Bias-induced light emission and thermal radiation from conducting channels of carbon nanotubes (CNTs) with defects are studied theoretically within the framework nonequilibrium Green's function method based on a tight-binding model. Localized states induced by single vacancy defect Stone-Wales in low energy range enhance electroluminescence significantly while they reduce under zero bias. The i...

The mechanical properties of nanostructures are a researcher’s favorite topics. In the meantime, and physical two dimensional structures nanotubes have attracted greater attention due to their wide application. Si (Si) consisting atoms that arranged as honeycombs. This structure has created some special in nanotubes. this paper, Young’s modulus values stress strain diagrams investigated using m...

We developed a chemical route to produce graphene nanoribbons (GNR) with width below 10 nanometers, as well as single ribbons with varying widths along their lengths or containing lattice-defined graphene junctions for potential molecular electronics. The GNRs were solution-phase-derived, stably suspended in solvents with noncovalent polymer functionalization, and exhibited ultrasmooth edges wi...

Unusually structure-selective growth of single-walled carbon nanotubes (SWNTs) has been attained using a CVD method with a solid supported catalyst. In this method, CO feedstock disproportionates on silica-supported catalytic nanoclusters of Co that are formed in situ from mixed salts of Co and Mo. The nanotube products are analyzed by spectrofluorimetry to reveal distributions resolved at the ...

We consider the Schrödinger operator with a periodic potential on quasi-1D models of armchair single-wall nanotubes. The spectrum of this operator consists of an absolutely continuous part (intervals separated by gaps) plus an infinite number of eigenvalues with infinite multiplicity. We describe the absolutely continuous spectrum of the Schrödinger operator: 1) the multiplicity, 2) endpoints o...

A model of (4, 4) single-walled boron-nitride nanotube as a representative of armchair boron-nitride nanotubes studied. At first the structure optimization performed and then Nuclear Magnetic Resonance parameters (NMR) by Density Functional Theory (DFT) method at B and N nuclei calculated. Resulted parameters evaluation presents electrostatic environment heterogeneity along the nanotube and esp...

A toroidal polyhex (resp. Klein-bottle polyhex) described by a string (p, q, t) arises from a p × q-parallelogram of a hexagonal lattice by a usual torus (resp. Klein bottle) boundary identification with a torsion t. A connected graph G admitting a perfect matching is kextendable if |V(G)| ≥ 2k + 2 and any k independent edges can be extended to a perfect matching of G. In this paper, we charact...

Molecular hydrogen and oxygen adsorptions on a (6, 6) armchair silicon nanotube have been studied by optimizing the distances of the admolecules from both inside and outside the tube. Full geometry and spin optimizations have been performed without any symmetry constraints with an all electron 3-21G* basis set and the B3LYP functional. The molecule is originally placed perpendicular or parallel...

We calculate the torsional moduli of single-walled transition metal dichalcogenide (TMD) nanotubes using ab initio density functional theory (DFT). Specifically, considering forty-five select TMD nanotubes, we perform symmetry-adapted DFT calculations to for armchair and zigzag variants these materials in low-twist regime at practically relevant diameters. find that follow trend: MS$_2$ $>$ MSe...