Polarity driven simultaneous growth of free-standing and lateral GaAsP epitaxial nanowires on GaAs (001) substrate

Abstract

Simultaneous growth of ⟨111⟩B free-standing and ±[110] lateral GaAsP epitaxial nanowires on GaAs (001) substrates were observed and investigated by electron microscopy and crystallographic analysis. It was found that the growth of both free-standing and lateral ternary nanowires via Au catalysts was driven by the fact that Au catalysts prefer to maintain low-energy {111}B interfaces with surrounding GaAs(P) materials: in the case of free-standing nanowires, Au catalysts maintain {111}B interfaces with their underlying GaAsP nanowires; while in the case of lateral nanowires, each Au catalyst remain their side {111}B interfaces with the surrounding GaAs(P) material during the lateral nanowire growth.

Surface effects of vapour-liquid-solid driven Bi surface droplets formed during molecular-beam-epitaxy of GaAsBi

“…For a zincblende GaAs-based system such as GaAsBi, the (111)B face has the lowest free energy61 and planar GaAs-based nanowires grown on GaAs (001) have been shown to share the same (111)B growth interface with vertical nanowires except the planar nanowire propagation direction is not orthogonal with the growth plane62. Relative to the (001) epitaxial growth surface, the growth facet plane shown in Fig.…”

“…adopted a less uncommon [110] growth axis, along with a lens-like V-shape through their transverse cross-section. This cross-sectional shape has been shown to associate with the [110] growth axis62, as the geometry permits the nanowire to retain a boundary with the [111]B side facets throughout growth. Investigations of the transverse cross-section of our buried nanowires (data not shown) does not reveal this features, rather they exhibit a simple flat bottom surface.…”

Vapor-Liquid-Solid Growth of Semiconductor Nanowires

“…Figure 9.12(a) shows GaAs planar nanowires grown along the two nonparallel surface projections of <111> B directions on (100) GaAs substrates offcut by 10 toward the [0-10] direction. Planar nanowires of materials other than GaAs have also been demonstrated, such as <110> In 0.04 Ga 0.96 As planar nanowires on (311)B GaAs substrates [132], <110> InAs planar nanowires on (100) InAs substrates [133], and <110> GaAsP planar nanowires on (100) GaAs substrates [134]. Although the growth mechanism of planar nanowires is still under investigation, good substrate-wetting capability of the compound alloy (catalyst NP alloyed with the group III species) is believed to be the key for growing high-yield planar nanowires [131].…”

Mechanism of periodic height variations along self-aligned VLS-grown planar nanostructures

“…[21][22][23][24] Moreover, the formation of preferentially orientated structures 25 are developed in parallel with advancing technological aims to employ bottom-up fabrication techniques. 19,[26][27][28][29] Nanowires which self-align on the surface could play an important role in combining the synthesis and assembly in a single step, while offering compatibility with traditional planar device structures. 25,[28][29][30][31] In this paper, we extend the current palette of non-monotonous one-dimensional nanostructures and investigate a new type of self-aligned GaAsBi planar nanotrack exhibiting periodic changes in height along its full length.…”

“…19,[26][27][28][29] Nanowires which self-align on the surface could play an important role in combining the synthesis and assembly in a single step, while offering compatibility with traditional planar device structures. 25,[28][29][30][31] In this paper, we extend the current palette of non-monotonous one-dimensional nanostructures and investigate a new type of self-aligned GaAsBi planar nanotrack exhibiting periodic changes in height along its full length. We find that an explanation for this unusual shape is outside the capacity of existing planar nanowire growth models 19,25 and develop a a Institute for Superconducting and Electronic Materials and School of Physics, University of Wollongong, Wollongong, New South Wales 2522, Australia.. E-mail: js598@uowmail.edu.au more pertinent semi-empirical growth model -one that accounts for the localized adsorption of species on the droplet surface and connects them to a functional describing the rate of nucleation across an inhomogeneous liquid-solid growth interface.…”