Thermal transport engineering in amorphous graphene:Non-equilibrium molecular dynamics study

摘要

Thermal conductivity of amorphous graphene was investigated using non-equilibrium molecular dynamics (NEMD) method for structures with different defect concentrations (up to 54%) and under various tensile strains (up to 0.12). Although the sensitivity of amorphous graphene to the imposed strain was found to be lower than that for single crystalline graphene, it was observed that the thermal conductivity decreases for both structures by increasing the strain. By considering hybrid pristine/amorphous graphene coplanar structure, the influence of defects distribution on thermal transport was investigated and it was shown that there exists no clear sign of Kapitza thermal resistance at their interface. The effect of temperature (300-700 K) on the thermal conductivity of amorphous and single crystalline graphene was also studied. It was observed that the variation of thermal conductivity with temperature for single crystalline graphene is more considerable than that of amorphous graphene. We finally discussed the underlying mechanism for thermal conductivity suppression in amorphous graphene by calculating the atomic bond length and phonon power spectra.