Phase Separation Induced by Au Catalysts in Ternary InGaAs Nanowires

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• 作者：Ya-Nan Guo ; Hong-Yi Xu ; Graeme J. Auchterlonie ; Tim Burgess ; Hannah J. Joyce ; Qiang Gao ; Hark Hoe Tan ; Chennupati Jagadish ; Hai-Bo Shu ; Xiao-Shuang Chen ; Wei Lu ; Yong Kim ; Jin Zou
• 刊名：Nano Letters
• 出版年：2013
• 出版时间：February 13, 2013
• 年：2013
• 卷：13
• 期：2
• 页码：643-650
• 全文大小：466K
• 年卷期：v.13,no.2(February 13, 2013)
• ISSN：1530-6992

文摘

We report a novel phase separation phenomenon observed in the growth of ternary In_xGa_1-xAs nanowires by metalorganic chemical vapor deposition. A spontaneous formation of core鈥搒hell nanowires is investigated by cross-sectional transmission electron microscopy, revealing the compositional complexity within the ternary nanowires. It has been found that for In_xGa_1-xAs nanowires high precursor flow rates generate ternary In_xGa_1-xAs cores with In-rich shells, while low precursor flow rates produce binary GaAs cores with ternary In_xGa_1-xAs shells. First-principle calculations combined with thermodynamic considerations suggest that this phenomenon is due to competitive alloying of different group-III elements with Au catalysts, and variations in elemental concentrations of group-III materials in the catalyst under different precursor flow rates. This study shows that precursor flow rates are critical factors for manipulating Au catalysts to produce nanowires of desired composition.

Keywords:

III鈭扸 semiconductor nanowires; phase separation; core鈭抯hell nanowires; ternary semiconductors; In_xGa_1-xAs