Abstract:In order to prepare high-performance thermal interface materials, the thermal characteristics of three-dimensional graphene-carbon nanotube composite structure were calculated by non-equilibrium molecular dynamics method. The effects of the size of the composite structure and the temperature of the system on the thermal conductivity of the overall structure were investigated. The results showed that the increase of the length in the z direction and the increase of the temperature of the composite structure can increase the thermal conductivity of the composite structure to a certain extent and gradually reach a saturation value. In order to further investigate the phonon energy transfer in the whole and local structure, the phonon vibrational density at both sides of the interface between the composite whole and the joint was calculated. The results showed that the deformation at the interface between carbon nanotubes and graphene is the main factor that hindered the increase of the thermal conductivity of the composite structure.