Preparation And Luminescent Properties Of YVO₄Particles Co-doped With Eu³⁺ And Alkaline Earth Ions

The uniform and dispersed quasi-spherical alkaline earth metals and Eu3+co-doped yttrium vanadate (YVO4:Eu3+, M2+(M=Mg, Ca, Sr, Ba)) sub-microluminescence material were synthesized by a facile low-temperature solvothermalprocess using EG as solvent in the presence of PVP under150oC for10h. X-raydiffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL)spectroscopy were used to characterise the microstructure, morophology, andluminescence properties of the as-prepared samples. The XRD patterns of YVO4:Eu3+doped with Mg2+, Ca2+, Sr2+and Ba2+ions exhibited the characteristic peaks of puretetragonal YVO4, which were well indexed to the values of the standard card (JCPDSNo.17-0341), and no extra phase related with dopant components was detected.Compared with that of YVO4:Eu3+phosphor, the morphology of YVO4:Eu3+phosphor had not obvious change after doping with alkaline earth dopants. Obviously,the absorption of V-O charge transfer band in the UV region after doping with thealkaline earth metals enhanced. Similarly, in comparison with those of YVO4:Eu3+phosphor, the intensity of red emission had greatly enhanced up to about200%forYVO4:Eu3+co-doped with the alkaline earth metals. The effect of mutual action andthe dopants (Ba2+or Sr2+and Eu3+) concentrations on luminescence properties wasstudied, and this indicated that each of the codopants in YVO4:Eu3+,M2+crystal had aquenching concentration when fixing the doping concentration of the other one.Furthermore, the investigation on the effect of thermal annealing on the luminescenceof YVO4:Eu3+,M2+(M=Sr, Ba) phosphors. After thermal annealing, theluminescence intensity of both YVO4:Eu3+and YVO4:Eu3+,M2+(M=Sr, Ba)phosphors had increased remarkably resulting from the improved crystallinity andespecially the reduced number of crystal defects and non-radiative traps after thermalannealing.