Nano Express

Nanoscale Research Letters

, Volume 4, Issue 6, pp 503-512

Open Access This content is freely available online to anyone, anywhere at any time.

Tapered ZnO Whiskers: {hkil}-Specific Mosaic Twinning VLS Growth from a Partially Molten Bottom Source

  • Bang-Hao HuangAffiliated withDepartment of Materials and Optoelectronic Science, Institute of Materials Science and Engineering, National Sun Yat-sen University
  • , Pouyan ShenAffiliated withDepartment of Materials and Optoelectronic Science, Institute of Materials Science and Engineering, National Sun Yat-sen University
  • , Shuei-Yuan ChenAffiliated withDepartment of Mechanical and Automation Engineering, I-Shou University Email author 

Abstract

Zn particulates overlaid with wurtzite (W)-type ZnO condensates having nearly orthogonal \( \left\{ { 10\bar{1}1} \right\} \) and \( \left\{ {11\bar{2} 1} \right\} \) 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 \( \left\{ { 10\bar{1}1} \right\} \) and \( \left\{ {2\bar{1} \bar{1} 1} \right\} \) 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.

Keywords

ZnO Whiskers Pulsed laser ablation VLS Photoluminescence