Scientists Analysing Butterflies to Improve Photovoltaic Technology
Scientists have discovered that butterfly wings may hold the secret to improving the efficiency of thin-film photovoltaic modules.
A team from the Karlsruhe Institute of Technology (KIT) have studied how the common rose butterfly’s wing absorbs sunlight, due to this particular species having completely black wings.
“The butterfly studied by us is very dark black. This signifies that it perfectly absorbs sunlight for optimum heat management. Even more fascinating than its appearance are the mechanisms that help reaching the high absorption,” said Dr Hendrik Hölscher from KIT’s Institute of Microstructure Technology.
Using a special microscope, they discovered that the tiny nanoholes in the butterfly’s wings are found in different sizes, varied between 133 to 343 nanometers, allowing the wings to absorb light at a variety of different angles.
When engineers imitated the pattern and size of the holes in the silicon-absorbing layer of a thin-film, the results showed that it enhanced the absorption of light, significantly increasing its efficiency.
When transferring this structure to photovoltaic systems it was found the optimisation potential was sizeable, and much higher than expected. In relation to a smooth surface, the absorption rate of perpendicular light increased by 97% and reached a 207% increase at an angle of incidence of 50 degrees.
If the findings of the research manage to make the transition to commercialisation and be used in industrial scale applications, it will have significant implications for the thin-film photovoltaics technology.