Abstract

Graphyne, a new two-dimensional carbon allotrope containing both sp and sp² hybridized states, is a current topic of focus in nanomaterial research community. Taking gamma (γ)-graphyne as an example, we investigate the stain effect on its thermal transport properties by using the nonequilibrium Green’s function approach. The results show that the thermal conductance can be modulated continuously and reversibly by varying the strength and direction of applied stain. Though analysis the phonon dispersion, we found that the reduction of thermal conductance is mainly attributed to the depression of phonon branches and decreasing of group velocity. In addition, the discrepancy between our results and molecular dynamic simulations is also discussed. It reveals the importance of anharmonic effect on the thermal transport property of stained γ-graphyne. The findings could shed light on the possibility of using strain to tuning the thermal conductance of γ-graphyne and thus improve its thermoelectric performance.

摘要

Graphyne，一种同时包含sp和sp ²的新型二维碳同素异形体 杂化状态，是纳米材料研究界关注的当前话题。以伽玛（γ）-石墨烯为例，我们通过非平衡格林函数方法研究了污渍对其热传递性质的影响。结果表明，通过改变所施加污渍的强度和方向，可以连续和可逆地调节热导率。通过分析声子的色散，我们发现热导率的降低主要归因于声子支路的凹陷和群速度的降低。此外，还讨论了我们的结果与分子动力学模拟之间的差异。它揭示了非调和作用对染色的γ-石墨烯的热输运性质的重要性。