几何尺寸及缺陷对石墨炔纳米带热输运特性的影响

Influence of geometrical dimensions and defects on the thermal transport properties of graphyne nanoribbons

基于分子动力学模拟方法,对石墨炔纳米带(GYNR)的热输运特性进行了深入研究,重点探讨了几何尺寸、缺陷类型及缺陷的位置(水平方向和垂直方向、苯环与乙炔链)和排列方式等对声子热输运的影响规律,揭示并分析了其声子热输运调控机理。研究结果表明,理想GYNR的热导率仅为18.22 W/(m·K),且相比于石墨烯,GYNR随尺寸增大热导率仅升至21.37 W/(m·K),对几何尺寸依赖较小;对于缺陷类型,空位缺陷的存在相比于氮掺杂对热导率抑制更强,可低至9.19 W/(m·K);对于缺陷位置,位于苯环上或靠近纳米带边界时相比于炔链热导率更低;多个缺陷若以平行分布相比于三角形结构分布可获得更低的热导率,低于8.00 W/(m·K)。研究结果可以为石墨炔材料在纳米器件的热电领域开发、应用及调控等方面提供理论支持和参考。

Based on the molecular dynamics simulation method,the thermal transport properties of graphyne nanoribbons(GYNR)are profoundly studied,focusing on the influence of geometrical dimensions,defect type and defect position(horizontal and vertical directions,benzene ring and acetylene chain),and arrangement on the phonon thermal transport,etc.,and the regulation mechanism of the phonon thermal transport is revealed and analyzed.The research results show that the ideal thermal conductivity of GYNR is only 18.22 W/(m·K).Compared with graphene,the thermal conductivity of GYNR only rises to 21.37 W/(m·K)with the increase of size.The thermal conductivity of GYRN is less dependent on the geometry size.For defect types,the thermal conductivity is suppressed more strongly in the presence of vacancy defects than nitrogen doping,which can be as low as 9.19 W/(m·K).For the location of defects,the thermal conductivity is lower when the defects are located on the benzene ring or near the nanoribbon boundary compared to the alkyne chain.If multiple defects are distributed in parallel,the thermal conductivity can lower than 8.00 W/(m·K)compared with the triangular structure distribution.The results can provide theoretical support and reference for the development,application and regulation of graphyne materials in the thermoelectric field of nano-devices.