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Long-lasting phosphor Y_2O_2S∶Eu 3+, Mg 2+, Ti 4+ was synthesized by a flux method and their luminescence properties were investigated. The result indicates that the unit cell parameter c is linearly increased with the increase of Eu_2O_3 content in Y_2O_2S∶Eu 3+_x(0.01≤x≤0.10). On the other hand, the change of unit cell parameter a is not linear dependence. In the Y_2O_2S∶ Eu 3+ crystal structure, Eu 3+ ions only replaced Y 3+ ions′ places in which it posited center position of c axis. With the increase of Eu_2O_3 content, the position of the strongest emission peak changed from 540 nm (5D_1→7F_2 transition) to 626 nm (5D_0→7F_2 transition), and the maximum intensity was obtained when x=0.09 in Y_2O_2S∶Eu 3+_x(0.01≤x≤0.10). This is due to the environment of trivalent europium in the crystal structure of Y_2O_2S. Doping with Mg 2+ or Ti 4+ ions alone cannot get the good long-lasting afterglow effect, whereas co-doping with Mg 2+ and Ti 4+ 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 h in the light perception of the dark-adapted human eye (0.32 mcd·m -2). Thus the LLP mechanism was analyzed.
Long-lasting phosphor Y_2O_2S: Eu 3+, Mg 2+, Ti 4+ was synthesized by a flux method and their luminescence properties were investigated. The result indicates that the unit cell parameter c is linearly increased with the increase of Eu_2O_3 content in Y_2O_2S : Eu 3 + _x (0.01≤x≤0.10). On the other hand, the change of unit cell parameter a is not linear dependence. In the Y_2O_2S: Eu 3+ crystal structure, Eu 3+ ions only replace Y 3+ ions ’Places in which it posited center position of c axis. With the increase of Eu_2O_3 content, the position of the strongest emission peak changed from 540 nm (5D_1 → 7F_2 transition) to 626 nm (5D_0 → 7F_2 transition), and the maximum intensity was obtained when x = 0.09 in Y_2O_2S: Eu 3 + _x (0.01≤x≤0.10). This is due to the environment of trivalent europium in the crystal structure of Y_2O_2S. Doping with Mg 2+ or Ti 4+ ions alone can not get the good long-lasting afterglow effect, but co-doping with Mg 2+ and Ti 4+ ions and excited with 365 The red and orange long-lasting phosphorescence (LLP) was also observed and the phosphorescence lasted nearly 3 h in the light perception of the dark-adapted human eye (0.32 mcd · m -2). Thus the LLP mechanism was analyzed.