Chiral vectors-tunable electronic property of MoS2 nanotubes

Abstract

It has been demonstrated that the mechanical and electronic properties of materials change significantly when the external dimension are confined to the nanoscale. Consequently, one-dimensional (1D) transition-metal dichalcogenide (TMDC) nanotubes (NTs), obtained from scrolling two-dimensional (2D) TMDC, have attracted much attentions because of their intriguing properties wherein the chirality of NTs plays a key role in affecting the electronic properties. Taking into the amount of speculations on the mechanism and the increasing needs for better device design and performance control, understanding the effect of chirality on the electronic properties is timely and relevant. Here, MoS 2 NTs are comprehensively studied by first-principles calculations. The results show that the armchair (6ch14) exhibits the indirect-band-gap and zigzag (10ch20) with direct-band-gap. Moreover, the carrier mobility is enhanced with the decrease of radial length, in accord with the smaller effective mass of hole and electron for both types NTs. Finally, the formation energy showed that the smaller the radial diameters is, the harder the NTs is to form. Moreover, the similarity of lattice parameters and formation energy implies a potential possibility of transition between two types of NTs with low index chiral vectors, such as ANT(6,6)/ZNT(10,0).

Transistor properties of relatively small-diameter tungsten disulfide nanotubes obtained by sulfurization of solution-synthesized tungsten oxide nanowires

“…Moreover, theoretical studies have suggested that the band structure of WS 2 nanotubes changes depending on their diameter (less than ∼17 nm) due to a curvature effect and low dimensionality. 9) Therefore, WS 2 nanotubes with small diameters are advantageous for their tunable band gap, 9) carrier mobility, 12,13) and thermoelectric properties. 11) Thus, it is important to develop a technique to prepare WS 2 nanotubes with small diameters for device applications.…”

Sorting Transition-Metal Dichalcogenide Nanotubes by Centrifugation

“…Thin nanotubes with a small diameter and few walls have great advantages for applications. , For instance, nanotubes with a small diameter can improve mechanical properties because they can endure a larger breaking strain . Additionally, theoretical studies suggested that small diameter nanotubes have a one-dimensional band structure due to quantum confinement, and we can tune the bandgap and enhance carrier mobility . However, the one-dimensional nature of TMDC nanotubes has not been revealed yet because of difficulties in the synthesis of thin nanotubes with a uniform diameter and wall number. − It is important to develop a technique to prepare nanotubes with thin diameters in a relatively small distribution.…”

MoS2-based nanostructures: synthesis and applications in medicine

“…Not surprisingly, chirality also influences the properties of MoS 2 nanotubes, such as electronic property which could be tuned by chiral vectors [71]. Mechanical and electronic properties of monolayer MoS 2 are also affected by the chiral vectors [72,73].…”