Structural and photoluminescence properties of Eu3+-doped (Y2.99-xGdx)Al5O12 phosphors under vacuum ultraviolet and ultraviolet excitation

• DOI: 10.1016/j.matchemphys.2019.02.035
• Publication Date: 2019-02-12T17:57:41Z
• Authors: Iure da S. Carvalho; Amanda I. dos S. ...; Ariosvaldo J.S. S...; Patresio A.M. Nas...; Adriano B. Andrade; David V. Sampaio; Danilo O. Junot; Thiago R. da Cunha; Lílian M. Jesus; Ronaldo S. Silva; Marcos V. dos S. ...
• Keywords: Ultraviolet; Lattice constant; Rietveld Refinement

Abstract Eu-doped (Y2.99-xGdx)Al5O12 phosphors (with x = 0, 0.5, 1, 1.5, 2, 2.5, and 2.99) were prepared by a sol-gel method using polyvinylalcohol (PVA) as gel agent. The crystal structures were characterized through X-ray diffraction and the resulting data were refined by the Rietveld method, which shows a linear increase of the lattice parameter with the Gd content. Further structural characterization was carried out via Raman spectroscopy. The effect of substituting Y3+ by Gd3+ on the Eu-doped Y3Al5O12 (YAG) photoluminescence properties was investigated using vacuum ultraviolet (VUV) and ultraviolet (UV) excitation. The excitation and emission spectra of the produced (Y2.99-xGdx)Al5O12 phosphors indicate that their luminescence properties are strongly dependent on the Gd3+ substitution. Our results also reveal a nonlinear decrease in the band-gap of these materials by increasing the Gd concentration.