Abstract The impact of the additive 1,8-diiodooctane on the morphology of bulk-heterojunction solar cells based on the systems P3HT:PC71BM, PTB7:PC71BM and PTB7-Th:PC71BM is studied using a combination of Small Angle Neutron Scattering (SANS) and Atomic Force Microscopy (AFM). The results clearly show that while in the P3HT:PC71BM system, the additive DIO promotes a slight coarsening of the phase domains (type I additive), in the systems PTB7:PC71BM and PTB7-Th:PC71BM, DIO promotes a large decrease in the size of the phase domains (type II additive). SANS is demonstrated as being particularly useful at detecting the minor morphological changes observed in the P3HT:PC71BM system, which can be hardly seen in AFM. This work illustrates how SANS complements AFM and both techniques when used together provide a deeper insight into the nanoscale structure in thin organic photovoltaic (OPV) device films.

中文翻译：

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1,8-二碘辛烷对有机光伏 (OPV) 器件形态的影响——小角中子散射 (SANS) 研究

摘要 使用小角中子散射 (SANS) 的组合研究了添加剂 1,8-二碘辛烷对基于系统 P3HT:PC71BM、PTB7:PC71BM 和 PTB7-Th:PC71BM 的体异质结太阳能电池形态的影响和原子力显微镜 (AFM)。结果清楚地表明，虽然在 P3HT:PC71BM 系统中，添加剂 DIO 促进了相域的轻微粗化（I 型添加剂），但在 PTB7:PC71BM 和 PTB7-Th:PC71BM 系统中，DIO 促进了相域的大量减少相域的大小（II 型添加剂）。SANS 被证明在检测 P3HT:PC71BM 系统中观察到的微小形态变化方面特别有用，这在 AFM 中几乎看不到。