A New Yellow Long Lasting Phosphor Y2O2S：Ti
摘要
A new kind of doped rare earth free phosphor Y2O2S∶xTi(0＜x≤0.10) with doped Ti as activative center was synthesized by solid state reaction and sintered at 1200 ℃ for 2.5 h under reducing atmosphere. XRD patterns, photoluminescence spectra, time-resolved phosphorescence spectra and decay curves of the phosphor were investigated. XRD results reveal that a single Y2O2S phase exists with Ti content up to 6%(mol fraction). Yellow long lasting phosphorescence for present materials was observed in the dark with naked eye after the removal of the excitation light. From the time-resolved phosphorescence spectra the broad emission band centered at 565 nm was confirmed to be responsible for the long lasting phosphorescence which could maintain above 1 h. The possible mechanism responsible for the long lasting phosphorescence of the Y2O2S∶Ti phosphor was proposed.