Solvent additives are known to modify the morphology of bulk heterojunction active layers to achieve high efficiency organic solar cells. However, the knowledge about the influence of solvent additives on the morphology degradation is limited. Hence, in operando grazing‐incidence small and wide angle X‐ray scattering (GISAXS and GIWAXS) measurements are applied on a series of PffBT4T‐2OD:PC₇₁BM‐based solar cells prepared without and with solvent additives. The solar cells fabricated without a solvent additive, with 1,8‐diiodoctane (DIO), and with o‐chlorobenzaldehyde (CBA) additive show differences in the device degradation and changes in the morphology and crystallinity of the active layers. The mesoscale morphology changes are correlated with the decay of the short‐circuit current J_sc and the evolution of crystalline grain sizes is codependent with the decay of open‐circuit voltage V_oc. Without additive, the loss in J_sc dominates the degradation, whereas with solvent additive (DIO and CBA) the loss in V_oc rules the degradation. CBA addition increases the overall device stability as compared to DIO or absence of additive.

中文翻译：

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在 Operando GISAXS 和 GIWAXS 中，基于 PffBT4T-2OD:PC71BM（含和不含溶剂添加剂）的有机太阳能电池稳定性研究。

已知溶剂添加剂可以改变本体异质结活性层的形态以实现高效有机太阳能电池。然而，关于溶剂添加剂对形态降解的影响的知识是有限的。因此，在操作中，小角度和广角 X 射线散射（GISAXS 和 GIWAXS）测量应用于一系列不含和含有溶剂添加剂制备的PffBT4T-2OD:PC _{71 BM 太阳能电池。}不使用溶剂添加剂、使用 1,8-二碘辛烷 (DIO) 和使用邻氯苯甲醛 (CBA) 添加剂制造的太阳能电池在器件降解以及活性层的形态和结晶度变化方面表现出差异。介观形态变化与短路电流J _sc的衰减相关，晶粒尺寸的演变与开路电压V _oc的衰减相关。没有添加剂时， J _sc的损失主导降解，而使用溶剂添加剂（DIO 和 CBA）时，V _oc的损失主导降解。与 DIO 或不添加添加剂相比，CBA 的添加提高了器件的整体稳定性。