughs in Improving Crystal Quality of GaN and Invention of the p-n Junction Blue-Light-Emitting Diode (Akasaki, I. and Amano, H.). Japanese Journal of Applied Physics 45: 9001-9010, 2006.

Profile is at the time of the award.

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