Isamu Akasaki

Born on 30 January 1929 in Chiran, Japan, Isamu Akasaki is a Nobel laureate who invented blue LEDs. He received a BS from Kyoto University in 1952 and a PhD in engineering from Nagoya University in 1964. After a stint working at the Matsushita Research Institute Tokyo, Akasaki returned to Nagoya in 1981 as a professor. Akasaki had been working on blue LEDs since the 1960s. Although red and green LEDs had already been developed, blue ones had proved much more elusive. Red and green LEDs used gallium arsenide and gallium phosphide, which were relatively easy to produce. Blue LEDs required the pairing of gallium with a lighter element from group V, nitrogen, which was more difficult to do. Through the use of a new technique called metalorganic vapor phase epitaxy developed in the mid 1970s, Akasaki and his student Hiroshi Amano were able to create high-quality gallium nitride crystals by layering the material with aluminum nitride and a sapphire substrate and doping it with magnesium. By 1992 they had created the first blue LEDs. Their work revolutionized the field of LED lighting and led to the development of high-resolution screens for cell phones and tablets. Akasaki and Amano shared the 2014 Nobel Prize in Physics with Shuji Nakamura. (Photo credit: 大臣官房人事課 (平成23年度　文化勲章受章者：文部科学省), CC BY 4.0 )

Date in History: 30 January 1929