Growth of gallium nitride nanorods by metalorganic molecular beam epitaxy

Without a catalyst or template layer, high-quality GaN nanorods have been grown by rf radical source metalorganic molecular beam epitaxy on c-sapphire substrates. Scanning electron microscopy, transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDX), and x-ray diffraction were employed to characterize the GaN nanorods. These nanorods have an average diameter of 50nm, and the rod areal density can reach 1×1010cm−2 depending on the growth parameters. High-resolution TEM results indicate that the well-aligned GaN nanorods have a single-crystal hexagonal wurtzite structure with preferential [0001] orientation, and no droplet was observed at the end of the nanorods. Meanwhile, EDX analysis revealed gallium and nitrogen as the only detectable elements. These high-quality and high-density GaN nanorods might be useful for practical applications in nanoscale optoelectronic and electronic devices.