Quantum Yield Heterogeneity among Single Nonblinking Quantum Dots Revealed by Atomic Structure-Quantum Optics Correlation Noah J. Orfield,†,‡ James R. McBride,*,†,‡ Feng Wang,§ Matthew R. Buck,§,∇ Joseph D. Keene,†,‡,⊗ Kemar R. Reid,⊥,‡ Han Htoon,*,§ Jennifer A. Hollingsworth,*,§ and Sandra J. Rosenthal*,†,‡,⊥,∥,#,¶ †
Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University, Nashville, Tennessee 37235, United States § Materials Physics & Applications Division: Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States ⊥ Department of Interdisciplinary Materials Science, Vanderbilt University, Nashville, Tennessee 37235, United States ∥ Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, United States # Department of Pharmacology, Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235, United States ¶ Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States ‡
S Supporting Information *
ABSTRACT: Physical variations in colloidal nanostructures give rise to heterogeneity in expressed optical behavior. This correlation between nanoscale structure and function demands interrogation of both atomic structure and photophysics at the level of single nanostructures to be fully understood. Herein, by conducting detailed analyses of fine atomic structure, chemical composition, and time-resolved single-photon photoluminescence data for the same individual nanocrystals, we reveal inhomogeneity in the quantum yields of single nonblinking “giant” CdSe/CdS core/shell quantum dots (g-QDs). We find that each g-QD possesses distinctive single exciton and biexciton quantum yields that result mainly from variations in the degree of charging, rather than from volume or structure inhomogeneity. We further establish that there is a very limited nonemissive “dark” fraction (
