Characterization and properties of a red and orange Y2O2S-based long afterglow phosphor

Eu3+-activated Y2O2S phosphors co-doped with Ti and Mg ions were prepared. The effect of various sintering atmospheric conditions on the crystalline phases and luminescent properties of the products were investigated in detail. Red and orange long afterglow was observed after phosphors were excited with 365 nm ultraviolet light. The main emission peaks were ascribed to Eu3+ ions transition from 5DJ (J=0,1) to 7FJ (J=0,1,2,3,4), and the phosphorescence lasted for nearly 3 h in the light perception of the dark-adapted human eye (0.32 mcd m−2). The phosphorescence mechanism was also investigated.