Electronic structure and magnetic properties of N monodoping and (Ag,N) codoped graphene-like ZnO sheet

We perform first principles density functional theory calculations to investigate the atomic structures, electronic structures and magnetic properties of dopant complexes involving Ag and N in graphene-like ZnO sheet (Gr-ZnO). The results indicate that monodoping of N in Gr-ZnO favours a spin polarised state. Ag substituted on the cation site (Ag-Zn) acts as a single acceptor and exhibits a strong attractive interaction with a nitrogen acceptor located at the nearest neighbour oxygen site, forming passive Ag-N complex. By introducing a higher concentration of nitrogen, Ag-2N complex forms. The ferromagnetism is decreased, but the formation energy can be evidently reduced for the defective system. Our findings suggest that (Ag, N) codoping of Gr-ZnO could turn the ferromagnetic stability and is likely to yield better p-type conductivity.