Will White LEDs Dethrone the Incandescent Bulb?
White LEDs are now available, thanks to progress in Gallium Nitride (GaN) and Indium GaN (InGaN). One versions combines a blue LED with a yellow phosphor to generate white light (slightly yellowish). Another uses a UV LED to excite red, blue and green phosphor (ala a fluorescent lamp) to get white light. Efficiencies of 20 lumens/watt have been demonstrated - which is better than an incandescent bulb. Someday in the not-too-distant future you will likely see them in Wal-Mart where the 100-year-old-technology bulbs sit today.