Evolution of InAs branches in InAs∕GaAs 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)

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

“…Generally, InAs nanowires show the wurtzite structure, whereas the GaAs nanowires show the zinc-blende structure. 11,12,14 As can be noted from Fig. 3͑c͒, the InAs nanowire section has grown as a zinc-blende structured segment above the wurtzite structured segment.…”

“…Subsequently Au catalyst-mediated InAs axial growth can be achieved in the form of InAs branches. 11 It is of interest to note that, in almost all the cases, InAs branch growth took place in ͗111͘ B directions at an inclination to the GaAs/InAs core/shell stems that grew in the ͓111͔ direction, 11 as shown in Fig. 1.…”

“…[10][11][12] Our recent observations of Au mediated axial growth of InAs on GaAs nanowires revealed that, during the InAs growth, Au catalysts slide down along the ͕112͖ sidewalls of GaAs nanowires due to their tendency to preserve an interface with GaAs. 10 This tendency is attributed to the lower Au/GaAs interfacial energy compared to the Au/InAs interfacial energy.…”

Polarity driven formation of InAs/GaAs hierarchical nanowire heterostructures

“…3 These semiconductor nanowires are generally grown via the vaporliquid-solid mechanism using metal nanoparticles to catalyze nanowire growth. 4,5 This mechanism has been exploited to produce well controlled single-crystalline nanowires ͑in terms of their diameter, shape, and location͒, 6,7 branched nanowire heterostructures, 8,9 and nanowire networks. 10 Nanowire heterostructures can be produced by modulating the composition of a nanowire axially 11 and radially.…”

Nature of heterointerfaces in GaAs/InAs and InAs/GaAs axial nanowire heterostructures

“…6 According to this phenomenon, the nucleation of a NW is a function of the interfacial energies between the catalyst droplet and the underlying substrate and between the catalyst droplet and the nucleating NW. [7][8][9] For axial NW heterostructures to be practically useful in device applications, it is essential to eliminate misfit dislocations at the strained heterointerface and to achieve sharp heterointerfaces. Although it is possible to eliminate misfit dislocations at the heterointerface of the axial NW heterostructures, 10 securing a sharp heterointerface has been a challenging task.…”