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
    Issue number11/12
    Publication statusPublished - 1997
    MoE publication typeA1 Journal article-refereed

    Fingerprint

    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 ; No. 11/12. pp. 41-48.
    @article{da7e5bcd8a9645328a8a0eaa0178ec0f,
    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",
    pages = "41--48",
    journal = "Physics of Low Dimensional Structures",
    issn = "0204-3467",
    publisher = "VSV Co Ltd",
    number = "11/12",

    }

    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, no. 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, No. 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

    SP - 41

    EP - 48

    JO - Physics of Low Dimensional Structures

    JF - Physics of Low Dimensional Structures

    SN - 0204-3467

    IS - 11/12

    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.