Combined vertically correlated InAs and GaAsSb quantum dots separated by triangular GaAsSb barrier
- Institute of Physics AS CR, v. v. i., Cukrovarnická 10, 162 00, Prague 6 (Czech Republic)
- Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece)
The aim of this work is to offer new possibilities for quantum dot (QD) band structure engineering, which can be used for the design of QD structures for optoelectronic and single photon applications. Two types of QDs, InAs and GaAsSb, are combined in self assembled vertically correlated QD structures. The first QD layer is formed by InAs QDs and the second by vertically correlated GaAsSb QDs. Combined QD layers are separated by a triangular GaAsSb barrier. The structure can be prepared as type-I, with both electrons and holes confined in InAs QDs, exhibiting a strong photoluminescence, or type-II, with electrons confined in InAs QDs and holes in GaAsSb QDs. The presence of the thin triangular GaAsSb barrier enables the realization of different quantum level alignment between correlated InAs and GaAsSb QDs, which can be adjusted by structure parameters as type-I or type-II like for ground and excited states separately. The position of holes in this type of structure is influenced by the presence of the triangular barrier or by the size and composition of the GaAsSb QDs. The electron-hole wavefunction overlap and the photoluminescence intensity alike can also be controlled by structure engineering.
- OSTI ID:
- 22257801
- Journal Information:
- Journal of Applied Physics, Vol. 114, Issue 17; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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