Conjugated D-A polymers with high charge mobilities have received increasing attentions in recent years. In this paper, we report a simple, but efficient approach to improve charge mobilities of conjugated polymers by partial replacement of branching alkyl chains with linear ones. With this strategy in mind, we designed and investigated three new DPP-quaterthiophene terpolymers PDPP4T-1, PDPP4T-2 and PDPP4T-3 containing both linear (n-dodecane) and branching (2-decyltetradecyl) alkyl chains with different ratios. On the basis of GIWAXS data, interchain packing order is improved for terpolymers PDPP4T-1, PDPP4T-2 and PDPP4T-3, in comparison with PDPP4T with only branching alkyl chains. The incorporation of linear alkyl chains can affect the interchain packing mode, and PDPP4T-3 with more linear alkyl chains among the three terpolymers adopts the edge-on chain arrangement on the substrate. Field effect transistors measurements indicate that PDPP4T-1, PDPP4T-2 and PDPP4T-3 exhibit higher hole mobilities than PDPP4T. Moreover, hole mobilities increase in the following order: PDPP4T-1 < PDPP4T-2 < PDPP4T-3 by increasing the contents of linear alkyl chains in these terpolymers. Thin film mobility of PDPP4T-3 can reach 6.1 cm2V-1s-1, which can be further increased to 9.1 cm2V-1s-1 after incorporating NMe4I.

中文翻译：

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通过用直链部分取代支链烷基链提高二酮吡咯并吡咯基共轭聚合物的电荷迁移率

近年来，具有高电荷迁移率的共轭DA聚合物受到越来越多的关注。在本文中，我们报告了一种简单而有效的方法，可通过将支链烷基链部分替换为线性烷基链来提高共轭聚合物的电荷迁移率。考虑到这一策略，我们设计并研究了三种新的DPP-四噻吩三元共聚物PDPP4T-1，PDPP4T-2和PDPP4T-3，它们同时含有不同比例的直链（正十二烷）和支链（2-癸基十四烷基）烷基链。根据GIWAXS数据，与仅具有分支烷基链的PDPP4T相比，三元共聚物PDPP4T-1，PDPP4T-2和PDPP4T-3的链间堆积顺序得到了改善。线性烷基链的掺入会影响链间的堆积方式，三种三元共聚物中具有更多直链烷基链的PDPP4T-3在基材上采用边对边链排列。场效应晶体管的测量表明，PDPP4T-1，PDPP4T-2和PDPP4T-3的空穴迁移率比PDPP4T高。而且，空穴迁移率按以下顺序增加：通过增加这些三元共聚物中线性烷基链的含量，PDPP4T-1 ＜PDPP4T-2 ＜PDPP4T-3。PDPP4T-3的薄膜迁移率可以达到6.1 cm2V-1s-1，在掺入NMe4I后可以进一步提高到9.1 cm2V-1s-1。通过增加这些三元共聚物中直链烷基链的含量来获得PDPP4T-3。PDPP4T-3的薄膜迁移率可以达到6.1 cm2V-1s-1，在掺入NMe4I后可以进一步提高到9.1 cm2V-1s-1。通过增加这些三元共聚物中直链烷基链的含量来获得PDPP4T-3。PDPP4T-3的薄膜迁移率可以达到6.1 cm2V-1s-1，在掺入NMe4I后可以进一步提高到9.1 cm2V-1s-1。