Crystallographically driven Au catalyst movement during growth of InAs/GaAs axial nanowire heterostructures

Abstract

The influence of the droplet composition on the vapor-liquid-solid growth of InAs nanowires on GaAs ( 1 ¯ 1 ¯ 1 ) B by metal-organic vapor phase epitaxy J. Appl. Phys. 104, 114315 (2008) The movement of Au catalysts during growth of InAs on GaAs nanowires has been carefully investigated by transmission electron microscopy. It has been found that Au catalysts preferentially stay on ͕112͖ B GaAs sidewalls. Since a ͕112͖ surface is composed of a ͕111͖ facet and a ͕002͖ facet and since ͕111͖ facets are polar facets for the zinc-blende structure, this crystallographic preference is attributed to the different interface energies caused by the different polar facets. We anticipate that these observations will be useful for the design of nanowire heterostructure based devices.

III–V semiconductor nanowires for optoelectronic device applications

“…As a consequence, the Au nanoparticle migrates to retain the energetically favourable Au-GaAs interface, even with continuing InAs growth: the Au nanoparticle slides off the nanowire tip and down the GaAs nanowire sidewall, assisting InAs growth as it migrates. The Au nanoparticle slides down one of the three {1 1 2}B sidewalls, which have lower interfacial energy than the three {1 1 2}A sidewalls [63]. The InAs forms a cap on top of the GaAs nanowires and then grows downward in a [1 1 1]A direction [64].…”

Growth and properties of III–V compound semiconductor heterostructure nanowires

“…Although GaAs/InAs two-dimensional (2D) heterostructures are one of the key material systems for optoelectronic device applications, their 1D counterparts are much less studied [24,25,[58][59][60][61][62][63][64] in spite of their potential optoelectronic and electronic applications. Not being able to grow InAs nanowires straight on GaAs nanowires is probably the most difficult challenge to be overcome to form DHS [24,25,59].…”

“…Not being able to grow InAs nanowires straight on GaAs nanowires is probably the most difficult challenge to be overcome to form DHS [24,25,59]. Paladugu et al have used TEM to investigate the growth mechanism of GaAs/InAs axial nanowire heterostructures in detail [25,[59][60][61][62][63]. Figure 7 shows SEM images taken from GaAs/InAs axial nanowire heterostructures grown with different growth times (1 min, 5 min and 30 min) for the InAs sections.…”

Sb Incorporation in Wurtzite and Zinc Blende InAs1−xSbx Branches on InAs Template Nanowires

“…Since nearly every observed branch had originated from a stacking fault, which is surprising given the relatively low density of stacking defects in the trunk nanowires, and the random distribution of the secondary Au particles, it could be speculated that Au particles on wurtzite InAs are able to migrate on the trunk sidewalls until a favorable nucleation site is reached . It appears that the existence of the zinc blende defect not only enables branch growth with a partially zinc blende crystal structure, but also facilitates growth of the wurtzite structure within the branch, alongside the zinc blende structure.…”