Doping effects on the electronic properties of armchair phosphorene nanoribbons: A first-principles study

On the basis of first-principles density functional theory, the different electronic structures of marginal or central doped armchair phosphorene nanoribbons with various species were calculated. It was found that the bonds between the foreign atoms and the adjacent P atoms are energetically more stable for central doping. The electronic properties of the doped ribbons are strongly related to the valence electron number of foreign atoms. B-, N-, F-, Al-doped (type Ⅰ) armchair phosphorene nanoribbons remain nonmagnetic semiconductors. The bandgap of the central doped nanoribbons is larger than that of the marginal doped nanoribbons. C, O, Si, S doping (type Ⅱ) at the edge introduce about 1 μB delocalized magnetic moment, while significantly decreasing for central doping, which is associated with electron transferring from foreign atoms to neighboring P atoms. The magnetism introduced by type Ⅱ dopants is provided by multiple orbits between the foreign atoms and the adjacent P atoms and delocalized on the edge for marginal doping. These results prove that the presence and the location of isolated electrons are both important factors for modulation of magnetic properties of armchair phosphorene nanoribbons through substitutional doping.