Perylene diimide (PDI) is one of most intensively studied non-fullerene small molecule acceptors (SMAs). By fluorination on the conjugated backbone, a new PDI with difluoride substitution on adjacent bay positions of PDI is prepared. Then, four propeller-like SMAs are obtained by linking four PDIs with an aromatic core, wherein the molecular geometry is modulated by ring fusion of the aromatic core. Further study reveals that fluorination is helpful to enhance the absorption intensity, and thus promote the current density in organic solar cells. In addition, the ring-fused strategy is able to suppress the distortion and rotation of relevant molecules. Therefore, these four acceptors exhibit significantly diversity of photovoltaic performance, wherein the acceptor FPDIF4-DTC consisting of a fused core and fluoro-substituted PDIs shows a best efficiency of 5.1%. This result implies that fluorination on PDI conjugated backbone is a successful way to construct promising SMAs.

ylene二酰亚胺（PDI）是研究最深入的非富勒烯小分子受体（SMA）之一。通过在共轭主链上氟化，制备了新的PDI，该PDI在PDI的相邻间隔位置上被二氟取代。然后，通过将四个PDI与芳族核连接而获得四个螺旋桨状SMA，其中通过芳族核的环融合来调节分子几何形状。进一步的研究表明，氟化有助于增强吸收强度，从而促进有机太阳能电池中的电流密度。另外，环稠合策略能够抑制相关分子的变形和旋转。因此，这四个受体表现出明显不同的光伏性能，其中受体FPDIF4-DTC由熔融核和氟取代的PDI组成的最佳效率为5.1％。此结果表明，在PDI共轭主链上进行氟化是构建有前途的SMA的成功方法。