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

Herein, unsubstituted poly‐para‐xylylene (parylene‐N) film as an encapsulation material for MAPbI3 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 MAPbI3‐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.