Amorphous titanium dioxide (TiO2) thin film has been prepared by a filtered cathodic vacuum arc technique at room temperature. It was concluded from the core level of Ti 2p3/2 (458.3 eV) and O 1s (529.9 eV) and their deviation in binding energy (ΔBE = 71.6 eV) that only one of Ti oxidation states, Ti4+, existed in the film and the film was of ideal stoichiometry. The film possessed high transmittance, which can reach as high as that of a quartz substrate, especially in the visible range, owing to its optical bandgap of 3.2 eV. The high refractive index (2.56 at 550 nm) and low extinction coefficient (∼10-4 at 550 nm) suggested that the film had a high packing density and a low scattering-center concentration. These good optical properties implied the film prepared by this technique was a promising candidate for optical application. Besides, the film was found to transform in the structure from amorphous to anatase crystalline when it was annealed at 300 °C, as evidenced by Raman and x-ray diffraction.
© 2004 Optical Society of America
Original Manuscript: May 9, 2003
Revised Manuscript: September 15, 2003
Published: February 20, 2004
Zhiwei Zhao, Beng Kang Tay, and Guoqing Yu, "Room-temperature deposition of amorphous titanium dioxide thin film with high refractive index by a filtered cathodic vacuum arc technique," Appl. Opt. 43, 1281-1285 (2004)