| Summary: | The preparation of ZnO:Al thin films on the glass substrate by DC sputtering method and characterization of their physical properties have been done. The crystalline structure of the films were characterized using XRD. The XRD's result showed that the ZnO:Al thin films deposited on the glass substrate were polycrystalline with c-axis oriented perpendicular and parallel to the substrate surface. The surface morphology of ZnO:Al thin films were determined using SEM, and its result showed that the grain size increase with the Al203-doping concentration and distributed homogeneously. From elemental composition analysis using EDS, it was found that the composition of ZnO:Al thin films at Al203-doping concentration of 2% was 43.55 at.% Zn, 42.59 at.% 0, and 3.11 at.% Al. The optical properties of ZnO:Al thin films were determined using UV-Vis spectrophotometer, its result showed that the transmittance of ZnO:Al thin films decrease with the increasing of substrate temperature at Al203-doping concentration of 2% and the average transmittance of the films was 85% in the wavelength range of (350+1100) nm. The addition of aluminum on ZnO thin films increased the refraction index, and trend to reach 1.9 for lower substrate temperature and 2.3 forhigher substrate temperature in the visible region. The electrical properties of ZnO:Al thin films were determined using four point probe technique, its result showed that the resistivity of ZnO:Al thin films depend strongly on Al203-doping concentration. The optimum Al203-doping concentration were obtained at concentration of 2% and the resistivity of films trend to decrease with the increasing of the substrate temperature.
Keywords : ZnO, ZnO:Al, sputtering, electrical and optical properties
|
|---|