Electrical properties and crystal structures of semiconductive Nb-doped BaTiO3 thin film prepared by MOCVD

Epitaxially grown semiconductive Nb-doped BaTiO3 thin films with a resistivity similar to single crystals were prepared by MOCVD on (001)MgO substrates at 800 degrees C. The smooth surface and grain boundary-free structure were observed. The film had c-axis orientation, and this orientation was caused by the strain from the thermal stress of cubic BaTiO3, The varying of conductivity was attributed to that of the carrier concentration, and the mobility was similar to that of bulk ceramics. The thermal activation energy of the film with 3.1 at% Nb was very small, 0.034 eV, and that was caused by a high carrier concentration.