Microstructures and Luminescent Properties of Sm³⁺-Doped KSr₂Nb₅O₁₅ Prepared by Molten Salt Synthesis Method

To explore the excellent luminescent activator and associated luminescent behavior for the development of the potential coupling effect about luminescent and photochromic properties of novel KSr₂Nb₅O₁₅ materials, the Sm³⁺-doped KSr₂Nb₅O₁₅ powders have been prepared using the molten salt method. The effects of Sm³⁺ doping on the phases, morphologies, bonding vibrations, and luminescent properties have been investigated. The results show that the Sm³⁺-doped KSr₂Nb₅O₁₅ powders can emit orange light (main peak wavelength around 601 nm) under the blue light (407 nm) excitation, and the optimal doping concentration of Sm³⁺ is 10 mol%. The main emission band is well matched with the photochromic absorption band of KSN host. The inversion symmetry of the environment around Sm³⁺ in KSN lattice and the electric dipole transition of Sm³⁺ are affected by the neighboring Nb(II)O₆ octahedrons. The related concentration quenching mechanism of luminescence and the effect of Sm³⁺ doping on the KSN lattice structures are further discussed.