Effects of mass and interaction mismatches on in-plane and cross-plane thermal transport of Si-doped graphene
Effects of mass and interaction mismatches on in-plane and cross-plane thermal transport of Si-doped graphene
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DOI：
10.1016/j.ijheatmasstransfer.2021.120979
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发表时间：
2021-04
影响因子：
5.2
通讯作者：
Yu-Kai Weng;A. Yousefzadi Nobakht;Seunghan Shin;K. Kihm;D. Aaron
中科院分区：
文献类型：
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作者：
Yu-Kai Weng;A. Yousefzadi Nobakht;Seunghan Shin;K. Kihm;D. Aaron
通过分子动力学模拟研究了硅掺杂对悬浮和二氧化硅（SiO2）负载石墨烯的面内和跨面热输运的影响。由于原子质量的大失配以及与相邻碳原子的相互作用，Si可以充当有效的声子散射体，从而抑制热输运。在这项研究中，我们评估的贡献的质量和相互作用失配的Si掺杂剂的减少在平面内的热导率和跨平面热阻通过系统控制的掺杂剂的属性。2%的Si掺杂由于增加的散射而使悬浮石墨烯的面内传输减少约94%，而SiO2支撑的石墨烯受到的影响较小。Si对声子散射随Si含量的增加而线性增加，相互作用失配对声子在面内输运过程中的动力学影响大于质量失配。相比之下，通过Si掺杂增强了跨平面输运，使界面热阻降低约30%，因为较弱的面内键合和较小的与衬底材料的原子质量失配导致了较强的界面相互作用。从这项研究中增强了对掺杂对热传输影响的理解，预计将为各种石墨烯结构中的有效热传输控制提供见解。
The effects of silicon (Si) doping on the in-plane and cross-plane thermal transport of suspended and silicon dioxide (SiO2) supported graphene were investigated via molecular dynamics simulations. Due to the large mismatch in atomic mass and interaction with neighboring carbon atoms, Si can act as an effective phonon scatterer, thus suppressing the thermal transport. In this study, we evaluated the contributions of mass and interaction mismatches of Si dopants to the reduction in the in-plane thermal conductivity and the cross-plane thermal resistance through systematic control of the dopant's properties. 2% Si doping reduces the in-plane transport of suspended graphene by ~94% due to the increased scattering, while the SiO2-supported graphene is less affected. The phonon scattering by Si linearly increases with the Si content, and the interaction mismatch has a greater influence on the phonon kinetics during in-plane transport than the mass mismatch. In contrast, the cross-plane transport is enhanced by Si doping, decreasing the interfacial thermal resistance by ~30%, because of the stronger interfacial interactions by weaker in-plane bonding and the smaller atomic mass mismatch with the substrate material. The enhanced understanding of doping effects on thermal transport from this research is expected to provide insights for effective thermal transport control in various graphene structures.