ADA ' DA small molecule acceptors with non-fully-fused core units

Two ADA ' DA small molecule acceptors, IDTBT-4F and IDTP-4F, with non-fully-fused core units were developed. The DA ' D core units were facilely prepared via Stille coupling of D and A ' fused-ring building blocks. IDTBT-4F and IDTP-4F show banana-shaped molecular configurations and good planarity. When blending with a wide-bandgap polymer donor L1-S, IDTBT-4F and IDTP-4F delivered decent PCEs of 12.00% and 11.92%, respectively, in organic solar cells.