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本文提出了基于量子修正的非平衡态分子动力学模型,可用于石墨烯纳米带热导率的表征.利用该模型对不同温度下,不同手性及宽度的石墨烯纳米带热导率进行了研究,结果发现:相较于经典分子动力学模型给出的热导率随温度升高而单调下降的结论,在低于Debye温度的情况下,量子修正模型的计算结果出现了反常现象.本文研究还发现,石墨烯纳米带的热导率呈现出明显的边缘效应及尺度效应:锯齿型石墨烯纳米带的热导率明显高于扶手椅型石墨烯纳米带;全温段的热导率及热导率在低温段随温度变化的斜率均随宽度的增加而增大.最后,文章用Boltzmann声子散射理论对低温段的温度效应及尺度效应进行了阐释,其理论分析结果说明文章所建模型适合在全温段范围内对不同宽度和不同手性的热导率进行精确计算,可为石墨烯纳米带在传热散热领域的应用提供理论计算和分析依据.
In this paper, a non-equilibrium molecular dynamics model based on quantum correction is proposed, which can be used to characterize the thermal conductivity of graphene nanoribbons. The thermal conductivity of graphene nanoribbons with different chirality and width at different temperatures The results show that compared with the classical molecular dynamics model, the thermal conductivity decreases monotonously with the increase of temperature. Under the condition of Debye temperature, the results of the quantum correction model appear abnormal. The study also found that the thermal conductivity of graphene nanoribbons showed obvious edge effect and scale effect: the thermal conductivity of zigzag graphene nanoribbons was significantly higher than armchair type graphene nanoribbons; the thermal conductivity of the whole temperature range And the slope of the thermal conductivity in the low temperature range with temperature increase with the increase of the width.Finally, the Boltzmann phonon scattering theory is used to explain the temperature effect and the scale effect of the low temperature section, and the theoretical analysis results show that the article The modeling model is suitable for accurately calculating the thermal conductivity of different widths and different chirals in the whole temperature range and can provide theoretical calculations for the application of graphene nanoribbons in the field of heat transfer and heat dissipation Analytical basis.