Titanium dioxide-coated fluorine-doped tin oxide thin films for improving overall photoelectric property

摘要

Titanium (Ti) layers were deposited by direct current (DC) magnetron sputtering on commercial fluorine-doped tin oxide (FTO) glasses, followed by simultaneous oxidation and annealing treatment in a tubular furnace to prepare titanium dioxide (TiO_2)/FTO bilayer films. Large and densely arranged grains were observed on all TiO_2/FTO bilayer films. The presence of TiO_2 tetragonal rutile phase in the TiO_2/FTO bilayer films was confirmed by X-ray diffraction (XRD) analysis. The results of parameter optimization indicated that the TiO_2/FTO bilayer film, which was formed by adopting a temperature of 400 ℃ and an oxygen flow rate of 15 sccm, had the optimal overall photoelectric property with a figure of merit of 2.30 × 10~(-2) Ω~(-1), higher than 1.78 × 10~(-2) Ω~(-1) for the FTO single-layer film. After coating a 500nm-thick AZO layer by DC magnetron sputtering on this TiO_2/FTO bilayer film, the figure of merit of the trilayer film achieved to a higher figure of merit of 3.12 × 10~(-2) Ω~(-1), indicating further improvement of the overall photoelectric property. This work may provide a scientific basis and reference for improving overall photoelectric property of transparent conducting oxide (TCO) films.