Transparent conductive characteristics of Ti:ITO films deposited by RF magnetron sputtering at low substrate temperature

Transparent conductive metal oxide films of titanium-doped indium–tin-oxide (Ti:ITO) and indium-tin-oxide (ITO) were deposited by a dual target type radio frequency (RF) magnetron sputtering, and the films were applied to dye-sensitized solar cells (DSCs). Electrical and optical properties of the films were investigated as well as the film structure and morphology. At an annealing temperature of 450 °C, the resistivity of the Ti:ITO and ITO films are about 5 × 104 and 1.1 × 103 Ωcm, and the transmittances of both films at a wavelength of 550 nm reach about 85–90%. The impedance in the Ti:ITO-based DSC sample is 31.9, 49.6, and 20.2, for the counter electrode, the TiO2/dye/electrolyte interface, and the carrier transport by ions within the electrolyte, respectively. The series resistance, Rs, is about 72.4 Ω. Photoconversion efficiency (η) in the Ti:ITO-based DSC sample is 3.75% (ff: 0.54, Voc: 0.71 V, Jsc: 9.82 mA/cm2) at 100 mW/cm2 light intensity.