Thermal Rectification in Graphene and Carbon Nanotube Systems Using Molecular Dynamics Simulations

We investigate the thermal rectification phenomena in asymmetric graphene and carbon nanotube systems using molecular dynamics (MD) simulations. The effects of various parameters, including mean temperature, temperature difference, and system size on rectification factor have been studied. In homogenous triangular graphene nanoribbons (TGNR), the heat current is normally higher from wide to narrow end than that in the opposite direction, resulting in a positive rectification factor. The rectification factor increases further for a double layered T-GNR. It is also found that varying the parameters like mean temperature can result in reverse of the sign of thermal rectification factor. In the case of carbon nanotube (CNT) silicon system, the heat current is higher when heat flows from CNT to silicon. The thermal rectification factor is almost independent of the diameter of CNT. In both cases, the rectification factor increases with the imposed temperature difference.