Biexciton state causes photoluminescence fluctuations in CdSe/ZnS core/shell quantum dots at high photoexcitation densities

N. Yoshikawa, H. Hirori, H. Watanabe, T. Aoki, T. Ihara, R. Kusuda, C. Wolpert, T. K. Fujiwara, A. Kusumi, Y. Kanemitsu, K. Tanaka

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Abstract

The excitation density dependence of photoluminescence (PL) blinking of single CdSe/ZnS quantum dots was studied by means of single-dot PL spectroscopy. As the excitation density increases, an intermediate state appears in addition to the highly emissive (ON) and nonemissive (OFF) states. The systematic study of the excitation density dependence of PL blinking behavior (PL intensity, probabilities of finding these states, time probability distributions, and PL spectra and lifetimes) suggests that the intermediate state can be attributed to a charged exciton (trion) state generated through biexciton generation and charging (ionization) of a quantum dot under a high-density excitation regime. Our results indicate that the biexciton generation is a precursor of the trion state and not of the OFF state.

Original languageEnglish
Article number155440
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume88
Issue number15
DOIs
Publication statusPublished - 2013 Oct 31

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Yoshikawa, N., Hirori, H., Watanabe, H., Aoki, T., Ihara, T., Kusuda, R., Wolpert, C., Fujiwara, T. K., Kusumi, A., Kanemitsu, Y., & Tanaka, K. (2013). Biexciton state causes photoluminescence fluctuations in CdSe/ZnS core/shell quantum dots at high photoexcitation densities. Physical Review B - Condensed Matter and Materials Physics, 88(15), [155440]. https://doi.org/10.1103/PhysRevB.88.155440