Two new donor (D) - acceptor (A) copolymers, named m-O-p-F-DFQx-BDT (OFQx-T) and m-EH-p-F-DFQx-BDT (EHFQx-T), which were based on meta-octyloxy-para-fluorophenyl and meta-ethylhexyloxy-para-fluorophenyl difluoroquinoxaline as acceptor units (O-DFQx/EH-DFQx) and alkylthienyl substituted benzodithiophene (BDT) as a donor unit, were designed and synthesized. EHFQx-T had higher absorption coefficient than OFQx-T which contributed to larger short-circuit current density (J_sc). EHFQx-T showed a lower the highest occupied molecular orbital (HOMO) which is beneficial for the voltage open-circuit (V_oc). The polymer solar cells (PSCs) based OFQx-T:PC₇₁BM and EHFQx-T:PC₇₁BM blended film as active layer showed high power conversion efficiency (PCE) of 7.60% and 8.44%, respectively, with 1,8-diiodooctane (DIO) solvent additive treatment. More importantly, OFQx-T:PC₇₁BM and EHFQx-T:PC₇₁BM had good fill factor (FF), especially the FF of OFQx-T:PC₇₁BM was over 70%. The high FF contributed to obtain high PCEs for OFQx-T and EHFQx-T. The more balanced and higher charge mobility, smaller geminate recombination and suitable nanoscale phase separation size of EHFQx-T demonstrate that changing octyl chain to ethylhexyl chain in DFQx acceptor unit is efficient to improve photovoltaic properties in fullerene solar cells.

两种新的供体（D）-受体（A）共聚物分别为m -O- p -F-DFQx-BDT（OFQx-T）和m -EH- p -F-DFQx-BDT（EHFQx-T）设计并合成了以间-辛氧基-对-氟苯基和间-乙基己氧基-对-氟苯基二氟喹喔啉为受体单元（O-DFQx / EH-DFQx）和烷基噻吩基取代的苯并二噻吩（BDT）为供体的化合物。EHFQx-T的吸收系数比OFQx-T高，这导致更大的短路电流密度（J _sc）。EHFQx-T显示出较低的最高占据分子轨道（HOMO），这有利于电压开路（V _oc）。以OFQx-T：PC ₇₁ BM和EHFQx-T：PC ₇₁ BM混合膜为活性层的聚合物太阳能电池（PSC）分别具有7.60％和8.44％的高功率转换效率（PCE），其中1,8-二碘辛烷（DIO）溶剂添加剂处理。更重要的是，OFQx-T：PC ₇₁ BM和EHFQx-T：PC ₇₁ BM具有良好的填充因子（FF），尤其是OFQx-T：PC ₇₁的FFBM超过70％。高FF有助于获得OFQx-T和EHFQx-T的高PCE。EHFQx-T具有更高的平衡性和更高的电荷迁移率，更小的叠整重组以及合适的纳米级相分离尺寸，证明DFQx受体单元中的辛基链变为乙基己基链可有效改善富勒烯太阳能电池的光伏性能。