Structure and luminescence characteristics of self-activated vanadate garnet phosphors

Abstract

Vanadate phosphors include [VO₄] tetrahedra with T_d symmetry. Due to the charge transfer (CT) between V⁵⁺–O²⁻, the phosphor with [VO₄] tetrahedra exhibits strong emission in the visible region and can effectively absorb ultraviolet (UV) light. Garnet structured vanadate phosphors have attracted much attention due to their easily controllable composition. In this paper, we successfully prepared phosphors with high quantum efficiency. The lattice structure and luminescent properties of the samples were studied in detail. Vanadate garnet phosphors have the same structure. The phosphors exhibit broadband emission peaks under 266 nm and 355 nm near-ultraviolet (UV) excitation, emitting bright greenish-white and yellowish-white light. The emission wavelength of the phosphor is red-shifted. The phosphors exhibit high internal quantum efficiency (IQE) for the NaSr₂Mg₂V₃O₁₂ and KCa₂Mg₂V₃O₁₂ samples. In this paper, the structure and luminescence characteristics of greenish-white-emitting and yellowish-white-emitting vanadate phosphors with high quantum efficiency are investigated.