Microstructural and optical properties of La-doped ZnO thin films deposited by spin coating on quartz glass

Abstract

In this work, we have produced pure and composite zinc oxide-lanthanum oxide thin films. In the process we have started with a pure ZnO thin films and ended up with several lanthanum oxide phases containing thin films (La₂O₃, La(OH)₃ and LaOOH) by introducing La in various levels of concentrations, ranging from 0% to 100%. We have managed to attain crystal phases in all doping concentrations. All the produced thin films have been crystallized at the annealing temperatures of 1000 °C for duration of 6 h. The X-ray diffraction (XRD) patterns have been taken to see the formation of crystal phases of all pure and composite ZnO-lanthanum oxide thin films. XRD results gave insight that the various crystal phases related to ZnO and lanthanum oxide laid together within the thin film matrices, which have been produced in different doping concentrations. The scanning electron microscopy (SEM) micrographs and UV-Vis absorption studies have also been performed to elucidate the composed film structures, together with some optical parameters evaluation such as refractive index and dielectric constant.