Biaxial strain effects on the electronic properties of silicene: the density-functional-theory-based calculations

The effects of biaxial strain on the electronic properties of silicene are studied by carrying out the density-functional-theory (DFT) calculations. We simulate planar and buckled structures and find that the buckled structure is more stable than the planar one. We next apply biaxial strain up to 12% and find that the applied tensile and compressive strains below 8% do not change the electronic structure. At tensile strains of 8% or more, the Dirac point at K-point shifts up from the Fermi level, indicating that such tensile strain behaves as p-type doping. Meanwhile at the compressive strains of 8% or more, the Dirac point at K-point shifts down from the Fermi level, indicating that the such compressive strain behaves as n-type doping. We find that silicene remains stable for the applied strain up to 12%. We also calculate the Fermi velocity around K-point, which is found to be 9.1 × 10⁵ m/s.