Influence of alkali metal compound fluxes on Gd₂O₂S:Tb particle and luminescence

Gd₂O₂S:Tb phosphors with different alkali-metal compound fluxes were synthesized by molten salt method, showing high luminous intensity, monodispersity and micron size characteristics. The results indicated that from K⁺ to Na⁺ and to Li⁺, the particles mean size tended to grow bigger. K⁺ could effectively reduce the particle size without depressing the luminescence intensity. Meanwhile, after comparing the strongest emission intensity among different fluxes, it was shown that K⁺ had most significance on improving the luminescence intensity. Li⁺ could promote the formation of hexagonal morphology. It was also found that CO₃²⁻, PO₄³⁻ had prominent effects on optimizing particles size (at 254 nm excitation).