The incandescent light bulb is a hot technology in one sense-it wastes 90 percent of its energy in heat. Now, experts say, the 122-year reign of the tungsten filament may be coming to an end. Taking its place is gallium nitride, a super material that's set to make billion-dollar waves in consumer markets from lighting to home entertainment.

First formulated more than 70 years ago, gallium nitride is a semiconductor that emits an intense blue light when electricity is passed through it. In the early 1990s, researchers at Japan's Nichia Chemical Industries were the first to master the material, turning it into bright, long-lasting light-emitting diodes (LEDs) of any color. Now, gallium nitride LEDs are finding their way into traffic lights, huge display signs, and the tail lamps of the 2000 Cadillac DeVille.