New viewpoint about the effects of boric acid on luminous intensity of Sr2MgSi2O7: Eu, Dy

In this work, high temperature solid phase method was applied to prepare Sr2MgSi2O7:Eu, Dy blue light long-persistence materials with different contents of H3BO3. Under the condition of low H3BO3 content, it was difficult for Eu and Dy to enter Sr2MgSi2O7 lattice, impurity phase of Sr3MgSi2O8 was observed, and initial afterglow luminance of the sample was very low. With the increase of H3BO3, Sr3MgSi2O8 phase disappeared, Eu and Dy entered Sr2MgSi2O7 lattice smoothly, and the grain size as well as initial afterglow luminance of samples increased significantly. The initial afterglow luminance of the sample reached the maximum while the H3BO3 content was 10% (molar ratio). As H3BO3 content increased further, the initial afterglow luminance reduced rapidly. After detailed analysis, we consider that the key factors influencing the afterglow luminance of samples are the formation and the density of luminous unit, which is greatly determined by the Eu and Dy's entering Sr2MgSi2O7 lattice as well as the grain size of Sr2MgSi2O7 crystal.