DFT study of electronic and magnetic properties of bare and substitutionally doped ZnO nanoribbons

First-principles calculations were carried out on electronic and magnetic properties of zinc oxide nanoribbons doped with 3d transitional metals with both zigzag and armchair edges. Bare armchair ZnO nanoribbons (aZnONRs) are nonmagnetic semiconductors whereas bare zigzag ZnO nanoribbons (zZnONRs) are metallic magnets. However, when zigzag edges are passivated with hydrogen, degeneracy between the up and down spin was found, which turns ribbons into nonmagnetic ones. The magnetization of the 3d-TM-impurity-doped aZnONRs and zZnONRs is configuration dependent. The band gap and carrier concentration of aZnONRs can be tuned by 3d-TM doping.