Luminescence sensitization of Ln3+ impurity ions in BaGdF5 host matrix: Structural investigation, color tunable luminescence and energy transfer

Abstract

A series of Sm3+ and/or Eu3+ doped luminescent BaGdF5 nanophosphors were synthesized hydrothermally at 180 °C for 24 h using EDTA as chelating ligand. The structure of synthesized nanophosphors was confirmed by XRD pattern, SEM and TEM studies. The Sm3+ and/or Eu3+ doped BaGdF5 nanophosphors showed irregular sphere like morphology. The minimum average particle size was about 105 nm. The multicolor luminescence was obtained upon excitation at 272 nm depending on the dopant lanthanide ions. The luminescence decay profile of BaGdF5:Sm3+,Eu3+ nanophosphors with different concentrations of Eu3+ ions were obtained by monitoring emission due to magnetic dipole transition at 589 nm for Sm3+ ions. The highest luminescence intensity was obtained for BaGdF5:0.03Sm3+,0.04Eu3+ nanophosphor as a result of efficient energy transfer from Gd3+ to Sm3+ ions and Sm3+ to Eu3+ ions. The color coordinates for all the synthesized nanophosphors were calculated and represented in the form of CIE chromaticity diagram. The energy transfer mechanism for nanophosphors was also explained.