Adatom condensation and quantum dot sizes in InGaAs/GaAs (001)

León, R.; Wellman, J.; Liao, Xiaozhou; Zou, Jin; Cockayne, D. J. H.

doi:10.1063/1.126095

Cited by 27 publications

(17 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The SAQD formed under higher AsH 3 partial pressures had lower densities than the ones grown under low partial pressure conditions [17].…”

Section: Resultsmentioning

confidence: 99%

“…6 As under different AsH 3 partial pressures and different growth temperatures. Lower growth temperatures have been identified previously as reducing surface segregation [11,12], but the role of AsH 3 on QD formation has only been speculated [16,17]. Conditions where surface segregation is suppressed and enhanced are identified.…”

Section: Growth Investigations On Ingaas Alloy Saqdmentioning

confidence: 97%

See 1 more Smart Citation

Quantum coherence in semiconductor nanostructures for improved lasers and detectors.

Chow¹,

Lyo²,

Cederberg³

et al. 2006

View full text Add to dashboard Cite

The potential for implementing quantum coherence in semiconductor self-assembled quantum dots has been investigated theoretically and experimentally. Theoretical modeling suggests that coherent dynamics should be possible in self-assembled quantum dots. Our experimental efforts have optimized InGaAs and InAs self-assembled quantum dots on GaAs for demonstrating coherent phenomena. Optical investigations have indicated the appropriate geometries for observing quantum coherence and the type of experiments for observing quantum coherence have been outlined. The optical investigation targeted electromagnetically induced transparency (EIT) in order to demonstrate an all optical delay line. 5 CONTENTS

show abstract

“…The SAQD formed under higher AsH 3 partial pressures had lower densities than the ones grown under low partial pressure conditions [17].…”

Section: Resultsmentioning

confidence: 99%

Section: Growth Investigations On Ingaas Alloy Saqdmentioning

confidence: 97%

Quantum coherence in semiconductor nanostructures for improved lasers and detectors.

Chow¹,

Lyo²,

Cederberg³

et al. 2006

View full text Add to dashboard Cite

show abstract

Section: Capping Process Of Inas Quantum Dotsmentioning

confidence: 99%

“…Nevertheless, once created, the QDs are subsequently capped, a step which is required for any device application. Although a lot of effort has been dedicated to understand the QD growth mechanism, 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.…”

Section: Capping Process Of Inas Quantum Dotsmentioning

confidence: 99%

“…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.…”

mentioning

confidence: 99%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

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

show abstract

The improvement of InAs/GaAs quantum dot properties capped by Graphene

Rezgui

Othmen

Cavanna³

et al. 2013

J Raman Spectroscopy

View full text Add to dashboard Cite

InAs self‐assembled quantum dots (QDs) were grown by molecular beam epitaxy on (001) GaAs substrate. Uncapped and capped QDs with GaAs and graphene layers were studied using atomic force microscopy and Raman spectroscopy. Graphene multi‐layer was grown by chemical vapor deposition and transferred on InAs/GaAs QDs. It is well known that the presence of a cap layer modifies the size, shape, and density of the QDs. According to the atomic force microscopy study, in contrast to the GaAs capped sample, which induce a dramatic decrease of the density and height of dots, graphene cap layer sample presents a slight influence on the surface morphology and the density of the islands compared with the uncapped one. The difference shown in the Raman spectra of the samples is due to change of strain and alloy disorder effects on the QDs. Residuals strain and the relaxation coefficients have been investigated. All results confirm the best crystalline quality of the graphene cap layer dots sample relative to the GaAs capped one. So graphene can be used to replace GaAs in capping InAs/GaAs dots. To our knowledge, such study has not been carried out until now. Copyright © 2013 John Wiley & Sons, Ltd.

show abstract

Adatom condensation and quantum dot sizes in InGaAs/GaAs (001)

Abstract: Articles you may be interested in Atomic structure and stoichiometry of In(Ga)As/GaAs quantum dots grown on an exact-oriented GaP/Si (001)

Cited by 27 publications

References 7 publications

Quantum coherence in semiconductor nanostructures for improved lasers and detectors.

Quantum coherence in semiconductor nanostructures for improved lasers and detectors.

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

The improvement of InAs/GaAs quantum dot properties capped by Graphene

Contact Info

Product

Resources

About