Structural and optical properties of heteroepitaxial anatase titania films on MgAl6O10 (100) substrates by MOCVD.

Titania (TiO 2 ) films were synthesized on MgAl 6 O 10 (100) substrates by high vacuum metalorganic chemical vapor deposition (MOCVD). The crystal structures, surface and interface morphologies as well as the optical properties of the obtained TiO 2 films depending on substrate temperature were studied in detail. A single-crystal anatase TiO 2 (a-TiO 2 ) film was obtained at the substrate temperature of 550 °C. The epitaxial relationship between the a-TiO 2 film and MgAl 6 O 10 (100) substrate was a-TiO 2 (001) || MgAl 6 O 10 (100) with a-TiO 2 [100] || MgAl 6 O 10 [001]. The a-TiO 2 film showed an average transmittance of 95.1% in the visible range, and an optical band gap of 3.46 eV. The refractive indexes and extinction coefficients of the obtained TiO 2 films as a function of wavelength were analyzed. A broad photoluminescence peak centered at 535 nm was observed at room temperature and the corresponding luminescence mechanisms were discussed. [ABSTRACT FROM AUTHOR]