Upconversion of Y[sub 2]O[sub 2]S:Tm, Mg, Ti Phosphor and Its Long-lasting Phosphorescence

Abstract

We report the upconversion luminescence of Tm 3 + in Y 2 O 2 S:Tm, Mg, Ti phosphor. The upconversion luminescence of Y 2 O 2 S:Tm, Mg, Ti phosphor and its unusually long-lasting phosphorescence properties have been discussed.Two upconversion emission bands located at 466 and 545 nm from Tm 3 + in Y 2 O 2 S:Tm, Mg, Ti phosphor are observed after near infrared light (λ = 798 nm) or red light (λ = 648 nm) excitation. The afterglow light of Y 2 O 2 S:Tm, Mg, Ti phosphor is so strong that it can be seen by the naked eye for above an hour. The possible mechanism of the unusual upconversion long-lasting phosphorescence is also discussed.