title: Quantum Yield Heterogeneity among Single Nonblinking Quantum Dots Revealed by Atomic Structure-Quantum Optics Correlation.
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 (<2%) among the studied g-QDs and present direct evidence that the g-QD core must lack inorganic passivation for the g-QD to be "dark". Therefore, in contrast to conventional QDs, ensemble photoluminescence quantum yield is principally defined by charging processes rather than the existence of dark g-QDs.
authors: Department of Chemistry, Vanderbilt University , Nashville, Tennessee 37235, United States.|Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors: Noah J
authors: NJ
authors: Orfield
authors: Department of Chemistry, Vanderbilt University , Nashville, Tennessee 37235, United States.|Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors: James R
authors: JR
authors: McBride
authors: Materials Physics & Applications Division: Center for Integrated Nanotechnologies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors: Feng
authors: F
authors: Wang
authors: Materials Physics & Applications Division: Center for Integrated Nanotechnologies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors: Matthew R
authors: MR
authors: Buck
authors: Department of Chemistry, Vanderbilt University , Nashville, Tennessee 37235, United States.|Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors: Joseph D
authors: JD
authors: Keene
authors: Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States.|Department of Interdisciplinary Materials Science, Vanderbilt University , Nashville, Tennessee 37235, United States.
authors: Kemar R
authors: KR
authors: Reid
authors: Materials Physics & Applications Division: Center for Integrated Nanotechnologies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors: Han
authors: H
authors: Htoon
authors: Materials Physics & Applications Division: Center for Integrated Nanotechnologies, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
authors: Jennifer A
authors: JA
authors: Hollingsworth
authors: Department of Chemistry, Vanderbilt University , Nashville, Tennessee 37235, United States.|Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University , Nashville, Tennessee 37235, 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.
authors: Sandra J
authors: SJ
authors: Rosenthal
keywords: correlation; heterogeneity; nanocrystal atomic structure; nanocrystal quantum dot; quantum yield