Nonuniform composition profile in In0.5Ga0.5As alloy quantum dots

被引:251
作者
Liu, N [1 ]
Tersoff, J
Baklenov, O
Holmes, AL
Shih, CK
机构
[1] Univ Texas, Dept Phys, Austin, TX 78712 USA
[2] IBM Corp, Div Res, TJ Watson Res Ctr, Yorktown Heights, NY 10598 USA
[3] Univ Texas, Dept Elect & Comp Engn, Austin, TX 78712 USA
关键词
D O I
10.1103/PhysRevLett.84.334
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
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.
引用
收藏
页码:334 / 337
页数:4
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