Akasaki, Isamu (1929-2021), a Japanese physicist, shared the 2014 Nobel Prize in physics with the Japanese physicist Hiroshi Amano and the Japanese-American physicist Shuji Nakamura. All three scientists received the award for their work in developing a blue light-emitting diode (LED). An LED is a tiny device that gives off light in response to an electric current. The breakthrough in blue LED’s enabled the development of LED devices that give off white light. Such devices are longer lasting and more energy efficient than traditional incandescent and fluorescent lights.
White light is actually a mixture of many colors, or wavelengths, of light. An LED, on the other hand, can produce only a single color. LED devices must produce white light by combining light from several LED’s of differing colors, generally red, green, and blue. The first visible-light LED’s, created in 1962, were red. Green LED’s were developed in the early 1970’s. Blue light, which is more energetic, proved extremely difficult to produce in an LED. In the early 1970’s, researchers at the American company RCA concluded that a material called gallium nitride (GaN), combining the metal gallium and nitrogen, could serve as the basis for a blue LED. However, the company encountered financial difficulties and canceled further research.
Akasaki later began working with gallium nitride. Amano joined him at Nagoya University as an undergraduate student in 1982. In 1986, the pair succeeded in manufacturing a suitable GaN crystal. Over the next decade, Akasaki and Amano and, separately, Nakamura refined the process of producing GaN crystals for blue LED’s. Akasaki and Nakamura created the first blue LED in 1989, but it was relatively dim. The pair developed a bright LED in 1992, with Nakamura creating a commercially viable blue LED in 1993.
Akasaki was born on Jan. 30, 1929, in the town of Chiran, in southwestern Japan. He graduated from Kyoto University in 1952. He then worked for the Kobe Kogyo Corporation, an electronics manufacturer, until becoming a research associate at the school of engineering at Nagoya University in 1959. In 1964, he received his Ph.D. degree and became an assistant professor at the university. That same year, he began work at Matsushita Electric Industrial Corporation.
Akasaki joined the faculty of Nagoya University as a professor of engineering in 1981. In 1992, he retired from Nagoya, becoming an emeritus professor, and joined Meijo University as a professor of engineering. He was awarded the position of distinguished professor at Nagoya University in 2004. In 2006, the university opened the Akasaki Institute, a technology research center named to honor his work. Akasaki died on April 1, 2021.
