Chemically sprayed ZnO:(F, Zr) thin films: Effect of starting solution ageing time and substrate temperature on the physical properties

Conductive and transparent fluorine and zirconium co-doped zinc oxide [ZnO:(F, Zr)] thin films have been deposited onto sodocalcic glass substrates by the chemical spray technique. The effects of starting solution ageing time and the substrate temperature on the transport, structural, and morphological properties of as-deposited ZnO:(F, Zr) thin films are presented in this paper. A decrease in the electrical resistivity values is observed as the starting solution used is more aged, reaching a minimum resistivity of the order of 1.3×10^-2 Ω cm in samples deposited from a 17-day-aged solution, then increasing in samples deposited from solutions aged beyond this ageing time. According to the characterization results, the surface morphology is dependent on the solution ageing time. The X-ray diffraction patterns reveal that the ZnO:(F, Zr) thin films are polycrystalline in nature, fitting well with a hexagonal wurtzite structure, and showing the (0 0 2) planes as preferential growth in all the deposited films. The average optical transmittance, measured in the near UV-visible region, was of the order of 75% in all the cases.