At an announcement in Stockholm on Tuesday, the Nobel Prize committee awarded this year's prize in physics to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura. The three men -- Akasaki from Meijo University, Amano from Nagoya University (both in Nagoya, Japan) and Nakamura from UC Santa Barbara -- produced blue light beams from their semi-conductors in the early 1990s. Until then, we could create red and green light, but blue remained elusive.
Red, blue, and green light combine to make the bright white produced by LED lightbulbs. Bulbs using blue light-emitting diodes are more efficient and have a longer lifetime than old fashioned bulbs (up to 100,000 hours, compared to 1,000 for incandescent bulbs and 10,000 hours for fluorescent lights).
What’s a blue light-emitting diode?
You probably know light-emitting diodes as LEDs. They’re little light bulbs that don’t rely on the filament you can see burning inside an old-fashioned bulb. Instead, electrons move through several layers of semiconducting materials – directly converting electricity into light, sparing the heat-waste of a traditional bulb (and keeping your fingers from getting burned!) Even in fluorescent lamps, which use less energy than fluorescent bulbs, the gas used creates both heat and light.
A red light-emitting diode was invented during the 1950s, but without that magic blue light we couldn’t create white – and if LEDs couldn’t light up our homes, they just weren’t living up to their full potential.
All three Nobel laureates are Japanese by birth, and worked in Japan at the time of their discoveries (Nakamura is now an American citizen, and serves on the faculty of UC Santa Barbara). Akasaki and Amano worked together at Nagoya University, and made early breakthroughs in the development of the semiconductor materials necessary for creating the diode during the 80s. In 1992, they presented their first working blue light.
Nakamura, working at Nichia Chemicals on the island of Shikoku, started work on his own blue LED in 1988. Just a few years after Akasaki and Amano, he developed his own way of creating the necessary layers of semiconductor, and ultimately created a cheaper and easier method of creating the LED.
All three men continued to improve on their work during the 90s, and also independently created blue lasers -- which, because of blue light's very short wavelength, allow for information to be stored much more densely than infrared light does. That’s how Blu-ray movie discs came to be.