CleanBeta

New Materials Create Perfect Solar Efficiencies

A new metallic material fabricated by a team of researchers at Boston College and Duke University absorbs light perfectly - consuming all of the from sunlight (solar energy) that touches it to a scientific standard of perfection.

The breakthrough was first reported in the current issue of Physical Review Letters.

The researchers engineered a synthetic “metamaterial” that transforms the electric and magnetic properties of a microwave so efficiently it achieves total absorption. Metamaterials have properties beyond the limits of their actual physical components, which allows them to produce “tailored” responses to radiation. Because their construction makes them geometrically scalable, metamaterials are able to operate across a significant portion of the electromagnetic spectrum.

“Three things can happen to light when it hits a material,” says Boston College Physicist Willie J. Padilla, one of the team’s researchers. “It can be reflected, as in a mirror. It can be transmitted, as with window glass. Or it can be absorbed and turned into heat. This metamaterial has been engineered to ensure that all light is neither reflected nor transmitted, but is turned completely into heat and absorbed. It shows we can design a metamaterial so that at a specific frequency it can absorb all of the photons that fall onto its surface.”

Based on computer simulations of earlier research, the team designed resonators that combine electric and magnetic fields that absorbs all incident radiation.

Because each element absorbs the electric and magnetic components of an electromagnetic wave separately the new metamaterial work equally well across a narrow frequency range.

The metamaterial is the first to achieve perfect absorption. Unlike other absorbers, the new material is made purely from metallic elements, which makes it substantially more flexible for purposes of collecting and detecting light.