We designed and synthesis a new conjugated polymer, BDT8TT, containing benzodithiophene and thienothiophene-flanked cyano acrylate side chain. The benzodithiophene (BDT) unit was selected to replace the thiophene moiety to reduce the HOMO energy level...
We designed and synthesis a new conjugated polymer, BDT8TT, containing benzodithiophene and thienothiophene-flanked cyano acrylate side chain. The benzodithiophene (BDT) unit was selected to replace the thiophene moiety to reduce the HOMO energy level of the polymer. Introducing the BDT unit in semiconducting polymers is effective for shifting the frontier molecular orbital energy levels down via the weak electron donating nature. The polymer solar cell fabricated fromthe blend of BDT8TT:PC<sub>71</sub>BM exhibited amoderate PCE with a high V<sub>oc</sub> of 0.77 V. This result suggests the potential to replace thiophene unit with benzodithiophene moiety in the design and synthesis of semiconducting polymers with efficient solar cell performance and, especially, to lower the HOMO energy levels of the conjugated polymers, thereby, boosting the open circuit voltage of solar cell devices.