Effects of Au catalyst on growth of β-Ga2O3 nanostructure at α-Al2O3 (0001) surface

On the α-Al2O3 (0001) surface low-dimensional nanostructure of β-Ga2O3 was synthesized on a large scale (1 cm square) at relatively low substrate temperature (650 °C) by thermal evaporation of Ga2O3 with presence or absence of Au catalyst. Whitish layer over the substrate surface consisted of rod-like or block-like β-Ga2O3 nanostructures with presence or absence of the catalyst, respectively. In growth with the catalyst, a nanosphere with diameter of 200–450 nm placed at the top of each nanorod with diameter of 250–700 nm and ∼4 μm long. In growth without the catalyst, distorted pentagonal nanoblock with longer and shorter sides for a section of 1–1.7 μm long and 300–400 nm long, respectively, reached as long as 5.5 μm. The shape and size of the nanostructure were affected by presence or absence of the catalyst in the deposition of Ga2O3. The vapor–liquid–solid growth using Au catalyst increased rather small rod-like nanostructure of β-Ga2O3 promising for nanodevice applications.

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