Enhanced luminescence performance of Sr2MgSi2O7:Eu2+ blue long persistence phosphor by co-doping with Ce3+ ions

A series of rare earth doped and co-doped di-strontium magnesium di-silicate phosphors namely: Sr2MgSi2O7:Ce3+, Sr2MgSi2O7:Eu2+ and Sr2MgSi2O7:Eu2+, Ce3+ were prepared by the solid state reaction method. The crystal structures of sintered phosphors were an akermanite type structure which belongs to the tetragonal crystallography. The chemical compositions of sintered phosphors were confirmed by energy dispersive X-ray spectroscopy (EDS). Under the ultraviolet excitation, the emission spectra of both Sr2MgSi2O7:Eu2+ and Sr2MgSi2O7:Eu2+, Ce3+ phosphors were composed of a broad band peaking at 460 nm, belonging to the broad emission band. When the Sr2MgSi2O7:Eu2+ phosphor is co-doped with Ce3+ ions, thermouminescence, photoluminescence, afterglow and mechanoluminescence (ML) intensity were strongly enhanced. The Sr2MgSi2O7:Eu2+ phosphor showed some afterglow with short persistence time. By incorporation of Ce3+ ions, an efficient energy transfer from Ce3+ to Eu2+ was found and emission intensity of Sr2MgSi2O7:Eu2+ was enhanced. The ML intensities of Sr2MgSi2O7:Ce3+, Sr2MgSi2O7:Eu2+ and Sr2MgSi2O7:Eu2+, Ce3+ phosphors were proportionally increased with the increase of impact velocity, which suggests that these phosphors can be used as sensors to detect the stress of an object. Thus the present investigation indicates that the piezoelectricity is responsible to produce ML in prepared phosphors.