Size and shape tunability of self-assembled InAs/GaAs nanostructures through the capping rate
| Autor: | Davide F. Grossi, Teresa Ben, D.F. Reyes, V. Braza, A. Gonzalo, Adrian Hierro, David González, Álvaro Guzmán, A. D. Utrilla, PM Paul Koenraad, JM José Maria Ulloa |
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| Přispěvatelé: | Photonics and Semiconductor Nanophysics, Center for Quantum Materials and Technology Eindhoven, Semiconductor Nanostructures and Impurities |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Nanostructure
Materials science Annealing (metallurgy) General Physics and Astronomy 02 engineering and technology Electronic structure Epitaxy 01 natural sciences Wetting layer 0103 physical sciences 010302 applied physics business.industry Quantum dot Surfaces and Interfaces General Chemistry Capping rate 021001 nanoscience & nanotechnology Condensed Matter Physics Dissolution process Surfaces Coatings and Films Nanocrystal Optoelectronics 0210 nano-technology business Molecular beam epitaxy Quantum ring |
| Zdroj: | Applied Surface Science, 444, 260-266. Elsevier |
| ISSN: | 0169-4332 |
| Popis: | The practical realization of epitaxial quantum dot (QD) nanocrystals led before long to impressive experimental advances in optoelectronic devices, as well as to the emergence of new technological fields. However, the necessary capping process is well-known to hinder a precise control of the QD morphology and therefore of the possible electronic structure required for certain applications. A straightforward approach is shown to tune the structural and optical properties of InAs/GaAs QDs without the need for any capping material different from GaAs or annealing process. The mere adjust of the capping rate allows controlling kinetically the QD dissolution process induced by the surface In-Ga intermixing taking place during overgrowth, determining the final metastable structure. While low capping rates make QDs evolve into more thermodynamically favorable quantum ring structures, increasing capping rates help preserve the QD height and shape, simultaneously improving the luminescence properties. Indeed, a linear relationship between capping rate and QD height is found, resulting in a complete preservation of the original QD geometry for rates above ∼2.0 ML s−1. In addition, the inhibition of In diffusion from the QDs top to the areas in between them yields thinner WLs, what could improve the performance of several QD-based optoelectronic devices. |
| Databáze: | OpenAIRE |
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