Tuning Phosphorene Nanoribbon Electronic Structure through Edge Oxidization

Molecular orbital theory predicts that interactions between lone-pair electrons give rise to van der Waals forces between layers due to the nonequivalent hybridization in bulk black phosphorus. First-principles calculations show that phosphorene nanoribbons (PNRs) have a high activity and can be bonded easily with oxygen atoms and hydroxyl groups, indicating that the PNRs can be oxidized easily. The cliff PNR configuration can be maintained when it is passivated with hydroxyl groups, indicating that it could be stable in a strong alkaline environment. Upon oxidation of their zigzag, armchair, and cliff edges, phosphorene nanoribbons can be changed from semimetallic to semiconducting, and the band gap can be changed from direct to indirect. OHO- [(OH + O)-] and OH- [(O + H)-] passivated PNRs have intrinsic spin magnetic moments of approximately 2.00 μ_B, which originate from the edge unsaturation electrons and the symmetry reduction. Therefore, oxidized PNRs might have potential applications in photoelectronic and spinelectronic devices.