▎ 摘　　要

Near-infrared plasmons in N-doped hexagonal graphene nanostructures were investigated using time-dependent density functional theory. Along a certain direction, N-doped hexagonal graphene nanostructures with a side length of 1 nm have more intense plasmon resonances throughout the near-infrared spectral region. The electrons that participate in these near-infrared plasmon resonances oscillate back and forth between the center and edge regions of the hexagonal nanostructures. The formation of a near-infrared plasmon resonance mode depends on the nitrogen-doping position and the scale size of the graphene nanostructure. It is only when the nitrogen-doped location is close to the edge of the nanostructures, near-infrared plasmon resonance mode of the graphene nanostructure will be formed. For N-doped hexagonal graphene nanostructures with a side length of less than 1 nm, there is no plasmon resonance in the nearinfrared spectral region.