Cobalt oxide thin films prepared by NSP technique: Impact of molar concentration on the structural, optical, morphological and electrical properties

Cubic cobalt oxide (Co3O4) thin films are deposited using cobalt chloride hexahydrate as precursor by nebulizer spray pyrolysis technique with different molar concentrations. The structural, optical, morphological and electrical properties are investigated. X-ray diffraction (XRD) analysis shows the polycrystalline nature of the films with cubic structure having preferential orientation through (220) plane. The maximum crystallite size is found to be similar to 21 nm. The optical bandgap energy of the film is decreased with the increase of molar concentration. The obtained maximum bandgap energy values are 2.88 and 1.56 eV for the films prepared at 0.025 M. High-resolution scanning electron microscope illustrates the overgrown crystals like structure and coalescence of grains. The electrical conductivity of the films increases with the increase of molar concentration. (C) 2016 Elsevier GmbH. All rights reserved.