Flexible Perovskite Solar Cells on Polycarbonate Film Substrates

The market for polycarbonate (PC), a versatile material, is growing rapidly. Despite its widespread use in many applications, poor chemical resistance and roughness have hindered its adoption as a substrate in solar cell technologies. Here, the first‐ever perovskite solar cell (PSC) is demonstrated on PC films. A solution‐processed planarizing layer is developed using a commercial ambient‐curable refractory resin through blade coating which decreased film roughness from 1.46 µm to 23 nm, lowered water vapor transmission rates (WVTR) by a half, and significantly improved solvent resistance enabling deposition of precursor inks. The PSCs are 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. These results open new pathways for integrating solar cells in many products made from PC materials, such as ID cards, smart cards, windows, skylights, buildings, and product packaging, as well as introducing a new solution for planarization and solvent barrier that can be used for other types of optoelectronic devices (LEDs, transistors, etc.) and substrates.