The continuous fiber networks with a balanced bimodal orientation of P(NDI2OD-T2) by controlling solution nucleation and face-on and edge-on crystallization rates
The continuous fiber networks with a balanced bimodal orientation of P(NDI2OD-T2) by controlling solution nucleation and face-on and edge-on crystallization rates
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DOI：
10.1016/j.polymer.2022.125435
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发表时间：
2022-11
期刊：
影响因子：
4.6
通讯作者：
Sichun Wang;Tao Zhang;Lu Zhang;Duo-Li Liu;Xinyu Liu;Junhang Li;Hongxiang Li;Qiang Zhang;Yanchun Han
中科院分区：
文献类型：
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作者：
Sichun Wang;Tao Zhang;Lu Zhang;Duo-Li Liu;Xinyu Liu;Junhang Li;Hongxiang Li;Qiang Zhang;Yanchun Han
具有长纤维的共轭半导体聚合物膜形态和优化的分子包装与电荷输运性能密切相关。在这里，我们报道了一种通过控制溶液成核和边上、面上结晶速率，获得具有平衡双峰取向的聚{[N，N ' -双（2-辛基十二烷基）-萘-1,4,5,8-双（二碳酰亚胺）-2,6-二基]-盐-5,5 ' -（2,2 ' -双噻吩）}[P(NDI2OD-T2)]薄膜的连续光纤网络的方法。通过在氯仿溶液中向P（NDI2OD- t2）中加入乙二醇（EG）（最佳含量为3 vol%），可以改善NDI2OD单元沿主干方向的极化和溶液的预聚集。因此，在原位偏振光学显微镜所表征的三相线后退过程中，晶核是在溶液状态下形成的。此外，随着溶剂的蒸发，聚集态的峰值强度增加，表明在干燥过程中成核和晶体生长同时进行。形成了平均纤维长度为531 nm的连续纤维网络的薄膜形态。此外，（100）峰面积在面外和面内方向随时间的斜率相似，表明边上和面上的结晶速率与原位掠入射广角x射线散射所得的结晶速率几乎相等。因此，边朝和面朝混合比的双峰方向近似为1。使用这种连续光纤网络的P（NDI2OD-T2）薄膜的场效应晶体管的平均电子迁移率达到0.2 cm2V−1s−1，与没有添加EG薄膜的器件相比，提高了近3倍。
The conjugated semiconducting polymer film morphology with long fiber and optimizing molecular packing is strongly correlated with charge transport properties. Herein, we report a method to obtain continuous fiber networks with a balanced bimodal orientation of poly{[N,N′-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5′-(2,2′-bithiophene)} [P(NDI2OD-T2)] thin films by controlling solution nucleation and edge-on and face-on crystallization rates. This is enabled by adding ethylene glycol (EG) (the optimal content is 3 vol%) to P(NDI2OD-T2) in chloroform solution which improves the polarization of the NDI2OD units along the backbone direction and solution pre-aggregation. Therefore, the crystal nuclei are formed in solution state during the three-phase line receding as characterized by in situ polarized optical microscopy. Moreover, the peak intensity of the aggregated state increases with solvent evaporation, illustrating that the nucleation and crystal growth proceed simultaneously in the drying process as revealed by in situ ultraviolet–visible absorption spectra. The film morphology of continuous fibrous networks with an average fiber length of 531 nm is formed. In addition, the slopes of (100) peak area vs time in the out-of-plane and in-plane directions are similar, indicating that the edge-on and face-on crystallization rates are almost equal as obtained from in situ grazing incidence wide-angle X-ray scattering. Thus, the bimodal orientation with an edge-on and face-on mixing ratio is approximately 1. The average electron mobility of the field effect transistors of P(NDI2OD-T2) films with this continuous fiber network reaches to 0.2 cm2V−1s−1, an almost 3-fold improvement compared with devices without EG addition films.