Transport Mechanism of B/P Codoped Armchair Graphene Nanoribbons

Based on the nonequilibrium Green's function method combined with density functional theory, a nanoscale tiny diode is designed by doping B and P in armchair graphene nanoribbons (AGNRs). Moreover, the mechanism of its rectification may be explored by the analysis of transmission spectrum and energy band. The analysis of simulation data shows that the relationship between rectification and transmission peak at -0.25 eV is very close, and the broadening and disappearance of the peak may be explained by the local device density of states (DOS) and electrostatic difference potential. In addition, the eigenstates of the highest occupied molecular orbital and the lowest unoccupied molecular orbital under different bias voltages also explain the change of the transmission spectra. Moreover, the occurrence of rectification also can be ascribed to the difference of effective mass between E
_v
and E
_c
and distinctive position of π and π* in band structure.