Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, SE-601 74, Norrköping, Sweden.
Technische Universität Dresden, Center for Advancing Electronics Dresden, D-01062, Dresden, Germany.
Adv Mater. 2018 Aug;30(31):e1801898. doi: 10.1002/adma.201801898. Epub 2018 Jun 6.
The synthesis of a novel naphthalenediimide (NDI)-bithiazole (Tz2)-based polymer [P(NDI2OD-Tz2)] is reported, and structural, thin-film morphological, as well as charge transport and thermoelectric properties are compared to the parent and widely investigated NDI-bithiophene (T2) polymer [P(NDI2OD-T2)]. Since the steric repulsions in Tz2 are far lower than in T2, P(NDI2OD-Tz2) exhibits a more planar and rigid backbone, enhancing π-π chain stacking and intermolecular interactions. In addition, the electron-deficient nature of Tz2 enhances the polymer electron affinity, thus reducing the polymer donor-acceptor character. When n-doped with amines, P(NDI2OD-Tz2) achieves electrical conductivity (≈0.1 S cm ) and a power factor (1.5 µW m K ) far greater than those of P(NDI2OD-T2) (0.003 S cm and 0.012 µW m K , respectively). These results demonstrate that planarized NDI-based polymers with reduced donor-acceptor character can achieve substantial electrical conductivity and thermoelectric response.
本文报道了一种新型萘二酰亚胺（NDI）-并噻唑（Tz2）基聚合物[P（NDI2OD-Tz2）]的合成，并对其结构、薄膜形貌、电荷输运和热电性能与母体和广泛研究的 NDI-并噻吩（T2）聚合物[P（NDI2OD-T2）]进行了比较。由于 Tz2 中的空间排斥作用远低于 T2，因此 P（NDI2OD-Tz2）具有更平面和刚性的骨架，增强了π-π 链堆积和分子间相互作用。此外，Tz2 的缺电子性质增强了聚合物的电子亲和力，从而降低了聚合物的给体-受体性质。当用胺掺杂时，P（NDI2OD-Tz2）实现了远大于 P（NDI2OD-T2）的电导率（≈0.1 S cm）和功率因子（1.5 µW m K）（分别为 0.003 S cm 和 0.012 µW m K）。这些结果表明，具有降低给体-受体性质的平面化 NDI 基聚合物可以实现显著的电导率和热电响应。
