The effect of growth temperature on the coaxial In _xGa _{1 - X}N/GaN nanowires grown by metalorganic chemical vapor deposition

We report on the growth of coaxial In _xGa _{1 - x}N/GaN nanowires (NWs) on Si(111) substrates by using pulsed flow metalorganic chemical vapor deposition. The coaxial In _xGa _{1 - x}N/GaN NWs were grown by a two step process in which the core (GaN) structure was grown at a higher temperature followed by the shell (In _xGa _{1 - x}N) structure at a lower temperature. Dense and well-oriented coaxial In _xGa _{1 - x}N/GaN NWs were grown with an average diameter and length of about 300 ± 50 nm and 1.5-2.0 μm, respectively. The coaxial In _xGa _{1 - x}N/GaN NW was confirmed by cathodoluminescence mapping and high-resolution transmission electron microscopy. It is proposed that the critical dissociation of precursors at an elevated growth temperature can lead to a clear formation of an outer-shell in coaxial In _xGa _{1 - x}N/GaN NWs.