Wavelength controlled multilayer-stacked linear InAs quantum dot arrays on InGaAsP/InP(100) by self-organized anisotropic strain engineering : a self-ordered quantum dot crystal

Multilayer-stacked linear InAs quantum dot (QD) arrays are created on InAs/InGaAsP superlattice templates formed by self-organized anisotropic strain engineering on InP (100) substrates in chemical beam epitaxy. Stacking of the QD arrays with identical emission wavelength in the 1.55 µm region at room temperature is achieved through the insertion of ultrathin GaAs interlayers beneath the QDs with increasing interlayer thickness in successive layers. The increment in the GaAs interlayer thickness compensates the QD size/wavelength increase during strain correlated stacking. This is the demonstration of a three-dimensionally self-ordered QD crystal with fully controlled structural and optical properties

Wavelength tuning of InAs/InP quantum dots: Control of As/P surface exchange reaction

Wavelength tuning of single and vertically stacked InAs quantum dot [QD] layers embedded inInGaAsP/InP [100] grown by metal organic vapor-phase epitaxy is achieved by controlling theAs/P surface exchange reaction during InAs deposition. The As/P exchange reaction is suppressedfor decreased QD growth temperature and group V-III flow ratio, reducing the QD size andphotoluminescence [PL]emission wavelength. The As/P exchange reaction and QD PL wavelengthare then reproducibly controlled by the thickness of an ultrathin [0¿2 ML] GaAs interlayerunderneath the QDs. Submonolayer GaAs coverages result in a shape transition from QDs toquantum dashes at low group V-III flow ratio. Temperature dependent PL measurements revealexcellent optical properties of the QDs up to room temperature with PL peak wavelengths in thetechnologically important 1.55 ¿region for telecom applications. Widely stacked QD layers arereproduced with identical PL emission to increase the active volume, while closely stacked QDlayers reveal a systematic PL redshift and linewidth reduction due to vertical electronic couplingwhich is proven by the linear polarization of the cleaved-side PL changing from in plane toisotropic. ¿ 2006 American Vacuum Society

InAs quantum dash or dot formation on InGaAsP/InP (100): The buffer layer morphology is crucial

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Formation of stacked linear InAs quantum dot arrays on InGaAsP/InP(100) by self-organized anisotropic strain engineering

We have previously demonstrated the formation of linear InAs quantum dot (QD) arrays based on self-organized anisotropic strain engineering of InAs/InGaAsP superlattice (SL) templates on InP(100) by chemical beam epitaxy (CBE). The important step forward is the vertical stacking of the QD arrays with identical emission wavelength, realizing a three-dimensionally self-ordered QD crystal. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Formation of linear InAs/InGaAsP/InP (1 0 0) quantum dot arrays by self-organized anisotropic strain engineering in chemical beam epitaxy

The formation of laterally ordered linear InAs quantum dot (QD) arrays based on self-organized anisotropic strain engineering is demonstrated. An InAs/InGaAsP superlattice (SL) on InP (1 0 0) serves as a template for the QD arrays grown by chemical beam epitaxy. The InAs QD arrays exhibit excellent photoluminescence emission up to room temperature which is tuned into the 1.55-µm telecom wavelength region through the insertion of ultra-thin GaAs interlayers. Stacking of the QD arrays with identical emission wavelength upon adjusting the GaAs interlayer thickness produces a three-dimensionally self-ordered QD crystal. © 2008 Elsevier B.V. All rights reserved

Wavelength controlled multilayer-stacked linear InAs quantum dot arrays on InGaAsP/InP(100) by self-organized anisotropic strain engineering : a self-ordered quantum dot crystal

Multilayer-stacked linear InAs quantum dot (QD) arrays are created on InAs/InGaAsP superlattice templates formed by self-organized anisotropic strain engineering on InP (100) substrates in chemical beam epitaxy. Stacking of the QD arrays with identical emission wavelength in the 1.55 µm region at room temperature is achieved through the insertion of ultrathin GaAs interlayers beneath the QDs with increasing interlayer thickness in successive layers. The increment in the GaAs interlayer thickness compensates the QD size/wavelength increase during strain correlated stacking. This is the demonstration of a three-dimensionally self-ordered QD crystal with fully controlled structural and optical properties

Evolution of ordered one-dimensional and two-dimensional InAs/InP quantum dot arrays on patterned InP (1 0 0) and (3 1 1)B substrates by self-organized anisotropic strain engineering

The formation of ordered InAs/InP quantum dot (QD) arrays is demonstrated on patterned InP (1 0 0) and (3 1 1)B substrates by the concept of self-organized anisotropic strain engineering in chemical beam epitaxy (CBE). On shallow- and deep stripe-patterned InP (1 0 0) substrates, depending on the stripe orientation, the linear one-dimensional InAs QD arrays are rotated away from their natural direction due to the presence of vicinal stepped sidewall planes modifying the self-organization process, coexisting with QD free steep side facets on the deep-patterned substrates. On shallow- and deep-patterned InP (3 1 1)B substrates only QD free side facets form with flat top and bottom areas, not affecting the natural ordering of the two-dimensional InAs QD arrays. On the deep-patterned substrates a row of dense QDs forms on top along the side facets due to their slow-growing behavior. The optical properties of the QD arrays on the patterned substrates are not degraded compared to those of arrays formed on planar substrates for both InP (1 0 0) and (3 1 1)B substrates showing the potential of self-organized anisotropic strain engineering combined with step engineering for the creation of advanced complex QD arrays and networks. © 2010 Elsevier B.V. All rights reserved. U7 - Export Date: 2 August 2010 U7 - Source: Scopus U7 - Article in Pres

Formation of linear InAs quantum dot arrays on InGaAsP/InP (100) by self-organized anisotropic strain engineering and their optical properties

The formation of linear InAs quantum dot (QD) arrays based on self-organized anisotropic strainengineering of an InGaAsP/InP (100) superlattice (SL) template in chemical beam epitaxy isdemonstrated, and the optimized growth window is determined. InAs QD formation, thin InGaAsPcapping, annealing, InGaAsP overgrowth, and stacking in SL template formation produce wirelikeInAs structures along (001) due to anisotropic surface migration and lateral and vertical straincorrelations. InAs QD ordering is governed by the corresponding lateral strain field modulation onthe SL template surface. Careful optimization of InGaAsP cap layer thickness, annealingtemperature, InAs amount and growth rate, and number of SL periods results in straight andwell-separated InAs QD arrays. The InAs QD arrays exhibit excellent photoluminescence (PL)emission up to room temperature which is tuned into the 1.55 um telecommunications wavelengthregion through the insertion of ultrathin GaAs interlayers. Temperature dependent PL measurementsand the linear polarization behavior indicate lateral electronic coupling of the QDs in the arrays

Surface morphology induced InAs quantum dot or dash formation on InGaAsP/InP (100)

We identify the surface morphol. of the buffer layer as key parameter for the formation of InAs quantum dots (QDs) or dashes (QDashes) by chem. beam epitaxy (CBE) on lattice-matched InGaAsP on InP (1 0 0) substrates. Growth conditions leading to the formation of QDashes are always accompanied by a rough buffer layer morphol. Although other growth parameters such as higher growth temp., larger As flux, and compressive buffer layer strain favor the formation of QDs, once, the buffer layer has a rough morphol., QDashes are formed during InAs growth. On smooth buffer layers we always find well-shaped and sym. QDs. Hence, we conclude that not the growth conditions during InAs deposition, but rather the related surface morphol. of the buffer layer dets. the formation of QDs or QDashes, which exhibit both high optical quality. [on SciFinder (R)

Combining selective area growth and self-organized strain engineering for site-controlled local InAs/InP quantum dot arrays

Ordered InAs quantum dot (QD) arrays are formed by self-organized anisotropic strain engineering of an InAs/InGaAsP superlattice template on truncated InP pyramids grown by selective-area chemical beam epitaxy. The ordering is changed from one-dimensional on planar substrates to two-dimensional in the limited pyramid top surface areas. Upon shrinking the pyramid top surface area, the photoluminescence linewidth of the QD arrays narrows. This indicates improved size uniformity of the QDs when self-organized in site-controlled, local arrays