Microstructure of ZnO:Er Films Prepared by Magnetron Sputtering

Er-doped ZnO (ZnO:Er) thin films were grown on quartz and p-Si substrates at 25 degrees C by radio-frequency magnetron sputtering method. The effect of the heat treatment at 600 and 900 degrees C on the properties of the films was analyzed by scanning electron microscopy, energy dispersive x-ray spectroscopy, atomic force microscopy and X-ray diffraction analysis. A homogeneous elements distribution is revealed for all investigated films on different substrates. ZnO:Er films were found to be uniform, pinhole-free, well adherent to the substrate and the crystal grain size is dependent on the type of substrate and the preparation conditions. All the films showed a (002) preferential orientation with the c-axis perpendicular to the substrate surface. The results obtained from XRD spectra reveal that Er3+ ions successfully substitute for Zn2+ ions in the ZnO lattice.