Systematically investigating the effect of the aggregation behaviors in solution on the charge transport properties of BDOPV-based polymers with conjugation-break spacers

Conjugation-break spacers of conjugated polymers significantly affect the aggregation behaviors in solutions, and further the morphology in the solid state. Herein, we develop five copolymers and two small molecules, in which different ratios of the non-conjugated bridge are introduced into the polymer/molecule backbone. The investigation precisely reveals that: all compounds facilely form aggregations, and the amount of the non-conjugation bridge plays a key role in the aggregation behaviors of these compounds in dilute solutions, which are subsequently inherited to the morphology structures in thin films, and then finally lead to different charge transport properties and doping efficiencies.