Structural Stability and Electronic Properties of InAs Nanowires and Nanotubes: Effects of Surface and Size

Abstract

The surface and size effects on the structural stability and electronic properties of InAs one-dimensional nanostructures are investigated by first-principles calculations within density functional theory. No matter what the diameters, the nanowires are more energetically favorable than the nanotubes due to the preferable sp3 hybridization for In and As atoms in the InAs nanostructures. The formation energies of these nanostructures satisfy a linear dependence relationship with the surface atom ratio. The calculated band structures reveal that the band gaps of InAs nanostructures are determined by two competition mechanisms. One is the quantum confinement effect, which favors the increase of the band gaps with the decreasing diameter or wall thickness. Another is the effect of surface dangling bonds, which induces the decrease of the band gaps with the decreasing diameter or wall thickness. With the same diameter, the band gaps of InAs nanowires are still less than those of the nanotubes. The result indicates that the quantum confinement effect in one-dimensional structures can be enhanced by the formation of tubes instead of wires.

Enhanced visible light absorption in ZnO/GaN heterostructured nanofilms

“…After structural optimization, both pure ZnO and GaN ) 00 1 1 ( _ and ) 0 2 11 ( _ nanofilms with given 8 and 10 layers exhibit slightly inward and outward motions of Zn (Ga) and O (N) at the surfaces, which has also been reported in previous studies [36,37]. The optimized supercell sizes For further examining the structural stability of ZnO/GaN heterostructured nanofilms, the formation energy has been calculated according to the following equation [38,39] , In the former, it increases monotonically, whereas it shows an oscillating increase in the latter.…”

“…Thus, the charge distributions of VBM and CBM are great significant for understanding the potential applications in photocatalytic field. For the low-dimensional nanostructures, size effects on electronic properties become remarkable and cannot be neglected [38,[42][43][44]. Consequently, this raises a question: what are the relationships between the optical properties and the sizes of ZnO/GaN heterostructured nanofilms?…”

Tailoring electronic properties of InAs nanowires by surface functionalization

“…7 Successful realization of these applications depends on the control of their structures and fundamental electronic properties. Both experimental [2][3][4]8 and theoretical studies [9][10][11][12] have been carried out and devoted to finding some feasible methods to control the electronic properties of InAs and other semiconductor nanowires. It has been found that the electronic structures of nanowires can be tailored by the nanowire size and morphology, doping, and surface functionalization.…”

Influence of Surface Passivation on Indium Arsenide Nanowire Band Gap Energies

“…Many experimental investigations for III-V NWs have been performed but diameters typically are much larger than the 10 nanometer upper limit required for advanced nanoelectronics geometries [24][25][26]. Theoretical studies of III-V NWs have typically considered unterminated NWs, idealized surface terminations using pseudo-hydrogen, or considering only a single atomic species for surface passivation [27][28][29][30].…”