Isamu Akasaki
Encyclopedia
is a Japanese scientist, best known for inventing p-n junction blue LED
s using gallium nitride (GaN
) as early as 1989.
. He received his PhD degree in Electronics from Nagoya University
. He started his research on blue LEDs in the late 1960s. Step by step, he improved the quality of GaN crystal
s 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. 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.
He and his group achieved stimulated emission in the ultraviolet
(UV) region with optical excitation from GaN at room-temperature in 1990 and stimulated emission by current injection from nitride-based quantum well
diode at room-temperature in 1995.
They also verified quantum size effect and quantum-confined Stark effect
in nitride system, respectively, in 1991 and 1997.
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. Those devices opened up a huge market and Professor Akasaki's patents have been rewarded as royalties.
LEd
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....
s using gallium nitride (GaN
Gan
Gan may refer to:-Computing and telecommunications:*.gan, the file extension for documents created by GanttProject*Generic Access Network formerly known as Unlicensed Mobile Access *Global Area Network- Mythology :...
) as early as 1989.
Blue LEDs
Akasaki was born in Kagoshima Prefecture in 1929, and received a Bachelor of Science degree in 1952 from Kyoto UniversityKyoto University
, or is a national university located in Kyoto, Japan. It is the second oldest Japanese university, and formerly one of Japan's Imperial Universities.- History :...
. He received his PhD degree in Electronics from Nagoya University
Nagoya University
Nagoya University is one of the most prestigious universities in Japan. It can be seen in the several rankings such as shown below.-General Rankings:...
. He started his research on blue LEDs in the late 1960s. Step by step, he improved the quality of GaN crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
s and device
Electronic component
An electronic component is a basic electronic element and may be available in a discrete form having two or more electrical terminals . These are intended to be connected together, usually by soldering to a printed circuit board, in order to create an electronic circuit with a particular function...
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
Nagoya University
Nagoya University is one of the most prestigious universities in Japan. It can be seen in the several rankings such as shown below.-General Rankings:...
, and in 1985, he and his group succeeded in growing a high quality single crystal
Single crystal
A single crystal or monocrystalline solid is a material in which the crystal lattice of the entire sample is continuous and unbroken to the edges of the sample, with no grain boundaries...
GaN on sapphire
Sapphire
Sapphire is a gemstone variety of the mineral corundum, an aluminium oxide , when it is a color other than red or dark pink; in which case the gem would instead be called a ruby, considered to be a different gemstone. Trace amounts of other elements such as iron, titanium, or chromium can give...
substrate by a low-temperature buffer layer technology. This high quality GaN enabled them to discover p-type
P-type semiconductor
A P-type semiconductor is obtained by carrying out a process of doping: that is, adding a certain type of atoms to the semiconductor in order to increase the number of free charge carriers ....
GaN doping with magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
(Mg) by MOVPE, to control n-type
N-type semiconductor
N-type semiconductors are a type of extrinsic semiconductor where the dopant atoms are capable of providing extra conduction electrons to the host material . This creates an excess of negative electron charge carriers....
conductivity by silicon
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
(Si) doping, and then to realize p-n junction blue LEDs in 1989.
He and his group achieved stimulated emission in the ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
(UV) region with optical excitation from GaN at room-temperature in 1990 and stimulated emission by current injection from nitride-based quantum well
Quantum well
A quantum well is a potential well with only discrete energy values.One technology to create quantization is to confine particles, which were originally free to move in three dimensions, to two dimensions, forcing them to occupy a planar region...
diode at room-temperature in 1995.
They also verified quantum size effect and quantum-confined Stark effect
Quantum-confined Stark effect
The quantum-confined Stark effect describes the effect of an external electric field upon the light absorption spectrum or emission spectrum of a quantum well . In the absence of an external electric field, electrons and holes within the quantum well may only occupy states within a discrete set...
in nitride system, respectively, in 1991 and 1997.
Their inventions; high quality GaN, p-type doping, conductivity control of n-type nitrides, p-n junction
P-n junction
A p–n junction is formed at the boundary between a P-type and N-type semiconductor created in a single crystal of semiconductor by doping, for example by ion implantation, diffusion of dopants, or by epitaxy .If two separate pieces of material were used, this would...
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. Those devices opened up a huge market and Professor Akasaki's patents have been rewarded as royalties.
Nagoya University Akasaki Institute
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 is situated in the center of the collaborative research zone in Nagoya University Higashiyama campus.Biography
- 1952 Bachelor of Science, Kyoto UniversityKyoto University, or is a national university located in Kyoto, Japan. It is the second oldest Japanese university, and formerly one of Japan's Imperial Universities.- History :...
- 1952 Research Scientist at Kobe Kogyo Corporation
- 1959 Research Associate, Assistant Professor and Associate Professor, Nagoya University
- 1964 DoctorDoctorateA doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder to teach in a specific field, A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder...
of Engineering, Nagoya UniversityNagoya UniversityNagoya University is one of the most prestigious universities in Japan. It can be seen in the several rankings such as shown below.-General Rankings:... - 1964 Head of Basic Research Laboratory 4, Matsushita Research Institute Tokyo, Inc.
- 1974 General Manager of Semiconductor Department, Matsushita Research Institute Tokyo, Inc.
- 1981 ProfessorProfessorA professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
, Nagoya University - 1987-90 JRU 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 JRU 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 growthCrystal growthA crystal is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. Crystal growth is a major stage of a crystallization process, and consists in the addition of new atoms, ions, or polymer strings into...
(JACG) Award (Japan) - 1991 The Chu-nichi Cultural Prize (Japan)
- 1995 The Heinrich WelkerHeinrich WelkerHeinrich Johann Welker was a German theoretical and applied physicist who invented the "transistron", a form of transistor made at Westinghouse independently of the first successful transistor made at Bell Laboratories...
Gold Medal (International) - 1996 The Medal with Purple RibbonMedals of Honor (Japan)Since the late 19th Century, the Government of Japan has issued six different types of to individuals for achievements in various fields.The Medals of Honor were established on December 7, 1881, and were first awarded the following year. Several expansions and amendments have been made since then...
(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 MontpellierUniversity of MontpellierThe University of Montpellier was a French university in Montpellier in the Languedoc-Roussillon région of the south of France. Its present-day successor universities are the University of Montpellier 1, Montpellier 2 University and Paul Valéry University, Montpellier III.-History:The university...
) (France) - 2001 The Toray Science and Technology Prize (Japan)
- 2001 The Asahi PrizeAsahi PrizeThe Asahi Prize is a prize awarded by the Japanese newspaper the Asahi shimbun for achievement in scholarship or the arts that has made a contribution to culture or society. It was established in 1929. Many recipients of this prize have later been honoured with a Nobel Prize...
(Japan) - 2002 Honoris Causa Title of Linkoping UniversityLinköping UniversityLinköping University is a state university in Linköping, Sweden. Linköping University was granted full university status in 1975 and is now one of Sweden's larger academic institutions. Education, research and PhD training are the mission of four faculties: Arts and Sciences, Educational...
(Sweden) - 2002 Outstanding Achievement Award (Japan Society of Applied PhysicsJapan Society of Applied Physics, abbreviated as JSAP, is a Japanese group of researchers in the applied physics field. JSAP originated in 1932 from a voluntary forum of researchers belonging to the University of Tokyo and the Institute of Physical and Chemical Research. During World War II, most research, even applied, was frozen...
(JSAP)) (Japan) - 2002 The Takeda AwardsTakeda AwardsThe Takeda Foundation, is an organisation based in Japan. In 2001 it launched an annual awards program, which presented awards accompanied by 100 million yen under the categories social/economic well-being, individual/humanity well-being, and world environmental well-being.- Social/Economic...
(Japan) - 2002 The Fujihara Prize (Japan)
- 2002 The Order of the Rising SunOrder of the Rising SunThe is a Japanese order, established in 1875 by Emperor Meiji of Japan. The Order was the first national decoration awarded by the Japanese Government, created on April 10, 1875 by decree of the Council of State. The badge features rays of sunlight from the rising sun...
, 3rd Class, Gold Rays with Neck Ribbon (the Japanese Government) - 2003 The Science Council of Japan President's Award (Japan)
- 2004 The Person of Cultural MeritPerson of Cultural Meritis an official Japanese recognition-honor which is awarded annually to select people who have made outstanding cultural contributions. This distinction is intended to play a role as a part of a system of support measures for the promotion of creative activities in Japan...
(the Japanese Government) - 2006 TMS John BardeenJohn BardeenJohn Bardeen was an American physicist and electrical engineer, the only person to have won the Nobel Prize in Physics twice: first in 1956 with William Shockley and Walter Brattain for the invention of the transistor; and again in 1972 with Leon Neil Cooper and John Robert Schrieffer for a...
Award (USA） - 2006 The Outstanding Achievement Award (JACG) (Japan)
- 2009 Kyoto PrizeKyoto PrizeThe has been awarded annually since 1985 by the Inamori Foundation, founded by Kazuo Inamori. The prize is a Japanese award similar in intent to the Nobel Prize, as it recognizes outstanding works in the fields of philosophy, arts, science and technology...
Advanced Sciences - 2011 IEEE Edison MedalIEEE Edison MedalThe Edison Medal is presented by the IEEE "for a career of meritorious achievement in electrical science, electrical engineering or the electrical arts." It is the oldest and most coveted medal in this field of engineering in the United States. The award consists of a gold medal, bronze replica,...
- 2011 Order of CultureOrder of CultureThe is a Japanese order, established on February 11, 1937. The order has one class only, and may be awarded to men and women for contributions to Japan's art, literature or culture; recipients of the order also receive an annuity for life...
(The Japanese Emperor)