Dip-coating of ITO films

Uniform, transparent indium tin oxide (ITO) films were prepared by dip-coating process using an organic sol composed of indium acetate-diethanolamine-tin octylate-n-propanol mixture and the relationship between their electrical properties, film morphology and dip-coating conditions have been investigated. The optimum Sn-doping concentration was about 4 mol% relative to In ion. The conductivity of as-prepared ITO films increased with an increase in firing temperature. Multiple coating of the layers as thin as a few tens of nanometers accelerated the growth of the ITO crystals and increased the conductivity of formed films. Thus, ITO films with a resistivity of 4 x 10(-4) Omega cm could be obtained by dip-coating and by subsequent post annealing in nitrogen. Through this study we conclude that the conductivity of dip-coated films was mainly controlled by the crystallite size and, hence, by carrier mobility. (C) 1997 Elsevier Science B.V.