A single-phase NaCa2Mg2V3O12:Sm3+ phosphor: Synthesis, energy transfer, and luminescence properties

NaCa₂Mg₂V₃O₁₂:Sm³⁺ phosphors are successfully prepared in air via solid-state reaction method. The crystal structures, concentration-dependent emission spectra, decay curves, and luminescence properties are investigated. The prepared samples have only a single phase (NaCa₂Mg₂V₃O₁₂). The excitation spectrum of host (NaCa₂Mg₂V₃O₁₂) monitored at 510 nm is observed in the region from 210 nm to 400 nm. The host (NaCa₂Mg₂V₃O₁₂) with excitation at 340 nm shows a strong broadband green emission with a maximum at 510 nm in the range of 400–800 nm. The excitation spectrum of NaCa₂Mg₂V₃O₁₂:Sm³⁺ phosphor monitored at 618 nm is shown in the region from 210 nm to 550 nm, which includes many absorption peaks. NaCa₂Mg₂V₃O₁₂:Sm³⁺ phosphor with excitation at 340 nm displays the tunable emission color in the region from green to yellow light with changing Sm³⁺ concentration, however, that with excitation at 406 nm only emits red light. The optimual Sm³⁺ concentration is about 4 mol% in NaCa₂Mg₂V₃O₁₂:Sm³⁺ phosphor. The lifetime of NaCa₂Mg₂V₃O₁₂:Sm³⁺ phosphor decreases from 929.16 μs to 832.11 μs with increasing Sm³⁺ concentration. The luminous mechanism of NaCa₂Mg₂V₃O₁₂:Sm³⁺ phosphor is explained by the configurational coordinate diagram of VO₄³⁻ and energy level diagram of Sm³⁺ ion. The experimental results are beneficial to the research of other Sm³⁺-doped luminescence materials.