Today, the Royal Swedish Academy of Sciences announced that it had awarded the Nobel Prize in Physics for 2014 to three scientists -Professors Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura -“for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources".
Red and green LEDs existed (they had been developed in the 1950s and 1960s , respectively) when the three researchers first started their investigations in the mid-1980s to create the elusive blue diode. All three believed that blue-light gallium nitride (GaN) was the correct material that needed to be introduced into the makeup of the diode’s architecture. The problem, however, was that high-quality gallium nitride crystals had yet to be produced with any consistency.
That changed in 1986 when Akasaki, teaching at Nagoya University in Japan, and Amano, a Ph.D. student at the university, created a high-quality gallium nitride crystal. They did this by putting a layer of aluminum nitride on a sapphire substrate and then placing the gallium nitride on top. They presented their first blue diode in 1992.
Nakamura’s blue LED investigations began in 1988 while working at Nichia Chemicals in Tokushima, Japan. In 1990, he also was successful in producing a high-quality gallium nitride crystal, but his method involved growing a thin layer of gallium nitride at a low temperature and then growing additional layers at higher temperatures. (This GaN-on-GaN architecture is the basis for the company he helped co-found in 2008, Soraa.) In the 1990s, both groups continued their work, improving the efficiency of their blue LEDs as well as the invention of the blue laser, of which the blue LED is a key component.
Akasaki, Amano, and Nakamura’s creation of a blue light from semiconductors revolutionized lighting technology since combining the new blue diode with a red diode and a green diode creates white light. The Nobel Committee for Physics recognized the three scientist’s work as “an invention of greatest benefit to mankind” and cited the achievement as one that contributes to creating a long-lasting more efficient light source. The committee went on to note that “The invention of the blue LED is just twenty years old, but it has already contributed to create white light in an entirely new manner to the benefit of us all.”
Akasaki, 85, a professor at Meijo University, Nagoya, Japan, and distinguished professor at Nagoya University, Japan; Amano, 54, also a professor at Nagoya University, Japan; and Nakamura, 60, professor of materials and of electrical and computer engineering, University of California, Santa Barbara, will share the $1.1 million prize (8 million Swedish Krona), which will be presented in Stockholm on Dec. 10.
The prize announcement can be watched here: