| 초록 |
Attributed to the multiple effects of fluorination on the photophysical properties of conjugated copolymers, insertion of fluorine (F) in molecular structure is considered the most reliable approach to design efficient photoabsorbent materials for organic solar cells (OSCs). Herein, we report two new wide-bandgap polymer donors, P1 and P2, with alternate thienyl benzodithiophene and phenylene cores with a different number of F-substituents. Enabled by F-insertion, these polymers had planar structures, and the extent of fluorination resulted in deep HOMO energy levels. The optimized OSCs obtained by blending P1 and P2 with an NF acceptor, IT-4F and Y6-BO-4Cl delivered impressive efficiencies of 8.8 and 10.2%, respectively. Microstructure studies reveal that blends based on P2 had more orderly molecular packing and superior nanoscale morphology than P1. Thus, this structure–relationship study will provide valuable insight for designing highly efficient WBG polymers. |
