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

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 VO43− (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.