The Preparation And Properties Of Rare Earth Doped Fluoride Multi-Color Luminescence Materials

As a new type of luminescent material, rare earth has a unique set of advantages, such as high colour purity,long fluorescence lifetime,easily absorbed excitation energy and a high rate of energy conversion and so on. So rare earth luminescent materials have the wide range of applications in the following three fields:lighting, display and testing. The choice of matrix materials has great influence on the luminescence properties of rare earth ions. In the field of the matrix material, the fluoride matrix material has a wide optical transparent region (IR-UV).As a doped activator for rare earth ions, the fluoride matrix materials have attracted a great deal of recent interest.This thesis focuses on rare earth doped fluoride, and is well researched in the following aspects:lanthanide fluoride (LaF3),alkaline earth metal fluoride (CaF2,MgF2) are doped substrate, and Eu3+,Tb3+ ions are doped activator. Different matrices in Eu3+,Tb3+ luminescence properties are investigated; using the co-precipitation method, Eu3+,Tb3+ ions was codoped in the same matrix material, and a series of multi-color light-emitting nanoparticles were obtained through the control of rare earth ions doping ratio; a core-shell structure was constructed according to the theory of coating, and fluorescence properties of rare earth ions can be cut by core-shell structure of nanoparticles, the regulation of the nuclear shell can effectively control different energy transfer by doping rare earth ions (ET).The main contents and conlusions are as follows:1,using co-precipitation method, a series of different Eu3+,Tb3+ doped multi-color nanocrystalline were successfully synthesized; and the nanoparticles' modification is generalized. The multi-color nanocrystalline modified with citric acid were clear in water. Compared with unmodification samples, hydrophilic property was improved; oleic acid modified nanoparticles in chloroform, cyclohexane and other organic solvents were dispersed well, and lipophilic property was also improved.2,A series of special shaped,multi-color light of CaF2 microspheres were successfully synthesized by hydrothermal method, through selecting the appropriate fluoride source (NaBF4), adjusting the pH value, controling the right temperature; The luminescent properties of rare earth ions were compared in different matrix materials.3,According to coating theory, the nuclear shell structure was synthesized by interactively dropping way. The three nuclear shell structure were LaF3:Eu3+@LaF3@LaF3:Tb3+. The nuclear shell structure has also been confirmed by XRD,TEM,PL analysis.To some extent, this nuclear shell structure can regulate energy transfer between rare earth ions.