Zinc Oxide Nanowires Grown by Vapor-Phase Transport Using Selected Metal Catalysts: A Comparative Study

We report a comparative study of metal-surface-catalyzed ZnO nanowire growth. The growth is initiated on Si and sapphire substrates, which were prepared with thermal vapor deposited thin metallic films. As described earlier for Au films, these films may change morphology at growth temperatures and catalyze ZnO nanowire growth. Here we use materials diagnostics based on synchrotron X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, photoluminescence, and energy-dispersive X-ray spectroscopy to compare the growth from Au, Ag, Fe, and Ni catalysts. We relate the materials properties of the ZnO nanowires to the substrate and catalyst surface structure and comment on the possible growth modes using each of these metal catalysts.