Preparation And Study Of Mn²⁺ Activated Silicate-based Red Phosphors

The applications of afterglow materials in biological imaging arouse more and more interests recently. Thus, the study on the luminescence mechanism of these kind of phosphorescent materials is of great advantage for the preparation of better materials. This paper mainly studies the impact of the concentration of Mg²⁺ ions in the host lattice and intentionally doped Mn²⁺ ions on the luminescence of the materials and the luminescence mechanism of Mn²⁺ on different sites. We prepared the phosphor with sol-gel method for the dry gel precursor and then treated the resulted opaque gel at high-temperature in a reductive atmosphere. Studying the impact of the concentration of Mg²⁺ on the luminescence of Mn²⁺, only Mn²⁺ was doped; But the impact of the concentration of Mn²⁺ on the luminescence of itself, the lattice was doped with Mn²⁺and rare earth ions, Eu²⁺ and Dy³⁺ acted as sensibilizer and traps.The results showed the reduce of Mg²⁺ made the emission peak intensity and lifetime of 650 nm of Mn²⁺ relatively strengthened. This is mainly because of the compensating of Zn²⁺, which decreased during the preparation. The impact of the concentration of Mn²⁺ on the luminescence of itself showed that with the increase of the concentration of Mn²⁺ , relative to the percentage of luminescence intensity of Eu²⁺, the orange luminescence of Mn²⁺ took less percentage and the red one took more. The red phosphorescence wasn't affected by the change of the concentration of Mn²⁺. Just the duration of the orange phosphorescence corresponding to M2 sites increased and then decreased, and the concentration of Mn²⁺ corresponding to the max intensity was 3.5%.