Isamu Akasaki, a Japanese physicist who helped develop blue light-emitting diodes, a breakthrough in the development of LEDs that earned him a Nobel Prize and transformed the way the world is illuminated, died on Thursday in a hospital in Nagoya, Japan. He was 92.
Meijo University in Nagoya, where he had been a professor, said the cause was pneumonia. He had also been affiliated with Nagoya University.
Dr. Akasaki shared the Nobel Prize in Physics in 2014 with Hiroshi Amano of Japan and Shuji Nakamura of the University of California, Santa Barbara. Their invention of blue light-emitting diodes led the way for a vast wave of light sources that are cheaper, more durable and environmentally safer than incandescent and fluorescent bulbs.
“They succeeded where everyone else had failed,” the Royal Swedish Academy of Sciences said in its prize citation. “Their inventions were revolutionary.”
Unlike incandescent bulbs, which heat metal filaments to create energy, and fluorescent lamps, which use ionized gas, LEDs are tiny semiconductor chips that emit photons of light when an electric current is applied to them.
First-generation LED lamps required a combination of red, green and blue light to produce familiar white light. While red and green diodes were first developed in the 1950s and ’60s, blue light proved to be a far more challenging hurdle.
Following early work at RCA in the late 1960s, Dr. Akasaki began trying to grow high-quality crystals of the semiconductor gallium nitride in the early ’70s at the Matsushita Research Institute Tokyo, an electronics company. Later, at the University of Nagoya, he was joined in his research by Dr. Amano, his graduate student at the time.
By the late ’80s they had managed to generate blue light from their chips. Around the same time, Dr. Nakamura, working at the Nichia Corporation, a chemical company in Tokushima, built on their breakthrough to produce a bright blue LED that would eventually enable the chips to be applied to lighting.
LEDs have since become ubiquitous, powering everything from flashlights and streetlights to televisions. They give off much less heat than incandescent bulbs, consume far less energy than fluorescents and last far longer.
Bob Johnstone, a technology journalist and the author of “L.E.D.: A History of the Future of Lighting” (2017), said in an email, “The prevailing opinion in the late 1980s was that, because of the number of flaws in the crystal structure of gallium nitride, it would never be possible to make light-emitting diodes from it, so why would you even try?”
Dr. Akasaki, he continued, “was willing to stick at what was almost universally recognized to be a lost cause, working away long after researchers at RCA and other U.S. pioneers of gallium nitride LED technology had given up.”
“Eventually,” Mr. Johnstone said, “his perseverance — sheer doggedness — paid off.”
Gerhard Fasol, a physicist with an extensive background in Japanese high technology, said by email that the potential of LEDs is especially far-reaching in developing countries without reliable electricity, where “LEDs in combination with batteries and solar cells can greatly improve quality of life and education and trade.”
In 2019, LED products accounted for nearly 60 percent of the global lighting market, compared with less than 10 percent in 2010, according to Strategies Unlimited, a market research firm based in Nashville. In the United States, LEDs are projected to reach over 80 percent of all lighting sales by 2030, saving Americans $26 billion per year in electricity costs, according to a 2015 report by the Department of Energy.
Isamu Akasaki was born on Jan. 30, 1929, in Chiran, in southernmost Japan. After graduating from Kyoto University in 1952, he worked for the Kobe Kogyo Corporation (later named Fujitsu) until 1959. He then attended Nagoya University, where he held several teaching positions before receiving his doctorate in engineering in 1964.
He continued his career at Matsushita before returning to Nagoya University in 1981 as a professor in the electronics department. He was named a professor emeritus in 1992 and later joined the faculty of Meijo University, also in Nagoya, where he was the director of its Research Center for Nitride Semiconductor Core Technologies. He was still working at the university as recently as 2019.
Dr. Akasaki was awarded hundreds of patents for his research over the years, and the royalties from his groundbreaking work with Dr. Amano eventually funded the building of a new research institute, the Nagoya University Akasaki Institute, completed in 2006. In addition to his Nobel, he received many other awards, including the Kyoto Prize in 2009, and was honored by the Japanese emperor with the Order of Culture in 2011.
He had a wife, Ryoko. Complete information on his survivors was not available.
When asked in a 2016 interview with the Electrochemical Society to summarize the philosophy guiding his many years of single-minded research, Dr. Akasaki replied, “No pain, no gain.”
“I say this to younger people: Experience is the best teacher,” he continued. “That is, sometimes there is no royal road to learning.”