Large‐Area Flexible Organic Solar Cells with a Robust Silver Nanowire‐Polymer Composite as Transparent Top Electrode

Abstract Upscaling of efficient flexible organic solar cells (OSCs) is still a challenging task, where flexible transparent electrode is a key limiting factor. Silver nanowires (AgNWs) are widely used as flexible transparent electrodes to fabricate efficient small‐area flexible OSCs, but the high surface roughness of AgNWs electrodes causes large leakage current and performance deterioration in large‐area OSCs. In this study, it is reported that a strategy of switching the bottom AgNWs electrode and the top Ag film electrode to avoid the detrimental effect of the high surface roughness of AgNWs electrodes. Mechanical robustness of the AgNWs has been enhanced by introducing a cross‐linked poly(sodium 4‐styrenesulfonate) layer. The AgNWs‐polymer transparent film is fabricated by water transfer printing as the top electrode. 21 cm 2 flexible organic modules containing 10 sub‐cells are fabricated and delivered power conversion efficiencies of 12.3% with the design of switched electrodes.