- Born:
- January 30, 1929, Chiran, Japan
- Died:
- April 1, 2021, Nagoya (aged 92)
- Awards And Honors:
- Nobel Prize (2014)
- Subjects Of Study:
- LED
Akasaki Isamu
-
Who was Akasaki Isamu?
Akasaki Isamu (1929–2021) was a Japanese materials scientist. He shared the 2014 Nobel Prize in Physics with Amano Hiroshi and Nakamura Shuji for inventing blue light-emitting diodes (LEDs). This innovation paved the way for energy-efficient white lighting.
After earning a doctorate in engineering from Nagoya University in 1964, Akasaki held research and teaching positions before returning to Nagoya University as a professor in 1981. Prior to Akasaki's work, red and green LEDs existed, but blue LEDs were considered impractical. Through research on gallium nitride (GaN), Akasaki and Amano created high-quality GaN crystals by placing an aluminum nitride layer on a sapphire substrate.
Akasaki's research led to the development of blue semiconductor lasers, useful in Blu-ray disc players. His awards include the Kyoto Prize (2009) and the Draper Prize (2015).
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What is a materials scientist?
A materials scientist studies the properties of solid materials, linking these properties to the material's composition and structure. This interdisciplinary field combines solid-state physics, metallurgy, and chemistry to design materials for diverse applications, such as computer microchips and structural steels.
Akasaki Isamu (1929–2021) was a Japanese materials scientist who won the 2014 Nobel Prize in Physics for inventing blue light-emitting diodes (LEDs). His work on gallium nitride (GaN) led to breakthroughs in creating high-quality crystals and p-type GaN, which enabled the production of blue LEDs.
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What important invention is Akasaki Isamu known for?
Akasaki Isamu was a Japanese materials scientist who won the 2014 Nobel Prize in Physics for inventing blue light-emitting diodes (LEDs). This invention, which he shared with Amano Hiroshi and Nakamura Shuji, paved the way for white LEDs when combined with red and green LEDs, and also for blue semiconductor lasers useful in Blu-ray disc players and other high-capacity optical-media devices.
Prior to Akasaki's work in the 1980s, scientists could produce red or green LEDs, but blue LEDs were considered impossible or impractical. Akasaki and Amano created high-quality gallium nitride (GaN) crystals by placing an aluminum nitride layer on a sapphire substrate. In 1989, they made p-type GaN, which glowed brighter under an electron microscope, showing that electron beams would improve the material. They combined the p-type and n-type layers to form blue LEDs in 1992.
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How did Akasaki Isamu's work change everyday technology?
Isamu Akasaki's work revolutionized everyday technology through his invention of blue light-emitting diodes (LEDs). Prior to his work, red and green LEDs were available, but the creation of blue LEDs was considered impossible.
Akasaki's breakthrough, achieved with Amano Hiroshi, involved using gallium nitride (GaN) to produce blue light. This innovation enabled the creation of white light by combining blue, green, and red LEDs, leading to more energy-efficient lighting. Blue LEDs also led to the development of blue semiconductor lasers, which are used in Blu-ray disc players and other high-capacity optical media devices. Today, LEDs are used in various applications, including indicator lamps, car brake lights, alphanumeric displays, and fiber-optic telecommunication systems.
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What challenges did Akasaki Isamu face in his research?
Akasaki Isamu faced significant challenges in his research on gallium nitride (GaN) for blue LEDs. Prior to his work in the 1980s, blue LEDs were considered impossible to make. A major hurdle was growing usable GaN crystals. Akasaki and Amano overcame this by creating high-quality GaN crystals using an aluminum nitride layer on a sapphire substrate. Another breakthrough was in 1989, when they created p-type GaN by doping GaN crystals with magnesium atoms, which glowed brighter under an electron microscope. These innovations paved the way for blue LEDs, which became commercially available in 1993.
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Why did Akasaki Isamu receive the Nobel Prize in Physics?
Isamu Akasaki, along with Hiroshi Amano and Shuji Nakamura, won the 2014 Nobel Prize in Physics for inventing blue light-emitting diodes (LEDs).
Before Akasaki's work, red and green LEDs existed, but blue LEDs were considered impossible to make, which prevented the creation of white light sources. In 1986, Akasaki and Amano discovered that high-quality gallium nitride (GaN) crystals could be created by placing an aluminum nitride layer on a sapphire substrate and then growing the crystals on that. In 1989, they made p-type GaN by doping GaN crystals with magnesium atoms. The combination of blue, green, and red LEDs produces white light, using much less energy than incandescent and fluorescent lamps.
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Akasaki Isamu (born January 30, 1929, Chiran, Japan—died April 1, 2021, Nagoya) was a Japanese materials scientist who was awarded the 2014 Nobel Prize for Physics for inventing blue light-emitting diodes (LEDs), paving the way for future innovation. He shared the prize with Japanese materials scientist Amano Hiroshi and Japanese-born American materials scientist Nakamura Shuji.
After Akasaki received a B.S. from Kyōto University in 1952, he worked for Kobe Kogyo Corp. (later named Fujitsu) until 1959. He then attended Nagoya University, where he held several teaching positions while obtaining a doctorate in engineering (1964). He subsequently served as the head of a basic research laboratory at the Matsushita Research Institute Tokyo, Inc., until he returned (1981) to Nagoya University as a professor. In 1992, when Akasaki left Nagoya University, he was made professor emeritus; he then joined the faculty of Meijo University in Nagoya. Nagoya University gave Akasaki the title of distinguished professor in 2004 and named the Akasaki Institute, completed in 2006, in his honour.
Prior to Akasaki’s work in the 1980s, scientists had produced LEDs that emitted red or green light, but blue LEDs had been considered impossible or impractical to make. Akasaki, Amano, and Nakamura succeeded in finding techniques for producing blue LEDs through many years of research on the semiconductor gallium nitride (GaN). (LEDs are semiconductor diodes that contain an interface between two types of semiconductor materials—n-type and p-type materials—which are formed by doping [introducing] different impurities into each.) When excited by electrons, GaN emits blue and ultraviolet light; however, growing usable GaN crystals was a challenge. A major breakthrough was Akasaki and Amano’s discovery in 1986 that high-quality GaN crystals could be created by placing an aluminum nitride layer on a sapphire substrate and then growing the crystals on that. The second breakthrough in Akasaki and Amano’s work came in 1989 when they discovered that p-type GaN could be formed by doping GaN crystals with magnesium atoms. They saw that the p-type layer glowed much brighter when they studied it under a electron microscope, thus showing that electron beams would improve the material. That p-type material was then used with existing n-type material to form blue LEDs in 1992. (Working independently at the same time, Nakamura made blue LEDs with slightly different techniques.) The combination of blue, green, and red LEDs produces a light that appears white to the eye and that can be produced for much less energy than that from incandescent and fluorescent lamps.
Akasaki continued research into GaN materials through the 1990s and early 2000s (blue LEDs became commercially available in 1993). His work helped lead to the development of blue semiconductor lasers, which proved useful for high-capacity optical-media devices such as Blu-ray disc players.
Akasaki was the recipient of numerous honours. In addition to the Nobel Prize, his other notable awards included the Kyoto Prize (2009) and the Draper Prize (2015).