Preparation of long persistent SrO·2Al2O3 ceramics and their luminescent properties

Long lasting strontium aluminate phosphors were synthesized by solid state reaction in the experiment. SrO·2Al2O3 ceramics with long afterglow was firstly fabricated at 1400 deg. C with the aid of B2O3. The effects of B2O3 on the phase composition, porosity, density and microstructure of the sintered ceramics were investigated, as well as the effects on luminescent properties. The results indicated that B2O3 stimulated the formation of SrO·2Al2O3 by consuming the intermediate phases and helped to produce dense ceramics at 1400 deg. C. The ceramics hold two emission peaks at 390 and 475 nm, due to the luminescent behavior of Eu2+ in 5SrO·4Al2O3 and SrO·2Al2O3, respectively. Emission at 390 nm showed slight afterglow characteristics while emission at 475 nm illustrated good long persistence. The afterglow property was enhanced by the addition of B2O3, due to the increase in the depth of the trap center in the ceramics