Researchers have developed a new transparent solar cell that is an advance toward giving windows in homes and other buildings the ability to generate electricity while still allowing people to see outside.

Their study appears in ACS Nano. The University of California, Los Angeles team describes a new kind of polymer solar cell (PSC) that produces energy by absorbing mainly infrared light, not visible light, making the cells nearly 70 per cent transparent to the human eye.

They made the device from a photoactive plastic that converts infrared light into an electrical current. “These results open the potential for visibly transparent polymer solar cells as add-on components of portable electronics, smart windows and building-integrated photovoltaics and in other applications,” said study leader Yang Yang.

Yang added that there has been intense world-wide interest in so-called polymer solar cells. “Our new PSCs are made from plastic-like materials and are lightweight and flexible,” he said. “More importantly, they can be produced in high volume at low cost.” Previously, many attempts have been made toward demonstrating visibly transparent or semitransparent PSCs.
 
However, these demonstrations often result in low visible light transparency and/or low device efficienc. The researchers have demonstrated highperformance through the incorporation of near-infrared light-sensitive polymer and using silver nanowire composite films as the top transparent electrode.
 
The near-infrared photoactive polymer absorbs more near-infrared light but is less sensitive to visible light, balancing solar cell performance and transparency.