Characterization of anatase TiO2 epitaxial films deposited on YSZ(100) substrates by metal-organic chemical vapor deposition

Anatase TiO2 (a-TiO2) thin films were successfully deposited on the Y-stabilized ZrO2 (YSZ)(100) substrates at different substrate temperatures (Ts) (500-650 °C) by metal organic chemical vapor deposition (MOCVD). The film deposited at 600 °C showed the best crystalline quality with a single growth orientation, for which the X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) measurements identified an epitaxial relationship of a-TiO2(001)||YSZ(100) and a-TiO2[110]||YSZ[001]. A schematic diagram was proposed to explain the epitaxial growth mechanism between the substrate and the film. The average transmittance of the film deposited at 600 °C exceeded 93% in the visible range and its optical band gap was estimated to be 3.16 eV.