Zhou Jing, Yang Kunming, Yang Bihuan, Zhong Boan, Yao Songsong, Ma Youcao, Song Jian, Fan Tongxiang, Tang Dawei, Zhu Jie, Liu Yue
School of Energy and Power Engineering, Key Lab of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian 116024, China.
State Key Lab of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
ACS Appl Mater Interfaces. 2022 Aug 3;14(30):35237-35245. doi: 10.1021/acsami.2c07796. Epub 2022 Jul 25.
As a typical two-dimensional material, graphene (Gr) has shown great potential to be used in thermal management applications due to its ultrahigh in-plane thermal conductivity (). However, low interface thermal conductance (ITC) between Gr and metals to a large extent limits the effective heat dissipation in Gr-based devices. Therefore, having a deep understanding on heat transport at Gr-metal interfaces is essential. Because of the semimetallic nature of Gr, electrons would possibly play a role in the heat transport across Gr-metal interfaces as heat carriers, whereas, However, how much the electron can participate in this process and how to optimize the total ITC considering both electron and phonon transportations have not yet been revealed yet. Therefore, in this work, hydrogenation-treated Gr (H-Gr) was sandwiched by nickel (Ni) nanofilms to compare with the samples containing pure Gr for investigating the interfacial electron behaviors. Moreover, both Gr and H-Gr sets of the samples were prepared with different layer numbers () ranging from 1 to 7, and the corresponding ITC was systematically studied based on both time-domain thermoreflectance measurements and theoretical calculations. We found that a larger ITC can be obtained when is low, and the ITC may reach a peak value when is 2 in certain circumstances. The present findings not only provide a comprehensive understanding on heat transport across Gr-metal interfaces byconsidering a combined effect of the interfacial interaction strength, phonon mode mismatch, and electron contributions, but also shed new lights on interface strucure optimiazations of Gr-based devices.
作为一种典型的二维材料，石墨烯（Gr）因其超高的面内热导率，在热管理应用中展现出了巨大潜力。然而，Gr与金属之间较低的界面热导率（ITC）在很大程度上限制了基于Gr的器件中的有效散热。因此，深入了解Gr-金属界面处的热传输至关重要。由于Gr的半金属性质，电子可能作为热载体在跨越Gr-金属界面的热传输中发挥作用，然而，电子在这个过程中能够参与多少以及如何在考虑电子和声子传输的情况下优化总ITC尚未得到揭示。因此，在这项工作中，氢化处理的Gr（H-Gr）被镍（Ni）纳米膜夹在中间，以与含有纯Gr的样品进行比较，从而研究界面电子行为。此外，Gr和H-Gr两组样品均制备了层数（）从1到7不等的不同样品，并基于时域热反射测量和理论计算系统地研究了相应的ITC。我们发现，当较低时可以获得更大的ITC，并且在某些情况下，当为2时ITC可能达到峰值。本研究结果不仅通过考虑界面相互作用强度、声子模式失配和电子贡献的综合效应，对跨越Gr-金属界面的热传输提供了全面的理解，而且为基于Gr的器件的界面结构优化提供了新的思路。
