Stress-induced band gap tuning in ⟨112⟩ silicon nanowires

We show via density functional calculations that the electronic band structures of < 112 >-oriented hydrogenated silicon nanowires (SiNWs) could be significantly altered by axial stresses. In particular, an axial compression could cause an indirect-to-direct band gap transition in < 112 > SiNWs. As direct energy band may induce strong light-emission properties of Si, the possibility of indirect-to-direct band transition via axial stress has fundamental implications in exploiting SiNWs for optoelectronic applications. (c) 2007 American Institute of Physics.