▎ 摘　　要

A two-dimensional honeycomb lattice of graphene, if heavily doped with electrons or holes, has been predicted to possess a wealth of fascinating properties including high-temperature superconductivity. Although such a material is possible with high concentration of N or B substitution, its experimental realization has been hindered due to its dynamic instability. Using density functional theory combined with a global structural search and phonon dispersion calculations, we show that an ordered 50% N- or B-doped graphene can be made energetically and dynamically stable by simultaneous doping carriers and applying biaxial tensile strain; carrier doping moves the system toward aromaticity while tensile strain reduces adverse effects associated with electrostatic interaction. Electron-phonon coupling calculations show that the N- or B-doped graphene is superconducting with critical temperature reaching above the melting point of nitrogen in the case of 50% N-doped graphene. In addition, the ideal strength of N-doped graphene is even higher than that of pure graphene.