Electronic structures and optical properties of sulfur-passivated InAs nanowires by first-principles study

Electronic structures and optical properties of S-passivated InAs nanowires are studied by first-principles. The computation is carried out on the InAs (110) surface, which has a low surface energy and is a common side facet of 111 -oriented zinc blende InAs nanowires. Through comparing different geometrical possibilities, it is found that S atoms prefer to insert the interchain bridge site, and occupy both the interchain bridge site and bridge site, for a non-diffused half-monolayer coverage and full non-diffused monolayer coverage, respectively. The electronic energy bands shift towards lower energy region and the band gap narrows after S adsorption. The density of states near Fermi level increases after S adsorption, indicating that S adsorption can enhance the conductivity and leads to a metallic-like nanowire surface. In addition, the adsorption of S significantly improves the absorption and optical conductivity of InAs nanowires in the low frequency range.

Automated summary

The study using first-principles showed that sulfur atoms prefer to occupy the interchain bridge site in InAs nanowires, enhancing conductivity and leading to a metallic-like surface after S adsorption.