Multilayered transparent conducting oxide (TCO) film structures have been designed and fabricated to achieve both high conductivity and high transmittance in the visible spectrum. Double-layered TCO structures consisting of Sn-doped CdO and Sn-doped CdIn2O4, Cd-rich Cd2SnO4, or Ga-doped ZnO are discussed. By optimizing the thickness of the individual layers and the doping levels within those layers, an effective conductivity of 20600 S/cm and an average transmittance larger than 85% in the 400-700 nm range have been achieved for films epitaxially gown on MgO substrates. Bi-layer films consisting of Sn-doped CdO and Ga-doped ZnO have also been deposited on plastic substrates at room temperature with resistivities of similar to1 x 10(-4) Omega cm and an average transmittance of 80-85% in the visible range. These properties are attractive for future TCO applications. (C) 2004 Elsevier B.V. All rights reserved.