Silicon and III-V compound nanotubes: structural and electronic properties

TL;DR

This paper provides a theoretical analysis of silicon and III-V compound nanotubes, exploring their stability, electronic properties, and potential for spintronic applications, expanding understanding beyond carbon nanotubes.

Contribution

It introduces the stability and electronic characteristics of silicon and III-V nanotubes, including magnetic and semiconducting properties, using first-principles calculations.

Findings

Silicon nanotubes with n > 6 are stable; those with n < 6 can be stabilized by metal adsorption.

Some silicon nanotubes exhibit magnetic ground states, indicating potential for spintronics.

Stable AlP, GaAs, and GaN nanotubes are semiconducting.

Abstract

Unusual physical properties of single-wall carbon nanotubes have started a search for similar tubular structures of other elements. In this paper, we present a theoretical analysis of single-wall nanotubes of silicon and group III-V compounds. Starting from precursor graphene-like structures we investigated the stability, energetics and electronic structure of zigzag and armchair tubes using first-principles pseudopotential plane wave method and finite temperature ab-initio molecular dynamics calculations. We showed that (n,0) zigzag and (n,n) armchair nanotubes of silicon having n > 6 are stable but those with n < 6 can be stabilized by internal or external adsorption of transition metal elements. Some of these tubes have magnetic ground state leading to spintronic properties. We also examined the stability of nanotubes under radial and axial deformation. Owing to the weakness of radial restoring force, stable Si nanotubes are radially soft. Undeformed zigzag nanotubes are found to be metallic for 6 < n < 11 due to curvature effect; but a gap starts to open for n > 12. Furthermore, we identified stable tubular structures formed by stacking of Si polygons. We found AlP, GaAs, and GaN (8,0) single-wall nanotubes stable and semiconducting. Our results are compared with those of single-wall carbon nanotubes.