Single Atom Selenium Substitution-Mediated P-Type Doping in Polythiophenes toward High-Performance Organic Electronics and Thermoelectrics
Single Atom Selenium Substitution-Mediated P-Type Doping in Polythiophenes toward High-Performance Organic Electronics and Thermoelectrics
复制标题
单原子硒取代介导的聚噻吩 P 型掺杂可实现高性能有机电子和热电学
DOI：
10.1002/aelm.202200053
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发表时间：
2022
影响因子：
6.2
通讯作者：
Chen C
中科院分区：
文献类型：
--
作者：
Chen C
主链上的重杂原子取代是改善聚合物半导体中分子堆积和电荷离域的有效策略。这种主链修饰还由于降低的电离电位（IP）而促进氧化掺杂。在这里，探讨了单原子硒取代对一类聚噻吩共聚物的掺杂和电荷传输性质的影响。掺杂的聚合物的室温（RT）电导率显着增强的硒取代的分子掺杂和离子交换掺杂。导电性的增强是由于含硒体系具有更好的结晶度，而含硒体系的结晶度可以通过热退火引起的扩链带状相形态来增强，这对掺杂来说是稳健的。掺杂的含硒体系的电荷离域的所得增加由温度依赖性电导率证明。在离子交换掺杂的薄膜中，掺杂的硒代聚合物实现了最大700 S cm− 1的电导率和46.5 μW m− 1 K − 2的高热电（TE）功率因数（PF），并观察到金属-绝缘体（M-I）转变的特征，这是异质导电系统的特征。结果表明，单原子硒取代是改善共轭聚合物电荷传输和TE性能的有效分子设计方法。
Heavy heteroatom substitution of the backbone is an effective strategy to improve molecular packing and charge delocalization in polymer semiconductors. Such a backbone modification also facilitates oxidative doping as a result of reduced ionization potential (IP). Here, the effect of single‐atom selenium substitution on doping and charge transport properties of a class of polythiophene copolymers is explored. The room temperature (RT) conductivities of the doped polymers are significantly enhanced by the selenium substitution for both molecular doping and ion exchange doping. The enhanced conduction is rationalized by the better crystallinity of the selenium‐containing system, which can be reinforced by a chain‐extended ribbon‐phase morphology induced by thermal annealing, which is robust toward doping. The resulting increase in the charge delocalization of the doped selenium‐containing system is evidenced by temperature‐dependent conductivities. In ion exchange doped films the maximum conductivity of ≈700 S cm−1and a high thermoelectric (TE) power factor (PF) of 46.5 μW m−1K−2is achieved for the doped selenophene polymer and signatures of a metal‐insulator (M–I) transition are observed that are characteristics for heterogeneous conduction systems. The results show that single‐atom selenium substitution is an effective molecular design approach for improving the charge transport and TE properties of conjugated polymers.