Optical and structural characterisation of zinc oxide thin films prepared by sol-gel process

Zinc oxide thin films have been prepared on different substrates by the sol-gel method using 2-methoxyethanol solution of zinc acetate dihydrate stabilized by monoethanolamine. The photoluminescence spectra of the films show the band-edge and sub-band transitions. The intensity of the band edge emission peak increases, while the intensity of the deep level emission peak decreases in the films coated on sapphire substrate. Transmittance spectra show that the films are transparent beyond 400 nm. The structural property of the films has been evaluated using X-ray diffraction. The X-ray peak intensity of the film (002) grown on sapphire substrate is higher than the films grown on glass and quartz substrates. The AFM images show improvement in the surface of the annealed films as compared to the as-grown ZnO films coated on sapphire substrates. (C) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.