Conductive and transparency characteristics of titanium-doped indium-tin oxide (InSnO 2 :Ti) films deposited by radio frequency magnetron sputtering

In order to find the potential applications of InSnO2 films for use as a transparent conducting oxide (TCO), the structural, electrical, and optical properties of InSnO2:Ti films were studied by changing Ti-doping concentration. InSnO2:Ti films were deposited by RF magnetron sputtering using an InSnO2 target containing 0.25–2.5 wt.% Ti under a fixed substrate temperature (300 °C), RF power (300 W), and argon (Ar) gas pressure (13 mbar). The thin film characteristics of the InSnO2:Ti were strongly influenced by the Ti-doping concentration. The optimum Ti-doping at 1.25 wt.% of InSnO2 was observed to improve the crystallinity the resistivity, the carrier mobility, and the band-gap energy of the films and to activate crystalline grain growth. However, higher Ti doping concentrations of 2.5 wt.% may induce TiO2 particle formation on the deposited InSnO2 film delaying InSnO2 grain growth and degrading other properties.