Study On Controllable Synthesis And Photoluminescent Properties Of Aluminate/Carbonate Phosphors

The aim of this dissertation is to prepare a series of aluminate/carbonate phosphors using hydrothermal synthetic method or sol-gel route simply by adjusting the factors such as the initial mole ratios, reaction temperature, the kind of the surfactant, and so on. The relationships between shape, size, phase and photoluminescent properties of phosphors were investigated. The major contents can be summarized as follows:1. Controllable Synthesis and Photoluminescence of M3Al2O6:Eu2+(Eu3+), Dy3+(M=Sr, Ca, Ba) Phosphors:①Sr3Al206:Eu2+(Eu3+), Dy3+phosphors have been prepared via hydrothermal synthetic approach by altering the factors such as the initial mole ratios, hydrothermal reaction temperature, surfactant, calcination temperature, and calcination atmosphere. The experimental results reveal that by choosing the optimal mole ratio of A1(NO3)3·9H2O, Sr(NO3)2, CO(NH2)2as3:2:20and the hydrothermal temperature as120℃,we can prepare one-dimensional nanoscale precursor. On the other hand, when introducing sodium citrate as surfactant into the above reaction, the as-obtained precursor takes on quasi-spheres. Chatacterized by means of PL technique, Sr3Al2O6:Eu2+(Eu3+), Dy3+phosphors exhibit excellent optical properties.②Using sol-gel method using pure ethylene glycol as solvent, we can prepare porous M3Al2O6:Eu3+, Dy3+(M=Sr, Ca, Ba) phosphors. The calcination temperature herein is much lower than that by hydrothermal synthetic approach.2. Controllable Synthesis and Photoluminescence of MAl2O4:Eu2+(Eu3+), Dy3+(M=Sr, Ca, Ba) Phosphors:MAl2O4:Eu2+(Eu3+), Dy3+(M=Sr, Ca, Ba) phosphors have been systematically prepared by Pechini-type sol-gel approach, mainly investigating the impact of experimental parameters including the mole ratio of citric acid to total metal cations concentration (CA/M) and solvent species on final shape and size of products. It indicates that spherical phosphors occur in pure ethylene glycol solvent, while irregular shaped phosphors appear in pure H2O reaction system.3. Controllable Synthesis and Photoluminescence of ZnAl2O4:Eu3+Phosphors: ①Utilizing Pechini-type sol-gel method, the effects of pH and calcination temperature on final shape and size of products have been studied in brief. It is found out that porous ZnAl2O4:Eu3+can be obtained at600℃.②ZnAl2O4: Eu3+can be obtained by changing the additive amount of Na2CO3in hydrothermal reaction system.4. Controllable Synthesis and Photoluminescence of MCO3:Eu3+(M=Sr, Ca, Ba) Phosphors:A series of carbonate minerals MCO3:Eu3+(M=Sr, Ca, Ba) phosphors have been prepared by chemical precipitation method at room temperature. The shape, size and phase of final products primarily depend on the volume composition of mixed solvents and the surfactants added. It reveals that simply adjusting the volume of mixed solvents (H2O-EG) or adding various surfactants to some extent result in the growth of carbonates in a controlled manner. In addition, based on PL test at room temperature, these as-prepared samples display red emission at613nm, revealing the excellent potential applications for phosphor hosts.