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Title: Investigation of oxygen vacancy and photoluminescence in calcium tungstate nanophosphors with different particle sizes

Highlights: • CaWO{sub 4} nanophosphors with different particle sizes were prepared by hydrothermal processes through controlling the concentration of surfactant. • Green emission band of oxygen vacancy in CaWO{sub 4} nanophosphor was clearly observed upon the irradiation of 350 nm excitation. • The concentration of oxygen vacancy in CaWO{sub 4} nanophosphor could be increased by reducing its size. - Abstract: Calcium tungstate (CaWO{sub 4}) nanophosphors with the particle sizes from 35 to 90 nm were synthesized by a hydrothermal process through exactly controlling the pre-treated conditions. The influence of particle size on oxygen vacancy and photoluminescence properties in CaWO{sub 4} nanophosphors was investigated and discussed. The crystal structure of the CaWO{sub 4} nanophosphors presented a certain level of distortion due to the high concentration of oxygen vacancy. Under 350 nm excitation, a clear green emission aroused by oxygen vacancy was observed. The possible luminescence processes for the matrix and oxygen vacancy were proposed. The luminescence spectra of the nanophosphors revealed that the emission and absorption intensity aroused by oxygen vacancy were both enhanced when the size is decreased. On the basis of the above results, the essential relationship between particle size and oxygen vacancy in CaWO{sub 4} nanophosphors was concludedmore » that the concentration of oxygen vacancy could be increased by reducing its size, which was further confirmed by decay lifetimes.« less
Authors:
 [1] ;  [2] ;  [3] ; ; ;  [1] ;  [4]
  1. Department of Physics, Gansu University of Traditional Chinese Medicine, Lanzhou 730000 (China)
  2. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)
  3. Department of Chemical and Biomolecular Engineering and Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269 (United States)
  4. Department of Materials Science, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000 (China)
Publication Date:
OSTI Identifier:
22345198
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 50; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION; CALCIUM; CALCIUM TUNGSTATES; EXCITATION; IRRADIATION; OXYGEN; PARTICLE SIZE; PHOTOLUMINESCENCE; SPECTRA; SURFACTANTS