A series of wide-bandgap random terpolymers were designed and synthesized for application as the donor polymers in non-fullerene polymer solar cells. The benzodithiophene (BDT) derivatives with phenyl and thienyl conjugated side chains (denoted as BDTP and BDTT, respectively) were paired with an electron-withdrawing moiety (TzBI-O) to construct a series of wide-bandgap random terpolymers. The highest occupied molecular orbital energy levels of the resulting polymers gradually decreased from −5.26 to −5.33 eV upon increasing the BDTP content from 0 to 100%, leading to improved open-circuit voltages from 0.85 to 0.90 V for the resulting photovoltaic devices. In particular, photovoltaic devices based on terpolymers containing 50% BDTP exhibited the highest performance with a power conversion efficiency of 8.55%. This improvement was attributed to the suppressed bimolecular recombination and more balanced charge carrier mobilities in the terpolymer-based devices. These results demonstrate that the use of terpolymers represents a feasible strategy for the construction of highly efficient donors for non-fullerene polymer solar cells.

设计并合成了一系列宽带隙无规三元共聚物，用作非富勒烯聚合物太阳能电池中的供体聚合物。将具有苯基和噻吩基共轭侧链的苯并二噻吩（BDT）衍生物（分别表示为BDTP和BDTT）与吸电子部分（TzBI-O）配对，以构建一系列宽带隙无规三元共聚物。当BDTP含量从0增加到100％时，所得聚合物的最高占据分子轨道能级从-5.26降至-5.33 eV，导致所得光伏器件的开路电压从0.85提高至0.90V。尤其是，基于包含50％BDTP的三元共聚物的光伏器件表现出最高的性能，功率转换效率为8.55％。这种改进归因于三元共聚物基器件中双分子重组的抑制和电荷载流子迁移的平衡。这些结果表明，使用三元共聚物代表了用于构建非富勒烯聚合物太阳能电池高效供体的可行策略。