Atom-resolved scanning tunneling microscopy of vertically ordered InAs quantum dots
Atom-resolved scanning tunneling microscopy of vertically ordered InAs quantum dots
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垂直有序 InAs 量子点的原子分辨扫描隧道显微镜
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
J. Harris
中科院分区：
文献类型：
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作者：
Warren Wu;J. Tucker;G. Solomon;J. Harris
我们目前的横截面扫描隧道显微镜（STM）图像的应变诱导，自组织生长在GaAs上的InAs量子点。含有5和10个顺序生长的点层的样品进行了研究，从不同的层的点被认为是在垂直列对齐。我们的STM图像与以前的结构成像，如横截面透射电子显微镜，一般协议，除了点冠出现更多的截断。虽然大多数列中的点的大小大致恒定，但在某些情况下观察到直径的单调变化。STM分析还揭示了许多新的原子分辨的电子结构的细节，包括溶解的InAs润湿层和点列之间的铟的存在下，我们归因于偏析和扩散的铟的润湿层在过度生长。
We present cross-sectional scanning tunneling microscopy (STM) images of strain-induced, self-organized InAs quantum dots grown on GaAs. Samples containing 5 and 10 sequentially grown dot layers are investigated, and dots from different layers are seen to align in vertical columns. Our STM images are in general agreement with previous structural imaging, such as cross-sectional transmission electron microscopy, except that dot crowns appear more truncated. Although the size of the dots in most columns is roughly constant, monotonic changes in diameter are observed in some cases. STM analysis also reveals many new atom-resolved details of electronic structure, including dissolution of the InAs wetting layer and the presence of indium between the dot columns, which we attribute to segregation and diffusion of indium out of the wetting layer during overgrowth.