Surface morphology evolution during the overgrowth of large InAs–GaAs quantum dots

Joyce, P. B.; Krzyzewski, T. J.; Bell, GR; Jones, T.S.

doi:10.1063/1.1420579

Cited by 98 publications

(65 citation statements)

References 19 publications

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“…It is well known that when islands are capped, they rapidly collapse in height but larger islands are expected to better maintain their height and have a larger In-content once capped. 24 The inset to Fig. 3 shows a bright field TEM image obtained from a bilayer sample with a seed layer grown at 492°C.…”

Section: A Effect Of Seed Layer Growth Temperaturementioning

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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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 Temperaturementioning

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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“…Fabrication of ͑In,Ga͒As quantum dots ͑QDs͒ by molecular-beam epitaxy ͑MBE͒ has been extensively studied in order to obtain high quality low-dimensional quantum structures. [1][2][3] However, the random nucleation process during the formation of QDs undesirably leads to large size fluctuations, which, consequently, result in broad photoluminescence ͑PL͒ peaks, typically with line widths of 40-100 meV. A small PL line width is, however, of importance for QD lasers to reduce the threshold current.…”

mentioning

confidence: 99%

Leveling and rebuilding: An approach to improve the uniformity of (In,Ga)As quantum dots

Gong

Nötzel

Hamhuis

et al. 2002

Applied Physics Letters

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We report on an approach to improve the uniformity of a single layer of (In,Ga)As quantum dots (QDs) grown by molecular-beam epitaxy. The key concept of our approach is to level and rebuild the (In,Ga)As QDs during insertion of a short period GaAs/InAs superlattice between the (In,Ga)As QD layer and the GaAs capping layer. For optimized layer thickness and number of superlattice periods this process results in uniform (In,Ga)As QDs with narrow photoluminescence line width of 20 meV at 4.5 K.

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“…For the InAs-GaAs system, it is well established that ͑a͒ an alloyed InGaAs wetting layer ͑WL͒ is first formed during InAs deposition; 1 ͑b͒ the final state of the QDs may be an alloy even for deposition of pure InAs; 2 and ͑c͒ further changes to QD shape and composition take place during the capping of a QD array with GaAs or InGaAs. [3][4][5] These processes are controlled by a complicated combination of surface segregation 6 and locally strain-dependent surface migration and attachment. 5 Several experimental techniques have been used to probe the In distribution in QDs, including grazing incidence x-ray diffraction ͑XRD͒, 7 cross-sectional scanning tunneling microscopy ͑XSTM͒, 5,8 transmission electron microscopy ͑TEM͒ and scanning TEM energy dispersive x-ray analysis.…”

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confidence: 99%