Enhanced Molecular Doping for High Conductivity in Polymers with Volume Freed for Dopants
Enhanced Molecular Doping for High Conductivity in Polymers with Volume Freed for Dopants
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DOI：
10.1021/acs.macromol.9b02048
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发表时间：
2019-12-24
期刊：
影响因子：
5.5
通讯作者：
Katz, Howard. E.
中科院分区：
文献类型：
--
作者：
Li, Hui;DeCoster, Mallory E.;Katz, Howard. E.
我们提出了两个新的聚噻吩异构体，PQTC 16-TT和PQTSC 16-TT，与典型的聚噻吩，如PQT（S）12和PBTTT（S）12相比，具有更多的分离和更低的主链上的侧链密度。引入间隔子单元以分离侧链改善了靠近聚合物主链的掺杂剂分子的容纳。因此，聚合物的层状结构和π-π堆叠被掺杂剂干扰可以忽略不计;事实上，在化学掺杂后观察到改进的有序性和更紧密的堆叠。此外，PQTSC 16-TT/NOBF 4的掺杂效率显著提高，电导率提高到330 S cm（-1），在较高掺杂浓度下仍保持在200 S cm（-1）。我们研究了电荷转移是如何影响的掺杂剂相对于聚合物重复单元的几何形状。结果表明，侧链中的硫作为掺杂剂的结合位点，导致在掺杂时的烷硫基取代的聚合物的更高的热稳定性和环境稳定性。
We present two new polythiophene isomers, PQTC16-TT and PQTSC16-TT, with more separation and lower side chain density on the backbone compared with the typical polythiophenes, such as PQT(S)12 and PBTTT(S)12. The introduction of spacer subunits to separate the side chains improves the accommodation of dopant molecules close to the polymer backbone. Therefore, the lamellar structure and pi-pi stacking of polymers were negligibly disturbed by dopants; in fact, improved ordering and closer it-stacking were observed after chemical doping. Furthermore, the doping efficiency is significantly enhanced and the electrical conductivity is improved up to 330 S cm(-1), still maintained at 200 S cm(-1) at higher doping concentration, for the combination of PQTSC16-TT/NOBF4. We investigate how charge transfer is affected by the geometry of the dopant with respect to the polymer repeat unit. It is shown that the sulfurs in the side chains act as binding sites for dopants, resulting in higher thermal and environmental stability of alkylthio-substituted polymers upon doping.