Self-branching in gan nanowires induced by a novel vapor-liquid-solid mechanism

Investigations of the growth morphology of AuPd-catalyzed GaN nanowires lead us to propose a vapor-liquid-solid (VLS) mechanism distinct from the well-established VLS growth of elemental wires. Here, nucleation and growth of GaN nanowires proceeds by direct spontaneous reaction between NH3 vapor and Ga dissolved in liquid AuPd alloy, rather than by solubility-limited supersaturation. A frequently observed self-branching growth mode can be explained by the proposed VLS scheme and the migration of Ga-enriched AuPd liquid on Ga-stabilized polar surfaces of mother nanowires.