1. Controlled Growth of Zn-Polar ZnO Films on Al-Terminated ?-Al2O3(0001) Surface by Using Wurtzite MgO Buffer.
- Author
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Yuan Hong, Liu Yu, Wang Xi, Li Han, Wang Yong, Zeng Zhao, Mei Zeng, Du Xiao, Jia Jin, Xue Qi, Kun and, and Zhang Ze
- Subjects
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ZINC oxide thin films , *ALUMINUM oxide , *WURTZITE , *MAGNESIUM oxide , *RADIO frequency , *MOLECULAR beam epitaxy , *ELECTRON diffraction - Abstract
The controlled growth of Zn-polar ZnO films on Al-terminated a-Al2O3 (0001) substrates is investigated by the radio-frequency plasma-assisted molecular beam epitaxy method. Prior to the growth, a-Al2O3 (0001) surface is modified by an ultrathin MgO layer, which serves as a uniform template for epitaxy of Zn-polar ZnO films. The microstructures of ZnO/MgO/Al2O3 interface are investigated by in-situ reflection high-energy electron diffraction observations and ex-situ high-resolution transmission electron microscopy characterization. It is found that under Mg-rich condition, the achievement of the wurtzite MgO ultrathin layer plays a key role in the subsequent growth of Zn-polar ZnO. An interfacial atomic model is proposed to explain the mechanism of polarity selection of both MgO and ZnO films. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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