There are two ways of generating light; one is blackbody radiation to raise the temperature of object like incandescent lamps and the other is quantum radiation to substitute photons to electrons like fluorescent lamps. LED is one of such light-emitting element of quantum radiation. LED creates light from the recombination of electron and hole so that will take lower voltage and higher efficiency. UV LED completes full-color variation with the other colored LEDs and infrared LEDs in the market.
Lights can be categorized by two different usages. One is to illuminate things like general lighting indoors, street lamps, spotlights and headlights of cars. The other is to give information such as electronics panels and displays, back light for mobile phones, dashboard lights and tail lights for automobiles and lights used for toys. Lights are giving us information everywhere.
Light source for giving information has been replaced to LEDs from the conventional lamps however many problems exist to overcome to replace LEDs to the conventional lamps used for general lighting purpose. The problems are color rendering properties, efficiencies and costs. Most concern is to create a reddish and warm white light for ordinary lighting. It is not pseudo white made from the combination of blue LEDs and yellow phosphor but UV light mixing red, blue and green phosphors that allows to create the real warm white color. The combination of UV LED mixing RGB phosphors is the most dominated approach to realize the future LED lighting.