Efficient molecular doping of polymeric semiconductors driven by anion exchange
Efficient molecular doping of polymeric semiconductors driven by anion exchange
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DOI：
10.1038/s41586-019-1504-9
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发表时间：
2019-08
期刊：
影响因子：
64.8
通讯作者：
Yu Yamashita;J. Tsurumi;M. Ohno;Ryo Fujimoto;S. Kumagai;Tadanori Kurosawa;T. Okamoto;J. Takeya;S. Watanabe
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文献类型：
--
作者：
Yu Yamashita;J. Tsurumi;M. Ohno;Ryo Fujimoto;S. Kumagai;Tadanori Kurosawa;T. Okamoto;J. Takeya;S. Watanabe
聚合物半导体的化学掺杂效率——以及由此获得的载流子密度——主要取决于π共轭聚合物和掺杂物之间的电化学氧化还原电位。因此，将其中一种的电子亲和力与另一种的电离势相匹配，可以实现有效的掺杂。在这里，我们描述了一个不同的过程——我们称之为“阴离子交换”——这可能会提高掺杂水平。该过程由离子液体溶剂介导，可以描述为传统的小p型掺杂阴离子与离子液体提供的第二阴离子的有效瞬时交换。将优化的离子盐（离子液体溶剂）引入到传统的二元供体-受体体系中，可以克服Marcus理论所描述的氧化还原电位限制，并允许阴离子交换效率接近100%。因此，每个单体单元几乎可以实现一个电荷的掺杂水平。这种增加掺杂水平、增加稳定性和优异输运性质的证明表明，阴离子交换掺杂可以使用几乎无限的离子盐，可以成为实现先进分子电子学的有力工具。
The efficiency with which polymeric semiconductors can be chemically doped—and the charge carrier densities that can thereby be achieved—is determined primarily by the electrochemical redox potential between the π-conjugated polymer and the dopant species,. Thus, matching the electron affinity of one with the ionization potential of the other can allow effective doping,. Here we describe a different process—which we term ‘anion exchange’—that might offer improved doping levels. This process is mediated by an ionic liquid solvent and can be pictured as the effective instantaneous exchange of a conventional small p-type dopant anion with a second anion provided by an ionic liquid. The introduction of optimized ionic salt (the ionic liquid solvent) into a conventional binary donor–acceptor system can overcome the redox potential limitations described by Marcus theory, and allows an anion-exchange efficiency of nearly 100 per cent. As a result, doping levels of up to almost one charge per monomer unit can be achieved. This demonstration of increased doping levels, increased stability and excellent transport properties shows that anion-exchange doping, which can use an almost infinite selection of ionic salts, could be a powerful tool for the realization of advanced molecular electronics.