Luminescent properties of Eu~(2+), Eu~(3+) and Dy~(3+) co-activated nanocrystals

摘要

By the control of the reducing atmospheres in the one-pot combustion reactions, Eu~(2+), Eu~(3+) and Dy~(3+) co-activated strontium aluminate oxide were synthesized. X-ray diffraction confirmed the formation of monoclinic SrAl_2O_4 nanocrystals. The photoluminescence spectra of the phosphors were measured. It is found that three sharp emissions at 483, 570 and 615 nm were superimposed onto the broad green emission band at about 520 nm. The origins of the broad green luminescent band, the sharp blue at 483 nm, and sharp yellow emissions at 570 nm and the sharp red emissions at 615 nm can be attributed to the 4f~65d~1—->4f~7 transitions of Eu~(2+) ions, the 4~F_(9/2)—>6~H_(15/2) transition of Dy~(3+) ions, the 4~F_(9/2)—>6~H_(13/2) transition of Dy~(3+) ions, and the 5~D_0-7~F_2 transition of Eu~(3+) ions in the SrAl_2O_4 nanocrystals, respectively. The results indicate that the white light emitting phosphors are possible by tuning the relative molar percentages of Eu~(2+), Eu~(3+) and Dy~(3+) in the phosphors.