AsianScientist (Oct. 8, 2014) – The 2014 Nobel Prize in Physics has been awarded to Professors Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for their role in the discovery of blue light-emitting diodes (LED). The SEK8 million (~US$1.12 million) prize money will be shared equally between the three Laureates.
Although red and green light emitting diodes have been around for more than 50 years, the ability to produce light in the blue spectrum proved to be much more challenging. Without blue light, it was not possible to form the highly desired white light required for most lighting purposes. As a result, most lights used incandescent or fluorescent bulbs which are much less efficient than LED lighting or contain toxic mercury respectively.
Based at Nagoya University, Prof. Akasaki and his then Ph.D. student Amano choose to work with gallium nitride (GaN) as a material to produce blue light, even though many others had failed due to the challenges of growing high quality GaN crystals. By 1986, Profs. Akasaki and Amano managed to obtain GaN crystals of a sufficient quality by growing them on a layer of aluminum nitride on a sapphire surface.
Working independently at Nichia Chemicals, Prof. Nakamura devised a cheaper and simpler method of growing GaN crystals and also developed a theory to explain how Akasaki and Amano’s method allowed them to generate the p-type layer required for light generation.
Aside from blue light-emitting LEDs, their research also contributed to the development of Blu-ray discs and better laser printers. In contrast to the dispersed light of the LED, the Laureates collaborated to invent a blue laser which is an intensely focused beam of light. Due to the short wavelength of blue light, storage devices based on blue light can store four times more information than those based on infrared light.
Given that approximately one fourth of the world’s energy is consumed by lighting needs, the improved efficiency of LED lights have the potential to significantly reduce the global electricity demand. Furthermore, with their low power requirements, LED lights in conjunction with cheap renewable power could be used to improve the quality of life for the over 1.5 billion people who lack access to electricity grids.
Source: Asian Scientist Magazine; Photo: Nobel Foundation.
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