As a promising electron-deficient (acceptor) unit, fluorinated benzotriazole (TAZ) was used widely to construct wide bandgap polymers for nonfullerene polymer solar cells (NF-PSCs). However, due to the S horizontal ellipsis F noncovalent interaction, the unit show good planarity and strong aggregation, which was not beneficial for the blend with the elongated nonfullerene acceptors. Here, we tried to choose new donor polymers to match with TAZ unit, which was expected to destroy the interchain aggregation of polymer and form favorable morphology of blends. Two new wide-bandgap polymers PBDTsPhPh-T1 and PBDTsThPh-T1 based on the unsymmetrical benzodithiophene (BDT) units with a benzene ring as lever arms were synthesized. As a result, these two polymers blend well with nonfullerene acceptor (ITIC). And then, PBDTsPhPh-T1 and PBDTsThPh-T1-based devices exhibit the decent photovoltaic properties with high power conversion efficiencies of 8.85 and 9.34%, respectively. The work demonstrates that the unsymmetrical BDT units could be outstanding for building donor materials toward high-performance NF-PSCs. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2762-2770