Structural, Electronic, and Mechanical Properties of Nitrogen Nanotubes: The Effect of Size and Strain

Abstract

Research on the investigation of new classes and new dimensionalities of materials has become considerably important in expanding the area of nanotechnology. Here, we investigate the structural, mechanical, and electronic properties of one-dimensional (1D) single-walled armchair and zigzag buckled nitrogen nanotubes by applying plane wave-based density functional theory calculations. We calculated the formation energy, structural parameters, Young's modulus, radial Poisson's ratio, and electronic band gap and band structures for both types of nanotubes and analyzed the change as a function of the tube radius and axial strain. The formation of armchair nanotubes is energetically favorable over that of the zigzag nanotubes. The electronic band gap increases as the size of the tube increases and decreases as the amount of strain increases. All armchair nanotubes are indirect band gap semiconductors, whereas zigzag nanotubes are direct band gap semiconductors. With a similar diameter, the Young's modulus of a zigzag nanotube is found to be higher than that of an armchair nanotube. The electronic band gap is tuned by applying both compressive and tensile strain, which is useful in nanodevice applications. Based on the above findings, the hollow cylindrical 1D NNTs will provide a plethora of opportunities to the scientific community in the design and development of new nanostructures and enable the development of next-generation electronic devices.

Dimerization Effects and Negative Strain Energy in Silicon Monosulfide Nanotubes

“…However, the Si-Si dimerization opens a non-negligible gap in the electronic structure of the regular (0,n) nanotubes, as shown for the dimerized SiS nanotube in Figure 4b, and the dimerized nanotubes turn into semiconductors. Using PBE is acceptable, but it is reported to underestimate the gap [32,33]. Note that the gap opening due to dimerization happens even when we use hybrid functionals, as discussed in Appendix B.…”