Analysis of the structural and optical properties of gold- and copper-catalyzed zinc oxide (ZnO) nanowires (NWs), grown in a high temperature tube furnace on a sapphire substrate shows non-uniformity over the substrate. The changes in the optical properties and the sizes of ZnO NWs grown on a sapphire substrate implicate the changes in the availability of the source material and catalyst over the substrate surface during growth. The copper-catalyzed NWs are longer than the gold-catalyzed NWs; the NW length increases along the carrier gas flow direction for both catalysts. There are systematic changes in the optical properties of the ZnO NWs from the center to the edge of the substrate, and also from upstream to downstream along the gas flow direction. These two distinct trends are labeled the edge trend and the gas flow trend. The edge trend in the copper-catalyzed NWs is due to the larger diameter of the NWs in the middle of the substrate, which leads to increased copper incorporation,. The change in optical properties is more pronounced for copper-catalyzed than gold-catalyzed NWs.
Citation: Journal of Physical Chemistry
Pub Type: Journals
copper, gold, nanotechnology, nanowires, photoluminescence, structural characterization, zinc