多层石墨烯纳米带的法向热传导

摘要

In order to explore the effects of cross area and junction,which may be caused during the manufacturing process,on the cross-plane thermal transport of multilayer graphene nanobundles,a calculation research is conducted by using the atomic Green’s function method,which can describe the phonon wave property and quantum effects on the nanoscale.The results show that the thermal conductance per unit area of multilayer graphene nanobundles is negatively dependent on the cross ar-ea and finally converges to the bulk value 100 MW/(m2 ·K).The reason is that the most increased parts of phonons are located in high-frequency region as the cross area increasing,while high-fre-quency phonons have lower transmission value at the interface than low-frequency phonons.In addi-tion,the results of phonon local density of states and transmission function show that the junction can change the heat conduction direction and reduce heat transport efficiency,thus decreasing the cross-plane thermal conductance.%为了探讨纳米带横截面积和制造过程中可能引起的凸起结构对多层石墨烯纳米带法向热传导的影响，采用了能够反映纳米尺度下声子波属性和量子效应的原子格林函数方法来进行计算研究。结果表明，石墨烯纳米带单位面积法向热导与横截面积呈负相关，并最终趋近于体态值100 MW／（m2·K）。造成此现象的原因是随着横截面积的增大，增加的声子支主要位于高频区域，而相对于低频声子，高频声子在界面处的透射值较小。另外，声子局域态密度和透射函数的计算结果表明，凸起会改变热流的传递方向和降低热流传递的效率，从而减小法向热导。