Gallium nitride (GaN) nanowire (NW) arrays were grown on a gold-coated Si(111) substrate by metal-organic chemical vapor deposition (MOCVD). Here we adopted two different experimental procedures to grow GaN NWs namely, with and without Ga predeposition on Au-coated Si(111) substrate before annealing. Comparative studies based on the morphology and growth behavior of GaN NWs were performed by using Au catalyst and Au + Ga solid solution nano-droplets. The grown GaN NWs were characterized by field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray (EDX) spectroscopy, photoluminescence (PL), cathodoluminescence (CL), high-resolution transmission electron microscopy (HR-TEM) and Raman spectroscopy. The nucleation of GaN NWs was explained in terms of Ga predeposition. As a result, we showed that the advantages of using the Au + Ga solid solution nano-droplets for growing GaN NWs. (C) 2010 Elsevier B.V. All rights reserved.