Black metals are made by treating their surface, roughening them at the nanoscale level to help them trap more light.

Scientist: Black metals with a nanostructured surface could be the key to creating better, more effective solar panels, trapping more light than ever before.

Mother Nature: So, clever clogs, how does the nanotechnology bit come into this?

I’m glad you asked! Black metals are made by treating their surface – roughening them at the nanoscale level to create dips and ridges just billionths of a metre apart. It actually makes them blacker. This gives them lower reflectivity and makes them able to absorb more wavelengths of light.

You need all the help you can get with solar energy harvesting – not going so well really, is it?

The team at the Lawrence Livermore National Laboratory in the US have been able to make nanostructures in black metals so that the material is actually tuneable: they can make them as black as they want and can then increase on demand the amount of solar energy the surface absorbs. Making solar cells out of them is next. . . .