Strain engineering for ZnO nanowires: First-principle calculations

We employ density-functional theory to investigate the strain engineering for infinitely long [0001] ZnO nanowires with rectangular cross sections. The structural and electronic properties of ZnO nanowires with uniaxial, lateral and shear strain are systemically calculated. The results show that the band-gaps of ZnONWs will decrease (increase) with increasing (decreasing) tensile (compressive) uniaxial strain. The tensile (compressive) lateral strain on {10 1̅0} surfaces will improve (reduce) the band-gaps for ZnONW with clearly nonlinear characteristic, while the change trend of band-gaps for ZnONW with lateral strain on {1 2̅10} surfaces is basically opposite. When we enhance shear strain on ZnONWs, the band-gaps are reduced. The increasing shear strain along [10 1̅0] direction will sharply reduce the band-gap and the curve is nonlinear, while the band-gap decreases nearly linearly with the increase of shear strain along [1 2̅10] direction.