The growth and properties of self-assembled GaN nanorods, nanoparticles and nanotubes on Si substrates by annealing GaN/ZnO films

摘要

GaN nanostructured films have been successfully grown through radio frequency magnetron sputtering system via annealing GaN/ZnO films in ammonia ambient at 950°C. The volatilization of ZnO buffer layer plays an important role in the formation process of GaN nanostructures. X-ray diffraction (XRD), transmission electron microscope (TEM), x-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) are used to analyze the structure, morphology, composition and optical properties of the as-grown products. The XRD and selected area electron diffraction (SAED) indicate that the reflections of the samples can be indexed to the hexagonal GaN phase. TEM shows that the products are of pure hexagonal GaN single crystal. By XPS spectra, quantification of peaks gives the atomic ratio of Ga to N of about 1:1.1. The photoluminescence (PL) spectrum indicates that the GaN have a good emission property, which will have potential advantages for applications in laser device using one-dimensional structures. Finally, the proposed growth mechanism is also briefly discussed.