Phase Segregation in AlInP Shells on GaAs Nanowires
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- 作者：Niklas Skö ; ld ; Jakob B. Wagner ; Gunnel Karlsson ; Tania Herná ; n ; Werner Seifert ; Mats-Erik Pistol ; Lars Samuelson
- 刊名：Nano Letters
- 出版年：2006
- 出版时间：December 2006
- 年：2006
- 卷：6
- 期：12
- 页码：2743 - 2747
- 全文大小：167K
- 年卷期：v.6,no.12(December 2006)
- ISSN：1530-6992
文摘
We have studied morphology and phase segregation of AlInP shells on GaAs nanowires. Photoluminescence measurements on single core-shell nanowires indicated variations in the shell composition, and phase segregation was confirmed by cross-sectional scanning transmissionelectron microscopy on 30 nm thin slices of the wires. It was discovered that Al-rich domains form in the <112> directions where two {110}shell facets meet during growth. We propose that the mechanism behind this phase segregation is a variation in the chemical potential alongthe circumference of the nanowire together with a difference in diffusion lengths for the different growth species. From the morphology of thecore and the shell, we conclude that the side facet growth is temperature dependent forming {112} facets at low growth temperature and{110} facets at high growth temperature.