Temperature-controlled catalytic growth of one-dimensional gallium nitride nanostructures using a gallium organometallic precursor

Catalytic growth of 1-D GaN nanostructures is achieved at temperatures from 550 to 850 °C using NH₃ and gallium acetylacetonate. Structural characterization of the 1-D GaN nanostructures by HRTEM shows that straight GaN nanowires, needle-like nanowires (nanoneedles), and bamboo-shoot-like nanoneedles are synthesized at 750, 650, and 550 °C, respectively. In addition to selecting a proper catalyst, providing sufficient precursors has been demonstrated to be a crucial factor for the low-temperature growth of 1-D GaN nanostructures via the VLS mechanism. Possible mechanisms for forming nanoneedles at low temperatures are proposed. PACS 61.46.+w; 68.65.–k; 81.07.–b