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arXiv · 1303.5298

Compared growth mechanisms of Zn-polar ZnO nanowires on O-polar ZnO and on sapphire

Guillaume Perillat-Merceroz·Robin Thierry·Pierre-Henri Jouneau·Pierre Ferret·Guy Feuillet
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Abstract

Controlling the growth of zinc oxide nanowires is necessary to optimize the performances of nanowire-based devices such as photovoltaic solar cells, nano-generators, or light-emitting diodes. In this view, we investigate the nucleation and growth mechanisms of ZnO nanowires grown by metalorganic vapor phase epitaxy either on O-polar ZnO or on sapphire substrates. Whatever the substrate, ZnO nanowires are Zn-polar, as demonstrated by convergent beam electron diffraction. For growth on O-polar ZnO substrate, the nanowires are found to sit on O-polar pyramids. As growth proceeds, the inversion domain boundary moves up in order to remain at the top of the O-polar pyramids. For growth on sapphire substrates, the nanowires may also originate from the sapphire / ZnO interface. The presence of atomic steps and the non-polar character of sapphire could be the cause of the Zn-polar crystal nucleation on sapphire, whereas it is proposed that the segregation of aluminum impurities could account for the nucleation of inverted domains for growth on O-polar ZnO.

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Guillaume Perillat-Merceroz, Robin Thierry, Pierre-Henri Jouneau, Pierre Ferret, Guy Feuillet. 2013-03-21. Compared growth mechanisms of Zn-polar ZnO nanowires on O-polar ZnO and on sapphire. https://doi.org/10.1088/0957-4484%2F23%2F12%2F125702

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