Independent tuning of electron and hole confinement in InAs/GaAs quantum dots through a thin GaAsSbN capping layer

Ulloa, J. M.; Reyes, Daniel; Montes, M.; Yamamoto, Kenji; Sales, D.; González, David; Guzmán, Á.; Hierro, A.

doi:10.1063/1.3673563

Cited by 23 publications

(18 citation statements)

References 15 publications

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“…12 This system allows a huge versatility for band structure engineering, allowing tuning of the band alignment from type-I to different type-II configurations.…”

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confidence: 99%

InAs quantum dot morphology after capping with In, N, Sb alloyed thin films

Keizer

Ulloa

Utrilla

et al. 2014

Applied Physics Letters

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Using a thin capping layer to engineer the structural and optical properties of InAs/GaAs quantum dots (QDs) has become common practice in the last decade. Traditionally, the main parameter considered has been the strain in the QD/capping layer system. With the advent of more exotic alloys, it has become clear that other mechanisms significantly alter the QD size and shape as well. Larger bond strengths, surfactants, and phase separation are known to act on QD properties but are far from being fully understood. In this study, we investigate at the atomic scale the influence of these effects on the morphology of capped QDs with cross-sectional scanning tunneling microscopy. A broad range of capping materials (InGaAs, GaAsSb, GaAsN, InGaAsN, and GaAsSbN) are compared. The QD morphology is related to photoluminescence characteristics.

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“…12 This system allows a huge versatility for band structure engineering, allowing tuning of the band alignment from type-I to different type-II configurations.…”

mentioning

confidence: 99%

InAs quantum dot morphology after capping with In, N, Sb alloyed thin films

Keizer

Ulloa

Utrilla

et al. 2014

Applied Physics Letters

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“…From the analysis of the strain data, the average Sb content in both samples was determined using the same procedure described in Ref. 17. The main conclusions of the TEM analysis are the following:…”

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confidence: 99%

High efficient luminescence in type-II GaAsSb-capped InAs quantum dots upon annealing

Ulloa

Llorens²,

Alén³

et al. 2012

Applied Physics Letters

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Polarization-resolved resonant fluorescence of a single semiconductor quantum dot Appl. Phys. Lett. 101, 251118 (2012) Optical cavity efficacy and lasing of focused ion beam milled GaN/InGaN micropillars J. Appl. Phys. 112, 113516 (2012) Competitive carrier interactions influencing the emission dynamics of GaAsSb-capped InAs quantum dots Appl. Phys. Lett. 101, 231109 (2012) Fluorescence quantum efficiency of CdSe/ZnS quantum dots embedded in biofluids: pH dependence J. Appl. Phys. 112, 104704 (2012) Modification of the conduction band edge energy via hybridization in quantum dots

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“…Thus, as reference conditions for the CL growth, those used in previous studies are considered [12], i.e., a 470°C growth temperature, a ratio of As 4 /Ga beam equivalent pressure of 32, a thickness of 5 nm, and a growth rate of 1 ML s −1 . Regarding the N and Sb contents, a power of 140 W for the RF plasma source and a temperature of 335°C for the Sb effusion cell were chosen as reference source conditions.…”

Section: Resultsmentioning

confidence: 99%

“…The incorporation of N in GaAs, according to the band anticrossing model [11], reduces only the conduction band (CB) of GaAs the same way Sb raises only its VB. Therefore, the use of the quaternary GaAsSbN CL on InAs/GaAs QDs allows tuning independently the electron and hole confinement potentials, as it has already been demonstrated [12]. Moreover, this approach allows modifying the band alignment from type I to type II in both the CB and the VB.…”

Section: Introductionmentioning

confidence: 98%

Long-wavelength room-temperature luminescence from InAs/GaAs quantum dots with an optimized GaAsSbN capping layer

et al. 2014

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An extensive study on molecular beam epitaxy growth conditions of quaternary GaAsSbN as a capping layer (CL) for InAs/GaAs quantum dots (QD) was carried out. In particular, CL thickness, growth temperature, and growth rate were optimized. Problems related to the simultaneous presence of Sb and N, responsible for a significant degradation of photoluminescence (PL), are thereby solved allowing the achievement of room-temperature (RT) emission. A particularly strong improvement on the PL is obtained when the growth rate of the CL is increased. This is likely due to an improvement in the structural quality of the quaternary alloy that resulted from reduced strain and composition inhomogeneities. Nevertheless, a significant reduction of Sb and N incorporation was found when the growth rate was increased. Indeed, the incorporation of N is intrinsically limited to a maximum value of approximately 1.6% when the growth rate is at 2.0 ML s−1. Therefore, achieving RT emission and extending it somewhat beyond 1.3 μm were possible by means of a compromise among the growth conditions. This opens the possibility of exploiting the versatility on band structure engineering offered by this QD-CL structure in devices working at RT.PACS81.15.Hi (molecular beam epitaxy); 78.55.Cr (III-V semiconductors); 73.21.La (quantum dots)

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Independent tuning of electron and hole confinement in InAs/GaAs quantum dots through a thin GaAsSbN capping layer

Cited by 23 publications

References 15 publications

InAs quantum dot morphology after capping with In, N, Sb alloyed thin films

InAs quantum dot morphology after capping with In, N, Sb alloyed thin films

High efficient luminescence in type-II GaAsSb-capped InAs quantum dots upon annealing

Long-wavelength room-temperature luminescence from InAs/GaAs quantum dots with an optimized GaAsSbN capping layer

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