Consideration of linear topological defects in silicene through molecular dynamics and ab-initio calculations

Abstract

Defects in two-dimensional materials are of significant interest because they have a significant impacton the properties of the material. Using the molecular dynamics method and ab-initio calculations,linear topological defects in silicene are studied. Silicene has an extended honeycomb structure, atwo-dimensional hexagonal structure with two atoms per unit cell, one above and one below relativeto the plane of the sheet. Silicene can have two energetically equivalent structures, depending onwhich of the two atoms of the unit cell is located above. Topological defects are formed at the junctionof these structures. Such defects do not imply the need to break bonds and cannot disappear from thestructure otherwise than through the annihilation of such topological defects of different signs. Relaxedstructures of linear topological defects in silicene are shown, defect energies are calculated, andmolecular dynamics and ab-initio data are compared. Similar defects exist in other two-dimensionalmaterials of group IVA, such as germanene, stanene, plumben, etc. As a result of the work usingab-initio, the existence of this type of defects was confirmed and options for its experimental detectionwere suggested.