Seven years ago, the Royal Swedish Academy of Sciences announced the Nobel Prize in Physics on October 7, 2014, local time. Japanese scientists (Isamu Akasaki), (Hiroshi Amano), and Japanese-American scientists (Shuji Nakamura) received this honor and shared Prizes totaling SEK 8 million for their invention of the blue light-emitting diode (LED).
This is another "invention" Nobel Prize in Physics after the "Semiconductor Imaging Device Charge-Coupled Device" (CCD) award in 2009. Compared with other Nobel Prize-winning high-end inventions, the blue light-emitting LED seems to be inconspicuous. Its chip is only the size of a sesame seed, but LED lights can be seen almost everywhere in life and are cheap.
LED lights have gone through five stages of development
Stage 1
The first LED was a red LED made of GaAsP material by Holonyak et al. in 1962. It was used as an indicator light because of its long life, anti-shock, and anti-vibration characteristics. It was commercialized in 1968. The first commercial secondary lamps were born.
Stage 2
In 1971, Pankove of the RCA laboratory in the United States discovered the impurity atoms forming the high-efficiency blue light-emitting center in the nitride material, and developed the MIS (metal-insulator-semiconductor) structure GaN blue LED device, which is the first birth in the world. Blue LED.
In the mid-1970s, technicians introduced the elements In and N into the secondary lamp tube to make the LED lamp produce three light effects of yellow, green and blue, and the light effect was also increased to 1 lumen/watt.
Stage 3
In 1989, the first white LED lamp was born. This LED lamp is composed of GaN chips and yttrium aluminum garnet (YAG) combined and packaged together.
Stage 4
Winners of the Physics Prize (from left) Tenured Professor Isamu Akasaki of Meijo University, Professor Hiroshi Amano of Nagoya University, and Professor Osamu Nakamura of the University of California, Santa Barbara, took a group photo with the medals.
In 1993, Japan successfully developed a blue light-emitting diode with high brightness, similar to traditional fluorescent lamps and white light bulbs. Since then, light-emitting diodes have jumped to become a new light source for lighting and displays in the 21st century, and have the advantages of environmental protection, power saving and long life, and have quickly been favored by all over the world.
Stage 5
In October 2018, the Chinese Academy of Sciences increased the external quantum efficiency of perovskite light-emitting diodes (LEDs) to 20.7%, which is nearly half the level of international counterparts.
The above are several development stages of LED lights.
Humans' pursuit of light is their own instinct. LED energy saving, environmental protection and high efficiency is the ideal light source that human beings dream of. LED is driving a new lighting revolution for the benefit of all mankind. LED lamps have a lifespan of up to 100,000 hours, while incandescent lamps are only 1,000 hours, and fluorescent lamps are 1,000 hours, so the use of LED lamps can greatly save resources. LED is a cold light source, there is no invisible infrared and ultraviolet light, and the energy consumption is only 1/8 of the energy consumption of incandescent lamps. Up to now, LED lights have been widely used in our lives.
The above is my sharing. I hope it helps you.
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