Hole doped Dirac states in silicene by biaxial tensile strain

The effects of biaxial tensile strain on the structure, electronic states, and mechanical properties of silicene are studied by ab-initio calculations. Our results show that up to 5% strain the Dirac cone remains essentially at the Fermi level, while higher strain induces hole doped Dirac states because of weakened Si-Si bonds. We demonstrate that the silicene lattice is stable up to 17% strain. It is noted that the buckling first decreases with the strain (up to 10%) and then increases again, which is accompanied by a band gap variation. We also calculate the Gruneisen parameter and demonstrate a strain dependence similar to that of graphene. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4794812]