Besides broadening of the absorption spectrum, modulating molecular energy levels, and other well‐studied properties, a stronger intramolecular electron push–pull effect also affords other advantages in nonfullerene acceptors. A strong push–pull effect improves the dipole moment of the wings in IT‐4F over IT‐M and results in a lower miscibility than IT‐M when blended with PBDB‐TF. This feature leads to higher domain purity in the PBDB‐TF:IT‐4F blend and makes a contribution to the better photovoltaic performance. Moreover, the strong push–pull effect also decreases the vibrational relaxation, which makes IT‐4F more promising than IT‐M in reducing the energetic loss of organic solar cells. Above all, a power conversion efficiency of 13.7% is recorded in PBDB‐TF:IT‐4F‐based devices.

中文翻译：

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非富勒烯受体的强分子内电子推挽效应使高效有机太阳能电池成为可能

除了扩大吸收光谱，调节分子能级和其他经过充分研究的特性外，更强的分子内电子推挽效应还为非富勒烯受体提供了其他优势。与PBDB-TF混合使用时，强大的推挽效应可改善IT-4F中机翼的偶极矩，优于IT-M，并具有比IT-M低的混溶性。此功能导致PBDB-TF：IT-4F共混物中更高的畴纯度，并为更好的光伏性能做出了贡献。此外，强大的推挽效应还减少了振动松弛，这使得IT-4F在降低有机太阳能电池的能量损失方面比IT-M更有希望。最重要的是，基于PBDB‐TF：IT‐4F的设备的电源转换效率为13.7％。