Abstract Tuning thermal conductivity of porous graphenes has attracted much interest in the thermal management of nanoelectronics devices due to the promising multifunctional properties of engineered nanomaterials. To explore the potential of tuning thermal properties of monolayer porous graphenes in multiple scales, non-equilibrium molecular dynamics (NEMD) and finite element method (FEM) are implemented to manipulate their thermal conductivity and temperature distribution by the engineering of pore topology. Results indicate that the thermal conductivity of porous graphenes can be significantly lower than a pristine graphene. The thermal conductivity reduction is attributed to phonon scattering at the boundaries of defects described by the phonon density of states analysis. It is found that the thermal conductivity and the temperature distribution of a porous graphene can be desirably tuned by the simultaneous engineering of relative density, pore topology, and pore orientation. Then, the effect of unit cell periodicity on the thermal conductivity of periodic porous graphenes, called phononic graphene or graphene metamaterial, is explored. Finally, comparing the results of continuum mechanics approach through the implementation of FEM and NEMD simulation presents the advantages of NEMD for predicting the thermal conductivity of engineered porous graphenes with characteristic length of lower than 50 nm.

中文翻译：

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通过孔拓扑工程调整多孔石墨烯的热导率：非平衡分子动力学与有限元研究的比较

摘要 由于工程纳米材料具有良好的多功能特性，多孔石墨烯的热导率调节在纳米电子器件的热管理方面引起了广泛关注。为了探索在多个尺度上调整单层多孔石墨烯热性能的潜力，实施了非平衡分子动力学 (NEMD) 和有限元方法 (FEM)，通过孔拓扑工程来操纵它们的热导率和温度分布。结果表明多孔石墨烯的热导率可以显着低于原始石墨烯。热导率的降低归因于声子态密度分析所描述的缺陷边界处的声子散射。研究发现，多孔石墨烯的热导率和温度分布可以通过相对密度、孔拓扑和孔取向的同时工程进行调节。然后，探讨了晶胞周期对周期性多孔石墨烯（称为声子石墨烯或石墨烯超材料）热导率的影响。最后，通过实施 FEM 和 NEMD 模拟比较连续介质力学方法的结果，展示了 NEMD 在预测特征长度小于 50 nm 的工程多孔石墨烯的热导率方面的优势。探索了晶胞周期对周期性多孔石墨烯（称为声子石墨烯或石墨烯超材料）热导率的影响。最后，通过实施 FEM 和 NEMD 模拟比较连续介质力学方法的结果，展示了 NEMD 在预测特征长度小于 50 nm 的工程多孔石墨烯的热导率方面的优势。探索了晶胞周期对周期性多孔石墨烯（称为声子石墨烯或石墨烯超材料）热导率的影响。最后，通过实施 FEM 和 NEMD 模拟比较连续介质力学方法的结果，展示了 NEMD 在预测特征长度小于 50 nm 的工程多孔石墨烯的热导率方面的优势。