Suppressing the excessive aggregation of nonfullerene acceptor in blade‐coated active layer by using n‐type polymer additive to achieve large‐area printed organic solar cells with efficiency over 15%

Abstract

AbstractIn this study, we demonstrate that high‐efficiency blade‐coated organic solar cells (OSCs) can be obtained by using polymer additive N2200 to suppress the excessive aggregation of nonfullerene acceptor. When using the blade‐coating method, OSCs based on the blends of PM6:IT‐4F and PM6:Y6 show moderate efficiencies of 9.9% and 13.2%, respectively. However, when a small amount of N2200 is added into the binary active layers, the resulting blade‐coated OSCs show much higher efficiencies of 13.0% and 16.0%. Careful investigation reveals that the polymer additive suppresses the excessive aggregation of nonfullerene acceptors in the blade‐coated active layer. This enhances the device performance by ensuring a more favorable morphology with appropriate domain size, improving charge extraction, and suppressing charge recombination. Based on this understanding, large‐area OSC devices (1.0 cm2) are successfully obtained by blade coating, which display encouraging efficiencies of 12.3% and 15.1%.Abstractimage