Effects of uniaxial strain on the bandstructures of silicon nanowires

The effects of uniaxial strain on the band structures of Lt100Gt silicon nanowires of width 2.75 - 3.84 nm are studied using sp³d⁵s^* orbital basis atomistic tight binding approach. The conduction band edge at Gamma point has almost no variation with strain and the second valley located at 0.36timespi/a of the wire Brilluoin moves down in energy with both compressive and tensile strains. The top valence band moves up in energy with both tensile and compressive strain, and therefore, the band gap reduces with both types of strain. We notice about 7% change in band gap for an application of 2% strain. The electron effective masses at Delta₄ and Delta₂ valleys show opposite dependence on strain, and the hole effective mass of top valence band has almost similar variation with both types of strain. We notice a significant change in hole effective mass with strain.