Synthesis of cobalt oxide interconnected flacks and nano-worms structures using low temperature chemical bath deposition

Interconnected flacks and nano-worms structures of cobalt oxide on glass and copper substrates have been deposited using chemical bath deposition method from aqueous alkaline cobalt chloride (CoCl2 center dot 6H(2)O) solution. The cobalt oxide films were examined with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), optical absorption and electrical resistivity techniques. The structural analyses showed that as-deposited amorphous CoO(OH) films converted into crystalline Spinel Co3O4 after annealing. Nanocrystalline grains with some overgrown clusters of cobalt oxide were revealed from surface morphological studies. TEM study showed the formation of nanocrystals with a diameter ranging from 5 to 10 nm. From optical studies, band gap of 2.4 eV was estimated for cobalt oxide thin film. The electrical resistivity exhibited semiconducting behavior of cobalt oxide thin film. (C) 2008 Elsevier B.V. All rights reserved.