Strain-induced quantum dots: Fabrication and optical properties

Jouni Ahopelto, Markku Sopanen, Harri Lipsanen, M. Taskinen, J. Tulkki, J. Sandmann, S. Grosse, G. von Plessen, J. Feldman, G. Hayes, R. Phillips, R. Rinaldi, P. Giugno, R. Cingolani

Research output: Contribution to journalArticleScientificpeer-review

Abstract

High quality quantum dots have been fabricated by using self-organized InP islands as stressors. The tensile strain due the islands creates local potential minima in an InGaAs/GaAs quantum well under the islands, and confines both electrons and holes into these minima. The ground state emission from the dots is redshifted by up to 105 meV from the quantum well emission due to this lateral confinement potential, and clearly resolved emission peaks are observed from the excited states. From the time-resolved photoluminescence measurements an interlevel relaxation time of 0.6 ns between the first excited state and the ground state and a radiative lifetime of 0.9 ns for the quantum dot ground state are obtained. Photoluminescence up-conversion measurements show subpicosecond onset of the dot luminescence at high excitation densities, suggesting that Coulomb scattering is responsible for the fast capture process. A large Zeeman splitting of the higher angular momentum states is observed in a magnetic field perpendicular to the sample surface.
Original languageEnglish
Pages (from-to)41 - 48
Number of pages8
JournalPhysics of Low Dimensional Structures
Volume11 - 12
Publication statusPublished - 1997
MoE publication typeA1 Journal article-refereed

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Ground state
Semiconductor quantum dots
Optical properties
quantum dots
Excited states
optical properties
Fabrication
Semiconductor quantum wells
fabrication
ground state
Photoluminescence
quantum wells
excitation
photoluminescence
Angular momentum
Tensile strain
radiative lifetime
Relaxation time
Luminescence
angular momentum

Cite this

Ahopelto, J., Sopanen, M., Lipsanen, H., Taskinen, M., Tulkki, J., Sandmann, J., ... Cingolani, R. (1997). Strain-induced quantum dots: Fabrication and optical properties. Physics of Low Dimensional Structures, 11 - 12, 41 - 48.
Ahopelto, Jouni ; Sopanen, Markku ; Lipsanen, Harri ; Taskinen, M. ; Tulkki, J. ; Sandmann, J. ; Grosse, S. ; Plessen, G. von ; Feldman, J. ; Hayes, G. ; Phillips, R. ; Rinaldi, R. ; Giugno, P. ; Cingolani, R. / Strain-induced quantum dots : Fabrication and optical properties. In: Physics of Low Dimensional Structures. 1997 ; Vol. 11 - 12. pp. 41 - 48.
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title = "Strain-induced quantum dots: Fabrication and optical properties",
abstract = "High quality quantum dots have been fabricated by using self-organized InP islands as stressors. The tensile strain due the islands creates local potential minima in an InGaAs/GaAs quantum well under the islands, and confines both electrons and holes into these minima. The ground state emission from the dots is redshifted by up to 105 meV from the quantum well emission due to this lateral confinement potential, and clearly resolved emission peaks are observed from the excited states. From the time-resolved photoluminescence measurements an interlevel relaxation time of 0.6 ns between the first excited state and the ground state and a radiative lifetime of 0.9 ns for the quantum dot ground state are obtained. Photoluminescence up-conversion measurements show subpicosecond onset of the dot luminescence at high excitation densities, suggesting that Coulomb scattering is responsible for the fast capture process. A large Zeeman splitting of the higher angular momentum states is observed in a magnetic field perpendicular to the sample surface.",
author = "Jouni Ahopelto and Markku Sopanen and Harri Lipsanen and M. Taskinen and J. Tulkki and J. Sandmann and S. Grosse and Plessen, {G. von} and J. Feldman and G. Hayes and R. Phillips and R. Rinaldi and P. Giugno and R. Cingolani",
year = "1997",
language = "English",
volume = "11 - 12",
pages = "41 -- 48",
journal = "Physics of Low Dimensional Structures",
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Ahopelto, J, Sopanen, M, Lipsanen, H, Taskinen, M, Tulkki, J, Sandmann, J, Grosse, S, Plessen, GV, Feldman, J, Hayes, G, Phillips, R, Rinaldi, R, Giugno, P & Cingolani, R 1997, 'Strain-induced quantum dots: Fabrication and optical properties', Physics of Low Dimensional Structures, vol. 11 - 12, pp. 41 - 48.

Strain-induced quantum dots : Fabrication and optical properties. / Ahopelto, Jouni; Sopanen, Markku; Lipsanen, Harri; Taskinen, M.; Tulkki, J.; Sandmann, J.; Grosse, S.; Plessen, G. von; Feldman, J.; Hayes, G.; Phillips, R.; Rinaldi, R.; Giugno, P.; Cingolani, R.

In: Physics of Low Dimensional Structures, Vol. 11 - 12, 1997, p. 41 - 48.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Strain-induced quantum dots

T2 - Fabrication and optical properties

AU - Ahopelto, Jouni

AU - Sopanen, Markku

AU - Lipsanen, Harri

AU - Taskinen, M.

AU - Tulkki, J.

AU - Sandmann, J.

AU - Grosse, S.

AU - Plessen, G. von

AU - Feldman, J.

AU - Hayes, G.

AU - Phillips, R.

AU - Rinaldi, R.

AU - Giugno, P.

AU - Cingolani, R.

PY - 1997

Y1 - 1997

N2 - High quality quantum dots have been fabricated by using self-organized InP islands as stressors. The tensile strain due the islands creates local potential minima in an InGaAs/GaAs quantum well under the islands, and confines both electrons and holes into these minima. The ground state emission from the dots is redshifted by up to 105 meV from the quantum well emission due to this lateral confinement potential, and clearly resolved emission peaks are observed from the excited states. From the time-resolved photoluminescence measurements an interlevel relaxation time of 0.6 ns between the first excited state and the ground state and a radiative lifetime of 0.9 ns for the quantum dot ground state are obtained. Photoluminescence up-conversion measurements show subpicosecond onset of the dot luminescence at high excitation densities, suggesting that Coulomb scattering is responsible for the fast capture process. A large Zeeman splitting of the higher angular momentum states is observed in a magnetic field perpendicular to the sample surface.

AB - High quality quantum dots have been fabricated by using self-organized InP islands as stressors. The tensile strain due the islands creates local potential minima in an InGaAs/GaAs quantum well under the islands, and confines both electrons and holes into these minima. The ground state emission from the dots is redshifted by up to 105 meV from the quantum well emission due to this lateral confinement potential, and clearly resolved emission peaks are observed from the excited states. From the time-resolved photoluminescence measurements an interlevel relaxation time of 0.6 ns between the first excited state and the ground state and a radiative lifetime of 0.9 ns for the quantum dot ground state are obtained. Photoluminescence up-conversion measurements show subpicosecond onset of the dot luminescence at high excitation densities, suggesting that Coulomb scattering is responsible for the fast capture process. A large Zeeman splitting of the higher angular momentum states is observed in a magnetic field perpendicular to the sample surface.

M3 - Article

VL - 11 - 12

SP - 41

EP - 48

JO - Physics of Low Dimensional Structures

JF - Physics of Low Dimensional Structures

SN - 0204-3467

ER -

Ahopelto J, Sopanen M, Lipsanen H, Taskinen M, Tulkki J, Sandmann J et al. Strain-induced quantum dots: Fabrication and optical properties. Physics of Low Dimensional Structures. 1997;11 - 12:41 - 48.