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

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.

Single layers and multilayers of GaN and AlN in square-octagon structure: Stability, electronic properties, and functionalization

“…Meanwhile, important optoelectronic applications [1] of 3D wz-GaN and wz-AlN rendered the synthesis of 2D SL AlN and GaN a priority study. Eight years after its first prediction [4], Tsipas et al [28] have demonstrated the epitaxial growth of ultrathin hexagonal h-AlN on Ag(111) substrate. More recently, Balushi et al [29] achieved the growth of one-to two-layer 2D h-GaN on SiC(0001) surface via graphene encapsulation method.…”

“…After the synthesis of graphene [3], questions have been raised as to whether group IV elemental and group III-V compound semiconductors can form stable single-layer (SL) graphenelike structures, despite the fact that they do not have layered structures like graphite. As early as in 2005, theoretical studies based on the total energy minimization have shown that, in fact silicon, GaN, GaAs, and AlN can form stable, SL structures in honeycomb structure with twodimensional (2D) hexagonal (h) lattice [4]. Motivated with this result, extensive studies based on ab initio density functional theory (DFT) calculations of total energy, phonon, and finitetemperature molecular dynamics calculations demonstrated that SL silicene [4,5], germanene [5], group IV-IV and III-V compounds [4,[6][7][8], as well as group II-VI compounds like ZnO [9], can form stable, free-standing, SL structures.…”

“…As early as in 2005, theoretical studies based on the total energy minimization have shown that, in fact silicon, GaN, GaAs, and AlN can form stable, SL structures in honeycomb structure with twodimensional (2D) hexagonal (h) lattice [4]. Motivated with this result, extensive studies based on ab initio density functional theory (DFT) calculations of total energy, phonon, and finitetemperature molecular dynamics calculations demonstrated that SL silicene [4,5], germanene [5], group IV-IV and III-V compounds [4,[6][7][8], as well as group II-VI compounds like ZnO [9], can form stable, free-standing, SL structures. Now, silicene and germanene can be grown on metal substrates [10][11][12].…”

First-principles investigation of pentagonal and hexagonal core-shell silicon nanowires with various core compositions

“…Moreover, Jang et al 56 have investigated magnetic properties of Fe-, Co-and Ni-doped infinite silicon nanotubes with hexagonal prism structure for two different numbers of dopants. Likewise, Durgun et al 21 have explored whether various structures doped with TM atoms in the pursuit of finding the energetically most favorable units can be generated by stacking of triangle, pentagons, or hexagons of Si.…”

“…Moreover, contact metals might account as an alternative to traditional doped source-drain device structures where one suffers from fundamental problems such as high leakage current and parasitic resistance arise from the sub-100 nm range scaling. On the contrary, silicon nanowire, 17 or nanotube [18][19][20][21][22] itself might be incorporated as nanocontact structure. Although the stability of various silicon nanotubes ͑SiNTs͒ has been verified from computational studies, [18][19][20][21][22] and energetics of SiNTs, for example dependence of strain energy on the tube diameter and chirality, is studied in detail, 23 it is very difficult to realize them experimentally because of sp 3 hybridization tendency of silicon in SiNTs.…”