Influence of TiO2 content on microstructures and optoelectronic properties of titanium-doped ZnO nanofilms

Thin films of TiO2-doped ZnO (TZO) with TiO2 contents from 0.5 to 3.0 wt.% were deposited on glass substrates by RF magnetron sputtering. The microstructures and optoelectronic properties of the TZO films were characterized by XRD, Hall effect analyzer, UV-VIS spectrophotometry and physical property measurement (PPMS-9). Results indicate that the microstructure and optoelectronic properties of TZO films are strongly affected by the TiO2 content. The best optoelectronic properties were obtained with the film having 2.0 wt.% TiO2. This film had superior crystal properties, high average optical transmittance (89.0%), and the lowest resistivity (9.58 x 10(-4) Omega . cm). Furthermore, the resistivity of this film changed with temperature between 10 and 350 K, they experienced an initial decrease followed by an increase as the temperature increased.