THE light-scattering structures that make butterfly wings so striking could be used to make cheaper, more efficient solar cells.
In dye-sensitised solar cells a dye coating on a titanium dioxide surface forms a 鈥減hotoanode鈥� that absorbs photons and pumps out electrons. To improve their efficiency, Di Zhang of Shanghai Jiao Tong University in China and colleagues borrowed the light-absorbing properties of the wings of the Paris peacock butterfly.
After soaking samples of the wing in a titanium-containing solution, they processed it to produce a titanium dioxide deposit that reproduced the wing鈥檚 honeycomb structure (Chemistry of Materials, ). When this was used to make a photoanode, the resulting cell鈥檚 efficiency was 10 per cent higher than normal.
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