As we all know, the wavelength range of the visible light spectrum is 380nm~760nm, which is the seven colors of light that can be felt by the human eye – red, orange, yellow, green, green, blue and purple. However, the seven colors of light are all monochromatic.
For example, the peak wavelength of red light emitted by LED is 565nm. There is no white light in the spectrum of visible light, because white light is not monochromatic light, but a composite light composed of a variety of monochromatic lights, just as sunlight is white light composed of seven monochromatic lights, while white light in color TV is also composed of three primary colors red, green and blue.
It can be seen that to make LED emit white light, its spectral characteristics should cover the entire visible spectral range. However, it is impossible to manufacture such LED under technological conditions. According to people’s research on visible light, the white light visible to human eyes requires at least a mixture of two kinds of light, namely, two wavelength light (blue light+yellow light) or three wavelength light (blue light+green light+red light). The white light of the above two modes requires blue light, so taking in blue light has become the key technology for manufacturing white light, that is, the “blue light technology” pursued by major LED manufacturing companies. There are only a few manufacturers that have mastered the “blue light technology” in the world, so the promotion and application of white LED, especially the promotion of high brightness white LED in China still has a process.
Post time: Jan-29-2024