Strain effect on the thermal transport property of gamma (γ)-graphyne

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.

Keywords:

• Thermal transport
• phonon
• graphyne
• graphene

Additional information

Funding

This work is supported by the Scientific Research Fund of Hunan Provincial Education Department (Grant No. 20A449) and Scientific research projects of Shaoyang science and Technology Bureau (Grant No. 2020GZ90).