Thermal conductivity of the popgraphene monolayer tailored by strain and defect: A molecular dynamics study

Abstract

As a new carbon allotrope, popgraphene comprising of 5-8-5 carbon rings has attracted great attention due to its extraordinary properties for its promising device applications, including the next-generation high-performance electronics, nano-electromechanical (NEMS) systems as well as nanocomposites. Herein, the thermal properties of popgraphene have been systematically studied via reverse non-equilibrium molecular dynamic and phonon spectrum analysis, focusing on size, strain, temperature, and defect effects. The in-plane thermal conductivity along the zigzag (x) direction is much higher than that along the armchair (y) direction at the same length, indicating a strong anisotropy. The thermal conductivity can be modulated by external strain, and it has a ∼T-0.37 dependence on temperature from 100 to 500 K. Additionally, the existence of defect can significantly decrease the thermal conductivity due to the suppressed in-plane phonon vibration in the high-frequency region. The findings provide helpful guidance in modulating the thermal conductivity of popgraphene, which is important for thermal management in NEMS applications.