Long wavelength emitting InAs∕Ga0.85In0.15NxAs1−x quantum dots on GaAs substrate

Richter, M.; Damilano, B.; Duboz, Jean‐Yves; Massies, J.; Wieck, A. D.

doi:10.1063/1.2209879

Cited by 27 publications

(42 citation statements)

References 18 publications

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“…The peak emission for this sample occurs at 1515 nm, which is the longest wavelength reported for a QD bilayer and is comparable with the longest wavelengths obtained from any QDs grown on GaAs substrates. [12][13][14][15][16] The emission has a narrow PL linewidth of 22 meV, which is consistent with previous reports of narrow emission linewidths from InAs/GaAs bilayers 4,27 and indicates a high degree of uniformity of the QDs. Emission from the seed layer is suppressed due to efficient electronic coupling between the layers: room temperature emission from the seed layer is expected to be around 1250 nm for QDs grown under these conditions.…”

Section: A Effect Of Seed Layer Growth Temperaturesupporting

confidence: 79%

“…Techniques for growth of InAs/GaAs QDs with room temperature emission at 1300 nm are now well established, [9][10][11] but further extension of InAs/GaAs QD emission wavelength toward the 1550 nm telecoms window is rarely reported. [12][13][14][15][16] By variation in the growth temperature of the seed layer, the number density of seed QDs can be varied over a range of 40-300 m −2 in a simple and reproducible manner. This in turn results in a comparable change in QD density in the second layer of bilayer structures and an accompanying variation in the height of QDs.…”

Section: Introductionmentioning

confidence: 99%

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Persistent template effect in InAs/GaAs quantum dot bilayers

Clarke

Howe

Taylor

et al. 2010

Journal of Applied Physics

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The dependence of the optical properties of InAs/GaAs quantum dot ͑QD͒ bilayers on seed layer growth temperature and second layer InAs coverage is investigated. As the seed layer growth temperature is increased, a low density of large QDs is obtained. This results in a concomitant increase in dot size in the second layer, which extends their emission wavelength, reaching a saturation value of around 1400 nm at room temperature for GaAs-capped bilayers. Capping the second dot layer with InGaAs results in a further extension of the emission wavelength, to 1515 nm at room temperature with a narrow linewidth of 22 meV. Addition of more InAs to high density bilayers does not result in a significant extension of emission wavelength as most additional material migrates to coalesced InAs islands but, in contrast to single layers, a substantial population of regular QDs remains.

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Section: A Effect Of Seed Layer Growth Temperaturesupporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

Persistent template effect in InAs/GaAs quantum dot bilayers

Clarke

Howe

Taylor

et al. 2010

Journal of Applied Physics

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“…7 Studies report an improvement of the optical properties for low N contents, accompanied by a red shift of the PL peak energy. 7,8 The quaternary alloy InGaAsN also induces strong red shifts 9,10 and long wavelength light emitting diodes have been fabricated with this approach.…”

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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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“…Several methods have been explored to reduce the value of DOP. These methods include (1) strain engineering by over-growing the InAs QDs with InGaAs quantum wells, also known as the strain reducing capping layers, 3 (2) inclusion of dilute impurities such as nitrogen "N," 19 antimony "Sb," 20 and phosphorous "P," 21 etc., (3) exploiting the strain interaction between the QDs in multi-layer QD stacks, 2,4,22 and (4) growing large stacks of QDs in the form of columnar QDs. 5,23 Among these techniques, the exploitation of strain interactions between the quantum dot layers in multi-layer QD stacks have shown great potential to generate polarization-insensitive optical transitions at telecommunication wavelengths.…”

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confidence: 99%

In-plane polarization anisotropy of ground state optical intensity in InAs/GaAs quantum dots

Usman¹

2011

Journal of Applied Physics

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The design of optical devices such as lasers and semiconductor optical amplifiers for telecommunication applications requires polarization insensitive optical emissions in the region of 1500 nm. Recent experimental measurements of the optical properties of stacked quantum dots have demonstrated that this can be achieved via exploitation of inter-dot strain interactions. In particular, the relatively large aspect ratio (AR) of quantum dots in the optically active layers of such stacks provide a two-fold advantage, both by inducing a red shift of the gap wavelength above 1300 nm, and increasing the TM001-mode, thereby decreasing the anisotropy of the polarization response. However, in large aspect ratio quantum dots (AR > 0.25), the hole confinement is significantly modified compared with that in lower AR dots-this modified confinement is manifest in the interfacial confinement of holes in the system. Since the contributions to the ground state optical intensity (GSOI) are dominated by lower-lying valence states, we therefore propose that the room temperature GSOI be a cumulative sum of optical transitions from multiple valence states. This then extends previous theoretical studies of flat (low AR) quantum dots, in which contributions arising only from the highest valence state or optical transitions between individual valence states were considered. The interfacial hole distributions also increases in-plane anisotropy in tall (high AR) quantum dots (TE110 not equal TE-110), an effect that has not been previously observed in flat quantum dots. Thus, a directional degree of polarization (DOP) should be measured (or calculated) to fully characterize the polarization response of quantum dot stacks. Previous theoretical and experimental studies have considered only a single value of DOP: either [110] or [-110]. (C) 2011 American Institute of Physics. [doi:10.1063/1.3657783

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Long wavelength emitting InAs∕Ga0.85In0.15NxAs1−x quantum dots on GaAs substrate

Cited by 27 publications

References 18 publications

Persistent template effect in InAs/GaAs quantum dot bilayers

Persistent template effect in InAs/GaAs quantum dot bilayers

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

In-plane polarization anisotropy of ground state optical intensity in InAs/GaAs quantum dots

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