Morphology, optical and luminescence properties of ZnO layers doped with Al or Ag and co-doped with rare earth ions

Abstract

In this paper we propose a method for measuring the negative refraction index of films of optically transparent materials. Morphological, optical and luminescence properties of rare earth doped ZnO layers prepared by a sol-gel method with spin-coating, by magnetron sputtering, and by aerosol spray pyrolysis are investigated in this paper by means of atomic force microscopy (AFM), optical absorption and luminescence spectroscopy at room temperature. It was found that the morphology of layers prepared by spin-coating is influenced by rare earth doping, a mechanism being proposed for the explanation of this influence. Optical transmission up to 90%, and the absorption edge in the region of exciton resonances have been demonstrated in ZnO layers prepared by sol-gel spin coating. The photoluminescence characterization of ZnO layers doped with Eu3+ and Er3+ ions suggests that the rare earth ion is incorporated into the wurtzite ZnO host by substitution on the Zn sublattice.