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 × 10−4 Ω ⋅ 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.