Morphology and growth of capped Ge/Si quantum dots

被引：5

作者：

Yacoby, Yizhak ^{[1
]}

Elfassy, Naomi ^{[2
]}

Ray, Samit K. ^{[3
]}

Singha, Raj K. ^{[3
]}

Das, Samaresh ^{[3
]}

Cohen, Eyal ^{[2
]}

Yochelis, Shira ^{[2
]}

Clarke, Roy ^{[4
,5
]}

Paltiel, Yossi ^{[2
]}

机构：

[1] Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel

[2] Hebrew Univ Jerusalem, Dept Appl Phys, IL-91904 Jerusalem, Israel

[3] Indian Inst Technol, Dept Phys & Meteorol, Kharagpur 721302, W Bengal, India

[4] Univ Michigan, Appl Phys Program, Ann Arbor, MI 48109 USA

[5] Univ Michigan, Ctr Solar & Thermal Energy Convers, Ann Arbor, MI 48109 USA

来源：

JOURNAL OF NANOPARTICLE RESEARCH | 2013年 / 15卷 / 05期

基金：

以色列科学基金会;

关键词：

Nano-crystals; Quantum dots; X-ray crystallography; Self-assembly; MBE; GE DOTS; COMPOSITION PROFILES; SOLAR-CELLS; ISLANDS; EVOLUTION;

D O I：

10.1007/s11051-013-1608-3

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The morphology, atomic structure, and chemical composition of small (4 nm average height and 20 nm average diameter), dense capped MBE-grown Ge/Si quantum dots are studied using an energy-differential extension of the direct X-ray phasing method, COBRA. Our results lead to the following conclusions: (i) the quantum dot system has a partial wetting layer; (ii) in the lower parts of the dots, the Ge content is small and increases toward the top; and (iii) the contact angle between the dots and the substrate is acute, consistent with the presence of a wetting layer. A growth mechanism compatible with these findings is proposed.

引用

页数：7

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