Ultra high stiffness and thermal conductivity of graphene like C3N

Abstract

Recently, single crystalline carbon nitride 2D material with a C3N stoichiometry has been synthesized. In this investigation, we explored the mechanical response and thermal transport along pristine, free-standing and single-layer C3N. To this aim, we conducted extensive first-principles density functional theory (DFT) calculations as well as molecular dynamics (MD) simulations. DFT results reveal that C3N nanofilms can yield remarkably high elastic modulus of 341 GPa nm and tensile strength of 35 GPa nm, very close to those of defect-free graphene. Classical MD simulations performed at a low temperature, predict accurately the elastic modulus of 2D C3N with less than 3% difference with the first-principles estimation. The deformation process of C3N nanosheets was studied both by the DFT and MD simulations. Ab initio molecular dynamics simulations show that single-layer C3N can withstand high temperatures like 4000 K. Remarkably, the phononic thermal conductivity of free-standing C3N was predicted to be as high as 815 ± 20 W/mK. Our atomistic modelling results reveal ultra high stiffness and thermal conductivity of C3N nanomembranes and therefore propose them as promising candidates for new application such as the thermal management in nanoelectronics or simultaneously reinforcing the thermal and mechanical properties of polymeric materials.