Department of Chemical Engineering, Indian Institute of Technology, Kharagpur 721302, India.
Sci Rep. 2016 Sep 15;6:33219. doi: 10.1038/srep33219.
We present molecular dynamics simulations of a ternary blend of P3HT, PCBM and P3HT-grafted silica nanoparticles (SiNP) for applications in polymer-based solar cells. Using coarse-grained models, we study the effect of SiNP on the spatial arrangement of PCBM in P3HT. Our results suggest that addition of SiNP not only alters the morphology of PCBM clusters but also improves the crystallinity of P3HT. We exploit the property of grafted SiNP to self-assemble into a variety of anisotropic structures and the tendency of PCBM to preferentially adhere to SiNP surface, due to favorable interactions, to achieve morphologies with desirable characteristics for the active layer, including domain size, crystallinity of P3HT, and elimination of isolated islands of PCBM. As the concentration of SiNP increases, the number of isolated PCBM molecules decreases, which in turn improves the crystallinity of P3HT domains. We also observe that by tuning the grafting parameters of SiNP, it is possible to achieve structures ranging from cylindrical to sheets to highly interconnected network of strings. The changes brought about by addition of SiNP shows a promising potential to improve the performance of these materials when used as active layers in organic photovoltaics.
我们呈现了 P3HT、PCBM 和 P3HT 接枝二氧化硅纳米粒子（SiNP）三元共混物的分子动力学模拟，用于聚合物基太阳能电池。使用粗粒化模型，我们研究了 SiNP 对 PCBM 在 P3HT 中空间排列的影响。结果表明，SiNP 的添加不仅改变了 PCBM 簇的形态，而且提高了 P3HT 的结晶度。我们利用接枝 SiNP 自组装成各种各向异性结构的特性以及 PCBM 优先粘附到 SiNP 表面的趋势，由于有利的相互作用，实现了具有活性层所需特性的形态，包括畴尺寸、P3HT 的结晶度和消除孤立的 PCBM 岛。随着 SiNP 浓度的增加，孤立的 PCBM 分子数量减少，这反过来又提高了 P3HT 畴的结晶度。我们还观察到，通过调整 SiNP 的接枝参数，可以实现从圆柱状到片状再到高度互联的字符串网络的结构。添加 SiNP 带来的变化显示出在将这些材料用作有机光伏活性层时提高性能的巨大潜力。
