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Title: Probing the structural dependency of photoinduced properties of colloidal quantum dots using metal-oxide photo-active substrates

We used photoactive substrates consisting of about 1 nm coating of a metal oxide on glass substrates to investigate the impact of the structures of colloidal quantum dots on their photophysical and photochemical properties. We showed during irradiation these substrates can interact uniquely with such quantum dots, inducing distinct forms of photo-induced processes when they have different cores, shells, or ligands. In particular, our results showed that for certain types of core-shell quantum dot structures an ultrathin layer of a metal oxide can reduce suppression of quantum efficiency of the quantum dots happening when they undergo extensive photo-oxidation. This suggests the possibility of shrinking the sizes of quantum dots without significant enhancement of their non-radiative decay rates. We show that such quantum dots are not influenced significantly by Coulomb blockade or photoionization, while those without a shell can undergo a large amount of photo-induced fluorescence enhancement via such blockade when they are in touch with the metal oxide.
Authors:
; ; ;  [1] ;  [1] ;  [2] ;  [3]
  1. Department of Physics, University of Alabama in Huntsville, Huntsville, Alabama 35899 (United States)
  2. (United States)
  3. Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma 73019 (United States)
Publication Date:
OSTI Identifier:
22306010
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; FLUORESCENCE; GLASS; LAYERS; METALS; OPTICAL PROPERTIES; OXIDATION; OXIDES; PHOTOCHEMISTRY; PHOTOIONIZATION; QUANTUM DOTS; QUANTUM EFFICIENCY; SUBSTRATES