Light-emitting diode emitted, so the attainment of high efficiency in blue LEDs was quickly followed by the development of the first white LED. In this device a :Ce (known as "YAG") cerium doped phosphor coating on the emitter absorbs some of the blue emission and produces yellow light through fluorescence. The combination of that yellow with remaining blue light appears white to the eye. However, using different phosphors (fluorescent materials) it also became possible to instead produce green and red light through fluorescence. The resulting mixture of red, green and blue is not only perceived by humans as white light but is
LED tattoo LED tattoo A light-emitting diode tattoo is a type of body modification similar to a tattoo, but specifically involves implantation of technologically based materials versus traditional ink injection into the layers of the skin. LED tattoos are accomplished by a combination of silicon-silk technology and a miniature lighting device known as a light-emitting diode. While there is potential for many applications in the medical, commercial and personal domains, the technology is still in the development stage. Once the ability is attained to condense the parts of a LED to a small enough level, it will be possible for the tattoos