Researchers from CHOSE (Centre for Hybrid and Organic Solar Energy) at Tor Vergata University of Rome, ENEA Frascati Research Centre, Fraunhofer FEP, University of Guilan and Halocell Europe have developed perovskite solar cells (PSCs) on polycarbonate films.
Despite polycarbonate's widespread use in many applications, poor chemical resistance and roughness have hindered its adoption as a substrate in solar cell technologies. These challenges were solved by developing a new planarizing layer over the polycarbonate films applied in liquid form using blade coating. This innovation reduced surface roughness from 1.46 µm to 23 nm, cut the water vapor transmission rate in half, and improved solvent resistance. As a result, the scientists achieved a power conversion efficiency of 13.0% for solar cells on polycarbonate substrates, with good durability and flexibility.
The PSCs were fabricated on the planarized PC substrate, with a customized ITO electrode with an average visible transparency of 78%, sheet resistance of 25 Ω/sq, and a safe bending radius of 20 mm. The power conversion efficiency (PCE) reached 13.0%. The unencapsulated PSCs retained 80% of initial PCE after 1776 h upon ISOS-D-1 shelf-life tests.
The research highlights the potential of these flexible perovskite solar cells for integration in the market of everyday products made from polycarbonate. With all layers, except the two electrodes, solution-processed at low temperatures (maximum 100 °C), the technology is compatible with low-cost manufacturing and easy integration with other printed electronic components.
The new solution for planarization and solvent barrier can also be used for other types of optoelectronic devices (LEDs, transistors etc.) and substrates. Opening up the market of flexible solar cells to new substrate materials can play a significant role in the future for energy harvesting, powering future electronic devices, and contributing to rapidly growing markets like smart windows, skylights, buildings, smart digital cards, product packaging, wearables, Internet of Things electronics.
