Scientists have been trying for decades to develop functional, flexible solar cells, because they could be integrated into fabrics and used to coat irregular shapes and surfaces. And now scientists at Fudan University in Shanghai have developed polymer solar cells that are light, flexible, cheap to produce, and thin enough to be used in fabrics.
According to Jon Cartwright at Chemistry World, to create these new solar cells, they figured out that they could interweave microscopic metal wires - coated in an active polymer designed to absorb sunlight - with titanium dioxide nanotubes and a second type of active polymer to form a textile. Together these components work by having the metal wires absorb sunlight and generate electrons and their positive counterparts, known as 'electron holes'. The electrons are then conducted by the titanium dioxide nanotubes, and the electron holes are conducted by the second active polymer. To complete the circuit, says Cartwright, the team painted each side of the textile with transparent, conductive sheets of carbon nanotubes.
Publishing their design in the journal Angewandte Chemie, the team report that the textile has been made to be symmetrical so it can absorb light from either side. It’s also extremely flexible, able to be bent more than 200 times with barely any effect on its overall efficiency. The one downside? It’s only the size of your fingernail. ‘The main difficulties encountered are how to scale up the solar-cell textile while maintaining high energy-conversion efficiencies,” lead researcher Huisheng Peng told Chemistry World.
Independent expert and materials scientist Anyuan Cao from the Department of Advanced Materials and Nanotechnology at Peking University in Beijing commented that while there is certainly potential in the technology, it will not hit the market until it can be upscaled and made more efficient. And that's exactly what Peng and his team are working on now.