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

摘要

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)·V^(−1)·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 Voc of 0.923 V,Jsc of 23.2 mA·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)·V^(−1)·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.