Ab initio study of semiconducting carbon nanotubes adsorbed on the Si(100) surface: diameter- and registration-dependent atomic configurations and electronic properties

TL;DR

This study uses first-principles calculations to explore how semiconducting carbon nanotubes interact with the Si(100) surface, revealing metallic behavior due to n-doping and how configurations depend on diameter and orientation.

Contribution

It provides detailed atomic configurations and electronic properties of semiconducting carbon nanotubes adsorbed on Si(100), highlighting the doping-induced metallicity and configuration dependence.

Findings

Adsorption causes metallicity in the combined system.

Semiconducting nanotubes are farther from the surface and transfer less charge.

Metallic nanotubes show stronger interaction and charge transfer.

Abstract

We present a first-principles study of semiconducting carbon nanotubes adsorbed on the unpassivated Si(100) surface. We have found metallicity for the combined system caused by n-doping of the silicon slab representing the surface by the SWNT. We confirm this metallicity for nanotubes of different diameters and chiral angles, and find the effect to be independent of the orientation of the nanotubes on the surface. We also present adsorption energetics and configurations which show semiconducting SWNTs farther apart from the surface and transferring less charge, in comparison with metallic SWNTs of similar diameter.