Nobel Prize in Physics goes to inventors of blue LEDs

The Nobel Prize in Physics has been awarded to two Japanese and an American for the invention of the blue LED. The inventors have succeeded where others have failed, according to the jury, and the blue LEDs have provided a new economical alternative to other light sources.

The 2014 Nobel Prize in Physics was awarded to Isamu Akasaki and Hiroshi Amano of the Japanese University of Nagoya and Japanese-born American Shuji Nakamura of the American University of California. The three receive the prestigious prize for developing the blue LED in the early 1990s.

According to the jury, the invention has led to a ‘fundamental transformation of light technology’. The development of a blue LED has been a long time coming, but it was fundamental to make LEDs a useful alternative to other light sources such as the incandescent lamp. Red and green LEDs were already developed in the late 1960s, but a blue LED was also necessary for white light. In addition to the combination of red, green and blue LEDs for white light, blue LEDs are also combined with yellow phosphor for efficient white LEDs.

In the following years, scientists’ efforts to develop high-brightness blue LEDs failed until Shuji Nakamura demonstrated his blue LED based on the semiconductor material indium gallium nitride in 1994. For a long time, an obstacle was the difficulty of growing gallium nitride on a substrate, but Nakamura managed to dope the material in a controlled manner.

The technology has helped maintain the trend of doubling the brightness of LEDs every 36 months, and white light bulbs have supplanted old alternatives. The record in terms of brightness is 300lm/W for LEDs, while it is 16 for incandescent lamps. Due to its economy and long life, LED lighting offers environmental benefits worldwide, the Nobel Foundation notes.