Effect of Al and Ag co-doping on the structural and optical properties of zinc oxide thin films

In view of the potential applications of Al-Ag co-doped ZnO materials in the fields of optoelectronic and microelectronic devices, in this work, we explored the influence of Al-Ag co-doping on the structure, morphology, bandgap and luminescent properties of ZnO films. ZnAgxAlyO (y=Al/Zn=0, 0.005, 0.01, 0.015 and 0.02; x=Ag/Zn=0.005) thin films were coated on glass substrates by a simple wet chemical method, namely the sol-gel method. The morphology, structure, composition and optical properties of the samples were analyzed by scanning probe microscopy, X-ray diffraction, energy dispersive spectroscopy, ultraviolet-visible absorption spectroscopy and photoluminescence, respectively. The results show that Al-Ag co-doping makes the grain size of ZnO decrease and the films surface become smoother. The c-axis orientation degree is decreased and the ultraviolet emission is weakened. However, within the range of doping concentration studied, Al-Ag co-doping has little effect on the optical bandgap of ZnO films. These results are compared with other reported experimental results about the influence of Al-Ag co-doping on ZnO thin films.