Journal article
Study of Size, Shape, and Etch pit formation in InAs/InP Droplet Epitaxy Quantum Dots
Nanotechnology, Vol.33(30), p.305705
07/23/2022
DOI: 10.1088/1361-6528/ac659e
PMID: 35395644
Abstract
We investigated metal-organic vapor phase epitaxy grown droplet epitaxy (DE) and Stranski-Krastanov (SK) InAs/InP quantum dots (QDs) by cross-sectional scanning tunneling microscopy (X-STM). We present an atomic-scale comparison of structural characteristics of QDs grown by both growth methods proving that the DE yields more uniform and shape-symmetric QDs. Both DE and SKQDs are found to be truncated pyramid-shaped with a large and sharp top facet. We report the formation of localized etch pits for the first time in InAs/InP DEQDs with atomic resolution. We discuss the droplet etching mechanism in detail to understand the formation of etch pits underneath the DEQDs. A summary of the effect of etch pit size and position on fine structure splitting (FSS) is provided via the k · p theory. Finite element (FE) simulations are performed to fit the experimental outward relaxation and lattice constant profiles of the cleaved QDs. The composition of QDs is estimated to be pure InAs obtained by combining both FE simulations and X-STM results. The preferential formation of {136} and {122} side facets was observed for the DEQDs. The formation of a DE wetting layer from As-P surface exchange is compared with the standard SKQDs wetting layer. The detailed structural characterization performed in this work provides valuable feedback for further growth optimization to obtain QDs with even lower FSS for applications in quantum technology.
Details
- Title: Subtitle
- Study of Size, Shape, and Etch pit formation in InAs/InP Droplet Epitaxy Quantum Dots
- Creators
- Raja S R Gajjela - Eindhoven University of TechnologyNiels R S van Venrooij - Eindhoven University of TechnologyAdonai R da Cruz - Eindhoven University of TechnologyJoanna Skiba-Szymanska - Toshiba (United Kingdom)R Mark Stevenson - Toshiba (United Kingdom)Andrew J Shields - Toshiba (United Kingdom)Craig E Pryor - University of IowaPaul M Koenraad - Eindhoven University of Technology
- Resource Type
- Journal article
- Publication Details
- Nanotechnology, Vol.33(30), p.305705
- DOI
- 10.1088/1361-6528/ac659e
- PMID
- 35395644
- NLM abbreviation
- Nanotechnology
- ISSN
- 0957-4484
- eISSN
- 1361-6528
- Publisher
- IOP Publishing
- Number of pages
- 9
- Grant note
- 721394 / European Union project FQLight / InnovateUK
- Language
- English
- Date published
- 07/23/2022
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984428809402771
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