Characterization of Y2O2S : Eu3+, Mg2+, Ti4+ long-lasting phosphor synthesized by flux method

Long-lasting phosphor Y2O2S: Eu3+ Mg2+ Ti4+ was synthesized by a flux method and their luminescence properties were investigated. The result indicates that the unit cell parameter e is linearly increased with the increase of EU2O3 content in Y2O2S: Eu-x(3+) (0.01 <= x <= 0.10). On the other hand, the change of unit cell parameter a is not linear de pendence. In the Y2O2S: Eu3+ crystal structure, Eu3+ ions only replaced Y3+ ions' places in which it posited center position of c axis. With the increase of EU2O3 content, the position of the strongest emission peak changed from 540 nm (5 D, ->F-7(2) transition) to 626 run (D-5(0)->F-7(2) transition), and the maximum intensity was obtained when x = 0. 09 in Y2O2S: Eu-x(3+) (0.01 <= x <= 0.10). This is due to the environment of trivalent europium in the crystal structure Of Y2O2S. Doping with Mg2+ or Ti4+ ions alone cannot get the good long-lasting afterglow effect, whereas co-doping with Mg2+ and V, ions and excited with 365 nm ultraviolet light, a strong thermoluminesence peak appeared, red and orange long-lasting phosphorescence (LLP) was also observed and the phosphorescence lasted nearly 3 It in the light perception of the dark-adapted human eye (0.32 med(.)m(-2)). Thus the LLP mechanism was analyzed.