Effect of H₂ carrier gas on the growth of gan nanowires on Si(111) substrates by metalorganic chemical vapor deposition

We report on the morphological changes of GaN nanowires (NWs) induced by varying H2 carrier gas flow rate. The GaN NWs were grown on Aucoated silicon (111) substrates by metalorganic chemical vapor deposition (MOCVD). The surface morphology and optical characterization of the grown GaN NWs were studied by field-emission scanning electron microscopy (FE-SEM) and photoluminescence (PL) and cathodoluminescence (CL) measurements, respectively. The GaN NWs with uniform diameters from bottom to top sizes ranging from 60 to 100nm and lengths up to 2- 3 mm were obtained. Energy-dispersive X-ray spectroscopy (EDX) analysis confirmed the presence of gallium and nitrogen in the grown GaN NWs. It was observed that the lateral growth behavior of the GaN NWs prevailed in the absence of H2 carrier gas. On the other hand, the vertically aligned growth tendency of the GaN NWs was induced by the supply of H₂ carrier gas.