Blue light chip in the white light LED

In normal conditions, white light LEDs have a blue light source. An ordinary white-light LED is consisted of the blue-light LED chip and the fluorescent substance. It works very simply, that is the chip illuminates blue-light to the fluorescent powders to emit the white light.

Whit light SMD LED

In the 1960s and 1970s, red and green LEDs were successively created. However, the blue-light chip has still not been invented, for it has greater photon energy, and is difficult to grow blue-light materials. Due to the difficulties and cost, a lot of institutes quit. However, two Japanese researchers who keep working at it and eventually invented blue-light LEDs for the first time in 1989. At that time, the light was very weak and had no practical application value, but it gave people hope of developing blue-light LEDs. Finally in 1993, a staff of Nichia, Nakamura Shuji invented the high-brightness blue-light chips technology. Thanks to this technology, the white light LED lighting has really stepped out of the laboratory into practical production and application. Today we can conclude that, without the blue-light chip, white-light LEDs is extremely hard to popularize.
There is some date show the influences that the blue-light LED brought to our lives and environment. According to relevant information, the worldwide annual electricity consumption is about 200 billion kWh, of which about 19% is used for lighting. Imagine if all incandescent lights (electrical conversion rate of about 10%), fluorescent lights (electrical conversion rate of about 30%) are replaced with white LED energy-saving lights (electrical light conversion rate of 50% or more), then a minimum of 1.52 billion kWh of electrical energy is saved on a yearly basis. Furthermore, it reduces coal consumption by about 500 million tons, reduces carbon dioxide emissions by about 1.3 billion tons, and reduces sulfur dioxide emissions by about 4.2 million tons. These tangible data highlight the significance of the blue light LED.