Synthesis, Properties, and Photovoltaic Characteristics of Donor-Acceptor Copolymers Based on Tetrafluoro-Substituted Benzodioxocyclohexene-Annelated Thiophene

摘要

We recently reported that a donor-acceptor (D-A) type copolymer based on our developed tetrafluoro-substituted benzodioxocyclohexene-annelated thiophene (C-0(F-4)) as an acceptor unit and dithienosilole (DTS) as a donor unit shows low photovoltaic characteristics due to the strong electron-accepting nature of C-0(F-4). Here we show that the incorporation of 3-allcylthiophene spacer unit into DTS-C-0(F-4) framework is an effective approach to tune frontier molecular orbital energy levels. Organic solar cells based on blend films of newly synthesized D-A copolymers and [6,6]-phenyl-C-71-butyric acid methyl ester showed improved photovoltaic responses with a power conversion efficiency of up to 4.83%. This result indicates that the C-0(F-4) unit can be an effective acceptor unit for D-A copolymers.