The Royal Swedish Academy of Sciences has awarded the Nobel Prize in Physics for 2014 to Isamu Akasaki of Meijo University and Nagoya University (both in Nagoya, Japan), Hiroshi Amano of Nagoya University, and Shuji Nakamura of the University of California, Santa Barbara (UCSB). The three researchers won the award "for the invention of efficient blue light-emitting diodes which has enabled bright and energy-saving white light sources." Such LEDs are based on the semiconductor gallium nitride (GaN).
The prize amounts to SEK 8 million (about $1.1 million), to be shared equally between the three researchers.
Nakamura, who was at Nichia Corp. (Anan, Japan) in the 1990s, was the driving force behind the commercialization of the first blue LEDs. Nichia also went on to develop blue and violet laser diodes. Nakamura left Nichia for USCB in 2000.
The list of devices resulting from the technology is long; the most well-known item on the list is, of course, LEDs for lighting. These come in two major forms: 1) blue LED plus yellow phosphor, and 2) red-green-blue (RGB) LED combinations. The first type has led to the most long-lived, efficient, and rugged white-light lamps ever produced, while the second results in lamps whose hues can be changed from white to any perceived color.
On the way are even more efficient GaN-based white-light sources: blue or UV laser diodes combined with phosphors being developed at UCSB.
GaN-based UV LEDs have their own unique uses; for example, as their wavelengths are pushed shorter, they have become a practical tool for sterilization of water and surgical instruments.
For more detail on many aspects of GaN-based LED technology, see: https://www.laserfocusworld.com/search?ebm_lfw%5Bquery%5D=GaN%20LED.