Flexible wearable electronics, when combined with outstanding thermoelectric properties, are promising candidates for future energy harvesting systems. Graphene and its macroscopic assemblies (e.g., graphene-based fibers and films) have thus been the subject of numerous studies because of their extraordinary electrical and mechanical properties. However, these assemblies have not been considered suitable for thermoelectric applications owing to their high intrinsic thermal conductivity. In this study, bromine doping is demonstrated to be an effective method for significantly enhancing the thermoelectric properties of graphene fibers. Doping enhances phonon scattering due to the increased defects and thus decreases the thermal conductivity, while the electrical conductivity and Seebeck coefficient are increased by the Fermi level downshift. As a result, the maximum figure of merit is 2.76 × 10^–3, which is approximately four orders of magnitude larger than that of the undoped fibers throughout the temperature range. Moreover, the room temperature power factor is shown to increase up to 624 μW·m^–1·K^–2, which is higher than that of any other material solely composed of carbon nanotubes and graphene. The enhanced thermoelectric properties indicate the promising potential for graphene fibers in wearable energy harvesting systems.

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柔性可穿戴电子设备与出色的热电性能结合使用，将成为未来能量收集系统的有希望的候选者。石墨烯及其宏观组装体（例如，基于石墨烯的纤维和薄膜）因其非凡的电气和机械性能而成为众多研究的主题。然而，由于它们的高固有热导率，这些组件尚未被认为适合于热电应用。在这项研究中，溴掺杂被证明是显着增强石墨烯纤维热电性能的有效方法。掺杂由于缺陷增加而增强了声子散射，从而降低了热导率，而电导率和塞贝克系数则通过费米能级的下移而增加。^–3，在整个温度范围内比未掺杂的光纤大约大四个数量级。此外，室温功率因数显示增加到624μW·m ^–1 ·K ^-2，这比仅由碳纳米管和石墨烯组成的任何其他材料的室温功率因数都高。增强的热电性能表明，石墨烯纤维在可穿戴式能量收集系统中具有广阔的发展前景。

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