Tunable luminescence and energy transfer properties in YVO₄:Bi³⁺, Eu³⁺ phosphors

Abstract

In this paper, YVO₄:Bi³⁺, Eu³⁺ phosphors have been synthesized by high-temperature solid-state method. The samples were characterized by X-ray powder diffraction, photoluminescence spectra, luminescence lifetime, and GSAS structure refinement. The excitation spectrum of YVO₄:Bi³⁺, Eu³⁺ monitoring at 622 nm was a broad band with major peak located at 280 nm. It contained the charge transfer from 2p orbit of O²⁻ to 4f orbit of Eu³⁺ (257 nm) and the absorbing from energy level transition of Bi³⁺ (¹S₀→³P₁, 346 nm) and VO₄ ³⁻ (^lA₁→¹T₂, 286 nm and ^lA₁→¹T₁, 320 nm) through gauss fitting. Upon excitation at a wavelength of 280 nm, the major emission peak of YVO₄:Bi³⁺, Eu³⁺ located at 622 nm (red) was attributed to the electric dipole transition ⁵D₀→⁷F₂ of Eu³⁺. The energy transfer mechanism of Bi³⁺→Eu³⁺ was also studied to be dipole–quadrupole mechanism of electric multipole interaction, and the critical distance between Eu³⁺ and Bi³⁺ was calculated by concentration quenching method. The emission color of YVO₄:Bi³⁺, Eu³⁺ can be tuned by the energy transfer of ions and the concentration of activator. In a word, the material has a good application prospects in the field of light-emitting diode under ultraviolet excitation.