Exciton dephasing and biexciton binding in CdSe/ZnSe islands

Hans Peter Wagner, H.-P. Tranitz, H Preis, Wolfgang Werner Langbein, Kristjan Leosson, Jørn Märcher Hvam

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Abstract

The dephasing of excitons and the formation of biexcitons in self-organized CdSe/ZnSe islands grown by molecular-beam epitaxy is investigated using spectrally resolved four-wave mixing. A distribution of exciton-exciton scattering efficiencies and dephasing times in the range of 0.5-10 ps are observed. This indicates the presence of differently localized exciton states at comparable transition energies. Polarization-dependent measurements identify the formation of biexcitons with a biexciton binding energy of more than four times the bulk value. With decreasing exciton energy, the binding energy slightly increases from 21.5 to 23 meV, while its broadening decreases from 5.5 to 3 meV. This is attributed to a strong three-dimensional confinement with improving shape uniformity for decreasing exciton energy. [S0163-1829(99)04739-6].
Original languageEnglish
JournalPhysical Review B
Volume60
Issue number15
Pages (from-to)10640-10643
ISSN2469-9950
DOIs
Publication statusPublished - 1999

Bibliographical note

Copyright (1999) by the American Physical Society.

Keywords

  • LASERS
  • ZNSE
  • WELLS
  • ENERGY
  • OPTICAL INVESTIGATIONS
  • STRAIN
  • EPITAXY
  • GROWTH
  • QUANTUM-DOT STRUCTURES
  • FILMS

Cite this

Wagner, H. P., Tranitz, H-P., Preis, H., Langbein, W. W., Leosson, K., & Hvam, J. M. (1999). Exciton dephasing and biexciton binding in CdSe/ZnSe islands. Physical Review B, 60(15), 10640-10643. https://doi.org/10.1103/PhysRevB.60.10640