Improving the composition uniformity of Au-catalyzed InGaAs nanowires on silicon

Spatial distribution of indium (In) atoms in ternary InxGa1−xAs nanowires (NWs) was investigated by the energy-dispersive X-ray spectroscopy, which were grown on Si (111) by metal-organic chemical vapor deposition. The NWs have a tapered morphology with thicker diameter and higher In composition in the bottom of NWs. However, decreasing growth temperature and V/III ratio resulted in straight NWs with constant In composition throughout the NWs. This was attributed to enhanced deposition on the sidewall of the NW with higher In composition through the vapor–solid mode, leading to a core-shell structure consisting of low and high In-content layers.

► We study the growth mechanism of the composition variation in the InGaAs nanowires.
► Indium distribution in the InGaAs nanowires was investigated by the X-ray analysis.
► We grow the ternary InGaAs nanowires having uniform alloy composition.