Fast Growth Synthesis of GaAs Nanowires with Exceptional Length

Abstract

We report the first synthesis of GaAs nanowires (NWs) by Au-assisted vapor-liquid-solid (VLS) growth in the novel hydride vapor phase epitaxy (HVPE) environment. Forty micrometer long rodlike <111> monocrystalline GaAs nanowires exhibiting a cubic zinc blende structure were grown in 15 min with a mean density of 10(6) cm(-2). The synthesis of such long figures in such a short duration could be explained by the growth physics of near-equilibrium HVPE. VLS-HVPE is mainly based on solidification after direct and continuous feeding of the arsenious and GaCl growth precursors through the Au-Ga liquid catalyst. Fast solidification (170 microm/h) is then assisted by the high decomposition frequency of GaCl. This predominant feeding through the liquid-solid interface with no mass and kinetic hindrance favors axial rather than radial growth, leading to twin-free nanowires with a constant cylinder shape over unusual length. The achievement of GaAs NWs several tens of micrometers long showing a high surface to volume ratio may open the field of III-V wires, as already addressed with ultralong Si nanowires.

GaAs nanowire Schottky barrier photovoltaics utilizing Au–Ga alloy catalytic tips

“…Notably, oxygen is also identified in the NW body ($10 at. %) which is well-recognized in the VLS/VSS grown GaAs NWs as a result of an amorphous oxide surface layer, 11,12 in which the oxide layer is further confirmed in the high-resolution TEM image in Fig. 1(a) inset.…”

Controlled morphology of regular GaN microrod arrays by selective area growth with HVPE

“…It was reported by Ramdani et al [29] and Avit et al [17] that the growth of ultralong nanowires by HVPE (in a short growth time of $ 15 min) is promoted by the rapid decomposition of GaCl, resulting in the axial preferential growth of nanowires with high crystalline quality (there is no competition between radial and axial growth). The nitrogen source was ammonia (NH 3 ), which was used as the group V flow and was directly introduced into the deposition zone.…”

Vapor liquid solid-hydride vapor phase epitaxy (VLS-HVPE) growth of ultra-long defect-free GaAs nanowires: Ab initio simulations supporting center nucleation

“…We have already demonstrated the feasibility of NWs growth by catalyst-assisted HVPE. 21,22 GaAs NWs synthesized by HVPE are grown at high axial growth rate (higher than 100 μm/h). They exhibit constant diameter on length varying from some micrometers to several tens of micrometers and were shown to be pure zinc blende for a mean diameter of 120 nm.…”

“…They exhibit constant diameter on length varying from some micrometers to several tens of micrometers and were shown to be pure zinc blende for a mean diameter of 120 nm. 21 We focus here on the crystal and optical characterizations of GaAs NWs grown by HVPE with a 50 nm mean diameter. Related theoretical investigations based upon DFT Car-Parrinello dynamics simulations of the mechanism governing the Ga diffusion in the catalyst droplet are discussed in order to analyze the exceptional high HVPE growth rate and the stability of the structure of NWs grown by HVPE over length of several tens of microns.…”