Isamu Akasaki

Who is Isamu Akasaki?

Isamu Akasaki is a Japanese scientist, known for inventing the bright gallium nitride p-n junction blue LED in 1989 and subsequently the high-brightness GaN blue LED as well.

For this and other work Isamu Akasaki was awarded the Kyoto Prize in Advanced Technology in 2009 and the IEEE Edison Medal in 2011.

Born in Kagoshima Prefecture, Akasaki graduated from Kyoto University in 1952, and received Dr. Eng. in Electronics from Nagoya University in 1964. He started working on GaN-based blue LEDs in the late 1960s. Step by step, he improved the quality of GaN crystals and device structures at Matsushita Research Institute Tokyo,Inc.,where he decided to adopt metalorganic vapor phase epitaxy 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 high-quality GaN on sapphire substrate by pioneering the low-temperature buffr layer technology.

This high-quality GaN enabled them to discover p-type GaN by doping with magnesium and subsequent activation by electron irradiation, to produce the first GaN p-n junction blue/UV LED, and to achieve conductivity control of n-type GaN and related alloys by doping with silicon,enabling the use of heterostructures and multiple quantum wells in the design of more efficient p-n junction light emitting structures.