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Title: TOF SIMS analysis and generation of white photoluminescence from strontium silicate codoped with europium and terbium

White light emitting terbium (Tb{sup 3+}) and europium (Eu{sup 3+}) codoped strontium silicate (Sr{sub 2}SiO{sub 4}) phosphors were prepared by a solid state reaction process. The structure, particle morphology, chemical composition, ion distribution, photoluminescence (PL), and decay characteristics of the phosphors were analyzed by x-ray diffraction (XRD), scanning electron microscopy (SEM), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and PL spectroscopy, respectively. The XRD data showed that our Sr{sub 2}SiO{sub 4} composed of two phases, namely, β-Sr{sub 2}SiO{sub 4} and α′-Sr{sub 2}SiO{sub 4}, and the α′-Sr{sub 2}SiO{sub 4} phase was more prominent than the β-Sr{sub 2}SiO{sub 4} phase. The SEM micrographs showed that the particles were agglomerated together and they did not have definite shapes. All ions (i.e., negative and positive) present in our materials were identified by TOF-SIMS. In addition, the chemical imaging performed with the TOF-SIMS demonstrated how the individual ions including the dopants (Eu{sup 3+} and Tb{sup 3+}) were distributed in the host lattice. White photoluminescence was observed when the Sr{sub 2}SiO{sub 4}:Tb{sup 3+}, Eu{sup 3+} phosphor was excited at 239 nm using a monochromatized xenon lamp as the excitation source. The phosphor exhibited fast decay lifetimes implying that it is not a good candidate for long afterglow applications.
Authors:
; ;  [1]
  1. Department of Physics, University of the Free State, P.O Box 339, Bloemfontein 9300 South Africa (South Africa)
Publication Date:
OSTI Identifier:
22258647
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 32; Journal Issue: 2; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CHEMICAL COMPOSITION; DECAY; DOPED MATERIALS; EUROPIUM; EUROPIUM IONS; EXCITATION; ION MICROPROBE ANALYSIS; MASS SPECTROSCOPY; PARTICLES; PHOSPHORS; PHOTOLUMINESCENCE; SCANNING ELECTRON MICROSCOPY; STRONTIUM SILICATES; TERBIUM; TERBIUM IONS; TIME-OF-FLIGHT METHOD; XENON; X-RAY DIFFRACTION