Giant reduction of thermal conductivity in a two-dimensional nitrogenated holey C₂N nanosheet

Thermal conductivities of monolayer holey C₂N nanosheets are investigated via equilibrium molecular dynamics simulations. As compared with graphene, the lattice thermal conductivities of C₂N decrease by two orders in magnitude, which are around 40 W m^-1 K^-1 at 300 K along both zigzag and armchair directions. The lattice dynamics calculations reveal that the reduced group velocities and shortened phonon lifetimes, due to the incorporation of nitrogen atoms and the holey structure, account for such a giant reduction in thermal conductivity. Our study also indicates that pyridinic-like nitrogen doping would be a more efficient way than graphite-like nitrogen doping to suppress the thermal conductivity of graphene.