The Synthesis And Luminescence Properties Of Doped And Self-activated Vanadate Luminescent Materials

In this work, we synthesiced well-crystallized YVO₄:Eu³⁺nanostructuresconsisting of YVO₄:Eu³⁺QDs via a hydrothermal process, which exhibit highluminescent intensity. We investigated whether the complex compound and Ph valuehad an effect on the samples of luminous intensity and micrographs. X-raydiffraction （XRD）, scanning electron microscopy （SEM） and photoluminescence（PL） technologies are used to study the luminescence properties and micrographs.The result showed that the Eu³⁺exhibits an intense emission in YVO₄host lattice bycontrolling synthetic conditions， while the particles have a very small sizedistribution with good luminous intensity. Such morphology can be useful for theapplication of the nanometer phosphor.YVO₄:Bi³⁺phosphors were synthesized by a convenient high-temperaturesolid-state method. We investigated whether the doping concentration、calcinationstemperature and flux had an effect on the samples of luminous intensity, and theluminescent mechanism was also discussed elementarily. Bi³⁺exhibits an intenseyellowish-white broad emission in YVO₄host lattice by controlling syntheticconditions. The experiment showed that1.5%Bi³⁺was the optimum concentrationand1000°C being the optimum sintering temperature for their preparation. Whenthe flux NH₄Cl is1%of the whole samples quality the Bi³⁺emission intensity canincrease by about6%. The Bi³⁺shows an intense wide emission band and broadexcitation band ranging form200to370nm, so they may be hopeful in the use ofhigh pressure mercury lamp and tricolor conversion phosphors.We also studied the phosphors based on Ca₂(K_xNa_1-x)Mg₂V₃O₁₂lattice synthesized by a solid-state reaction. By adjusting the K/Na ratio in Ca₂(K_xNa_1-x)Mg₂V₃O₁₂the luminescence intensity can be largely enhanced comparedwith that of Ca₂KMg₂V₃O₁₂and Ca₂NaMg₂V₃O₁₂. The emission intensity reaches itsmaximum at K/Na ratio=1. It is clear that the VO43excitation spectrum ofCa₂KMg₂V₃O₁₂extends into the near UV, so this phosphor can be efficiently excitedby350nm, and may be a potential vanadate garnet converting the ultravioletemission of a UV-LED into white light with good luminescence effect for ultravioletlight-emitting diode （UV-LED） phosphor. Moreover, in some extent the study mayoffer a method of enhancing the luminescence intensity of Ca₂KMg₂V₃O₁₂phosphors. Further investigation about other cation doping effect on the VO43-luminescence property in Ca₂KMg₂V₃O₁₂phosphors is necessary in the laterscientific research.It suggest a method to improve the PL intensity of Ca2（KxNa1-x）Mg₂V₃O₁₂phosphors to be applied for LEDs.