Isamu Akasaki
Name in native script: 赤崎勇
1929–2021, Chiran, Kagoshima, Japan, Nagoya, Japan
Japanese physicist, 'father of the blue LED' — first to master p-type doping of GaN for high-efficiency light-emitting diodes.
Akasaki pursued GaN — a material abandoned by the semiconductor industry — since the 1960s. At Nagoya he developed buffer-layer growth on sapphire substrates (1973 onward) and in 1989, with Hiroshi Amano, produced p-type GaN via electron-beam irradiation, enabling the blue LEDs commercialized by Nakamura at Nichia.
Nobel-winning work
Blue LEDs needed perfect GaN crystals and hole-conducting (p-type) regions. Akasaki showed electron irradiation 'activates' Mg acceptors in GaN, and his AlN buffer layer yielded high-quality crystals on sapphire. With Amano and Nakamura, the blue LED completed the solid-state light trio — enabling white LED lamps replacing incandescent bulbs, saving energy worldwide.
Workplaces: Nagoya University, Meijo University
Japan