Effects of Au catalyst on growth of beta-Ga_2O_3 nanostructure at alpha-Al_2O_3 (0001) surface

摘要

On the alpha-Al_2O_3 (0001) surface low-dimensional nanostructure of beta-Ga_2O_3 was synthesized on a large scale (1 cm square) at relatively low substrate temperature (650 deg C) by thermal evaporation of Ga_2O_3 with presence or absence of Au catalyst. Whitish layer over the substrate surface consisted of rod-like or block-like beta-Ga_2O_3 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 approx 4 mum long. In growth without the catalyst, distorted pentagonal nanoblock with longer and shorter sides for a section of 1-1.7 mum long and 300-400 nm long, respectively, reached as long as 5.5 mum. The shape and size of the nanostructure were affected by presence or absence of the catalyst in the deposition of Ga_2O_3. The vapor-liquid-solid growth using Au catalyst increased rather small rod-like nanostructure of beta-Ga_2O_3 promising for nanodevice applications.