Magnetic and optoelectronic modification of graphene-like ZnO monolayer by doping of Ag, Au and Pt atoms

Abstract

The magnetic and optoelectronic properties of graphene-like ZnO monolayers (g-ZnO) doped with noble metal elements (NME: Ag, Au, and Pt) were investigated using density functional theory. It shows that the doping of NMEs can transfer the g-ZnO into magnetic material, regulate the band structure, decrease the band gap and the work function, making the g-ZnO semi-metallic. Consider the magnetic coupling of the dopant atoms, as the distance between two same doping atoms (Au or Pt) increases, the g-ZnO undergoes nonmagnetic to ferromagnetic or ferromagnetic to antiferromagnetic transitions. Additionally, the absorption spectrum demonstrates a red-shift phenomenon, expanding the absorption range of g-ZnO to the visible region. These promote the applications of NME-doped g-ZnO in spintronic devices and photocatalytic degradation. • Graphene liked ZnO monolayers (g-ZnO) doped with noble metal elements are studied by DFT calculations. • Ag, Au and Pt doping regulates the band structure, decreases the band gap and work function. • Ag, Au and Pt doping causes the g-ZnO magnetically transformed and shows semi-metallicity. • The magnetic coupling type of two doping atoms can be regulated by changing the distance between them. • Ag, Au and Pt doping expands the absorption region of g-ZnO into the visible light.