Two novel small-molecules PO-PhQ and PO-PhQNO, in which both polar phosphine oxide (PO) and N–oxide (NO) groups are incorporated in phenyl quinolone core unit were synthesized as efficient cathode interfacial layers (CILs) for inverted organic solar cells (IOSCs). Because of the phenylquinoline (PhQ) group, both PO-PhQ and PO-PhQNO are endorsed with high electron mobility. Due to the presence of polar P=O and N-oxide groups in their molecular structure, PO-PhQ and PO-PhQNO possess good solubility in polar solvents which make them as suitable candidates for interfacial modification of solution processed multilayer IOSCs. As a result, the power conversion efficiency (PCE) of the inverted devices based polythieno[3,4-b]-thiophene-co-benzodithiophene (PTB7):(6,6)-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM) active layer with PO-PhQ and PO-PhQNO as CILs achieve PCE values of 9.03 and 8.53%, respectively, with 10–16% improvement than that of the control device with ZnO. In addition, both PO-PhQ and PO-PhQNO make certain the IOSC devices with long-term stability. To the best of our knowledge, this is the first time that cathode interfacial materials based on the combination of PhQ and P=O groups is reported. The effective application of these alcohol solution processed CILs indicate that the lending P=O to PhQ could be very promising strategy in developing high performance and eco-friendly solar cells. Our findings would contribute to enhancing the OSC device performances from synthetically view point of designing new materials.

合成了两种新颖的小分子PO-PhQ和PO-PhQNO，其中极性氧化膦（PO）和N-氧化物（NO）均结合在苯基喹诺酮核心单元中，作为有效的阴极界面层（CIL），用于有机反相太阳能电池（IOSC）。由于苯基喹啉（PhQ）基团，PO-PhQ和PO-PhQNO均具有高电子迁移率。由于极性P = O和N-氧化物基团在分子结构中的存在，PO-PhQ和PO-PhQNO在极性溶剂中具有良好的溶解性，这使其成为溶液加工多层IOSC界面改性的合适候选物。其结果是，反相设备的基于聚噻吩并的功率转换效率（PCE）[3,4 b ] -噻吩共-苯并二噻吩（PTB7）:( 6,6）-苯基-C _71-丁酸甲酯（PC ₇₁以PO-PhQ和PO-PhQNO作为CIL的BM）活性层的PCE值分别达到9.03和8.53％，比含ZnO的控制器件的PCE值提高10-16％。此外，PO-PhQ和PO-PhQNO均可确保IOSC设备具有长期稳定性。据我们所知，这是首次报道基于PhQ和P = O基团的阴极界面材料。这些经过醇溶液处理的CIL的有效应用表明，将P = O借给PhQ可能是开发高性能和生态友好型太阳能电池的非常有前途的策略。从设计新材料的综合角度来看，我们的发现将有助于提高OSC器件的性能。