Light-emitting diode ways of producing white light-emitting diodes (WLEDs), LEDs that generate high-intensity white light. One is to use individual LEDs that emit three primary colors—red, green, and blue—and then mix all the colors to form white light. The other is to use a phosphor material to convert monochromatic light from a blue or UV LED to broad-spectrum white light, much in the same way a fluorescent light bulb works. The 'whiteness' of the light produced is essentially engineered to suit the human eye. The yellow phosphor in LEDs is cerium-doped YAG crystal, in powder form and may be suspended in plastic,
Light-emitting diode In this case, the bond wire(s) are attached to the ITO film that has been deposited in the LEDs. The YAG phosphor in the LED's encapsulation compound is why white LEDs look yellow when off. Some LED light bulbs use a single plastic cover with YAG phosphor (remote phosphor) for several blue LEDs instead of using a diffuser and single chip white LEDs. Remote phosphor LED light bulbs may have behind the plastic cover a white plastic reflector. Others shape the remote phosphor as a dome, or sphere, and place it atop a single PCB containing blue LEDs; this assembly