DFT calculations on the structural and electronic properties of vacancy effects in the silicon nanowires

A theoretical study was undertaken of the effects of single and multiple vacancies created at different surface sites of a non-passivated silicon nanowire (SiNW) with diameter ~11.0 Å, grown in the [001] direction. The results showed that vacancies at vertex site were most energetically favorable, due to the surface dimerization process, which was responsible for metallic or semi-metallic behavior in the perfect [001] SiNW. Modifications at wavefunction localization due surface dimerization and their consequences at electronic properties were also investigated and provided helpful information on application of these materials as gas-sensing nanodevices. Graphical abstract