Applications of blue LEDs in biology include sterilization and hygiene, and in electronics include flat screens and data storage. Blue LED light has been shown to kill harmful bacteria that can cause dental and skin problems. Blue LEDs are also used in compact disks to store data and are credited with making the flat screen television possible. White LEDs, however, are primarily just used for lighting applications, like reading and seeing things.
Blue LEDs generate a much narrower spectrum of light then white LEDs. An ideal white LED generates a color spectrum that includes every color. An ideal blue LED would just generate the color blue. The color blue has a wavelength of 470 nanometers. However, blue LEDs can be found that have wavelengths within the entire blue spectrum, between 440 and 490 nanometers. Most blue LEDs produce shades of blue within the 450 to 470 nanometer spectrum.
Blue LED light is considered potentially more dangerous than LED white light. Blue light is highly energized and close in the color spectrum to ultraviolet light, the same type of light in sunlight that causes sunburns and cancer.
The invention of the blue LED is considered of greater historical importance than the white LED. And the main reason is that the blue LED was the essential missing piece needed to create the white LED. As well, the blue LED allowed for the creation of disk drives that could store significantly more information than other types of LEDs. The Inamori Foundation awarded its 2010 Kyoto Prize in Advanced Technology to Dr. Isamu Akasaki, the inventor the blue LED.
The blue LED is made with a production process that is now based on Indium-Gallium-Nitride (InGaN). a chemical compound. Scientist and manufacturers now study blue LED technologies such as InGaN and silicon carbide, SiC, to create different shades of blue light with different light intensities and at lower costs. Because the industry strives to create a pure white LED, scientists immerse themselves in the study of optics to create an LED that mixes together the optimum combination of red, blue and green light. Pure white is the light combination that the sun produces.
Because the manufacturing of white LEDs is based on blue LEDs, the process to make white LEDs requires more steps. The generation of white light, because it a combination of all the colors of light, requires the use of blue, red and green LEDs together or the use of a blue LED that is coated with a chemical compound.