Ultra-Efficient Solar Power

摘要

Harry Atwater thinks his lab can make an affordable device that produces more than twice the solar power generated by today's panels. The feat is possible, says the Caltech professor of materials science and applied physics, because of recent advances in the ability to manipulate light at a very small scale. Solar panels on the market today consist of cells made from a single semiconducting material, usually silicon. Since the material absorbs only a narrow band of the solar spectrum, much of sunlight's energy is lost as heat: these panels typically convert less than 20 percent of that energy into electricity. But the device that Atwater and his colleagues have in mind would have an efficiency of at least 50 percent. It would use a design that efficiently splits sunlight, as a prism does, into six to eight component wavelengths—each one of which produces a different color of light.