Pine-needle-shaped GaN nanorods have been successfully synthesized on Si(111) substrates by ammoniating Ga2O3/Nb films at 950 degrees C in a quartz tube. The products are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and field-emission transmission electron microscope (FETEM). The results show that the pine-needle-shaped nanorods have a pure hexagonal GaN wurtzite with a diameter ranging from 100 to 200 run and a length up to several microns. The photoluminescence spectra (PL) measured at room temperature only exhibit a strong emission peak at 368 nm. Finally, the growth mechanism of GaN nanorods is also briefly explored. (c) 2007 Elsevier Ltd. All rights reserved.