Deformation effect on graphene quantum dot/graphane and silicene quantum dot/silicane array

Abstract

This article presents a design for the two-dimensional heterostructure systems (2DHS) consisting of graphene quantum dot (QD) array in graphane (GQD/Graphane) and silicene QD array in silicane (SiQD/Silicane). First-principles method was used to evaluate the effect of deformation on the magnetism and electronic properties of these 2DHS. For the band engineering, the tuning range of the energy gap of GQD/Graphane and SiQD/Silicane 2DHS can be up to 1.20 and 1.35 eV, respectively, through strains ranging from −7% to 10 %. A strain-sharing effect is found, wherein the hydrogenated region shares a portion of strain within the QD array. This effect is stronger in SiQD/silicane than in GQD/graphane. Strain sharing enhances band coupling between the QDs and their hydrogenated counterpart in the low-energy region. This alters the electronic properties of the 2DHS and the magnetic properties of triangular and parallelogram SiQD/Silicane arrays under large compressive strain. Strain modulates the band gap of 2DHS, triggers a phase transition from semiconductor to metal in SiQD/Silicane systems under homogeneous strain, and removes the magnetism of triangular and parallelogram SiQD arrays under compressive strain. These findings suggest that the 2DHS could be promising for designing nanoelectronic devices and binary logic based on nanoscale magnetism.