Type I - type II band alignment of GaAsSb/InAs/GaAs quantum dot heterostructure influenced by dot size and strain reducing layer composition

0391944 - FZÚ 2014 RIV GB eng J - Journal Article
Hospodková, Alice - Zíková, Markéta - Pangrác, Jiří - Oswald, Jiří - Kubištová, Jana - Kuldová, Karla - Hazdra, P. - Hulicius, Eduard
Type I - type II band alignment of GaAsSb/InAs/GaAs quantum dot heterostructure influenced by dot size and strain reducing layer composition.
Journal of Physics D-Applied Physics. Roč. 46, č. 9 (2013), "095103-1"-"095103-9". ISSN 0022-3727. E-ISSN 1361-6463
R&D Projects: GA ČR GAP102/10/1201; GA MŠMT(CZ) LM2011026
Institutional support: RVO:68378271
Keywords : quantum dot * band alignment * InAs/GaAs * GaAsSb * MOVPE
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 2.521, year: 2013
http://iopscience.iop.org/0022-3727/46/9/095103/

The aim of this work is to redshift quantum dot (QD) photoluminescence (PL) towards telecommunication wavelengths by engineering the MOVPE prepared structure of InAs/GaAs QDs covered by GaAsSb strain reducing layer. Our results proved that the type I or type II band alignment can be controlled by both, GaAsSb composition and QD size. Maintaining type I heterostructure is important for high luminescence efficiency and emission wavelength stability of QD structure. The simulation of electron structure in InAs QD covered with GaAsSb strain reducing layer as well as experimental results suggest the importance of increasing QD size for obtaining a longer wavelength PL from type I heterostructure. The PL maximum wavelength 1371 nm was achieved for the MOVPE prepared type I QD structure with 14% of Sb in GaAsSb. This type of structure exhibits seven times higher PL intensity, twice narrower PL peak and 85 meV red shift in comparison to similarly prepared QDs covered by GaAs.
Permanent Link: http://hdl.handle.net/11104/0220900