The eyes of flies may hold the secret to perovskite solar cell design, according to American researchers.
While perovskites show great promise as a low-cost solar cell material, they are incredibly fragile thanks to their brittle, salt-like crystal structure.
Reinhold Dauskardt, a professor of materials science and engineering at Stanford University, says they created a compound solar cell consisting of a vast honeycomb of perovskite microcells, each encapsulated in a hexagon-shaped scaffold 500 microns wide.
“We were inspired by the compound eye of the fly, which consists of hundreds of tiny segmented eyes,” said Dauskardt.
“It has a beautiful honeycomb shape with built-in redundancy: If you lose one segment, hundreds of others will operate. Each segment is very fragile, but it’s shielded by a scaffold wall around it.”
The scaffold is made of an inexpensive epoxy resin widely used in the microelectronics industry, and is resilient to mechanical stresses.
Tests conducted during the study revealed that the scaffolding had little effect on how efficiently perovskite converted light into electricity.
“We got nearly the same power-conversion efficiencies out of each little perovskite cell that we would get from a planar solar cell,” Dauskardt said.
“So we achieved a huge increase in fracture resistance with no penalty for efficiency.”
To find out if the new device withstand the kind of heat and humidity that conventional rooftop solar panels endure, the researchers exposed encapsulated perovskite cells to temperatures of 85°C and 85 percent relative humidity for six weeks. Despite these extreme conditions, the cells continued to generate electricity at relatively high rates of efficiency.
[Close-up of a fly eye. Photo: Virvoreanu-Laurentiu/Pixabay]