Nano Express
Tapered ZnO Whiskers: {hkil}-Specific Mosaic Twinning VLS Growth from a Partially Molten Bottom Source
1 Department of Materials and Optoelectronic Science, Institute of Materials Science and Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan, ROC
2 Department of Mechanical and Automation Engineering, I-Shou University, Kaohsiung, Taiwan, ROC
Nanoscale Research Letters 2009, 4:503-512 doi:10.1007/s11671-009-9273-2
Published: 25 February 2009Abstract
Zn particulates overlaid with wurtzite (W)-type ZnO condensates having nearly orthogonal
and 
facets were found to self-catalyze unusual tapered W-ZnO whiskers upon isothermal
atmospheric annealing, i.e., thermal oxidation, at 600 °C. Analytical electron microscopic
observations indicated that such whiskers formed tapered slabs having mosaic 
and 
twinned domains. The tapered whiskers can be rationalized by an alternative vapor–liquid–solid
growth, i.e., {hkil}-specific coalescence twinning growth from the ZnO condensates taking advantage of
a partially molten bottom source of Zn and the adsorption of atoms at the whisker
tips and ledges under the influence of capillarity effect. The tapered whiskers having
strong photoluminescence at 391 nm and with a considerable flexibility could have
potential applications.
