Semiconducting and piezoelectric nanoarchitectures of ZnO

ZnO is a semiconducting and piezoelectric material. The structure of ZnO can be described as a number of alternating planes composed of tetrahedrally coordinated O$^{2-}$ and Zn$^{2+}$ ions, stacked alternatively along the $c$-axis. The oppositely charged ions produce positively charged (0001)-Zn and negatively charged (000-1)-O polar surfaces, resulting in a normal dipole moment and spontaneous polarization along the $c$-axis. We have synthesized a series of novel nanostructures of ZnO utilizing the effect from the polar surface [1-4]e. The piezoelectric coefficient of a piezoelectric nanobelt has been found to be almost tripled compared to the value of the bulk [5], clearly indicating the exciting applications of piezoelectric ZnO nanobelts for nano-scale electromechanical coupled sensors, transducers, switches and resonators. This presentation will focus on the growth mechanisms and potential applications of piezoelectric nanobelts, nanorings and nanosprings. \newline \newline [1] Z.W. Pan, Z.R. Dai and Z.L. Wang, \textit{Science}, 209 (2001) 1947. [2] X.Y. Kong and Z.L. Wang, \textit{Nano Letters}, 2 (2003) 1625 + cover. [3] Z.L. Wang, X.Y. Kong and J.M. Zuo, \textit{Phys. Rev. Letts}. 91 (2003) 185502. [4] X.Y. Kong, Y. Ding, R.S. Yang, Z.L. Wang, Science, 303 (2004) 1348. [5] M. Zhao, Z.L. Wang, S. X.Mao, Nano Letters, 4 (2004) 587. [6] For details please visit http://www.nanoscience.gatech.edu/zlwang/