Growth mechanism and optical properties of In2O3 nanorods synthesized on ZnO/GaAs (1 1 1) substrate

Indium oxide (In2O3) nanorods have been grown on a ZnO-buffered GaAs (1 1 1) substrate by radio-frequency magnetron sputtering at a substrate temperature of 350 °C. The growth directly on a GaAs (1 1 1) substrate under the same conditions results in In2O3:In nanoclusters rather than in In2O3 nanorods, and an increase in the oxygen pressure leads to a dense In2O3 thin film with grain sizes smaller than 50 nm. The influence of the ZnO buffer layer on the synthesis of the In2O3 nanorods is associated with the presence of three-dimensional defects on the surface via the formation of Zn(/In) eutectics. Photoluminescence emissions are observed from the grown In2O3 nanorods and thin films at room temperature, and the optical bandgap of In2O3 is determined to be ∼3.66 eV.