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.2Al(2)O(3) ceramics with long afterglow was firstly fabricated at 1400 degreesC 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.2Al(2)O(3) by consuming the intermediate phases and helped to produce dense ceramics at 1400 degreesC. The ceramics hold two emission peaks at 390 and 475 nm, due to the luminescent behavior of Eu2+ in 5SrO.4Al(2)O(3) and SrO.2Al(2)O(3), respectively. Emission at 390 nm showed slight afterglow characteristics while emission at 475 mn 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. (C) 2002 Elsevier Science B.V. All rights reserved.