Ab initio Energy Gap Calculations of ZnO Nanowires Based on LDA-1/2 Approach

Ab initio calculations of ZnO nanowires (NW) were performed using density functional theory within LDA-1/2, to account for the excited states energies. The effects of hydrogenpassivated and non-passivated nanowires in a range of diameters were studied. For passivated cases it was obtained a band gap of 5.5 eV for the thinnest wire (∼0.6 nm thick) and 4.0 eV for the thickest NW (∼1.6 nm) (and similar to bulk for the non-passivated). The LDA confinement was found to be superestimated if compared to LDA-1/2, which also predicts experimental band gaps of ZnO nanowires with excellent precision.