Enhanced physical characteristics of ZnO thin films through Sr and Mg co-doping

In this study, undoped ZnO, (Sr, Mg) co-doped ZnO (SMZO) thin films were synthetised on heated glass substrates at a temperature of 250°C by using ultrasonic spray technique. Doping strontium (Sr) and magnesium (Mg) into zinc oxide (ZnO) offers an important way to modify various properties. X-ray diffraction (XRD) confirmed that the films exhibited the hexagonal wurtzite structure of ZnO with a favored orientation along (002) plane. Scanning electron microscope (SEM) showed a strong change in the surface morphology while Energy dispersive X-ray spectrometer (EDX) and mapping confirmed the purity of the films. UV-Visible studies demonstrated that the optical transmittance was improved to an average value above 94% and that Mg-doping induces an increase of the band gap indicating high optical quality of the films. From the fabricated films, SMZO3 is the most appropriate for optoelectronic applications where a low resistivity and high figure of merit were obtained. © 2021 Informa UK Limited, trading as Taylor & Francis Group.