Synthesis And Characterization Of Ion Doped Upconversion Luminescent Materials With Fluoride Matrix

Rare earth upconversion luminescent materials,which may be infrared excited to give off visible light have good application prospects in fluorescence labeling,optical fiber communication,laser,display areas such as biomedical,three-dimensional display,and other fields.However,the current research on the rare earth upconversion luminescent materials is still in the initial experiment stage,and its low luminous efficiency and the lack of effective regulation mechanism seriously restrict the application of this kind of material.Therefore,the research field of rare earth conversion luminescent materials needs to be expanded.In this paper,many rare earth upconversion luminescent nanomaterials with different kind of host material were prepared by means of ion doping to improve the luminous performance of materials and explore the influence of doping on rare earth luminescence materials.The specific research contents are as follows:?1?Using KYb₂F₇ as host material,the upconversion luminescent material with rodlike structure was prepared by doping Er³⁺and Sc³⁺using hydrothermal synthesis method.When doped with rare earth ions of luminescence center Er³⁺,the light-emitting color of material changed little.When the doping amount of Er³⁺reached 2%,the intensity of luminescence was the best.And it would be quenched in case of exceeding the doping concentration.When the doped rare earth element was the non-luminous center Sc³⁺,the luminescence intensity of the material changed with rising levels of concentration.The luminescence intensity of the product was five times than that of unadulterated when the amount of Sc³⁺reached 10%.It was proved that the doping of non-luminous center could influence the luminescence of the products to a certain extent,and could be used as a means to control the luminescence of materials.?2?Using BaGdF₅ as substrate,the upconversion luminescent materials were prepared by doping Ca²⁺and Sr²⁺using hydrothermal synthesis method.Finally,we obtained the product composed by irregular spherical nanoparticles in 5-10nm.When the doped ions were Ca²⁺,the particle size of the synthetic products gradually becomes smaller,and the luminous intensity realized five times than that of the undoped materials when the doping amount reaches 15%.When the doped ions were Sr²⁺,the optical properties changed a lot while the morphology of the products did not change significantly.The color of the material showed a linear change with the doping concentration,and the luminescence intensity was 6 times of unadulterated ones when the doping amount was 15%.It can be seen that the doping of different metal ions have different effects on the luminescence of the upconversion luminescent materials.?3?The upconversion fluorescence materials using NaGdF₄ as substrate were synthesized by solvothermal method by doping K⁺in the synthesis process,and then the NaGdF₄ shell was overgrown.Results showed that the morphology of material have taken place great changes with the change of the doping concentration,and the luminous intensity of corresponding product changed in the meantime.When the doping concentration of K⁺reached 10%,the morphology of product was basically stable for long elliptic shape particles with a small number of spherical particles.At the same time,the luminous intensity was 1.4 times of that for undoped materials.The luminescent intensity of homogeneous shell coated product with 10%K⁺has promoted1 time,proved that the shells play an important role in weakening the surface quenching,and is advantageous to the materials.