Nobel award for the new darling of Blu ray LED blue disaster?

Blue light emitting diode (LED) recently put great luster, such as the Japanese scientist Akasaki Yong, the 2014 Nobel prize in physics. LED production in China, the largest country, the news has become a positive signal to stimulate the industry.

Looking back at the discovery of Blu ray LED, in the enjoyment of science and technology to bring the colorful and bright, its security has also been discussed several ups and downs and increasingly fierce. Is there a blue light hazard in LED? Is this a serious "blue disaster", or is it under control?

Waited 30 years

As early as before the invention of the blue LED, red LED, yellow light LED, green LED has been published, one of the three primary colors - the emergence of blue LED, scientists have worked for more than 30 years.

In 1960, American scholars realized the transition from the semiconductor light emitting infrared to red, the first human LED get visible red light, but the band gap of the material system is relatively small, it can only be sent to the yellow light, cannot emit blue light. Three Japanese scientists who won the 2014 Nobel prize in physics conquered the material.

Japanese scientist Akasaki Yong to the Nagoya University, decided to do gallium nitride material, and found that it is very stable, laid the foundation for the Blu ray LE D research, his students made a substantial breakthrough in the study of Amano Hironori.

Department of optical engineering, Huazhong University of Science and Technology doctoral tutor Wu Zhihao introduced, said Amano Hiroshi very hard to do the experiment, not much progress is very depressed, and just one day there have been some experimental equipment fault, the temperature drop after freezing and increased material on the president. Based on the usual efforts to find a certain extent to solve the problem of crystal growth.

Amano Hiroshi went to Japan NTT internship, through low-energy electron beam bombardment, so that gallium nitride materials to produce holes, the true realization of the type P doping, the results of the report triggered a boom in research. At this time, the development of Japanese company Nichia Nakamura Shuji suggested that the company used for GaN Blue LED, "industrialization goal is to rely on him to do it. Wu Zhihao evaluation.

Blu ray LED appeared in the lighting industry had a disruptive effect. In the light of the puzzle, Blu ray LED is the most important, the most difficult one, three scientists not only in the laboratory to do it, and found a way to industrialization". Zhang Shanduan, deputy director of the Institute of electric light sources, Fudan University, this is the 2014 physics prize awarded to blue LED inventor reasons.

After the emergence of Blu ray LED, the entire LED industry has achieved a leap, while China is currently the world's largest manufacturing base of LED lamps. According to last year, the semiconductor science and technology development in 12th Five-Year special plan shows that by 2015, LED's share of China's general lighting market to reach 30%. Zhang Shanduan predicts that by 2020, in our lives, the use of lamps, which accounted for half of the LED.

However, the increasingly widespread use of LED, accompanied by "blue light hazard" concerns.

Orange warning

In daily life, the use of LED lights and computers for a long time, the eyes will usually appear tired, dry, tingling and discomfort, which is actually the LED light in the blue light.

Department of electronic engineering Tsinghua University professor Huo Yujing introduction, the human eye is very sensitive to yellow light and the green light, the two power lighting can be relatively low, but the human eye is not sensitive to blue light, the need to increase the power to see clearly.

LED light source is a white light, but the formation of white light is mainly on the wavelength of 450 - 460nm blue light excitation phosphor. Usually LED light source factory wavelength control in the 500nm, is generally 450 - 455 nm or 455 - 460 nm, are the most radiation damage. And manufacturers in order to pursue brightness, usually strengthen the intensity of the L E D light source, if the human eye for a long time, inevitably injured.

"Blue harm" has become a 500nm 400 refers to the blue band, high brightness in the eyes for a long time, open source may cause retinal photochemical damage of vocabulary.

In medical research, blue light will be absorbed by retinal pigment epithelial cells, causing free radical formation. Free radical is a kind of oxygen with strong oxidation ability. Under normal conditions, the free radical will be absorbed by the human body and the metabolism of the blood. If the long-term work in the lighting environment containing more blue component with life, excessive high-energy blue light into the eye, will produce excessive free radicals, the antioxidant substances in the body can not be completely eliminated, they will accelerate the macular macular absorption is not oxidation, will directly damage the visual cells in blue. The visual cells are non renewable after death.

The World Health Organization Eye Institute at the end of 2009 issued a "Blue Orange signal warning radiation on human potential hidden threats will be far more than tonyred, melamine, SARS and HINI of the destructive", and also announced figures: in 2006 to 2008 3 years, due to the Blu ray radiation led to more than 30 thousand people worldwide each year blindness.

Chinese Medical Association of Ophthalmology branch data show that in China 420 million Internet users, 63.5% of Internet users due to blue light radiation decreased vision, cataracts, blindness and other degrees of eye disease. The American Academy of Ophthalmology (AAO) in 2010, there is an article that, blue light relative to other wavelengths of light is more likely to affect the retina, especially the macula, there is a tendency to aggravate age-related macular degeneration.

Ophthalmological Center of Zhongshan University, chief physician professor He Mingguang said that the impact of blue light on the human eye in the industry known as blue disaster"