A synthetic approach that endows high doping efficiency on high-mobility diketopyrrolopyrrole (DPP)-copolymers is described in this paper. Typical DPP-copolymers are not suitable for molecular doping, which relies on intermolecular charge transfer, presumably because of their relatively high ionization potential or weak intermolecular charge transfer characteristics between the dopant and acceptor of copolymers. Herein, we introduce new DPP-copolymers with strategically designed sparse intramolecular alkyl chain spacing where dopant molecules can reside. The resulting two type A₁-D₁-A₂-D₁ and A₁-D₂-A₂-D₂ terpolymers consist of cyclopentadithiophenes or cyclopentadithiophenyl thiophene as alternative donors, diketopyrrolopyrrole as an acceptor, and difluorinated benzothiadiazole as another acceptor. These new DPP-copolymers have significantly enhanced doping efficiency compared to conventional DPP-copolymers, exhibiting typical features of integer charge transfer, as confirmed by ultraviolet-visible-near-infrared absorption spectroscopy, electron paramagnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and thin film conductivity analyses. Moreover, doping-induced solubility control, which is not possible with other conventional DPP-copolymers due to low doping efficiency, is applicable, thus resulting in arrays of high-mobility organic field-effect transistors and complementary all-polymer inverters. This study sheds light on the possibility of tuning the doping efficiency of donor-acceptor copolymers without sacrificing their intrinsic properties, such as their well-ordered molecular packing and high charge carrier mobility.

中文翻译：

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通过引入稀疏分子内烷基链间距提高二酮吡咯并吡咯共聚物的掺杂效率

本文描述了一种对高迁移率二酮吡咯并吡咯 (DPP)-共聚物具有高掺杂效率的合成方法。典型的 DPP 共聚物不适用于依赖分子间电荷转移的分子掺杂，这大概是因为它们具有相对较高的电离电位或共聚物的掺杂剂和受体之间较弱的分子间电荷转移特性。在此，我们介绍了具有战略性设计的稀疏分子内烷基链间距的新型 DPP 共聚物，其中掺杂剂分子可以驻留。由此产生的两种类型 A ₁ -D ₁ -A ₂ -D ₁和 A ₁ -D ₂ -A ₂ -D ₂三元共聚物由作为替代供体的环戊二噻吩或环戊二噻吩噻吩、作为受体的二酮吡咯并吡咯和作为另一受体的二氟化苯并噻二唑组成。与传统的 DPP 共聚物相比，这些新型 DPP 共聚物的掺杂效率显着提高，表现出整数电荷转移的典型特征，如紫外-可见-近红外吸收光谱、电子顺磁共振光谱、傅里叶变换红外光谱和薄薄膜电导率分析。此外，由于掺杂效率低，其他常规 DPP 共聚物无法实现掺杂诱导的溶解度控制，因此可以应用，从而产生高迁移率的有机场效应晶体管阵列和互补的全聚合物反相器。