Nonuniform composition profile in In0.5Ga0.5As alloy quantum dots
Nonuniform composition profile in In0.5Ga0.5As alloy quantum dots
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DOI：
10.1103/physrevlett.84.334
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发表时间：
2000-01-10
影响因子：
8.6
通讯作者：
Shih, CK
中科院分区：
文献类型：
--
作者：
Liu, N;Tersoff, J;Shih, CK
我们使用横截面扫描隧道显微镜检查的形状和成分分布的In0.5Ga0.5As量子点（QD）形成的覆盖异质外延岛。QD具有截棱锥形状。该组合物呈现高度不均匀，具有反三角形形状的富In核。因此，相对于器件建模中通常假设的均匀组成，电子特性将急剧改变。量子点生长的理论分析表明，一个简单的解释，意想不到的形状的富铟核心。
We use cross-sectional scanning tunneling microscopy to examine the shape and composition distribution of In0.5Ga0.5As quantum dots (QDs) formed by capping heteroepitaxial islands. The QDs have a truncated pyramid shape. The composition appears highly nonuniform, with an In-rich core having an inverted-triangle shape. Thus the electronic properties will be drastically altered, relative to the uniform composition generally assumed in device modeling. Theoretical analysis of the QD growth suggests a simple explanation for the unexpected shape of the In-rich core.