Researchers at the Karlsruhe Institute of Technology (KIT) have succeeded in transferring these nanostructures to solar cells thereby increasing their light absorption rate by up to 200%. The scientists have published their findings in Science Advances.
"The butterfly we have examined has an obvious peculiarity: it is extremely dark black. This is due to the fact it absorbs sunlight particularly well. Even more exciting than its appearance are the mechanisms by which it reaches the high absorption. The potential for optimization of these structures for photovoltaics, was much higher than we had expected, "says Dr. Hendrik Hölscher from the Institute for Microstructure Technology (IMT) at KIT.
"The butterfly we have examined has an obvious peculiarity: it is extremely dark black. This is due to the fact it absorbs sunlight particularly well. Even more exciting than its appearance are the mechanisms by which it reaches the high absorption. The potential for optimization of these structures for photovoltaics, was much higher than we had expected, "says Dr. Hendrik Hölscher from the Institute for Microstructure Technology (IMT) at KIT.
The scientists led by Hendrik Hölscher and Radwanul H. Siddique (formerly KIT, now at CalTech) were able to form the wing’s nanostructures on the silicon layer of a thin-film solar cell.
The researchers determined the diameter and arrangement of the nanoplates on the wing of the butterfly using an electron microscope. They analyzed the intensity of the light absorption utilizing varying hole patterns in a computer simulation: irregular holes with differing diameters, as found in the butterfly, showed the most stable absorption rates over the entire spectrum and different angles of incidence.
The researchers were working with amorphous silicon, but stated any kind of thin film photovoltaic modules could be improved with such nanostructures, even on an industrial scale.
