Growth
of gallium nitride nanowires on etched sapphire and GaN
substrates using binary catalytic alloy were investigated by manipulating
the growth time and precursor-to-substrate distance. The variations
in behavior at different growth conditions were observed using X-ray
diffractometer, Raman spectroscopy, X-ray photoelectron spectroscopy,
cathodoluminescence spectroscopy, optical microscopy, atomic force
microscopy, and scanning electron microscopy. It was noticed that,
in respect of both the substrates, when growth time and/or precursor-to-substrate
distance is increased, thickness of the nanowires around the etch
pits remains unaltered, but there is variation in the density of nanowires.
In addition, formation of gallium nitride microwires within the etch
pits was also observed on etched sapphire substrates. Similarly, the
thickness and density of the microwires were found to increase with
increase in growth time and decrease with increase in precursor-to-substrate
distance. The dimensionality scaling of gallium nitride was found
to have a positive effect in improving the luminescence property and
band gap of the grown nanowires. This method of nanowire growth can
be helpful in increasing the probability of multiple reflections in
the materials which makes them a suitable candidate for optoelectronic
devices.