Effect of Al doping and TiO2 interlayer on the physical properties of ZnO thin films deposited by spray pyrolysis

Abstract

In this study, the effects of Aluminum doping and a titanium dioxide (TiO2) interlayer on the structural and optical properties of ZnO thin films were investigated. Undoped (ZG) and Al-doped ZnO (AZG) films were fabricated on glass substrates, with and without a TiO2 interlayer, using spray pyrolysis technique. The samples underwent characterization via FTIR, and UV–Vis spectroscopy. FTIR analysis particularly confirmed the presence of vibrational modes related to TiO2 and ZnO as well as the successful incorporation of Al into the ZnO crystal. UV–Vis results indicated significant impacts on transparency and the Urbach energy, with Al doping alone reducing the band gap. The determination of the refractive index of the thin films has been performed by exploitation UV-Vis transmittance spectra.