Synthesis, energy transfer and luminescence properties of KSrVO₄:Eu³⁺ red phosphor

KSrVO₄:Eu³⁺ phosphors are synthesized by solid-state reaction method in air. Host KSrVO₄ under excitation at 345 nm emits green–yellow light with the CIE chromaticity coordinates (0.3466, 0.4425), and its broad emission band peaking at ~545 nm covers the range 400–750 nm due to ³T_1,2 → ¹A₁ transitions in [VO₄]³⁻ group. KSrVO₄:Eu³⁺ phosphor under excitation at 315 and 394 nm shows red emission with the CIE chromaticity coordinates (0.6279, 0.3717), and the emission spectra in the range of 560–750 nm contains four narrow emission bands owing to ⁵D₀ → ⁷F _J (J = 1, 2, 3, and 4) transitions of Eu³⁺ ion, respectively. The optimal Eu³⁺ doping concentration is ~4 mol%. The lifetime decreases from 0.991 to 0.893 ms with increasing Eu³⁺ concentration within the range 0.5–6 mol%. The possible luminous mechanism is analyzed by the simplified energy level diagrams of VO₄ ³⁻ group and Eu³⁺ ion, and energy transfer process in KSrVO₄:Eu³⁺ phosphor. The experimental results indicate that KSrVO₄:Eu³⁺ phosphor will be possible to be used as red phosphor candidate for white light-emitting diode (LED) based on ultraviolet (~315 nm) and near ultraviolet (~395 nm) LED chips.