Structural and Luminescence Properties of Nanocrystalline Eu~(3+)-doped Gd_2O_3

摘要

The present work addresses the synthesis and characterization of red emitting Gd_(2-x)Eu_xO_3 nanocrystalline phosphors by a modified sol-gel based method. The effects of the annealing temperature and atomic fraction of Eu~(3+) ions, 'x', on the structural and luminescence properties of the produced oxides have been systematically investigated. X-ray diffraction analyses revealed that crystalline cubic-Gd_2O_3 host structure was obtained when the intermediates (x=0.01-0.30) were annealed at different temperatures in air. Photoluminescence spectra of doped Gd_2O_3 powders showed all transitions of Eu~(3+) species, being the ~5D_0 → ~7F_2 transition the most intense. On a common sample-weight basis, the highest photoluminescence intensity was obtained at 'x'= 0.15. The energy transfer from host to dopant was verified for all evaluated 'x' values, which suggest the actual incorporation of Eu species into the Gd-oxide lattice. It was also found that the photoluminescence intensity was strongly dependent on the annealing temperature and dopant concentration.