Study And Preparation Method Of Cr³⁺ Doped Gallate Deep Red-near Infrared Luminescent Material

In this paper,the chromium-doped luminescent materials were successfully prepared by high temperature solid-phase method using gallium compound as matrix.The structure,synthesis and luminescence properties of Cr3+ ion-doped gallium compounds were systematically studied.The specific research results were as follows:1.Firstly,a series of Zn3Ga2-xAlxGe2O10:0.5at%Cr3+(0<x≦2.0)were successfully synthesized by high temperature solid phase method.By adjusting the proportion of gallium and aluminum,the influence of the proportion of gallium and aluminum on the preparation and properties of the material was explored.The luminescence property results showed that when Ga:Al=1:3,the material exhibits the best luminescence intensity in the emission spectrum excited at 404nm.On this basis,a series of Cr3+ doped Zn3Ga0.5Al1.5Ge2O10 materials were successfully synthesized,the phosphors of diffuse-reflectance spectra,excitation spectra,emission spectra and phosphor decay curves were measured at room temperature.The results showed three absorption bands centered were located at 235nm,404nm and 554nm,respectively.The Zn3Ga2-xAlxGe2O10:yCr3+(x=0-2.0,y=0-2.0at%)phosphors under 404nm excitation showed a narrow emission band centered at about 698nm.The photoluminescence intensity of Zn3Ga0.5Al1.5Ge2O10:1.7at%Cr3+ at 423K dropped to 73.17%of its room-temperature value.2.A series of near-infrared(NIR)phosphors CsGaGe2O6:xCr3+(x=0.8-2.Oat%)were prepared successfully by using traditional high-temperature solid state reaction.The phase formation of CsGaGe2O6:Cr3+ was characterized by using the powder X-ray diffraction(XRD).The optical band gap and energy band structure of CsGaGe2O6:1.Oat%Cr3+ was investigated by using the density functional theory(DFT).The phosphors of diffuse-reflectance spectra,excitation spectra,emission spectra and phosphor decay curves were measured at room temperature.Three absorption bands centered were located at 260nm,434nm and 617nm,respectively.The CsGaGe2O6:Cr3+ phosphors under 434nm excitation showed a narrow emission band centered at about 691nm.With the increase Cr3+ ion concentration,the emission intensity and phosphor decay time gradually increased in the range of 0.5-2.0 at%,and then decreased in the further range.The critical quenching concentration of Cr3+ ion was about 1.0 at%.The photoluminescence intensity of CsGaGeO6:1.Oat%Cr3+ at 423K dropped to 72.27%of its room-temperature value.