The Elusive Blue LED

In 2014, three Japanese physicists received the Nobel Prize in Physics: Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura for their invention of the blue LEDs. But the story behind it is probably one that the ordinary person wouldn’t know, even though it’s because of their invention that we get to enjoy many technological advancements that make our lives more convenient.

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The story began in the late 1980s when many technology companies and semiconductor manufacturers were in a race to create the blue LED. For decades, only red and green LEDs were available, and that’s because creating the blue LED was much more technically challenging, requiring a lot of trial and error. It needed somebody who had the guts to take risks.

Enter Shuji Nakamura, who was an engineer at Nichia Corporation, in a time when the company was almost at its lowest point. His coworkers and bosses were haranguing him for a lack of results in his research, and so he submitted a proposal to the then-president Nobuo Ogawa, that led him on the journey to unlocking the secrets of blue LED.

The first phase of this journey brought him to Florida, where he worked on an MOCVD, a machine used to grow crystalline layers, an important component in producing LEDs. After spending a year tinkering with a non-functional MOCVD, he returned to Japan and ordered a fully-functional MOCVD for Nichia.

With that in his arsenal, he spent about a year and a half working on making gallium nitride crystals suitable for LEDs. At the time, the consensus among LED manufacturers and scientists was that zinc selenide was the more plausible path toward the blue LED, so Nakamura went against the grain and tried to make the less popular gallium nitride work.

This is where Akasaki and Amano come in, who have been researching on the matter before Nakamura entered the picture. There were three problems that these scientists tried solving to make gallium nitride viable for blue LED production, and for the first two problems, Nakamura took the lead from Akasaki and Amano, adding a few tweaks to improve on their initial results.

The third problem became a difficult obstacle for Akasaki and Amano, but Nakamura’s innovative thinking helped him break through and solve the problem. In 1992, Nakamura showed Nichia’s chairman the very first functional blue LED. The company announced it to the world, catching everybody by surprise, and this resulted in double and later, triple the profits for Nichia.

But as with many inventions, their inventors don’t always get compensated properly. Nakamura later quit Nichia and migrated to the US. Legal battles were fought along the way, and Nakamura still has a tense relationship with Nichia to this day.

At the moment, Nakamura is currently working at the University of California Santa Barbara, and making progress on the next generation of LEDs, paving the way for technologies like augmented and virtual reality, and even a solution to COVID-19.

For the full details of the science behind the making of blue LEDs, you may watch Veritasium’s video above. – via Laughing Squid

(Video credit: Veritasium/Youtube)

Source: neatorama

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