The Synthesize And Performance Study Of Nanosized Rare Vanadate Luminescent Materials

In the present paper a series of nanosized rare earth activated LnVO₄ phosphors were synthesized by chelate sol-gel method, in which YVO4 and GdVO₄ were used as matrix, Eu, Er and Tm as dopant, this series of phosphors include YVO₄:Eu which emitting red light, YVO₄:Er emitting green light, GdVO₄:Tm emitting blue light. Through X-ray diffraction (XRD), SEM and fluorescence spectra, the author investigated the effect of process and condition on the products' structure, morphology and properties, which would be helpful for the investigation and application of Nanosized Rare Vanadate Luminescent Materials with high performance.The result indicated that the series of luminescent materials are tetragonal, which have high phase purity, the phase transformation basically completed when the annealing temperature was 700℃. the products show good phase stability, When annealed at 900℃for 3h, The grain size of the products are between 50nm and 90nm, and the particles' morphology are nearly sphericity.The investigation of blue luminescent material GdVO₄:Tm show that its emission intensity gets higher when increasing the annealing temperature, but when the temperature was beyond 900℃, the emission intensity descended, so 900℃is thought as the optimal annealing temperature, its emission intensity gets higher when the temperature-holding time is prolonged. GdVO4:Tm can be excited by 200～320nm ultraviolet radiation. It emits typical blue fluorescence whose wavelength is 478nm.Based on GdVO₄:Tm, the effect of the content of Y on nanosized luminescent material Gd_1-xY_xVO₄:Tm with multiple matrix had been investigated, the result show that when the content of Y increased, the emission intensityget higher, and the emission wavelength have no change.Green luminescent material YVO₄:Er has a broad excitation spectra located between 200nm～308nm in ultraviolet region, and has a intensive emission spectra between 510～560nm, which has two peaks located at 530nm and 560nm respectively. When annealed between 700℃～1000℃, the optimal emission intensity is obtained at 900℃.Red luminescent material YVO₄:Eu was obtained when annealed at 900℃for 3h. there is a highest peak near 623nm when it is excited by 260nm ultraviolet radiation. The optimal intensity is obtained when the content of Eu is 0.5ï¼….In this paper a certain degree of analysis about luminescent mechanism was made based on the experiment.Based on the results of the research, it can be concluded that through the control of the condition of the chelate sol-gel method, vanadate matrix nanosized luminescent material with good performance can be obtained, through the emission spectra and chromaticity diagram it can be known that tricolor phosphors have been obtained.