Ripening of self-organized InAs quantum dots

Pötschke, K.; Müller‐Kirsch, L.; Heitz, R.; Sellin, R.L.; Pohl, Udo W.; Bimberg, D.; Zakharov, N.; Werner, P.

doi:10.1016/j.physe.2003.11.089

Cited by 64 publications

(51 citation statements)

References 11 publications

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“…The difficulty to incorporate antimony inside InAs and InGaAs quantum dots and quantum wells has repeatedly been reported in the literature. [9][10][11] In this work, we show clear evidence of Sb incorporation inside GaSb capped InAs quantum dots with room temperature luminescence at the technologically important wavelength of 1.3 m.…”

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confidence: 53%

Incorporation of Sb in InAs∕GaAs quantum dots

Molina

Sánchez

Beltrán

et al. 2007

Applied Physics Letters

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The formation of a quaternary InGaAsSb alloy is shown to occur in the core of epitaxial GaSb capped InAs/ GaAs quantum dots emitting at 1.3 m. The existence of the four constituent elements is demonstrated by using spatially resolved low-loss electron energy loss spectroscopy and aberration-corrected high angle annular dark field scanning transmission electron microscopy. The intermixing process giving rise to the formation of this quaternary alloy takes place despite the large miscibility gap between InAs and GaSb binary compounds, and is probably driven by the existence of strain in the quantum dots.

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confidence: 53%

Incorporation of Sb in InAs∕GaAs quantum dots

Molina

Sánchez

Beltrán

et al. 2007

Applied Physics Letters

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“…From the figures it is evident that ripening-like behaviour, observed in most of the heteroepitaxial systems [18,19], occurs at the time of in situ annealing during dot pause at high growth temperature (520°C). It is reported that in strained semiconductor systems, the growth pause applied after the formation of self-assembled QDs favours the adatom transfer towards preferential sites on the growth plane like previously formed dots [20].…”

Section: Resultsmentioning

confidence: 97%

A comprehensive study of the effect of in situ annealing at high growth temperature on the morphological and optical properties of self-assembled InAs/GaAs QDs

et al. 2008

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We investigate the effect of in situ annealing during growth pause on the morphological and optical properties of self-assembled InAs/GaAs quantum dots (QDs). The islands were grown at different growth rates and having different monolayer coverage. The results were explained on the basis of atomic force microscopy (AFM) and photo-luminescence (PL) measurements. The studies show the occurrence of ripening-like phenomenon, observed in strained semiconductor system. Agglomeration of the selfassembled QDs takes place during dot pause leading to an equilibrium size distribution. The PL properties of the QDs are affected by the Indium desorption from the surface of the QDs during dot pause annealing at high growth temperature (520°C) subsiding the effect of the narrowing of the dot size distribution with growth pause. The samples having high monolayer coverage (3.4 ML) and grown at a slower growth rate (0.032 ML s −1 ) manifested two different QD families. Among the islands the smaller are coherent defect-free in nature, whereas the larger dots are plastically relaxed and hence optically inactive. Indium desorption from the island surface during the in situ annealing and N. Halder · R. Rashmi · S. Chakrabarti ( ) Centre

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“…This effect is based on material redistribution between the QDs via the WL and is known as ripening. During this ripening process small QDs are dissolved while larger QDs accumulate material, thus the QD density decreases [Pöt04]. Driven by the need to minimize the total QD layer energy, the QD size increases towards a theoretically predicted stable equilibrium [Mol98,Shc99], although experimentally only metastable QD ensembles are observed.…”

Section: Growth Interruptionmentioning

confidence: 99%

“…• Ripening of larger dots for long wavelength emission leads to a reduced QD density, reducing the gain per active layer [Pöt04].…”

Section: Laser Diodes At 13 µMmentioning

confidence: 99%

Design and Realization of Novel GaAs Based Laser Concepts

Germann

2012

Springer Theses

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ZusammenfassungHalbleiterlaser stellen die Grundlage für eine zunehmende Vielzahl von Anwendungen dar, die von der Informationsspeicherung und digitalen Kommunikation bis hin zur Materialbearbeitung reichen. Neuartige Konzepte überwinden bisherige Limitierungen und erschließen neue Anwendungsgebiete. Viele dieser Anwendungsgebiete verlangen nach kostengünstigen Bauelementen, die maximale Brillanz und hohe Ausgangsleistungen oder höchste Geschwindigkeiten erreichen.Diese Arbeit stellt dar, wie essentielle Leistungsmerkmale von Halbleiterlasern durch das Design von Nanostrukturen und epitaktischen Wachstumsprozessen maßgeschneidert werden können. Hierbei wird auf alle Schritte der Laserherstellung eingegangen, vom Design über das Wachstum der Nanostrukturen mittels metallorganischer Gasphasenepitaxie (MOVPE), bis hin zur Herstellung und Charakterisierung kompletter Bauelemente. AbstractSemiconductor lasers represent the backbone for an increasing variety of applications ranging from information storage and communication, to material treatment. Novel concepts are pushing the limits and are enabling new application areas. Many of these areas demand low-cost laser devices with high-brilliance and high-power light output or high-speed performance.This thesis demonstrates how key performance characteristics of semiconductor lasers can be tailored using nanostructure design and epitaxial growth. All aspects of laser fabrication are discussed, from design to growth of nanostructures using metal-organic vapor-phase epitaxy (MOVPE), to fabrication and characterization of complete devices. By employing industrial tools, all developed processes are compatible with mass production.Pulsed high power laser operation up to 8 W and a ultra-low lasing threshold of 66 A/cm 2 is achieved with electrically pumped quantum dots (QD)-based edge emitters at 1.25 µm due to an improved understanding of the QD growth process. This novel process enables 1.3 µm edge emitters for telecom applications in the established InGaAs/GaAs system. At the heart of these achievements is the careful investigation and optimization of nearly all layers of the laser device structure. Designs are altered and precisely tuned by employing AlGaAs or InGaP claddings and varied doping schemes in order to develop new waveguides to meet different requirements.High-power vertical external-cavity surface-emitting lasers (VECSELs) promise continuous-wave (CW) lasing with perfect circular beam quality, plus direct access to the cavity. While the concept is ideal for a multitude of applications, conventional quantumwell based systems exhibit problematic temperature sensitivity during operation. Here, for the first time, VECSELs with sub-monolayer structures and QDs as active layers are realized by MOVPE. These optically pumped devices cover a wide spectral range from 950 nm to 1210 nm, and achieve excellent temperature-stable CW lasing due to the use of QDs and CW output powers of up to 1.4 W.In order to overcome the physical limitations of directly modulated vertical-c...

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Ripening of self-organized InAs quantum dots

Cited by 64 publications

References 11 publications

Incorporation of Sb in InAs∕GaAs quantum dots

Incorporation of Sb in InAs∕GaAs quantum dots

A comprehensive study of the effect of in situ annealing at high growth temperature on the morphological and optical properties of self-assembled InAs/GaAs QDs

Design and Realization of Novel GaAs Based Laser Concepts

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