Synthesis And Luminescent Properties Of （Ce,Tb）MgAl₁₁O₁₉ Green Phosphor By Low Temperature Method

This thesis comprehensive review the preparation methods of Ce0.67Tb0.33MgAl11O19green phosphor at home and abroad. On this basis, exploring the preparative technique of chemical precipitation and ion doped of high temperature solid phase method as the main contents. XRD, SEM and photoluminescence （PL）measurements are used to characterize the phase of the powder, particle size, surface morphology and luminescence properties.First, this thesis explore the preparative technique of chemical precipitation fromseeking low temperature synthesis of CTMA phosphor. In the experiment, usingdouble drops method and controling the pH value can eliminate the impurity phaseAl2O3. And the pH value at8.0, controling Mg content can eliminate the impurityphase Tb3Al2Al3O12. synthesizing CTMA phosphor at1350℃and keeping heat for4hours. This synthesize temperature reduces250℃than high temperature solid method,and the products have smoother flake morphology, the particle diameter between0.5μm¹.0μm and has a good dispersity. The sample’s luminous property as well asthe sample synthesize by high temperature solid method. So this process have vasepotential prospects in realizing the industrialization by chemical method.In order to explore the influence of luminescent spectrum by ion doped, this thesissynthesize CTMA by high temperature solid method by ion doped. The results showthat the spectrum appears the characteristic launch peaks when there are otheractivators ion, which only has pure green emitting originally. When Eu²⁺partly replacethe Ce³⁺position, there are4f-5d transition absorption of Ce³⁺and4f65d-4f7transitionabsorption of Eu²⁺. The week emission at450nm is belong to the blue light emission ofEu²⁺. With the Eu²⁺concentration increasing,the characteristics emission of Tb³⁺areweaken gradually When Eu²⁺partly replace the Tb³⁺position, and the450nm emissionwhich belong to the blue light emission of Eu²⁺is strengthen. Partly replace the Tb³⁺position by Mn²⁺, when completely replace, there are no characteristics of Tb³⁺emission in spectrum. But there is a new emission at516nm which belong to4T （t412geg）61A（t3212geg）transition emitting of Mn²⁺. When Mn²⁺partly replace the Mg²⁺position,there are two ions emission since two activators ions in matrix. The serialssamples are all have the characteristics emission of Tb³⁺. And there is a emission peakat514nm in spectrum which belong to4T （t41geg）6A（t321212geg）transition emitting of Mn²⁺when Mn²⁺ion enter into the matrix. With increasing the Mn²⁺concentration, theMn²⁺emitting is strengthen gradually.