Influence of excitation wavelengths on luminescent properties of Sr_3Al_2O_6:Eu~(2+),Dy~(3+) phosphors prepared by sol-gel-combustion processing

摘要

Eu~(2+) and Dy~(3+) ion co-doped Sr_3Al_2O_6 red-emitting long afterglow phosphor was synthesized by sol-gel-combustion methods using Sr(NO_3)_2. A1(NO_3)_3·9H_2O, Eu_2O_3, Dy_2O_3, H_3BO_3 and C_6H_8O_7H_2O as raw materials. The crystalline structure of the phosphors were characterized by X-ray diffraction, luminescent properties of phosphors were analyzed by fluorescence spectrophotometer. The effect of excitation wavelengths on the luminescent properties of Sr_3Al_2O_6:Eu~(2+), Dy~(3+) phosphors was discussed. The emission peak of Sr_3Al_2O_6:Eu~(2+), Dy~(3+) phosphor lays at 516 nm under the excitation of 360 nm, and at 612 nm under the excitation of 468 nm. The results reveal that the Sr3Al206:Eu2*, Dy3* phosphor will emit a yellow-green light upon UV illumination, and a bright red light upon visible light illumination. The emission mechanism was discussed according to the effect of nephelauxetic and crystal field on the 4f~65d~1→4f~7 transition of the Eu~(2+) ions in Sr_3Al_2O_6. The afterglow time of (Sr_(0.94)Eu_(0.03)Dy_(0.03))_3 A1_2O_6 phosphors lasts for over 600s after the excited source was cut off.