Morphology/size effect on the luminescence properties of the [(Y Gd1-)0.98Dy0.02]2O3 phosphor with enhanced yellow emission

• DOI: 10.1016/j.jlumin.2017.07.046
• Publication Date: 2017-08-24T04:00:20Z
• Authors: Wenzhi Wang; Jinkai Li; Guangbin Duan; Weilin Zhao; Bingqiang Cao; Zongming Liu
• Keywords: Morphology; Quantum Efficiency

Abstract The [(Y 0.05 Gd 0.95 ) 0.98 Dy 0.02 ] 2 O 3 phosphor with different particle size and morphology was obtained through precursor synthesis via urea-based homogeneous precipitation (UBHP) method, followed by annealing. The synthesis, particle morphology/size control, luminescent properties and energy transfer of the [(Y 0.05 Gd 0.95 ) 0.98 Dy 0.02 ] 2 O 3 phosphor were systematically studied by the combined techniques of XRD, FE-SEM, FT-IR, PLE/PL spectroscopy, fluorescence decay and quantum efficiency analysis. Partly replacing water with ethylene glycol (EG) addition as solvent, the precursor morphology gradually changed from sphere to flower, and the size of sphere decreased with the ethylene glycol addition. The pure [(Y 0.05 Gd 0.95 ) 0.98 Dy 0.02 ] 2 O 3 oxide remains the precursor morphology even at the high temperature of 1000 °C. The phosphors all exhibit strong yellow emission band at ~574 nm ( 4 F 9/2 → 6 H 13/2 transitions of Dy 3+ ) under optimal UV excitation into the 8 S 7/2 → 6 I J intra f-f transition of Gd 3+ at ~276 nm indicating the efficient Gd 3+ →Dy 3+ energy transfer. The Gd 3+ →Dy 3+ energy transfer efficiency gradually decreases with the Y 3+ concentration increasing. The particle morphology/size does not alter the fluorescence lifetime (~0.69 ± 0.04 ms), color coordinate (~0.45, ~0.48), temperature (~3200 K) and color purity (~82.09%), but brings about appreciable change to the emission intensity and quantum efficiency, and the detailed effect mechanism was discussed in this work. The size/morphology controlled phosphor of [(Y 0.05 Gd 0.95 ) 0.98 Dy 0.02 ] 2 O 3 with yellow-emitting is expected to be widely used in the lighting and display areas.