AbstractThe blend nanomorphology of electron‐donor (D) and ‐acceptor (A) materials is of vital importance to achieving highly efficient organic solar cells. Exogenous additives especially aromatic additives are always needed to further optimize the nanomorphology of blend films, which is hardly compatible with industrial manufacture. Herein, we proposed a unique approach to meticulously modulate the aggregation behavior of NFAs in both crystal and thin film nanomorphology via self‐regulation effect. Nonfullerene acceptor Z9 was designed and synthesized by tethering phenyl groups on the inner side chains of the Y6 backbone. Compared with Y6, the tethered phenyl groups participated in the molecular aggregation via the π–π stacking of phenyl‐phenyl and phenyl‐2‐(5,6‐difluoro‐3‐oxo‐2,3‐dihydro‐1H‐inden‐1‐ylidene)malononitrile (IC‐2F) groups, which induced 3D charge transport with phenyl‐mediated super‐exchange electron coupling. Moreover, ordered molecular packing with suitable phase separation was observed in Z9‐based blend films. High power conversion efficiencies (PCEs) of 19.0 % (certified PCE of 18.6 %) for Z9‐based devices were achieved without additives, indicating the great potential of the self‐regulation strategy in NFA design.
摘要 电子供体(D)和受体(A)材料的混合纳米形态对于实现高效有机太阳能电池至关重要。要进一步优化共混薄膜的纳米形态,总是需要外源添加剂,尤其是芳香族添加剂,这很难与工业化生产相匹配。在此,我们提出了一种独特的方法,通过自我调节效应在晶体和薄膜纳米形态中精细调节非烯烃的聚集行为。通过在 Y6 骨架的内侧链上拴系苯基基团,设计并合成了非
富勒烯受体 Z9。与 Y6 相比,拴系的苯基通过苯基-苯基和苯基-2-(5,6-二
氟-3-氧代-2,3-二氢-1H-
茚-1-亚基)
丙二腈(IC-2F)基团的 π-π 堆积参与分子聚集,从而通过苯基介导的超交换电子耦合诱导三维电荷传输。此外,在基于 Z9 的混合薄膜中还观察到了具有适当相分离的有序分子堆积。基于 Z9 的器件在不使用添加剂的情况下实现了 19.0% 的高功率转换效率 (PCE)(认证 PCE 为 18.6%),这表明自调节策略在 NFA 设计中具有巨大的潜力。