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Title: Sample-Averaged Biexciton Quantum Yield Measured by Solution-Phase Photon Correlation

The brightness of nanoscale optical materials such as semiconductor nanocrystals is currently limited in high excitation flux applications by inefficient multiexciton fluorescence. We have devised a solution-phase photon correlation measurement that can conveniently and reliably measure the average biexciton-to-exciton quantum yield ratio of an entire sample without user selection bias. This technique can be used to investigate the multiexciton recombination dynamics of a broad scope of synthetically underdeveloped materials, including those with low exciton quantum yields and poor fluorescence stability. Here in this study, we have applied this method to measure weak biexciton fluorescence in samples of visible-emitting InP/ZnS and InAs/ZnS core/shell nanocrystals, and to demonstrate that a rapid CdS shell growth procedure can markedly increase the biexciton fluorescence of CdSe nanocrystals.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Chemistry
Publication Date:
OSTI Identifier:
1210710
Grant/Contract Number:
SC0001088; FG02-07ER46454; 9P41EB015871-26A1
Type:
Accepted Manuscript
Journal Name:
Nano Letters
Additional Journal Information:
Journal Volume: 14; Journal Issue: 12; Journal ID: ISSN 1530-6984
Publisher:
American Chemical Society
Research Org:
Energy Frontier Research Centers (EFRC). Center for Excitonics (CE)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Institutes of Health (NIH)
Contributing Orgs:
CE partners with Massachusetts Institute of Technology (lead); Brookhaven National Laboratory; Harvard University
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; solar (photovoltaic); solid state lighting; photosynthesis (natural and artificial); charge transport; optics; synthesis (novel materials); synthesis (self-assembly); synthesis (scalable processing); multiexcitons; Photon correlation; semiconductor nanocrystals; single-molecule spectroscopy