Structural characterization of InAs quantum dot chains grown by molecular beam epitaxy on nanoimprint lithography patterned GaAs(100)

Hakkarainen, Teemu; Tommila, J.; Schramm, Andreas; Tukiainen, Antti; Ahorinta, Risto; Dumitrescu, M.; Guina, Mircea

doi:10.1088/0957-4484/22/29/295604

Cited by 15 publications

(12 citation statements)

References 21 publications

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“…1a–d we show the AFM images of site-controlled surface QDs aligned in [010]-oriented grooves with periods of 200, 500, 1000, and 2000 nm, respectively. We used here in this experiment the [010] direction in order to circumvent any GaAs growth anisotropies we have observed previously [21]. We observe that nearly all the QDs have grown into the groove structures.…”

Section: Resultsmentioning

confidence: 99%

“…QD chains create a bridge from zero- to one-dimensional nanostructures and show interesting optical [17–19] and transport behaviors [20]. Previously, we could show that InAs QD chains grown onto groove-like patterns show different growing behaviors than their self-assembled counterparts, and thus their optical properties show differences [21]. These studies were focused on dense QD chains with a period of 200 nm and thus, we could mainly investigate the ensemble properties.…”

Section: Introductionmentioning

confidence: 99%

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The Role of Groove Periodicity in the Formation of Site-Controlled Quantum Dot Chains

et al. 2015

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Structural and optical properties of InAs quantum dot (QD) chains formed in etched GaAs grooves having different periods from 200 to 2000 nm in [010] orientation are reported. The site-controlled QDs were fabricated by molecular beam epitaxy on soft UV-nanoimprint lithography-patterned GaAs(001) surfaces. Increasing the groove periods decreases the overall QD density but increases the QD size and the linear density along the groove direction. The effect of the increased QD size with larger periods is reflected in ensemble photoluminescence measurements as redshift of the QD emission. Furthermore, we demonstrate the photoluminescence emission from single QD chains.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The Role of Groove Periodicity in the Formation of Site-Controlled Quantum Dot Chains

et al. 2015

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“…This gives rise to InAs accumulation on the groove sidewalls, which reduces QD density in the grooves. 18 The influences of the anisotropic In migration and facetted pattern make the situation different compared to InAs deposition on shallow pit patterns, where typically QD density and/or size are larger than on planar area due to the increase of nucleation rate arising from the local surface curvature. 22 TEM investigations were carried out using a Jeol JEM 3010 microscope operating at 300 kV, equipped with a GATAN slow-scan charge-coupled device camera.…”

Section: Methodsmentioning

confidence: 99%

Impact of the non-planar morphology of pre-patterned substrates on the structural and electronic properties of embedded site-controlled InAs quantum dots

Hakkarainen

Luna

Tommila

et al. 2013

Journal of Applied Physics

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We present an experimental and theoretical analysis of the influence of a surface nanopattern on the properties of embedded InAs/GaAs quantum dots (QD). In particular, we analyze QDs grown on nanoimprint lithography (NIL) patterned grooves and investigate the influence of the non-planar surface morphology on the size, shape, strain distribution, and electronic structure of the embedded QDs. We show that the height reduction of InAs QDs during GaAs capping is significantly less pronounced for the QDs grown on the pattern than for the self-assembled QDs. Furthermore, the pattern has a strong impact on the strain and composition profile within the QD. The experimentally observed strain distribution was successfully reproduced with a three-dimensional model assuming an inverse-cone type composition gradient. Moreover, we show that the specific morphology of the QDs grown in the grooves gives rise to an increase of the vertically polarized photoluminescence emission which was explained by employing 8-band k.p calculations. Our findings emphasize that the surface curvature of the pattern not only determines the nucleation sites of the QDs but also has a strong impact on their morphological properties including shape, size, composition profile, and strain distribution. These properties are strongly cross-correlated and determine the electronic and optical characteristics of the QDs. V C 2013 AIP Publishing LLC.

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“…One of the main problems is the growth condition of InAs/GaAs selfassembled QDs which strongly influence their size, shape, and the wetting layer structure. A number of investigations have been performed to probe the formation mechanisms of InAs QDs by atomic force microscopy (AFM) [4,5], scanning tunneling microscopy (STM) [6,7], or transmission electron microscopy (TEM) [8]. It is well known that the variation of shape and energy gap for self-assembled InAs QDs significantly depends on Arsenic to Indium flux ratios (V/III ratios) [9].…”

Section: Introductionmentioning

confidence: 99%

Temperature Dependent Photoluminescence from InAs/GaAs Quantum Dots Grown by Molecular Beam Epitaxy

Lee

Kim

et al. 2017

Appl. Sci. Converg. Technol.

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We have reported structural and optical properties of self-assembled InAs/GaAs quantum dot (QD) grown by molecular beam epitaxy with different arsenic to indium flux ratios (V/III ratios). By increasing the V/III ratio from 9 to 160, average diameter and height of the InAs QDs decreased, but areal density of them increased. The InAs QDs grown under V/III ratio of 30 had a highest-aspect-ratio of 0.134 among them grown with other conditions. Optical property of the InAs QD was investigated by the temperature-dependent photoluminescence (PL) and integrated PL. From the temperature dependence PL measurements of InAs QDs, the activation energies of E a1 and E a2 for the InAs QDs were obtained 48 ± 3 meV and 229 ± 23 meV, respectively. It was considered that the values of E a1 and E a2 are corresponded to the energy difference between ground-state and first excited state, and the energy difference between ground-state and wetting layer, respectively.

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Structural characterization of InAs quantum dot chains grown by molecular beam epitaxy on nanoimprint lithography patterned GaAs(100)

Cited by 15 publications

References 21 publications

The Role of Groove Periodicity in the Formation of Site-Controlled Quantum Dot Chains

The Role of Groove Periodicity in the Formation of Site-Controlled Quantum Dot Chains

Impact of the non-planar morphology of pre-patterned substrates on the structural and electronic properties of embedded site-controlled InAs quantum dots

Temperature Dependent Photoluminescence from InAs/GaAs Quantum Dots Grown by Molecular Beam Epitaxy

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