Solar buzz: QUT team inspired by fly’s eye to boost solar cell efficiency

Queensland University of Technology researchers have taken inspiration from the humble fly, in the eternal quest to boost the efficiency of solar cells.

As Dr Karl Kruszelnicki explained on ABC Radio late last year, “some 45 million years ago, on our planet there was a fly that (we think) was active in the dim light around dawn and dusk.

“One particular fly got caught in the slowly flowing sap of a tree, and ended up both dying and being almost perfectly preserved in what became a block of solid amber.

“Some 45 million years after it died, modern scientists looked at it with a high-powered electron microscope …(and) noticed some very fine regular corrugations on the front of the fly’s eyes. These corrugations were a regular 250 nanometres apart — less than half the wavelength of blue light.”

The effect these nano-structures, he added, was that when light was shined on the fly’s eye, no colours were emitted and no light at all was reflected. All the light landing on the front surface of the fly’s eye was entering the eye.

And, as Dr Karl put it, “here’s where we can learn from nature.”

The QUT researchers have mimicked the fly eye design to create a three-zone nanomaterial that captures energy across a wider solar spectrum than conventional solar cells, using only one material – zinc oxide.

According to Dr Ziqi Sun, a senior research fellow at QUT’s Science and Engineering Faculty, the fly-eye solution comes “very close to perfection,” and could readily be incorporated into modern solar cells for an impressive boost in energy harvesting.

Dr Sun is talking about the underlying technology that he and his colleagues have developed to make nano-structures using sheets of metal oxides at this week’s Physics Congress in Brisbane, and the new solar cell design will be published in Materials Today Chemistry.