Room temperature deposition of Al-doped ZnO thin films on glass by RF magnetron sputtering under different Ar gas pressure

Al-doped ZnO (AZO) thin films were deposited on glass substrates at room temperature by RF magnetron sputtering. The effects of Ar gas pressure on the structural, optical, and electrical properties were investigated. As the Ar gas pressure increased, the resistivities of the AZO thin films increased, the mobilities decreased, and the carrier concentrations were constant. X-ray photoelectron spectroscopy (XPS) showed that higher Ar gas pressures promoted O-Zn bond formation and reduced the number of oxygen vacancies. The reduction in mobility, which increased the resistivity, was attributed to increased lattice scattering by the oxygen atoms. In AZO thin films deposited at room temperature, the conduction characteristics are primarily influenced by the mobility. (C) 2010 Elsevier B.V. All rights reserved.