For decades, LEDs have been used as indicator lights on myriad products ... they produce white light. Another method uses a blue LED and yellow or red phosphors. THIS DEFINITION IS FOR PERSONAL ...

While research highlights the energy and cost efficiency of LEDs, experts warn that they may also be one of the most harmful ...

These are a blue LED with yellow phosphors ... and around seven times the cost of compact fluorescent lamps, based on normalized light output), when averaged out over the lifetime of the product ...