A self-consistent calculation of band structure in silicon nanowires using a tight-binding model

The properties of silicon nanowire (SNW), resulting from the band structure calculation using a four-orbital sp³ tight-binding method, are discussed in this paper. A number of intrinsic properties including band gap, density of states and parabolic effective masses have been derived from the computed electronic structure for different SNW widths. A self-consistent solver of coupled 3D Poisson-Schrodinger equations using the tight-binding model has been developed to analyze the effect of gate bias on the SNW band structure at room temperature. The spatial distribution of carriers in the nanowire is calculated and the impact of gate bias on subbands is discussed. Finally, effective mass model is compared to tight-binding model to assess the validity of this approximation in narrow SNW.