Synthesis of the Nano-sized SrAl2O4 Phosphors by Wet Processing and its Photoluminescence Properties

Eu2+ and Dy3+ co-doped strontium aluminate, SrAl2O4 long phosphorescent phoshor was fabricated and its photoluminescence was characterized. The phosphor, SrAl2O4:Eu2+, Dy3+ was synthesized by a coprecipitation in which metal salts of Sr(NO3)(2), Al(NO3)(3)center dot 9H(2)O, were dissolved in (NH4)(2)CO3 solution with adding Eu(NO3)(3)center dot 5H(2)O and Dy(NO3)(3)center dot 5H(2)O as a activator and co-activator, respectively. The coprecipitated products were separated from solution, washed, and dried in a vacuum dry oven. The dried powders were then mixed with 3 wt% B2O3 as a flux and heated at 800 similar to 1400 degrees C for 3 h under the reducing ambient atmosphere of 95% Ar+5% H-2 gases. For the synthesized SrAl2O4:Eu2+, Dy3+, properties of photoluminescence such as emission, excitation and decay time were examined. The emission intensity increased as the annealing temperature increased and showed a maximum peak intensity at 510 nm with a broad band from 400 similar to 650 nm. Monitored at 520 nm, the excitation spectrum showed a maximum peak intensity at 315 similar to 320 nm wavelength with a broad band from 200 similar to 500 nm wavelength. The decay time of SrAl2O4:Eu2+,Dy3+ increased as the annealing temperature increased.