Size and Shape Evolution of GaAsSb-Capped InAs/GaAs Quantum Dots: Dependence on the Sb Content

Autor: Khairiah Alshehri, Abdelmajid Salhi, Niyaz Ahamad Madhar, Bouraoui Ilahi
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Crystals, Vol 9, Iss 10, p 530 (2019)
Druh dokumentu: article
ISSN: 2073-4352
DOI: 10.3390/cryst9100530
Popis: Capping InAs/GaAs quantum dots (QDs) with a thin GaAsSb layer alters the QDs structural properties, leading to considerable changes in their optical properties. The increase of the Sb content induces a redshift of the emission energies, indicating a change in the buried QDs shape and size. The presence of well-defined ground- and excited-state emission bands in all the photoluminescence spectra allow an accurate estimation of the buried QDs size and shape by numerical evaluation and tuning of the theoretical emission energies. For an Sb content below 14%, the QDs are found to have a type I band alignment with a truncated height pyramidal form. However, for higher Sb content (22%), the QDs are present in a full pyramidal shape. The observed behavior is interpreted in terms of increasing prevention of InAs QDs decomposition with increasing the Sb content in the cap layer.
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