http://dx.doi.org/10.1166/jctn.2014.3568
Nano- to micron-sized monolayered materials of both carbon (graphene)
and silicon (silicene) were modeled with molecular dynamics. Graphene
was modeled using an optimized parameterization of the Tersoff
potential, while silicene was modeled using parameterizations of the
Tersoff potential
for silicon. Thermal conductivities were determined from direct
non-equilibrium molecular dynamics. The present results indicate that as
the lengths of both materials increased, the corresponding thermal
conductivities increased as well, such that graphene had far higher
thermal conductivity
than silicene across all length scales. Armchair and zigzag chiralities
in both graphene and silicene had no significant differences in thermal
conductivities, given the fact that these monolayered materials were
modeled with infinite widths. Graphene was found to possess
significantly higher
thermal conductivities than silicene at every length scale and
chirality, and this can be attributed to the higher phonon group
velocities of the dominant acoustic modes in graphene, shown through
studies on the vibrational density of states and the phonon dispersion
curves.