To achieve high-efficiency polymer solar cells (PSCs), it is not only important to develop high-performance small molecule acceptors (SMAs) but also to find a matching polymer donor to achieve optimal morphology and matching electronic properties. Currently, state-of-the-art SMAs mostly rely on a donor polymer named PM6. However, as the family of SMAs continues to expend, PM6 may not be the perfect polymer donor due to the requirement of energy level matching. In this work, we tune the energy level of PM6via the strategy of ternary copolymerization. We achieve two donor polymers (named PL-1 and PL-2) with upshifted HOMO (the highest occupied molecular orbital) energy level (compared with PM6), and can thus match with the SMAs with upshifted HOMO energy levels compared with Y6. These two copolymers exhibit slightly higher order of molecular packing and similar charge transport properties, which demonstrate that the method of ternary copolymerization can fine tune the HOMO level of donor polymers, while the morphology and mobility of the blend film remain mostly unaffected. Among them, the best device based on PL-1: Y6 exhibits power conversion efficiencies (PCEs) of 16.37% with lower open circuit voltage (V_oc) but higher short circuit current voltage (J_sc) and fill factor (FF) than that of the device based on PM6: Y6. This work provides an effective approach to find polymer matches for the SMAs with upshifted HOMO levels.

为了实现高效的聚合物太阳能电池（PSC），不仅重要的是开发高性能的小分子受体（SMA），而且找到匹配的聚合物供体以实现最佳的形态和匹配的电子性能。当前，最先进的SMA大多依赖于名为PM6的供体聚合物。但是，随着SMA系列的继续发展，由于能级匹配的要求，PM6可能不是理想的聚合物供体。在这项工作中，我们通过三元共聚策略调整了PM6的能级。我们获得了两种供体聚合物（分别称为PL-1和PL-2），其HOMO（最高占据分子轨道）能级提高了（与PM6相比）），因此与Y6相比，HOMO能级提高的SMA可以匹配。这两种共聚物表现出稍高的分子堆积顺序和类似的电荷传输性能，这表明三元共聚方法可以微调给体聚合物的HOMO水平，而共混膜的形态和迁移率几乎不受影响。其中，基于PL-1：Y6的最佳器件的功率转换效率（PCE）为16.37％，开路电压（V _oc）较低，而短路电流电压（J _sc）和填充系数（FF）则更高。基于PM6的设备的外观：Y6。这项工作提供了一种有效的方法，可以找到HOMO水平升高的SMA的聚合物匹配物。