On the afternoon of October 7, the Royal Swedish Academy of Sciences announced that it will jointly award the 2014 Nobel Prize in Physics to Japanese scientists, Isamu Akasaki, Hiroshi Amano, and the Japanese-American scientist Nakamura of the University of California, Santa Barbara. Shuji Nakamura, in recognition of their contribution to the invention of a new energy-efficient light source, namely blue light-emitting diodes (LEDs), opens up new possibilities for energy savings.
For details, click on the Blue LED: Illuminate the world's last "primary light"
Not discovering, is an invention that affects humans
"Blu-ray LEDs don't sound so sinister or tall, but they are results that can have a great impact on human society," said Ji Xiangdong, professor of physics at Shanghai Jiaotong University.
Red and green diodes have been around for a long time, but to produce white light, red, blue, and green primary colors are required to work at the same time. The original diodes only emit red and green light because the luminescence energy is too low, and blue light means that higher energy light needs to be emitted. In the late 1980s, Akasaki and Amano co-operated at Nagoya University, while Nakamura Shuji was an employee of a chemical company in Tokushima Prefecture. He proposed the idea of ​​preparing gallium nitride blue light-emitting diodes. Only three years after proposing this idea, Nakamura Shuji published his first English article in Applied Physics Letters: a novel for growing gallium nitride. Metal organic chemical vapor deposition. The publication of the paper sensationalized the world's semiconductor industry and the scientific community. At that time, many large companies and famous university research institutions in the world were struggling with the preparation process of semiconductor blue light source film materials, and GaN was the III-V family. The most promising wide bandgap optical material in semiconductor materials.
Subsequently, the study of Akasaka Yong, Nakamura Shuji, and Amano was able to enter a revolution in light source. "As they say, this is not a discovery, but an invention. This requires a major breakthrough in materials and devices, and it takes the road from theory to application. It is precisely because these three scholars have done different things. Breakthrough makes the promotion of LED lighting applications possible.†Lu Wei, director of the Shanghai Institute of Technical Physics of the Chinese Academy of Sciences, said that many scholars and three scholars are engaged in the research of blue-light diodes at the same time, but they are unable to manufacture materials and devices. A breakthrough was made and I was unable to achieve my research intentions, and I had to choose to give up.
This is also why, when the Nobel Prizes Committee yesterday called Nakamura Shuji and told him to win the Nobel Prize in Physics this year, Nakamura had two minutes to react. Later, when asked what he thought, he paused for a long time and even said a few "yes", and then only said "it is simply too hard to believe." It is understood that the three scientists are constantly improving their results to get more efficient luminous flux. The latest record is 300 lumens / watt, equivalent to 16 ordinary bulbs and nearly 70 fluorescent lamps. According to reports, one-quarter of the world's electricity consumption is now used for lighting, and more efficient LED lights help save the earth's resources.
Another way to take the path of others not to go
On the Nobel website, you can see the description of the three winners - "When Akasaki and Amano, and Nakamura Shuei participated in the celebration of the Nobel Prize Committee in early December, they should notice the lights on the streets of Stockholm. They use the energy-saving LED white light street lamp they invented. Red and green light diodes have been with us for half a century, but blue light is the technology that really brings revolutionary changes. Only the light of these three primary colors can form white light, illuminate us. The world. These three scholars have worked hard in academic research and industry to solve the problems that have existed for more than 30 years...
"They won't win their theoretical breakthroughs, but their breakthrough in material technology and device fabrication." Professor Chen Liangwei, who has been working on optical devices for a long time in Fudan University, said: "Nakamura Shuji studied blue-light diodes in the company that year. I personally modified the MOCVD long film, and I have a deep understanding of the long film mechanism. The quality of the GaN film made by others is very poor. Many people have given up, he just made it, and finally succeeded a little bit. This is not to be said. His technical breakthrough."
In fact, many scientists know that GaN, physics about the band structure of this material, PN conductivity type regulation and luminescence properties, have a lot of theoretical and experimental results, the real headache is that To achieve deviceization of this material, the substrate material must be lattice matched to the gallium nitride. At that time, many scientists followed the trend to develop new semiconductor materials. As Nakamura Shuji later joked, because the research and development power of large companies filled the hills of new material development, he had only another way to take the path of others.
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