Molecular Dynamics Study of Hypothetical Silicon Nanotubes Using the Tersoff Potential

Structure and Energetics of Single-Walled Armchair and Zigzag Silicon Nanotubes

“…The bond lengths between neighboring silicon atoms in the remaining structures varied little among the nanotubes, averaging 2.245 Å. This is significantly less than the bulk-silicon bond length of 2.352 Å, as expected, and is in excellent agreement with the values on 2.245 Å calculated by Fagan et al, 2.25 Å calculated by Zhang et al, and 2.305 Å calculated by Kang et al The diameters of 7.48 Å and 9.96 Å for the (6,0) and (8,0) SiNTs, respectively, were however slightly over those reported by Fagan et al of 7.44 Å and 9.92 Å, respectively.…”

“…Theoretical predictions have also been made of the electronic structure and stability of GaSe, GaN, and P nanotubes, as well as various fullerenic and tubular silicon structures. − The ab-initio electronic, structural, and thermal properties of “hypothetical” infinite SiNTs have been compared with CNTs by Fagan et al , More recently, Zhang et al have compared the electronic structure of a finite silicon nanotube with a comparable silicon nanowire and carbon nanotube, while the structure and thermal behavior of silicon nano-cages and nanotubes have been investigated by Kang et al using classical molecular dynamics with the Tersoff potential. The results indicate that, under appropriate conditions, SiNT structures may be stable.…”

Stabilizing Zigzag Single-Walled Silicon Nanotubes and Tailoring the Electronic Structures by Oxygen Atoms: First-Principles Studies

“…However, silicon atoms favor the formation of sp 3 hybridization and, accordingly, promote the formation of silicon nanowires and thick-walled single-crystalline nanotubes. − The pristine SWSiNTs built analogously to carbon nanotubes consist of threefold coordinated silicon atoms along with dangling bonds and are thus less stable. This has been confirmed by various theoretical works. − Hydrogen atoms or metal cations were used to stabilize the SWSiNTs by saturating the dangling bonds on the tube walls. , …”

Faceted Silicon Nanotubes: Structure, Energetic, and Passivation Effects

“…The faceted DWSiNTs (as shown in Figure d,e) are energetically more favorable than this SiNW by about 0.078 eV/atom. In view of the recent experimental progresses in synthesizing SiNWs with diameter as small as 13.0 Å [6], these faceted DWSiNTs can therefore quite possibly be fabricated in future experiments as metastable forms of Q1D silicon nanostructures, although they still have high formation energies and the tendency to become nanowires at high temperature 3 Band structures of pristine (a) h -DWSiNT and (b) t -DWSiNT and hydrogen-passivated (c) h -DWSiNT and (d) t -DWSiNT along (0,0,0) π /a − X (0,0,1) π/ a direction.…”

“…Quasi-one-dimensional (Q1D) silicon nanostructures, i.e., silicon nanowires (SiNWs) and silicon nanotubes (SiNTs), are currently attracting great interest − as promising building blocks for the “bottom-up” approach to future nanoscale devices. − Particularly exciting are their potential applications in optical and photonic devices that are impossible for bulk silicon. Different from carbon atom, the favorable formation of sp 3 hybridization in silicon atoms promotes the formation of SiNWs rather than single-walled silicon nanotubes (SWSiNTs). − This was also confirmed by the high formation energies of the cylindrical SWSiNTs characterized analogously as carbon nanotubes (CNTs) , or rolling Si(111) sheets − with respect to the bulk silicon in diamond structure. In the conventionally used models of pristine SWSiNTs, each silicon atom is threefold coordinated, facilitating the formation of a dangling bond.…”