Mechanical Strain in Capped and Uncapped Self-Assembled Ge/Si Quantum Dots



Document title: Mechanical Strain in Capped and Uncapped Self-Assembled Ge/Si Quantum Dots
Journal: Brazilian journal of physics
Database: PERIÓDICA
System number: 000389444
ISSN: 0103-9733
Authors: 1
1
2
Institutions: 1Universidade Federal de Goias, Instituto de Ciencias Exatas e Tecnologicas, Jatai, Goias. Brasil
2Universidad de Pamplona, Departamento de Fisica y Geologia, Pamplona, Norte de Santander. Colombia
Year:
Season: Dic
Volumen: 45
Number: 6
Pages: 615-620
Country: Brasil
Language: Inglés
Document type: Artículo
Approach: Experimental, aplicado
English abstract In this study, we numerically calculate the spatial profile of mechanical strain on self-assembled germanium (Ge) quantum dots (QDs) grown on a silicon (Si) substrate. Although the topic has been exhaustively studied, interesting features have not been explained or even mentioned in the literature yet. We studied the effect of the cap layer considering two cases: capped QDs (where a Si cap is present above the Ge QDs) and uncapped QDs (where no Si is present above the Ge QDs). We observed that Ge in the capped QDs is more strained compared with the uncapped QDs. This expected effect is attributed to the additional tension from the Si cap layer. However, the situation is opposite for the Si substrate, it is more strained in the uncapped QD because the Ge layer is less strained in this case. We also calculated the band-edge alignment for the electrons and holes
Disciplines: Física y astronomía
Keyword: Física de materia condensada,
Puntos cuánticos,
Esfuerzos mecánicos,
Perfil espacial
Keyword: Physics and astronomy,
Condensed matter physics,
Quantum dots,
Mechanical strain,
Spatial profile
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