Characterization of single crystalline a-TiO2 films on MgAl2O4(100) substrates by MOCVD

Anatase phase TiO2 (a-TiO2) films have been deposited on MgAl2O4(100) substrates at the substrate temperatures of 500–650 °C by the metal organic chemical vapor deposition (MOCVD) method using tetrakis-dimethylamino titanium (TDMAT) as the organometallic (OM) source. The structural analyses indicated that the TiO2 film prepared at 600 °C had the best single crystalline quality with no twins. The out-of-plane and in-plane epitaxial relationships of the film were a-TiO2(001)||MgAl2O4(100) and TiO2[100]||MgAl2O4[100], respectively. A uniform and compact surface with stoichiometric composition was also obtained for the 600 °C-deposited sample. The average transmittance of all the TiO2 films in the visible range exceeded 91% and the optical band gap of the films varied from 3.31 to 3.41 eV.