Planarized Polymer Acceptor Featuring High Electron Mobility for Efficient All-Polymer Solar Cells

Significant progress has been achieved for all-polymer solar cells (APSCs) in the last few years by the use of polymerized small molecular acceptors (PSMAs). Developing high electron mobility polymer acceptors has been considered a feasible solution to further improve the photovoltaic performance of APSCs and fabricate thick film devices, which contributed to roll-to-roll printing techniques. In this work, we designed and synthesized PSV, an A-DA'D-A small molecule acceptor-based PSMA with the vinyl group as a bridged linkage to reduce the steric hindrance between the 1,1-dicyanomethylene-3-indanone (IC) terminal group. In comparison with the C-C bond linked polymer acceptor PS, PSV exhibits an almost planar conjugated framework and well-ordered molecular stacking in the thin film. Moreover, PSV exhibits superior n-type semiconducting properties with high electron mobility of up to 0.54 cm(2)center dot V-1 center dot s(-1), which is the highest value among reported PSMAs. By utilizing PM6 as a polymer donor, PSV-based blend forms a favorable nanomorphology and exhibits high and well-balanced hole/electron mobilities, which is beneficial for exciton separation and charge transport. Consequently, APSCs based on PM6:PSV achieved high power conversion efficiencies of up to 15.73%, with a simultaneously realized high V-oc of 0.923 V, J(sc) of 23.2 mA center dot cm(-2), and FF of 0.734. Such superior features enable PSV with excellent thickness-insensitive properties and over 13% PCE was obtained at 300 nm. To the best of our knowledge, the high PCE of 15.73% with excellent electron mobility of 0.54 cm(2)center dot V-1 center dot s(-1) is the highest values reported for APSCs. These results point to the great significance of developing polymer acceptors with a high electron mobility for boosting the performance of APSCs.