Tunable growth of (GaxIn1−x)2O3 nanowires by water vapor

The tunable growth of In-doped Ga2O3 (Ga2O3:In) and Ga-doped In2O3 (In2O3:Ga) nanowires (NWs) on Au-coated Si substrates was achieved by modulating the amount of water vapor in flowing Ar at 700–750 °C via carbothermal reduction of Ga2O3/In2O3 powders with a fixed weight ratio. In Ar, only the Ga2O3:In NWs were grown, while in wet Ar the In2O3:Ga NWs were synthesized instead. The Ga concentration in In2O3 NWs decreased with the increment of water vapor in flowing Ar. The growth of both Ga2O3:In and In2O3:Ga NWs followed the vapor–liquid–solid process. The In and Ga doping induced a redshift and a blueshift in the optical bandgaps of Ga2O3 NWs and In2O3 NWs, respectively. The growth mechanisms and optical properties of Ga2O3:In and In2O3:Ga NWs were discussed.

► The growth of Ga2O3:In and In2O3:Ga NWs can be modulated by water vapor.
► The composition and bandgap of (GaxIn1−x)2O3 NWs can be tuned by water vapor.
► The hybridization of band structures determines the bandgap of (GaxIn1−x)2O3 NWs.