Abstract
This paperreportsthephotoluminescenceandafterglowofSr2SiO4 doped withEu2þ and Dy3þ. Factors governingtheformationofthemonoclinicororthorhombicphaseofthisortho-silicatearedescribed and theimpactofthecrystallographicmodificationontheluminescenceandafterglowunderUVand VUV excitationarediscussedandinsightinfactorslimitingtheefficiencyofthisyellowafterglow materialisgiven.