Why is white LED used as raw material for blue LED chips?

- Aug 15, 2019-

According to the Guangming Daily, although the light of the white LED is bright and bright, it has a pure "blue light core". LEDs are also semiconductor light emitting diodes. Generally, a white LED lamp is composed of a blue-emitting LED chip and a fluorescent conversion material that emits yellow light under blue light excitation. After the power is turned on, the blue light emitted by the chip illuminates the fluorescent material to become yellow light, and the yellow light and the remaining blue light are mixed to obtain white light.

In the 1960s and 1970s, red and green LEDs were successively invented. However, the other color of the three primary colors of white light, the blue LED, was delayed. Compared with red and green light, blue light has higher photon energy, and it is difficult to grow blue light-emitting materials. Many research institutions have chosen to give up after repeated setbacks. But there are very few people who persist in it and finally create a miracle. In 1989, Japan’s Akasaka and Amano’s masters developed blue LEDs for the first time. Although the blue LED light was weak at the time and had no practical application value, it ignited people's enthusiasm and hope for blue LED research. In 1993, Nakamura Shuji, who worked in Nichia, successfully developed high-brightness blue LED technology, which made the blue LED practical, and really opened the era of LED lighting. Their persistence and dedication eventually broke the prediction that blue LEDs could not be realized in the 20th century.

Blue LEDs have achieved white LED lighting, and white LEDs have in turn helped Blu-ray LEDs to win the Nobel Prize in Physics in 2014. It can be seen that its meaning is extraordinary. We can do a calculation to learn more about the changes that blue LEDs under Nobel's aura have brought to our lives. According to incomplete statistics, the annual electricity consumption in the world is about 200 billion kWh, of which about 19% is used for lighting. If all incandescent lamps (electrical conversion rate is about 10%) and fluorescent lamps (electrical conversion rate is about 30%) are replaced with White LED energy-saving lamps (electrical light conversion rate of more than 50%), then the annual global savings of at least 152 billion kWh, compared to about 500 million tons of coal, reducing carbon dioxide emissions by about 1.3 billion tons, reducing sulfur dioxide emissions by about 420 Ten thousand tons. These tangible data highlight the great wisdom and power of the small blue core. We have reason to believe that the white light that the blue core is lit will surely illuminate the million!