ITO films deposited by rf-PERTE on unheated polymer substrates—properties dependence on In–Sn alloy composition

The study of the influence of different tin concentrations in the In–Sn alloy on the properties of indium tin oxide (ITO) thin films deposited by radio frequency (rf) plasma enhanced reactive thermal evaporation (rf-PERTE) onto flexible polymer and window glass substrates at room temperature is presented. The polymer substrate used is polyethylene terephthalate (PET). The tin concentration in the source alloy varied in the range 5–20 wt.%. The average thickness of the ITO films is of about 90 nm. Results show that ITO thin films deposited on PET from the evaporation of a 85%In:15%Sn alloy exhibit the following characteristics: an average visible transmittance of 80% and an electrical resistivity of 1.6×10−3 Ω cm. On glass the value of the average visible transmittance increases (85%) and the resistivity decreases to 7.6×10−4 Ω cm. The electrical properties of ITO films on PET are largely affected by the low carrier mobility.