Selective Area Growth of GaN Nanowire: Partial Pressures and Temperature as the Key Growth Parameters

Selective area growth of Ga-polar GaN nanowires by metal organic chemical vapor deposition provides a path to achieve arrays of uniform nanowires with controllable dimensions. A systematic investigation on the growth parameters of GaN nanowires demonstrates that although a low V/III ratio and low precursor flows are necessary, V/III ratio is not a sufficient parameter to determine the morphology of GaN nanowires. Partial pressures of the constituent gases, on the other hand, can be used as a single parameter, at a particular growth temperature, to explain the resulting morphology. By correlating the partial pressures of precursors and H2 in the carrier gas with the morphology of the nanowires, we can then determine the flow rates for precursors and hence the range of V/III ratios required for achieving the growth of GaN nanowires.