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Title: Fluorescence modulation in single CdSe quantum dots by moderate applied electric fields

Single molecule time-resolved fluorescence spectroscopy of CdSe/ZnS core-shell quantum dots (QDs) under the influence of moderate applied electric fields reveals distributed emission from states which are neither fully on nor off and pronounced changes in the excited state decay. The data suggest that a 54‚ÄČkV/cm applied electric field causes small perturbations to the QD surface charge distribution, effectively increasing the surface trapping probability and resulting in the appearance of gray states. We present simultaneous blinking and fluorescence decay results for two sets of QDs, with and without an applied electric field. Further kinetic modeling analysis suggests that a single trapped charged cannot be responsible for a blinking off event.
Authors:
 [1] ;  [2] ; ; ;  [1] ;  [3]
  1. Department of Physics and Optical Science, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States)
  2. (United States)
  3. Department of Chemistry, University of North Carolina at Charlotte, 9201 University City Boulevard, Charlotte, North Carolina 28223 (United States)
Publication Date:
OSTI Identifier:
22275706
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 3; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; CADMIUM SELENIDES; CHARGE DISTRIBUTION; ELECTRIC FIELDS; EXCITED STATES; FLUORESCENCE; FLUORESCENCE SPECTROSCOPY; HETEROJUNCTIONS; INTERFACES; MODULATION; MOLECULES; QUANTUM DOTS; SURFACES; TIME RESOLUTION; TRAPPING; ZINC SULFIDES