Catching some rays — lots of them
Metamaterials are a new class of artificial substances with properties unlike anything found in the natural world. Some have been designed to act as invisibility cloaks; others as superlenses, antenna systems or highly sensitive detectors. Now, researchers at MIT and elsewhere have found a way to use metamaterials to absorb a wide range of light with extremely high efficiency, which they say could lead to a new generation of solar cells or optical sensors.Nicholas X. Fang, the Brit (1961) and Alex (1949) d’Arbeloff Career Development Associate Professor in Engineering Design in MIT’s Department of Mechanical Engineering, says that most thin materials used to fully capture light are limited to a very narrow range of wavelengths and angles of incidence. The new design uses a pattern of wedge-shaped ridges whose widths are precisely tuned to slow and capture light of a wide range of wavelengths and angles of incidence.These metamaterials can...