Synthesis And Research On Properties Of YV?P?O₄:Dy³⁺ Phosphors By Precipitation Method

Yttrium vanadate and Yttrium orthophosphate are tetragonal phase zircon structure materials thus they have excellent chemical stability and thermal stability,high absorption in ultraviolet region,so YVO₄:Dy³⁺ and YPO₄:Dy³⁺ phosphor became a rare white-light-emitting luminescent material used for UV-LED.It is a research hotspot that enhance the luminoius intensity of phosphor by optimizing preparation technology.Dy³⁺ was a potential single white light center because its emission color of the luminescence is.close to white owing to the yellow?4F9/2?6H13/2?and blue?4F9/2?6H15/2?emissions,belongs to electric dipole transition which apparently affected by the crystal field around Dy³⁺ and magnetic dipole transition which almost unaffected by the crystal field respectively.As a result,research effect of pH value and concentration on yellow-to-blue emission intensity ratio?Y/B?,systematic analyze relationships and mechanisms of yellow-to-blue emission intensity ratio belong with crystal field environment,like crystal symmetry and the lattice of doped ions,which is significant to promote the development of phosphors.YVO₄:Dy³⁺ and YPO₄:Dy³⁺ phosphor was prepared by precipitation method,solved the problem of change of V' valence states,synthesized spherical vanadate phosphors which have pure phase and uniform and controllable morphology,and researched effect of pH value,concentration,surfactant and nano-ZnO on morphology and luminescence properties of YVO₄:Dy³⁺ phosphors.The influence of pH value and concentration on yellow-to-blue emission intensity ratio of YPO₄:Dy³⁺ phosphor were studied.The phase and mophology of samples were analyzed by XRD,EDS,SEM and laser particle analyzer.The excitation and emission spectra of phosphor were determined under the UV fluorescence spectrophotometer.Moreover,the color coordinate and colour temperature of the emission were calculated.The results showed that:?1?The solution initial pH value have a great impact on morphology of YVO₄:Dy³⁺phosphors.When solution initial pH value less than 2.5,the morphology of YVO₄:Dy³⁺phosphors is massive texture around 2?m,more and more spherical particle with pH value increased gradually,the shape became spherical particle finally and size about 2?m.?2?With the increase of concentration,the luminescence intensity of YVO₄:Dy³⁺ phosphors first increases then decreased,and reaching the maximum in 0.05mol/L.?3?Deploy reaction that surfactant of sodium dodecyl benzene sulfonate?SDBS?and YVO₄:Dy³⁺ ratios of 1:50,and surfactant of polyethylene glycol 2000?PEG?and YVO₄:Dy³⁺ratios of 1:1,all could got uniform spherical morphology.?4?The moderate amounts of nano-ZnO was very useful for enhancing the luminescence intensity of YVO₄:Dy³⁺ phosphor.When the ratio of nano-ZnO to YVO₄:Dy³⁺ was 1:40,intensity reached the maximums,compared with the YVO₄:Dy³⁺ of not added nano-ZnO,the intensity increased approximately 70%.?5?The pH value of cationic solution have larger effects on peak shape of excitation spectrum to be compared with solution concentration in YPO₄:Dy³⁺ phosphor.In the emission spectrum,Excitation wavelength not only effect luminescence intensity,but also impact yellow-to-blue emission intensity ratio.