Roll-to-Roll AgNWs Networks/Ag Finger by Self-Masking Protection for Large-Area Monolithic Flexible Organic Solar Cells

Flexible large-area monolithic organic solar cells suffer from electrical loss during up-scaling due to the limited conductivity of transparent electrodes. In this work, highly conductive silver grid fingers are integrated onto a roll-to-roll gravure-printed silver nanowire electrode via roll-to-roll screen printing, significantly reducing the composite sheet resistance from 15 to 1.5 Ω sq^-1. A numerical model is established to optimize grid width and spacing, achieving an equivalent sheet resistance of 1 ~ 2 Ω sq^-1 for higher-resistance electrodes. A self-masking strategy is developed to prevent shunting caused by uneven grid surfaces. As a result, monolithic flexible organic solar cells with areas of 4 and 16 cm² achieve power conversion efficiencies of 15.20% and 14.24%, respectively, demonstrating minimal efficiency loss with increased area. Additionally, the devices exhibit excellent mechanical flexibility and shelf stability, enabled by a robust photoresist passivation layer.