Transparent conducting indium zinc oxide (In2O3-ZnO) thin films were fabricated by a sol-gel method. Zinc acetate dihydrate [Zn(CH3COO)(2)(.)2H(2)O] and indium nitrate trihydrate [In(NO3)(3)(.)3H(2)O] were used as starting precursors, and 2-methoxyethanol as a solvent. Monoethanolamine was added as a stabilizer. The starting solution was spin-coated onto a glass substrate. Thin films at several atomic ratios of Zn/(Zn+In) were annealed at 650 degrees C. The minimum resistivity (rho approximate to 1.5 x 10(-3) Omega cm) and maximum carrier concentration (n approximate to 3.0 x 10(20) cm(-3)) were obtained for the film whose atomic ratio was 0.5. The optical transmittance in the visible region was 80-85% irrespective of atomic ratios. After the Zn2In2O5 (a homologous compound ZnkIn2Ok+3 where k=2 and corresponds to the atomic ratio of 0.5) films were post-annealed in a reducing atmosphere, the carrier concentration increased to approximately 4.0 x 10(20) cm(-3) and the optical window was narrower, although the resistivity slightly increased. (c) 2005 Elsevier B.V. All rights reserved.