Looks like the 130-year-old incandescent light bulb's days are numbered, because OLEDs (organic light emitting diodes)—the same devices that light up screens in cellphones—are now able to emit brilliant white light when electric current is applied. They can be printed in thin sheets, and can turn walls, ceilings, furniture, or anything else into a light-emitting source. They don't heat up like conventional light bulbs, either.
Best of all, once they get this thing perfected, researchers think the devices will be 100% efficient, turning all of the energy applied to them into light. As soon as they work out that pesky problem of moisture sensitivity, these OLEDs will be good to go for sheets of light.
Natural light 'to reinvent bulbs' [BBC News]