Comparison of MOVPE grown GaAs, InGaAs and GaAsSb covering layers for different InAs/GaAs quantum dot applications

0474047 - FZÚ 2018 RIV NL eng J - Článek v odborném periodiku
Zíková, Markéta - Hospodková, Alice - Pangrác, Jiří - Oswald, Jiří - Hulicius, Eduard
Comparison of MOVPE grown GaAs, InGaAs and GaAsSb covering layers for different InAs/GaAs quantum dot applications.
Journal of Crystal Growth. Roč. 464, Apr (2017), s. 59-63. ISSN 0022-0248. E-ISSN 1873-5002
Grant CEP: GA MŠMT LO1603
Institucionální podpora: RVO:68378271
Klíčová slova: MOVPE * quantum dot * strain reducing layer * InAs * GaAsSb * InGaAs
Obor OECD: Condensed matter physics (including formerly solid state physics, supercond.)
Impakt faktor: 1.742, rok: 2017

InAs/GaAs QD HS with different covering layers (CLs) prepared by MOVPE are compared. The recombination energy of a structure covered only by GaAs depends nonlinearly on CL thickness. Experimental data of PL were supported by theoretical simulations. These simulations prove that the strain plays a major role. Due to the strain reduction, the recombination energy is decreased, so the structure has longer PL wavelength. By theoretical simulations it was shown that for high content of In in InGaAs covering layer (45% and more), the heterostructure is type II, which would normally be unreachable for flat layers. For the structure with GaAsSb SRL, the band alignment is highly dependent on the SRL composition. The type I/type II transition occurs for approximately 15% of Sb, this value also slightly depends on the QD size. All structures were also studied by HRTEM to show different behavior of the CLs on the interface with InAs which highly influences the structure quality.
Trvalý link: http://hdl.handle.net/11104/0271146