Improved Anisotropic Thermoelectric Behavior of Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) via Magnetophoresis
Improved Anisotropic Thermoelectric Behavior of Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) via Magnetophoresis
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DOI：
10.1021/acsomega.8b00999
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发表时间：
2018-10
期刊：
影响因子：
4.1
通讯作者：
V. Zarubin;Tai-De Li;S. Humagain;H. Ji;K. Yager;S. Greenbaum;L. Vuong
中科院分区：
文献类型：
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作者：
V. Zarubin;Tai-De Li;S. Humagain;H. Ji;K. Yager;S. Greenbaum;L. Vuong
在从能量收集到自旋电子学的许多潜在应用中，对实现导电聚合物的形态控制有强烈的需求。在这里，静态磁场诱导的聚（3，4-乙撑二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT：PSS）粒子的排列被证明。PEDOT：PSS薄膜在适度的mT级磁场下浇铸，表现出四倍的塞贝克系数和两倍的电导率增加。原子力显微镜测量证实存在的导电岛，表现出10倍的增加，在当地的电荷载流子迁移率和阈值行为，这是与相分离。高分辨率扫描电子显微镜确定了一致的结构线圈到棒的过渡，和三维飞行时间二次离子质谱成像显示，棒状结构与PEDOT域，一般对齐的磁场和集群的外表面上。掠入射小角度X射线散射，拉曼光谱，电子顺磁共振，和圆二色性光谱点的物理性质的磁泳排列，这是预期发生通过磁耦合的PEDOT域与极化子模式。由于在mT级磁场下浇铸增加了PEDOT：PSS薄膜的电导率和塞贝克系数，而没有额外的掺杂剂，通常限制热电性能，我们的研究表明，低场磁泳显着影响PEDOT：PSS的结构和相应的物理性能。我们的研究结果还指出，在实验室环境中的小的外部磁场的存在下，可能会明显和无意中影响的PEDOT：PSS的形态在沉降，干燥，或退火过程中的关注。
There is strong demand for achieving morphological control of conducting polymers in its many potential applications, from energy harvesting to spintronics. Here, the static magnetic-field-induced alignment of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) particles is demonstrated. PEDOT:PSS thin films cast under modest mT-level magnetic fields exhibit a fourfold increase in the Seebeck coefficient and doubled electrical conductivity. Atomic force microscopy measurements confirm the presence of conducting islands that exhibit a 10-fold increase in the local charge carrier mobility and threshold behavior that is associated with phase separation. High-resolution scanning electron microscopy identifies a consistent structural coil-to-rod transition, and three-dimensional time-of-flight secondary-ion mass spectrometry imaging shows that the rodlike structures coincide with PEDOT domains that generally align with the magnetic field and cluster on the outer surface. Grazing-incidence small-angle X-ray scattering, Raman spectra, electron paramagnetic resonance, and circular dichroism spectroscopy point to the physical nature of the magnetophoretic alignment, which is expected to occur via magnetic coupling of PEDOT domains with polaron modes. Because casting under mT-level magnetic fields increases the electrical conductivity and Seebeck coefficient of PEDOT:PSS thin films without additional dopants that commonly limit the thermoelectric performance, our research reveals that low-field magnetophoresis significantly influences the structure and corresponding physical properties of PEDOT:PSS. Our results also point to concerns that the presence of small external magnetic fields in laboratory settings may appreciably and inadvertently influence the PEDOT:PSS morphology during settling, drying, or annealing processes.