Vacuum‐Free and Solvent‐Free Deposition of Electrodes for Roll‐to‐Roll Fabricated Perovskite Solar Cells

Abstract Perovskite solar cells (PSCs) are attracting widespread attention due to their exceptional photovoltaic performance and their potential for large‐scale production via low‐cost, high‐throughput roll‐to‐roll (R2R) methods. Full realization of this production approach requires replacement of the evaporated metal electrode commonly used in PSCs. Here, a novel vacuum‐free R2R‐compatible method is introduced to fabricate and deposit printed electrodes based on electrically conductive pastes, which avoids potential loss of PSC performance due to solvent migration from the pastes. Flexible R2R‐fabricated PSCs with record power conversion efficiencies (PCEs) of up to 16.7% are produced by vacuum‐free deposition of all functional layers, apart from the transparent conductive electrode. This performance compares very favorably with that of control flexible PSCs comprising an evaporated gold electrode, which displays PCEs of up to 17.4%. Furthermore, the PSCs comprising a printed electrode demonstrate outstanding operational and mechanical stability, with negligible loss of PCE after 24 h of continuous 1‐sun illumination and retention of more than 90% of their initial PCE after 3000 cyclic bends.