Abstract: The effects of different doping concentration of Eu²⁺ on the properties of Sr₂Al₆O₁₁-based phosphor
were studied. The results indicate that there are two main emission peaks at 403nm and 493nm existing in the phosphor, while the doping concentration
of Eu²⁺ is below 0.01mol, which are corresponding to various Sr1 and Sr2 sites in the Sr₂Al₆O₁₁ matrix. While increasing the doping
concentration of Eu²⁺, the emission peak of 403nm disappears and the peak of 493nm becomes strong simultaneously due to the energy transfer
between the different Eu²⁺ centers. Decay curves imply that the phosphor without co-doping Dy³⁺ has no long afterglow properties.
When the doping concentration of Eu²⁺ is 0.01mol, the long afterglow is the best in three experimental samples with different Eu²⁺ contents.
The luminescent properties will decrease while increasing the doping concentration of Eu²⁺ due to the concentration quenching.

Key words: phosphor, emission spectra, long afterglow