Morphology-control of crystallites precipitated from ZnO gel films by applying electric field during hot-water treatment

The effect of an external direct current (DC) electric field induction during hot-water treatment (HWT) on sol3gel derived ZnO coatings for controlled formation of good crystalline ZnO films was investigated. The electric field induced hot-water treatment (EF-HWT) was found to influence the formation of crystalline ZnO nanostructures on the ZnO gel films at low-temperature of 50 °C for 3 h. The effects of time, voltage and substrates used during the EF-HWT were investigated. Flower-like precipitates of hexagonal zinc oxide were generated from the zinc acetate derived ZnO gel film on a silicon single crystal substrate at the negative electrode by applying an electric field. Significant c-axis orientation of hexagonal ZnO on the silicon substrate was confirmed from XRD patterns. These results demonstrated that the EF-HWT of sol3gel derived ZnO films is a promising, low-temperature technique to control the morphology and crystallinity of oxide coatings.