Improved Operational Lifetime of MAPbI3 Solar Cells Encapsulated with Parylene‐N

Herein, unsubstituted poly‐para‐xylylene (parylene‐N) film as an encapsulation material for MAPbI 3 perovskite solar cells (PSCs) is assessed. Unlike more commonly used parylene‐C, parylene‐N is cheaper and does not contain Cl which makes it a promising encapsulant for perovskite materials. Being deposited by room temperature chemical vapor deposition in a vacuum, 2 mm‐thick parylene film stabilizes MAPbI 3 ‐based solar cells and inhibits the degradation even under stress test conditions (85 °C in the air). Moreover, the solar cells, encapsulated with the parylene‐N film and cover glass, show stable characteristics for over 3800 h in a dark ambient atmosphere, retaining 92% of their initial power conversion efficiency. Such results demonstrate the potential of unsubstituted parylene for PSC stabilization, paving the way for novel and highly stable PSCs.