LAUSR

Abstract Aluminium doped zinc oxide (AZO) films were achieved using co-spray method. Different techniques including UV–Visible (UV–Vis), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), Fourier transform infrared (FTIR) and photoelectrochemical (PEC) were used to characterize the obtained films. XRD indicated that all films exhibited single-phase ZnO hexagonal Wurtzite structure. AZO films showed a transparency more than 80% in the visible region with direct optical band gap ranging between 3.24 and 3.28 eV. A broad absorption band due to the stretching vibration of Zn–O bond located at 410 cm−1 was observed for all samples. In the high frequency region, all EIS spectra have only one single half-circle and the diameter decreases in the presence of a specific amount of Al (2–4%). The values of the exponent αCPE from EIS results indicated that ZnO:Al films presented a good homogeneity and smoothness. PEC study indicated that the film generates maximum photocurrents up to 1.2 μA/cm2 for a doping level of 2%.