Characterization of pure ZnO thin films prepared by a direct photochemical method

In this paper, amorphous ZnO thin films were obtained by direct UV irradiation of beta-diketonate Zn(II) precursor complexes spin-coated on Si(I 0 0) and fused silica substrates. ZnO films were characterized by means of XPS, X-ray diffraction (XRD) and Atomic Force Microscopy (AFM). These analyses revealed that as-deposited films are amorphous and have a rougher surface than thermally treated films. Optical characterization of the films showed that these are highly transparent in the visible spectrum with an average transmittance of up to 95% over 400 nm, and an optical band-gap energy of 3.21 eV for an as-deposited film, and 3.27 eV for a film annealed at 800 degrees C. Low resistivity values were obtained for the ZnO films (1.0 X 10(-2) Omega cm) as determined by Van der Pauw four-point probe method. (c) 2006 Elsevier B.V. All rights reserved.