ZnO Nanospheres to Nanorods - Morphology Transition via Fe-doping

Fe-doped and undoped polycrystalline nanostructured ZnO thin films were deposited on glass substrates at 523 K by spray pyrolysis technique and subsequently post-annealed at 723 K to increase the crystallinity. The X-ray diffraction (XRD) pattern confirmed the hexagonal wurtzite structure of the ZnO films with polycrystalline nature. The crystallinity and the crystallite size were increased with increase in Fe-dopant concentration. A significant change in the surface morphology from nanosphere to nanorod was observed with increase in the dopant concentration. The optical absorbance characteristics of the thin films were studied using UV-vis spectrophotometer in the wavelength range of 300-800 nm. The spectra showed sharp absorption edge and it was shifted towards the higher wavelength when the dopant concentration was increased. Decrease in optical band gap with increase in Fe dopant concentration was observed. The electrical conductivity of the film was increased with increase in Fe doping. (C) 2013 Elsevier Ltd. All rights reserved.