Structural, electrical, and optical properties of transparent conductive In2O3-SnO2 films

Transparent conductive In2O3-SnO2 films were deposited by dc magnetron sputtering on unheated glass substrates using high-density ceramic targets with various SnO2 concentrations (0-100 wt. %). These films were subsequently postannealed in various atmospheres [air, Ar (100%) or Ar(97%) + H-2(3%)] for 1 h at 200 degrees C. All the as-deposited films were amorphous by X-ray diffraction (XRD). After the postannealing, XRD profiles of the films deposited using the targets in the range of 0-20 wt. % SnO2 showed bixbyte In2O3 polycrystalline structure, whereas all the films deposited using the targets with 44.5 wt. % SnO2 and 100 wt. % (pure SnO2) were amorphous. Resistivity of the films deposited using the targets in the range of 0-20 wt. % SnO2 went from about 4.0 x 10(-4) to 2.0 x 10(-4) Omega(.)cm by the postannealing under all atmospheres due to increased carrier density. This implies an increase in the number of the substitutional Sn4+ at In3+ sites during crystallization. The work function of the postannealed films was inversely proportional to the two-thirds power of carrier density. (c) 2005 American Vacuum Society.