Pyridine-based organic molecules (POMs), 4-phenylpyridine (4-Py) and 4-tert-butylpyridine (4-tbp) were used to modify the sol-gel ZnO surface for inverted polymer solar cells (PSCs). X-ray photoelectron spectroscopic (XPS) results showed the formation of NZn bonding and the reduction of oxygen vacancies (V_o), depicting that POMs chemisorbed on V_o sites of ZnO surface to passivate O defects. From ultraviolet photoelectron spectroscopic (UPS) data, the work function (WF) of ZnO slightly decreased due to interfacial dipole, enhancing the electron extraction from ZnO surface. ZnO surface modified with POMs (ZnO/POMs) possessed smoother morphology and more hydrophobicity than the pristine ZnO surface, providing good interfacial contact with polymeric active layer. The improved surface properties benefited power conversion efficiency (PCE) of bulk-heterojunction (BHJ) PSCs and their stability. As a result, PSCs with ZnO/4-tbp and ZnO/4-Py achieved 9.29% and 9.07% respectively, while 8.16% with the pristine ZnO. Especially, PSCs with ZnO/4-tbp possessed the best PCE because of its intramolecular dipole from electron donating group. This study demonstrates the benefits of POMs modifying the sol-gol ZnO surface for inverted PSCs.

基于吡啶的有机分子（POM），4-苯基吡啶（4-Py）和4-叔丁基吡啶（4-tbp）用于修饰倒置聚合物太阳能电池（PSC）的溶胶-凝胶ZnO表面。X射线光电子能谱（XPS）结果显示N Zn键的形成和氧空位（V _o）的降低，表明POMs在V _o上化学吸附ZnO表面的钝化部位以钝化O缺陷。根据紫外光电子能谱（UPS）数据，由于界面偶极子的作用，ZnO的功函数（WF）略有降低，从而增强了从ZnO表面的电子提取。与原始ZnO表面相比，用POM（ZnO / POM）改性的ZnO表面具有更光滑的形态和更大的疏水性，提供了与聚合物活性层的良好界面接触。改善的表面性能有利于体异质结（BHJ）PSC的功率转换效率（PCE）及其稳定性。结果，具有ZnO / 4-tbp和ZnO / 4-Py的PSC分别达到9.29％和9.07％，而原始ZnO为8.16％。尤其是具有ZnO / 4-tbp的PSC，由于其来自供电子基团的分子内偶极子，因此具有最好的PCE。