Here the effect of solvent quality on the microstructure and organic field‐effect transistor (OFET) performance of thin films of the high mobility naphthalene‐diimide‐thiophene‐based n‐type semiconducting copolymer P(NDI2OD‐T2) is investigated. A strong correlation between OFET mobility and solvent quality is observed with average electron mobility increasing from 0.21 cm² V⁻¹ s⁻¹ for samples prepared from tolerably good solvents to 0.56 cm² V⁻¹ s⁻¹ for samples prepared from poor solvents, with a maximum electron mobility of 1.5 cm² V⁻¹ s⁻¹ observed for transistors processed from toluene. The variation in transistor performance with solvent quality is linked to the nature and extent of the solution aggregation of P(NDI2OD‐T2) chains. Small angle X‐ray scattering measurements reveal elongated rod‐like aggregates up to 300 nm in length in solutions prepared using poor solvents, in contrast to more coil‐like chains with radius of gyration of ≈10–15 nm for solutions based on good to tolerably poor solvents. Thin films produced from decreasing solvent quality show an increase in the extent of correlated ordering of backbones and the degree of edge‐on orientation of polymer chains at the air/film interface. This work establishes the important link between solution‐phase chain aggregation behavior, thin‐film microstructure, and transistor performance in the P(DNI2OD‐T2) system.

中文翻译：

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溶液聚合的性质和程度决定了P（NDI2OD-T2）薄膜晶体管的性能

在此研究了溶剂质量对高迁移率萘二酰亚胺-噻吩基n型半导体共聚物P（NDI2OD-T2）薄膜的微结构和有机场效应晶体管（OFET）性能的影响。观察到OFET迁移率与溶剂质量之间存在很强的相关性，平均电子迁移率从使用耐受性良好的溶剂制备的样品的0.21 cm ² V ^-1 s ^-1增加到使用不良溶剂制备的样品的0.56 cm ² V ^-1 s ^-1，最大电子迁移率为1.5 cm ² V ^-1 s ^-1观察到由甲苯加工的晶体管。晶体管性能随溶剂质量的变化与P（NDI2OD-T2）链溶液聚集的性质和程度有关。小角度X射线散射测量显示，在使用不良溶剂制备的溶液中，棒状聚集体的长度可达300 nm，而对于质量较好的溶液，与之相比，线圈形链的回转半径约为10–15 nm耐受性差的溶剂。溶剂质量下降产生的薄膜显示出主链相关顺序的增加以及空气/薄膜界面处聚合物链的边沿取向程度的增加。这项工作在P（DNI2OD-T2）系统中在溶液相链聚集行为，薄膜微结构和晶体管性能之间建立了重要的联系。