Controlling 'black metal' surface could incease photovoltaic efficiency

The Lawrence Livermore National Laboratory (LLNL) Materials Engineering Division (MED) research team has made the breakthrough by experimenting with black metals. These nanostructured metals are designed to have low reflectivity and high absorption of visible and infrared light.

The MED research team recently published their black metals research results in an article in Applied Physics Letterstitled Plasmonic Black Metals in Resonant Nanocavities.

Authored by MED physicist and research team member Mihail Bora, the article details the work of the nanophotonics and plasmonics research team led by LLNL engineer Tiziana Bond.

The team’s concept of black metals are not classic metals but can be thought of as an extension of the black silicon concept. When silicon is treated in a certain way, such as being roughened at the nanoscale level, it traps light by multiple reflections, increasing its solar absorption. This gives the silicon a black surface that’s able to better trap the full sun’s wavelength spectrum.