First principles study on the stability and thermodynamic properties of N[sbnd]Au co-doped graphene

Abstract

Based on first-principles density functional perturbation theory and first-principles molecular dynamics (MD) method, the effects of N and Au dopants as well as doping concentration on the structure stability, thermal stability and thermodynamic properties of graphene were systemically studied. It is found that the formation energy, phonon dispersion curve and MD simulation analysis indicate that N-doped graphene is more stable than Au and NAu co-doped graphene at the ground state or room temperature (300 K). The graphene doped with N, Au and NAu pair at different doping concentration can significantly affect its thermodynamic properties. Regardless of low or high concentrations, the specific heat and entropy of the doped graphene system increase as temperature increases, whereas free energy decreases. The results provide a theoretical basis for regulating the thermal conductivity of graphene and for relevant developing device applications.