Influence of strain and electric field on the properties of silicane

Abstract

We investigate the influence of strain and electric field on the properties of a silicane sheet. Some elastic parameters of silicane, such as an in-plane stiffness of 52.55 N/m and a Poisson's ratio of 0.24, are obtained by calculating the strain energy. Compared with silicene, silicane is softer because of its relatively weaker Si—Si bonds. The band structure of silicane is tunable by a uniform tensile strain, with the increase of which the band gap decreases monotonously. Moreover, silicane undergoes an indirect—direct gap transition under a small strain, and a semiconductor-metal transition under a large strain. The electric field can change the Si—H bond length of silicane significantly. When a strong field is applied, the H atom at the high potential side becomes desorbed, while the H atom at the low potential side keeps bonded. So an external electric field can help to produce single-side hydrogenated silicene from silicane. We believe this study will be helpful for the application of silicane in the future.