石墨烯纳米带的热输运性能研究

Study on the thermal transport properties of graphene nanoribbons

基于分子动力学模拟方法,研究了本征石墨烯纳米带的尺寸效应以及存在空位、N掺杂、B掺杂缺陷时,温度、缺陷浓度和不同缺陷类型对石墨烯纳米带热输运性能的综合影响,深入研究了石墨烯纳米带的声子热输运机理。结果表明:本征石墨烯纳米带的热导率在400K时为107.0W/(m·K),且均随长度和宽度的增加而增加。当缺陷和温度混合效应存在时,由于声子散射和高频声子的激发,使热导率均会随浓度和温度的增加而下降。同时,不同缺陷类型在同一温度下,空位缺陷在低浓度时对热导率影响较大,但在高浓度时掺杂缺陷影响显著。其中N掺杂的影响强于B掺杂,这是由于不同原子的质量不同造成的。研究结果有助于调控石墨烯热输运特性,可为微纳电子器件的高效散热提供理论指导。

The molecular dynamics simulation method was used to study the effects of size,temperature,defect concentration and different types of defects with vacancy,N doping,B doping on the thermal transport properties of graphene nanoribbons.The phonon thermal transport mechanism of graphene nanoribbons was investigated in depth.The results showed that the thermal conductivity of intrinsic graphene nanoribbons was 107.0W/(m·K)at 400K,and it increased with the increase of length and width.When the mixed effect of defects and temperature existed,the thermal conductivity decreased with the increase of concentration and temperature due to the scattering of phonons and the excitation of high frequency phonons.Meanwhile,under the same temperature,for different types of defects,the vacancy defects had a great effect on the thermal conductivity at low concentration,but the doping defects had a significant effect at high concentration.The effect of N doping defect was stronger than B doping defect,which was due to the different masses of different atoms.The results are helpful to regulate the thermal transport properties of graphene and provide theoretical guidance for efficient thermal dissipation of micro and nano electronic devices.