Transparent conductive ITO thin films through the sol-gel process using metal salts

The electrical and optical properties, structure and morphology of ITO thin films were investigated. Ten percent by weight Sn-doped indium oxide (ITO) films were prepared on soda-lime-silicate glass substrate by the sol-gel s pin coating method using inorganic metal salts. All layers studied with a t hickness range of 50-350 nm were polycrystalline with grain sizes in the ra nge 20-30 nm depending on the annealing conditions. SnO or SnO2 phase was n ot detected in terms of XRD, TEM analysis techniques and the resultant phas e was only In2O3 cubic bixbyite. The sheet resistance of 250 nm thin films annealed at 400 degrees C was 6.18 x 10(3) Ohm/rectangle in air, 1.09 x 10( 3) rectangle/Ohm in nitrogen, 15.21 x 10(3) Ohm/rectangle in oxygen, respec tively. Four-hundred degree centigrade-annealed 150 nm films showed more th an 85% of the average visible transmittance, regardless of annealing atmosp heres. According to AFM analysis RMS roughness was 18 Angstrom for a 50 nm film and 25 Angstrom for a 350 nm film, respectively. XPS results revealed that Sn was incorporated into In2O3 structure substitutionally. (C) 1999 El sevier Science S.A. All rights reserved.