We report the first synthesis of a difluorinated 4,7-dibromo-2-(2-butyloctyl)-5,6-difluoroisoindoline-1,3-dione (dibromoffIDD) unit flanked with 3-octylthieno[3,2-b]thiophene π-bridges to form the novel acceptor unit dibromoTTffIDD, which was then polymerized with a donor unit based on benzo[1,2-b:4,5-b']dithiophene (BDT) to yield the polymer PBDT-TTffIDD for applications in organic solar cells (OSCs). To determine the effects in this system of fluorination on photovoltaic performance, we designed two electron donor-and-acceptor copolymers, difluorinated PBDT-TTffIDD and unfluorinated PBDT-TTIDD, and studied their properties systematically. The maximum power-conversion efficiencies of OSCs based on PBDT-TTffIDD:PC₇₁BM and PBDT-TTIDD:PC₇₁BM were found to be 4.1% and 3.8% respectively.

我们报告了侧翼为3-辛基噻吩并[3,2-b]噻吩的二氟4,7-二溴-2-（2-丁基辛基）-5,6-二氟异吲哚-1,3-二酮（dibromoffIDD）单元的首次合成π桥形成新的受体单元dibromoTTffIDD，然后与基于苯并[1,2-b：4,5-b']二噻吩（BDT）的供体单元聚合，得到聚合物PBDT-TTffIDD，可用于有机太阳能电池（OSC）。为了确定该氟化体系对光伏性能的影响，我们设计了两种电子给体和受体共聚物，即二氟化PBDT-TTffIDD和未氟化的PBDT-TTIDD，并系统地研究了它们的性能。发现基于PBDT-TTffIDD：PC ₇₁ BM和PBDT-TTIDD：PC ₇₁ BM的OSC的最大功率转换效率分别为4.1％和3.8％。