Point defects in the silicon nanowire

The single vacancy, the interstitial atom and the substitution atom are the point defects existing in the semiconductors mainly. The geometry and the effect of point defects on the electronic property of the silicon nanowire (SiNW) were theoretically studied in this work. The energy calculation showed that the substitution-vacancy pair was an energetically favored defect formed in SiNWs. Moreover, from the electronic band structures it was found that, the coupling between a substitution atom and a vacancy takes place at a long distance. The formation of a substitution-vacancy pair results in an energy shift of the bands and the vanishment of the donor level of the doped SiNW. So, the existence of a single vacancy takes great effect on the manufacture of the doped SiNWs.