Highly conducting indium-tin-oxide transparent films prepared by dip-coating with an indium carboxylate salt

Tin-doped In2O3 (ITO) transparent conducting films were prepared by the dip-coating process using a novel solution, indium triformate, In(OCHO)3, and tin dichloride, SnCl2·2H2O, dissolved in the ethanol containing 2-aminoethanol, H2NC2H4OH. The composition of the films (thickness, ∼295 nm) agreed approximately with that of the solution when the dipping and the heating in air at 600 °C for 30 min were repeated 30 times. The ITO films were highly transparent in the visible range. The influence of the film composition [Sn/(In+Sn)] on the electrical properties of the as-deposited films was investigated between 0 and 20 at.%Sn. The maximum carrier concentration (1.0×1021 cm−3) and minimum resistivity (2.1×10−4 ohm cm) were obtained at 6.1 at.%Sn with relatively high mobility (28 cm2 V−1 s−1) after annealing in N2–0.1%H2 flow at 600 °C for 1 h.