Electrochemically deposited gallium oxide nanostructures on silicon substrates

We report a synthesis of β-Ga₂O₃ nanostructures on Si substrate by electrochemical deposition using a mixture of Ga₂O₃, HCl, NH₄OH, and H₂O. The presence of Ga³⁺ ions contributed to the deposition of Ga₂O₃ nanostructures on the Si surface with the assistance of applied potentials. The morphologies of the grown structures strongly depended on the molarity of Ga₂O₃ and pH level of electrolyte. β-Ga₂O₃ nanodot-like structures were grown on Si substrate at a condition with low molarity of Ga₂O₃. However, Ga₂O₃ nanodot structures covered with nanorods on top of their surfaces were obtained at higher molarity, and the densities of nanorods seem to increase with the decrease of pH level. High concentration of Ga³⁺ and OH^- ions may promote the reaction of each other to produce Ga₂O₃ nanorods in the electrolyte. Such similar nature of Ga₂O₃ nanorods was also obtained by using hydrothermal process. The grown structures seem to be interesting for application in electronic and optoelectronic devices as well as to be used as a seed structure for subsequent chemical synthesis of GaN by thermal transformation method.