Researchers at the Pratt School of Engineering at Duke University in North Carolina have discovered that microscopic metallic cubes may allow metamaterials, human-made materials that are not found in nature, to absorb light, leading to cost-effective and efficient large-area absorbers for sensors or solar cells.
Metamaterials are constructed with the ability to control the properties of light waves. However, by creating such structures using lithography, there are limitations; the process is expensive and is difficult to scale-up to large surface areas required for many applications.
Duke researchers say their process may allow them to create more efficient solar panels that can cover larger areas. Metamaterials based on metallic elements absorb efficiently since design can dictate the magnetic and electrical properties.
Major components comprise the method: a thin layer of gold film coated with a nano-thin layer of an insulator and dusted with millions of nanocubes fabricated out of silver. The nanocubes function as tiny antennae that eliminate reflectance of the metal surface. Researchers think this may one day be utilized in exotic applications like dynamic inks.
Results of this research were published in the December issue of the journal Nature.