Equilibrium Molecular Dynamics (MD) Simulation Study of Thermal Conductivity of Graphene Nanoribbon: A Comparative Study on MD Potentials

The thermal conductivity of graphene nanoribbons (GNRs) has been investigatedusing equilibrium molecular dynamics (EMD) simulation based on Green-Kubo (GK)method to compare two interatomic potentials namely optimized Tersoff and 2nd generationReactive Empirical Bond Order (REBO). Our comparative study includes the estimation ofthermal conductivity as a function of temperature, length and width of GNR for both thepotentials. The thermal conductivity of graphene nanoribbon decreases with the increase oftemperature. Quantum correction has been introduced for thermal conductivity as a functionof temperature to include quantum effect below Debye temperature. Our results show that fortemperatures up to Debye temperature, thermal conductivity increases, attains its peak andthen falls off monotonically. Thermal conductivity is found to decrease with the increasinglength for optimized Tersoff potential. However, thermal conductivity has been reportedto increase with length using 2nd generation REBO potential for the GNRs of same size.Thermal conductivity, for the specified range of width, demonstrates an increasing trend withthe increase of width for both the concerned potentials. In comparison with 2nd generationREBO potential, optimized Tersoff potential demonstrates a better modeling of thermal Electronics 2015, 41110 conductivity as well as provides a more appropriate description of phonon thermal transportin graphene nanoribbon. Such comparative study would provide a good insight for theoptimization of the thermal conductivity of graphene nanoribbons under diverse conditions.