Synthesis, characterization and growth mechanism of ZnO microprisms over Ce(NO₃)₃-coated Si substrates

Institute of Semiconductor, Shandong Normal University, Jinan, 250014, P.R. China

^a e-mail: zhuanghuizhao@sdnu.edu.cn

Received: 6 September 2010
Accepted: 10 December 2010
Published online: 21 July 2011

Abstract

Synthesis of ZnO microprisms was achieved on Si substrates coated with Ce(NO₃)₃ thin films by a simple carbon-thermal evaporation method. The pre-deposited Ce(NO₃)₃ films may decompose at about 200 °C to be CeO₂ microparticles, which can provide growing sites for the ZnO microstructures. The structural and optical properties of the as-obtained ZnO microstructures were characterized by a number of techniques, including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, Fourier transform infrared spectrum and photoluminescence. The results indicate that the as-prepared ZnO microprisms exhibit hexagonal prism-like platforms showing well-defined crystallographic facets and hexagonal pyramid-like tops. Room temperature photoluminescence spectrum of the microstructures shows a strong ultraviolet emission band accompanied by a broad weak green emission band. Finally, the growth mechanism was discussed based on the experimental conditions and the ZnO crystal growth habits.