Morphology-controlled synthesis and structural characterization of ternary AlxGa1−xN nanostructures by chemical vapor deposition

Abstract

Wurtzite aluminum gallium nitride (Al_xGa_1−xN) nanostructures with manifold morphologies, including nanonails, nanoneedles, nanorods, nanoflowers, nanomultipods and nanotowers, have been fabricated on bare Si (100) substrates by a simple halide chemical vapor deposition process. The detailed morphological and structural characteristics of these nanostructures have been examined by field emission scanning electron microscopy, X-ray diffraction spectroscopy, and transmission electron microscopy. All Al_xGa_1−xN nanostructures exhibit a hexagonal wurtzite single-phase structure and a preferred orientation along the [0001] direction. The evolution of the various Al_xGa_1−xN nanostructures has been systematically investigated in terms of the saturation vapor pressure of the precursors by tuning the growth parameters. A vapor–solid growth mechanism combined with the surface diffusion process is responsible for the formation and evolution of the series of nanostructures.