Effect of growth temperature on gallium nitride nanostructures using HVPE technique

The growth of hexagonal wurzite one dimensional (1D) gallium nitride (GaN) nanostructures on sapphire substrates using hydride vapor phase epitaxy (HVPE) process was carried out at two different temperatures (973 K and 1023 K). The GaN nanoneedles were formed at 973 K and hexagonal nanorods get formed at 1023 K. The morphologies of these nanostructures were studied using high resolution scanning electron microscope. X-ray diffraction and micro-Raman spectroscopy measurements confirmed that the as grown GaN nanostructures are of hexagonal wurtzite structure without any oxide phase. The emission properties of these nanostructures have been investigated using photoluminescence.