There's pretty good chance you have a piece of this year's physics Nobel prize-winning invention in your pocket. The blue light-emitting diode (LED) is found in the screens of millions of phones as well as our bright, new energy-efficient LED lightbulbs. Today, the Nobel Prize in physics was awarded to the three scientists who made this revolutionary discovery.
Isamu Akasaki, Hiroshi Amano and Shuji Nakamura were all working on the a blue LED in Japan back in the 1990s. At that time, red and green LEDs had already existed for decades, but blue proved elusive. Remember that red, green and blue light together create white light, so for lightbulbs and full-colour screens, the missing blue LED was crucial.
To get LEDs to glow blue, the researchers had to create a new material. LEDs emit light when electrons pass through layers of semiconducting material—the color of light depends on the composition of that material. Akasaki, Amano, and Nakamura ended up making blue LEDs out of the element gallium.
Twenty years later, LEDs are well on their way to taking over the world, thanks to their brightness and energy-efficiency. (LEDs don't emit as much heat as your old incandescent bulbs) They're already in loads of smartphone, televisions, computers—pretty much anything with a lit display. LED lightbulbs are also now replacing incandescent and fluorescent bulbs, changing the look of our cities, movies, and lighting fixtures.
It's not every year that the impact of Noble-winning physics discovery is so obvious around us. Everywhere you look—including the very screen on which you're reading this, probably—you'll going to find LEDs. [Nobel]
Top image: Blue LEDs. Credit: Gussisaurio/CC