Sol-gel synthesis and the effect of boron addition on the phosphorescent properties of SrAl2O4 : Eu2+,Dy3+ phosphors

The effects of boron addition on the microstructure and afterglow propertie s of the long-phosphorescent SrAl2O4:Eu2+,Dy3+ (SAED), synthesized via a no vel sol-gel route, were systematically investigated. Significant improvemen t on luminescence intensity and the lengthening of afterglow persistent tim e in boron-added SAED (BSAED) phases were observed, as compared to those wi thout boron addition and commercial phosphors. Typical bluish-green emissio ns attributed to the doublet phosphorescence with wavelengths peaking at 41 2 and 501 nm for BSAED phase and 398 and 486 nm for the pristine SAED phase were observed. Afterglow with wavelengths peaking at 403 and 485 nm was ob served for BSAED phase, whereas that with wavelengths peaking at 486.5 nm w as found for the pristine SAED phase, as indicated by time-dependent afterg low decay profiles. Results from scanning electron microscopic morphologica l studies were used to investigate the modification of microstructure of th e BSAED phases.