Akita Masahiro, Osaka Itaru, Takimiya Kazuo
Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8527, Japan.
RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan.
Materials (Basel). 2013 Mar 18;6(3):1061-1071. doi: 10.3390/ma6031061.
Incorporation of pigment or dye molecules as building units is of great interest in the development of semiconducting polymers, due to their strong intermolecular interactions arising from the strong local dipoles in the unit structure, which would facilitate the charge transport property. In this paper, semiconducting polymers based on well-known pigments, namely, quinacridone and diketopyrrolopyrrole, are synthesized and characterized. The π-stacking distances are found to be 3.5-3.8 Å, which is fairly narrow for semiconducting polymers, indicating that they possess strong intermolecular interactions. Interestingly, polymer orientation is influenced by the composition of alkyl side chains. While the edge-on orientation is observed when the linear alkyl groups are introduced for all the side chains, the face-on orientation is observed when the branched alkyl groups are introduced either in the quinacridone or diketopyrrolopyrrole unit. It is found that the electronic structure of the present polymers is mostly affected by that of the diketopyrrolopyrrole unit, as evidenced by the absorption spectra and computation. Although the field-effect mobility of the polymers is modest, , in the order of 10-10 cm²/Vs, these findings could be important information for the development of semiconducting polymers.
将颜料或染料分子作为构建单元引入到半导体聚合物的开发中具有重大意义，这是因为它们在单元结构中具有由强局部偶极产生的强分子间相互作用，这将有助于电荷传输性能。在本文中，合成并表征了基于著名颜料喹吖啶酮和二酮吡咯并吡咯的半导体聚合物。发现π堆积距离为3.5 - 3.8 Å，这对于半导体聚合物来说相当窄，表明它们具有强分子间相互作用。有趣的是，聚合物取向受烷基侧链组成的影响。当所有侧链都引入线性烷基时观察到边对边取向，而当在喹吖啶酮或二酮吡咯并吡咯单元中引入支化烷基时观察到面对面取向。通过吸收光谱和计算证明，发现本聚合物的电子结构主要受二酮吡咯并吡咯单元的影响。尽管聚合物的场效应迁移率适中，约为10⁻¹⁰ cm²/Vs，但这些发现对于半导体聚合物的开发可能是重要信息。
