Tuning the electronic properties of Stone-Wales defected graphene using uniaxial longitudinal and horizontal strain: A first-principles study

Abstract

We investigated the influence of horizontal and longitudinal strain on the electronic proprieties of Stone-Wales defected honeycomb graphene structure using the density functional theory. Tensile and compressive uniaxial strains were independently applied on the armchair (horizontal) and the zigzag (longitudinal) directions of a defected honeycomb graphene monolayer. We found the responses of the band gap are dependent on the applied strain direction. Likewise, the induced band gap openings show evident correlations between Stone-Wales defect orientations and the applied strain directions. Our results show that by choosing the strain values and directions the band gap values can be precisely achieved. Additionally, the effects of the applied strain were calculated and analyzed for the Fermi level, work function and the charge distributions. For both the defect-free and the defected samples, Fermi level shifts up in response to the compressive strain while it shifts down in response to the tensile strain. Our study shows the electronic properties are significantly affected by the alignment between the Stone-Wales C-C middle bond orientation and the applied stain direction. Finally, we hope providing a precise tuning for the electronic properties of defected graphene will allow for future nanodevice applications.