Structural and Hydrophobic Properties of Cobalt Doped ZnO Thin Films Prepared by Electrodeposition Method

In this work, thin films of cobalt-doped ZnO were prepared by thermal oxidation method of electrodeposited zinc layer on aluminum substrates for fabrication of hydrophobic coatings. XRD, Raman spectroscopy, and FEG-SEM methods used for characterization of studied samples. By measuring the contact angle between the film's surface and a deposited water drop, the wettability characteristics of the synthesized films were evaluated (WCA). The manufactured ZnO thin films were found to be polycrystalline with Wurtzite hexagonal structures, growing predominantly along the (101) plan, according to structural characterisation by XRD. No secondary phase for the cobalt-doped sample; this is confirmed by Raman spectroscopy. FEG-SEM images reveal that the grains shape is spherical for cobalt-doped ZnO thin film, however the undoped sample exhibit a compact grains with nanostructured pyramidal shape. Incorporation of cobalt into zinc ions sites leads to the decrease of crystallites size from 39 to 31 nm and enhanced the hydrophobic property of studied ZnO thin film.