Effect of Electric Field on Defected Silicene Sheet: DFT Study

Silicene, a hexagonal mesh of silicon atoms, has attracted significant interest from both academia and electronics industry because it exhibits comparable electronic characteristics as graphene, e.g. [1, 2]. silicene could be synthesized and processed using mature semiconductor techniques, but Defects are almost inevitable during the fabrication process, and their existence strongly affects thermodynamic and electronic properties of two-dimensional materials. It is proposed that absent and present of vertical electric field can open band gap in silicene [3]. The goal of the present work was comparison energy on Defects in silicene with absent and present of electric field. All our density functional theory (DFT) Calculations were carried out within the generalized-gradient approximation (GGA) for the exchange correlation functional with the parametrization of Perdew− Burke−Ernzerhof (PBE), as implemented in the Dmol3 package [4, 5]. According to our calculations for pristine silicene and its vacancies (missing atoms) V1, V2, V3, V4, V5 and V6 in absent and present of electric field, we can conclude that the double vacancies is stable structure and a vertical electric field can open a tunable band gap in silicene and its vacancies without degrading the electronic properties.