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Researchers have designed more efficient light-gathering structures for solar cells inspired by butterfly wings.

Dye-sensitized solar cells – which contain dye particles on a titania thin film – are cheap and easy to produce. But their efficiency converting light to useful energy needs to be better. Researchers are focusing attention on the photoanode – where light is absorbed.

When light is absorbed by a solar cells, the photons ricochet around in the material rather like a pinball machine, except some of the photons bounce right back out. But preventing photons from escaping from the material increases the conversion efficiency.

Now researchers have found that mimicking the structures on butterfly wings – which consist of a honeycomb pattern of ridges and ribs – can improve the light absorbing properties of photoanodes.

“This amazing natural structure enhances the light harvesting efficiencies, as it has done for the butterfies’ success in species competition over millions of years,” says researcher Di Zhang of Shanghai Jiao Tong University.

Although the improvement covers only part of that needed to boost the performance of dye-sensitized solar cells, the researchers believe that it could inspire simple and swift manufacture of more efficient solar cells and even other devices.

For further information:
Wang Zhang, Di Zhang, Tongxiang Fan, Jiajun Gu, Jian Ding, Hao Wang, Qixin Guo and Hiroshi Ogawa. Novel Photoanode Structure Templated from Butterfly Wing Scales. Chemistry of Materials (2009) 21 (1), 33–40.