Recent advances in organic solar cells based on non-fullerene acceptors (NFAs) come with reduced non-radiative voltage losses (ΔV_nr). Here we show that, in contrast to the energy-gap-law dependence observed in conventional donor:fullerene blends, the ΔV_nr values in state-of-the-art donor:NFA organic solar cells show no correlation with the energies of charge-transfer electronic states at donor:acceptor interfaces. By combining temperature-dependent electroluminescence experiments and dynamic vibronic simulations, we provide a unified description of ΔV_nr for both fullerene- and NFA-based devices. We highlight the critical role that the thermal population of local exciton states plays in low-ΔV_nr systems. An important finding is that the photoluminescence yield of the pristine materials defines the lower limit of ΔV_nr. We also demonstrate that the reduction in ΔV_nr (for example, <0.2 V) can be obtained without sacrificing charge generation efficiency. Our work suggests designing donor and acceptor materials with high luminescence efficiency and complementary optical absorption bands extending into the near-infrared region.

基于非富勒烯受体 (NFA) 的有机太阳能电池的最新进展伴随着非辐射电压损失 (Δ V _nr ) 的降低。在这里，我们表明，与在常规供体：富勒烯混合物中观察到的能隙定律依赖性相反，最先进的供体：NFA 有机太阳能电池中的ΔV _nr值与电荷能量没有相关性- 在供体：受体界面转移电子状态。通过结合温度相关的电致发光实验和动态振动模拟，我们为基于富勒烯和 NFA 的器件提供了 Δ V _nr的统一描述。我们强调了局部激子态的热种群在低 Δ V _{nr中所起的关键作用}系统。一个重要的发现是原始材料的光致发光产率定义了 Δ V _nr的下限。我们还证明，可以在不牺牲电荷产生效率的情况下获得ΔV _nr的降低（例如，<0.2 V）。我们的工作建议设计具有高发光效率和延伸到近红外区域的互补光学吸收带的供体和受体材料。