ZnO Nanowires Synthesized by Vapor Phase Transport Deposition on Transparent Oxide Substrates
1 Department of Mechanical Engineering, Virginia Commonwealth University, 401 W. Main Street, P.O. Box 843015, Richmond, VA, 23284-3015, USA
2 Department of Chemistry and Environmental Science, University of Texas at Brownsville, 80 Fort Brown, Brownsville, TX, 78520, USA
3 Department of Mechanical Engineering, Virginia Commonwealth University, 401 W. Main Street, P.O. Box 843015, Richmond, VA, 23284-3015, USA
4 Department of Materials Science and Engineering, University of Florida, 320 MAE, Gainesville, FL, 32611, USA
5 Department of Mechanical and Aerospace Engineering, University of Florida, 320 MAE, Gainesville, FL, 32611, USA
Nanoscale Research Letters 2010, 5:1333-1339 doi:10.1007/s11671-010-9649-3Published: 28 May 2010
Zinc oxide nanowires have been synthesized without using metal catalyst seed layers on fluorine-doped tin oxide (FTO) substrates by a modified vapor phase transport deposition process using a double-tube reactor. The unique reactor configuration creates a Zn-rich vapor environment that facilitates formation and growth of zinc oxide nanoparticles and wires (20–80 nm in diameter, up to 6 μm in length, density <40 nm apart) at substrate temperatures down to 300°C. Electron microscopy and other characterization techniques show nanowires with distinct morphologies when grown under different conditions. The effect of reaction parameters including reaction time, temperature, and carrier gas flow rate on the size, morphology, crystalline structure, and density of ZnO nanowires has been investigated. The nanowires grown by this method have a diameter, length, and density appropriate for use in fabricating hybrid polymer/metal oxide nanostructure solar cells. For example, it is preferable to have nanowires no more than 40 nm apart to minimize exciton recombination in polymer solar cells.