Fabrication and photoluminescence of ββ-Ga2O3 nanorods

ββ-Ga2O3 nanorods were successfully synthesized through annealing Ga2O3/Mo films deposited on the Si(111) substrate by a radio frequency magnetron sputtering technique. The as-synthesized nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The results show that the formed nanorods are single-crystalline Ga2O3 with monoclinic structure. The diameters of nanorods are in the range of 200–400 nm and lengths typically up to several micrometers. X-ray photoelectron spectroscopy (XPS) confirms the formation of bonding between Ga and O, and yields the surface stoichiometry of Ga to N of 2:3. The representative photoluminescence spectrum at room temperature exhibits a strong and broad emission band centered at 414 nm and a relatively weak emission peak located at 438 nm. The growth process of ββ-Ga2O3 nanorods is also discussed.