Electronic Structure Control of Sub-nanometer 1D SnTe via Nanostructuring within Single-Walled Carbon Nanotubes

Abstract

Nanostructuring, e. g., reduction of dimensionality in materials, offers a viable route toward regulation of materials electronic and hence functional properties. Here, we present the extreme case of nanostructuring, exploiting the capillarity of single-walled carbon nanotubes (SWCNTs) for the synthesis of the smallest possible SnTe nanowires with cross sections as thin as a single atom column. We demonstrate that by choosing the appropriate diameter of a template SWCNT, we can manipulate the structure of the quasi-one-dimensional (1D) SnTe to design electronic behavior. From first principles, we predict the structural re-formations that SnTe undergoes in varying encapsulations and confront the prediction with TEM imagery. To further illustrate the control of physical properties by nanostructuring, we study the evolution of transport properties in a homologous series of models of synthesized and isolated SnTe nanowires varying only in morphology and atomic layer thickness. This extreme scaling is predicted to significantly enhance thermoelectric performance of SnTe, offering a prospect for further experimental studies and future applications.

Thermoelectric Properties of InA Nanowires from Full-Band Atomistic Simulations

“…Since the pioneering work by Hicks and Dresselhaus, efforts have also been focused on utilizing the sharp features in the low-dimensional density-of-states to improve the power factor as well [17,18]. Theoretical studies on the thermoelectric power factor of NWs showed that one-dimensional (1D) modes could provide power factor improvements even up to 30% [19][20][21][22]. Experimentally, however, this has not yet been achieved, because to observe the true 1D nature, one needs to consider NW diameters down to a few nanometers (as in the case of Si) [23].…”

Two-dimensional nanomaterials: fascinating materials in biomedical field

“…B NSs with single-atom thickness have attracted great interest due to its extraordinarily optical, electronic, thermal and anisotropic mechanical properties [149]. As for SnTe NSs material, it has been considered as an ideal substitute for narrow bandgap nanomaterials with low toxicity and NIR optical activity [150]. In the following part, we will introduce biomedical applications of AM, B NSs and SnTe NSs respectively.…”

Exploring Chemical Bonding in Phase‐Change Materials with Orbital‐Based Indicators

“…One of many directions is given by so‐called “encapsulated PCMs,” where ultra‐small structures are confined within carbon nanotubes, and where other structural motifs and guiding principles may be present than in the known bulk phases. This has been computationally studied, for example, for the case of GeTe and the heavier homologue SnTe where experimental TEM images are available for comparison. In these systems, it would now be interesting to compare the bonding (that is, that of close atomic contacts within the ultrathin PCM wires) to the bonding situation in the bulk.…”