Defects in Phosphorene

Abstract

Defects are inevitably present in materials and always can affect their properties. Here, first-principles calculations are performed to systematically study the stability, structural and electronic properties of ten kinds of point defects in semiconducting phosphorene, including the Stone-Wales (SW-1 and SW-2) defect, single (SV59 and SV5566) and double vacancy (DV585-1, DV585-2, DV555777-1, DV555777-2, DV555777-3 and DV4104) defects. We find that these defects are all much easily created in phosphorene with higher areal density compared with graphene and silicene. They are easy distinguish each other and correlate with their defective atomic structures with simulated scanning tunneling microscopy images at positive bias. The SW, DV585-1, DV555777 and DV4104 defects have little effect on phosphorene's electronic properties and defective phosphorene monolayers still show semiconducting with similar band gap values to perfect phosphorene. The SV59 and DV585-2 defects can introduce unoccupied localized states into phosphorene's fundamental band gap. Specifically, the SV59 and 5566 defects can induce hole doping in phosphorene, and only the stable SV59 defect can result in local magnetic moments in phosphorene different from all other defects.