From PBS Nova:

The winners of this year’s Nobel Prize in Physics are Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura, three scientists who contributed to the development of light-emitting diodes, or LEDs. LEDs generate light by moving electrons through layered semiconducting materials; they are dramatically more efficient and long-lasting than familiar incandescent bulbs.

From the Royal Swedish Academy of Science’s press release:

When Isamu Akasaki, Hiroshi Amano and Shuji Nakamura produced bright blue light beams from their semi-conductors in the early 1990s, they triggered a fundamental transformation of lighting technology. Red and green diodes had been around for a long time but without blue light, white lamps could not be created. Despite considerable efforts, both in the scientific community and in industry, the blue LED had remained a challenge for three decades.

The choice reflects the LEDs’ potential impact as an environmentally friendly, energy-efficient source of light:

In the spirit of Alfred Nobel the Prize rewards an invention of greatest benefit to mankind; using blue LEDs, white light can be created in a new way. With the advent of LED lamps we now have more long-lasting and more efficient alternatives to older light sources….The LED lamp holds great promise for increasing the quality of life for over 1.5 billion people around the world who lack access to electricity grids: due to low power requirements it can be powered by cheap local solar power.

Learn more about the winners and the science of LEDs at Nobelrize.org and HowStuffWorks: How Light-Emitting Diodes Work. Read the personal story of Shuji Nakamura’s achievement in this 2000 Scientific American profile.