A new method to synthesize long afterglow red phosphor

Long afterglow phosphor Y2O2S:Gd,Eu,Ti,Mg was synthesized by a gas absorption method and the effect of Ti4+ and Mg2+ ions doping on the luminescent properties was also investigated. Single phase Y2O2S can be obtained by calcining the oxide mixture in a graphite crucible absorbed with sulfur. Ti4+ and Mg2+ ions decrease the luminescent intensity of the phosphor, but either Ti4+ or Mg2+ ion doping results in red long afterglow. A strong thermoluminescence peak appears when codoping Ti4+ and Mg2+ ions in the phosphor.