Microstructural and electrical characterizations of transparent Er-doped ZnO nano thin films prepared by sol–gel process

In this study, rare earth element (Er) doped ZnO nano thin films which have dual structure of (Zn_1−xEr_x)O (x = 0.0, 0.01, 0.02, 0.03, 0.04 and 0.05) are prepared by using sol–gel method. The microstructure and electrical properties of prepared nano thin films are investigated. Nano thin films are coated on the glass substrate by using the dip coating method. The films are annealed at 600 °C for 30 min. The X-ray diffractometer (XRD), scanning electron microscopy and atomic force microscopy are used to determine the structural properties such as crystal structures, grain sizes, surface morphology; Hall effect measurements system is used to investigate the electrical properties of materials. XRD results showed that all Er doped nano thin films have a hexagonal structure and (002) orientation. Surface morphologies of ZnErO thin films are denser and more uniform than the undoped ZnO thin film. According to the Hall effect measurements, the resistivity of the films decreased with increasing Er concentration from 0 to 4 % and then slightly increased at 5 % Er.