Role of group V exchange on the shape and size of InAs/InP self-assembled nanostructures

Gutiérrez, Humberto; Cotta, M. A.; Bortoleto, J. R. R.; Carvalho, M.M.G. de

doi:10.1063/1.1524014

Cited by 48 publications

(30 citation statements)

References 17 publications

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“…5.1), where the dots were grown on InGaAsP, supports this explanation (As/P exchange is reduced on an InGaAsP surface) [90]. Similar observations have been previously reported for InAs QDs grown on (001) InP, and explained in a similar way [92]. Figure 5.32 is representative of what was observed when CLl was 2 or 3 nm thick.…”

Section: Double Capping Processsupporting

confidence: 75%

InAs Quantum Dot Formation Studied at the Atomic Scale by Cross-sectional Scanning Tunnelling Microscopy

Ulloa

Offermans

Koenraad

2008

Handbook of Self Assembled Semiconductor Nanostructures for Novel Devices in Photonics and Electronics

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Introduction Quantum dot formationSelf-assembled quantum dots (QDs) have attracted much attention in the last years [1,2]. These nanostructures are very interesting from a scientific point of view because they form nearly ideal zero-dimensional systems in which quantum confinement effects become very important. These unique properties also make them very interesting from a technological point of view. For example, InAs QDs are employed in QD lasers [3,4], single electron transistors [5], midinfrared detectors [6,7], single-photon sources [8,9], etc. InAs QDs are commonly created by the Stranski-Krastanov growth mode when InAs is deposited on a substrate with a bigger lattice constant, like GaAs or InP [10]. Above a certain critical thickness of InAs, three-dimensional islands are spontaneously formed on top of a wetting layer (WL) to reduce the strain energy. Once created, the QDs are subsequently capped, a step which is required for any device application.For any application based on InAs QDs, an accurate control of their electronic properties is required. The electron and hole states in the dot are very sensitive to the QD size, shape and composition (as well as to the surrounding material), and therefore an accurate control of the QD structural properties is necessary for applications. This explains the strong effort dedicated in the last years to the structural characterization of QDs [11], which is essential in order to have a deep understanding of the QD formation process. Although a lot of effort has been dedicated to study surface QDs, there are relatively few studies focused on the effect of the capping process [12][13][14][15][16][17][18][19][20]. Some of these studies have already shown significant differences in size, shape and composition between uncapped and capped QDs. For example, an important collapse of the QD height has been reported for InAs/GaAs QDs capped with GaAs [14,15,[17][18][19], revealing the big influence of the capping process on the structural properties of the QDs. Indeed, critical issues affecting the dot take place during capping like dot decomposition, intermixing, segregation, As/P exchange and composition modulation in the capping layer. This means that the real buried QDs must be studied in order to understand the complete QD formation process. Cross-sectional scanning tunnelling microscopy is an especially useful technique for this purpose, because it allows the structure of the capped dots at the atomic scale to be assessed. Cross-sectional scanning tunnelling microscopy (X-STM)The scanning tunnelling microscope is part of the family of scanning probe microscopes, which are able to provide direct real space information of a physical property at the atomic scale. This

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Section: Double Capping Processsupporting

confidence: 75%

InAs Quantum Dot Formation Studied at the Atomic Scale by Cross-sectional Scanning Tunnelling Microscopy

Ulloa

Offermans

Koenraad

2008

Handbook of Self Assembled Semiconductor Nanostructures for Novel Devices in Photonics and Electronics

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“…The InAs/InP system differs from the InAs/GaAs one because group V atoms rather than the group III atoms are changed between the QDs and the buffer layer. A significant As/P exchange occurs at the InAs/InP interfaces [6,7]. In previous papers [8,9], a two-step capping layer growth method has been proposed, which allows the control of emission wavelength.…”

Section: Introductionmentioning

confidence: 99%

Emission wavelength control of InAs quantum dots in a GaInAsP matrix grown on InP(311)B substrates

Caroff

Bertru

Platz

et al. 2005

Journal of Crystal Growth

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“…This was required since the buried dots tend to become shorter compared to the surface dots due to exposure to P flux during capping [59] which causes the InP adatoms (formed at the top layer of InAs) to migrate towards the region in between the Qdots due to the strain mismatch. This process was further improved by a double capping procedure [60], introduced by Ledentsov et al [61] and Gutierrez et al [62] on InAs/GaAs and InAs/InP Qdots, respectively, as shown in Fig. 10(b).…”

Section: Qdots On (100) Inp Substratementioning

confidence: 99%

Self-assembled InAs/InP quantum dots and quantum dashes: Material structures and devices

Khan

Ooi

2014

Progress in Quantum Electronics

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The advances in lasers, electronic and photonic integrated circuits (EPIC), optical interconnects as well as the modulation techniques allow the present day society to embrace the convenience of broadband, high speed internet and mobile network connectivity. However, the steep increase in energy demand and bandwidth requirement calls for further innovation in ultra-compact EPIC technologies. In the optical domain, innovation in the laser technologies beyond the current quantum well (Qwell) based laser technologies are already taking place and presenting very promising results. Homogeneously grown quantum dot (Qdot) lasers, can serve in the future energy saving information and communication technologies (ICT) as the work-horse for transmitting information through optical fiber. The encouraging results in the zero-dimensional (0D) structures emitting at 980 nm, in the form of vertical cavity surface emitting laser (VCSEL), are already operational at low threshold current density and capable of 40 Gbps error-free transmission at 108 fJ/bit. Eventual achievements for lasers operating in the O-, C-, L-, U-bands, and beyond will eventually lay the foundation for green ICT. On the hand, the inhomogeneously grown quasi 0D quantum dash (Qdash) lasers are brilliant solutions for potential broadband connectivity in server farms or access network. A single broadband Qdash laser operating in the stimulated emission mode can replace tens of discrete narrow-band lasers in dense wavelength division multiplexing (DWDM) transmission thereby further saving energy, cost and footprint. In this article, we review the progress of both Qdots and Qdash devices based on the InAs/InGaAlAs/InP and InAs/InGaAsP/InP material systems, from the angles of growth and device performance.2

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Role of group V exchange on the shape and size of InAs/InP self-assembled nanostructures

Cited by 48 publications

References 17 publications

InAs Quantum Dot Formation Studied at the Atomic Scale by Cross-sectional Scanning Tunnelling Microscopy

InAs Quantum Dot Formation Studied at the Atomic Scale by Cross-sectional Scanning Tunnelling Microscopy

Emission wavelength control of InAs quantum dots in a GaInAsP matrix grown on InP(311)B substrates

Self-assembled InAs/InP quantum dots and quantum dashes: Material structures and devices

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