Effects of excitation spectral width on decay profile of weakly confined excitons

O. Kojima, T. Isu, Junko Hayase, A. Kanno, R. Katouf, M. Sasaki, M. Tsuchiya

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We report the effect due to a simultaneous excitation of several exciton states on the radiative decay profiles on the basis of the nonlocal response of weakly confined excitons in GaAs thin films. In the case of excitation of single exciton state, the transient grating signal has two decay components. The fast decay component comes from nonlocal response, and the long-lived component is attributed to free exciton decay. With an increase of excitation spectral width, the nonlocal component becomes small in comparison with the long-lived component, and disappears under irradiation of a femtosecond-pulse laser with broader spectral width. The transient grating spectra clearly indicates the contribution of the weakly confined excitons to the signal, and the exciton line width hardly changes by excitation spectral width. From these results, we concluded that the change of decay profile is attributed not to the many-body effect but to the effect of simultaneous excitation of several exciton states.

Original languageEnglish
Pages (from-to)966-968
Number of pages3
JournalJournal of Luminescence
Volume128
Issue number5-6
DOIs
Publication statusPublished - 2008 May
Externally publishedYes

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Keywords

  • Nonlocal response
  • Optical nonlinear response
  • Thin film
  • Transient grating
  • Weakly confined exciton

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Atomic and Molecular Physics, and Optics

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