Non-fused polymerized small-molecular acceptors containing thieno[3,4-c] pyrrole-4,6-dione core for all-polymer solar cells

The innovation of polymer acceptors through the polymerized small molecular acceptors (PSMAs) strategy has promoted the rapid development of all-polymer solar cells (all-PSCs) in recent years. However, the non-fused PSMAs have been rarely investigated compared with the fused-ring non-fullerene counterpart. In this work, we reported the synthesis of non-fused PSMAs with thieno[3,4-c]pyrrole-4,6-dione (TPD) core, exhibiting planar configuration, simplified synthesis, and near-infrared absorption. Two PSMAs with regiorandom or regioregular structures were prepared based on the TPD core, in which all-PSCs offered efficiencies of 4.00% for the regiorandom polymer and 10.99% for the regioregular polymer, respectively, which is among the highest per- formance for non-fused PSMAs. Further morphological and electrical characterizations unveiled that higher device performance of regioregular TPD-based PSMAs was due to the efficient exciton separation and charge transport with more ordered backbone packing in the solid state. This work demonstrates that the TPD unit is a promising building block for the construction of PSMA polymers, providing more selections for the design of high-performance all-PSCs.