Effects of Ho3+ and Yb3+ doping concentrations and Li+ co-doping on the luminescence of GdVO4 powders
DOI: 10.1016/j.optmat.2015.03.013
Title: Effects of Ho3+ and Yb3+ doping concentrations and Li+ co-doping on the luminescence of GdVO4 powders
Journal Title: Optical Materials
Volume: 45
Publication Date: July 2015
Start Page: 76
End Page: 81
Published online: online 26 March 2015
ISSN: 0925-3467
Affiliations:
  • University of Belgrade, Vin?a Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Serbia
  • Abstract: nt the structural and luminescent properties of Ho3++/Yb3+-doped GdVO4 and Li+-co-doped GdVO4:Ho3++/Yb3+ powder phosphors. The materials were prepared by high-temperature solid state method with different concentrations (between 0.5 and 2 mol%) of dopant Ho3++ emitting ions and different concentrations (between 5 and 20 mol%) of sensitizer Yb3+ ions. The dopant ions provided the material with intense luminescence emission; green emissions (centered at 542 nm from 5F4,5S2 → 5I8 electronic transition of Ho3++ ions) resulted upon ultraviolet excitation, and red (centered at 659 nm from 5F5 → 5I8 electronic transition of Ho3++ ions) upon near-infrared excitation. The co-doped materials were obtained under identical experimental conditions by adding Li+ ions (5, 7.5, 10, and 15 mol%). The powders co-doped with 7.5 mol% Li+ ions showed a downconversion emission intensity more than twice as high as the samples without Li+ co-doping. In upconversion, an equal intensification of emission was achieved with co-doping with 10 mol% Li+. The influences of Ho3++/Yb3+ concentration ratio and Li+ co-doping level on emission color and emission branching was investigated and analyzed for both downconversion and upconversion emission. Increasing Yb3+ concentration was found to increase the share of dominant emission (green) in downconversion, but decreased the share of dominant emission (red) in upconversion.
    Accepted: 10 March 2015
    Received: 20 February 2015
    Keywords: Ho3+-doped orthovanadate; Green downconversion; Red upconversion; Li+ co-doping
    Tel: +381 11 6408 607.Copyright ©
    Email: dramican@vinca.rs

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