Complete suppression of Blinking and convergence to a single emissive state in giant nanocrystal quantum dots

ORAL

Abstract

We report a systematic study of photoluminescence (PL) emission intensities and lifetimes of individual core-shell CdSe/CdS ``giant'' nanocrystal quantum dots (gNQDs) as a function of the shell thickness. We observed a complete suppression of blinking for gNQDs overcoated with more than 16 monolayers (ML) of CdS shell. An analysis of the photon emission statistics reveals a highly super-Poissonian distribution for thin shell (4-12 ML) gNQDs and near perfect Poissonian distribution for non-blinking, thick-shell gNQDs. Measurements of PL decay rates as a function of PL intensity show that while PL lifetimes vary continuously with PL intensity for thin-shell gNQDs, only one PL decay constant is observed for the thicker shell gNQDs. This result clearly indicates that while the thin-shell gNQDs possess continuous distribution of emission states, PL of the non-blinking, thick-shell gNQDs originates from a single emissive state.

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Authors

  • Anton Malko

    • The University of Texas at Dallas, Department of Physics
    • University of Texas at Dallas

  • Siddharth Sampat

    • The University of Texas at Dallas, Department of Physics

  • Young-Shin Park

    • Los Alamos National Laboratory, Chemistry Division and Center for Integrated Nanotechnologies

  • Javier Vela

    • Los Alamos National Laboratory, Chemistry Division and Center for Integrated Nanotechnologies

  • Youngfen Chen

    • Los Alamos National Laboratory, Chemistry Division and Center for Integrated Nanotechnologies

  • Jennifer Hollingsworth

    • Los Alamos National Laboratory, Chemistry Division and Center for Integrated Nanotechnologies

  • Victor Klimov

    • Los Alamos National Laboratory, Chemistry Division and Center for Integrated Nanotechnologies

  • Han Htoon

    • Los Alamos National Laboratory, Chemistry Division and Center for Integrated Nanotechnologies