Energy Technology Division, School of Energy, Environment and Materials , King Mongkut's University of Technology Thonburi , 126 Pracha-Uthit Road , Bangmod, Thungkhru, Bangkok 10140 , Thailand.
National Nanotechnology Center (NANOTEC) , National Science and Technology Development Agency (NSTDA) , 111 Thailand Science Park, Phahonyothin Road , Khlong Nueng, Khlong Luang, Pathum Thani 12120 , Thailand.
ACS Appl Mater Interfaces. 2019 Feb 13;11(6):6624-6633. doi: 10.1021/acsami.8b19767. Epub 2019 Feb 5.
Thermoelectric generation capable of delivering reliable performance in the low-temperature range (<150 °C) for large-scale deployment has been a challenge mainly due to limited properties of thermoelectric materials. However, realizing interdependence of topological insulators and thermoelectricity, a new research dimension on tailoring and using the topological-insulator boundary states for thermoelectric enhancement has emerged. Here, we demonstrate a promising hybrid nanowire of topological bismuth telluride (BiTe) within the conductive poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) matrix using the in situ one-pot synthesis to be incorporated into a three-dimensional network of self-assembled hybrid thermoelectric nanofilms for the scalable thermoelectric application. Significantly, the nanowire-incorporated film network exhibits simultaneous increase in electrical conductivity and Seebeck coefficient as opposed to reduced thermal conductivity, improving thermoelectric performance. Based on comprehensive measurements for electronic transport of individual nanowires revealing an interfacial conduction path along the BiTe core inside the encapsulating layer and that the hybrid nanowire is n-type semiconducting, the enhanced thermoelectricity is ascribed to increased hole mobility due to electron transfer from BiTe to PEDOT:PSS and importantly charge transport via the BiTe-PEDOT:PSS interface. Scaling up the nanostructured material to construct a thermoelectric generator having the generic pipeline-insulator geometry, the device exhibits a power factor and a figure of merit of 7.45 μW m K and 0.048, respectively, with an unprecedented output power of 130 μW and 15 day operational stability at Δ T = 60 °C. Our findings not only encourage a new approach to cost-effective thermoelectric generation, but they could also provide a route for the enhancement of other applications based on the topological nanowire.
用于大规模部署的在低温范围（<150°C）下提供可靠性能的热电产生一直是一个挑战，主要是由于热电材料的性能有限。然而，通过实现拓扑绝缘体和热电的相互依存关系，出现了一个新的研究维度，即用于热电增强的拓扑绝缘体边界态的设计和利用。在这里，我们使用原位一锅合成法展示了一种有前途的拓扑碲化铋（BiTe）混合纳米线，该纳米线位于导电聚（3,4-乙二氧基噻吩）：聚苯乙烯磺酸盐（PEDOT：PSS）基质中，以整合到自组装混合热电纳米薄膜的三维网络中，用于可扩展的热电应用。显著地，与热导率降低相反，纳米线掺入的薄膜网络表现出电导率和塞贝克系数的同时增加，从而改善了热电性能。基于对单个纳米线电子输运的综合测量，揭示了在封装层内的 BiTe 核心内部存在界面传导路径，并且混合纳米线是 n 型半导体，增强的热电性能归因于电子从 BiTe 到 PEDOT：PSS 的转移引起的空穴迁移率增加，并且重要的是通过 BiTe-PEDOT：PSS 界面进行电荷传输。将纳米结构材料放大到构建具有通用管道-绝缘体几何形状的热电发生器，该器件表现出 7.45 μW m K 的功率因子和 0.048 的品质因数，分别具有前所未有的输出功率 130 μW 和在 ΔT = 60°C 下 15 天的操作稳定性。我们的发现不仅鼓励了一种具有成本效益的热电产生的新方法，而且还为基于拓扑纳米线的其他应用的增强提供了途径。
