Structure, luminescence properties and energy transfer behavior of color-adjustable Sr3Gd2(Si3O9)2:Ce3+, Tb3+/Mn2+ phosphors†
Abstract
A series of single-phased and emission-tunable Sr3Gd2(Si3O9)2 (SGSO):Ce3+, Tb3+/Mn2+ phosphors have been successfully prepared via the solid-state reaction, and the crystal structures, luminescence properties, energy transfer of Ce3+ → Tb3+ and Ce3+ → Mn2+, color tuning and thermally stability were systematically investigated respectively. The energy transfer from Ce3+ to Tb3+ or Mn2+ ions were deduced from the spectral overlap between the Ce3+ emission and Tb3+/Mn2+ excitation spectra. The energy transfer mechanisms of Ce3+ → Tb3+ and Ce3+ → Mn2+ in the host were verified to be a dipole–quadrupole interaction and dipole–dipole interaction, respectively, which made the emission color shift from blue to green and near white with the corresponding Commission Internationale deL'Eclairage (CIE) chromaticity coordinates from (0.174, 0.060) to (0.286, 0.615) and (0.319, 0.367), respectively. The good thermal stability of SGSO:0.26Ce3+, 0.60Tb3+ and SGSO:0.26Ce3+, 0.45Mn2+ samples showed about 72.3% and 86.1% at 150 °C of its initial emission intensity at room temperature due to the different energy transfer efficiency through Ce3+ → Tb3+ and Ce3+ → Mn2+. The maximum quantum yields (QYs) of as-prepared SGSO:0.26Ce3+, 0.10Tb3+ and SGSO:0.26Ce3+, 0.57Mn2+ phosphors could reach 80.2% and 62.4%, respectively. All these properties indicate that the SGSO:Ce3+, Tb3+/Mn2+ phosphors have potential applications as ultraviolet-convertible phosphors.