Excitons, biexcitons, and phonons in ultrathin CdSe/ZnSe quantum structures

F. Gindele, Ulrike Woggon, Wolfgang Werner Langbein, Jørn Märcher Hvam, K. Leonhardi, D. Hommel, H. Selke

    Research output: Contribution to journalJournal articleResearchpeer-review

    614 Downloads (Pure)

    Abstract

    The optical properties of CdSe nanostructures grown by migration-enhanced epitaxy of CdSe on ZnSe are studied by time-, energy-, and temperature-dependent photoluminescence and excitation spectroscopy, as well as by polarization-dependent four-wave mixing and two-photon absorption experiments. The nanostructures consist of a coherently strained Zn1-xCdxSe/ZnSe quantum well with embedded islands of higher Cd content with sizes of a few nanometer due to strain-induced CdSe accumulation. The local increase in CdSe concentration results in a strong localization of the excitonic wave function, in an increase in radiative lifetime, and a decrease of the dephasing rate. Local LO-phonon modes caused by the strong modulation of the Cd concentration profile are found in phonon-assisted relaxation processes. Confined biexcitons with large binding energies between 20 and 24 meV are observed, indicating the important role of biexcitons even at room temperature.
    Original languageEnglish
    JournalPhysical Review B
    Volume60
    Issue number12
    Pages (from-to)8773-8782
    ISSN2469-9950
    DOIs
    Publication statusPublished - 1999

    Bibliographical note

    Copyright (1999) by the American Physical Society.

    Keywords

    • DOT STRUCTURES
    • PHOTOLUMINESCENCE
    • SPECTROSCOPY
    • WELL STRUCTURES
    • OPTICAL INVESTIGATIONS
    • LOCALIZED EXCITONS
    • SOLID-SOLUTIONS
    • SEMICONDUCTOR NANOCRYSTALS
    • GAIN
    • ZNSE MATRIX

    Fingerprint Dive into the research topics of 'Excitons, biexcitons, and phonons in ultrathin CdSe/ZnSe quantum structures'. Together they form a unique fingerprint.

    Cite this