Synthesis And Optical Properties Of Dowm-conversion Luminescent Materials Doped By Eu\Tb

For years, scientists have not stopped the exploitation and exploration of new types of light-emitting materials. The unique electronic structure of tombarthite ions enables tombarthite mixed with light-emitting materials to have the qualities of possessing the stability of photochemistry, long life span of fluorescence, a high productivity of quantum, a narrow optical spectrum, a large Stokes shift etc. It has long been the focus of the study. Eu3+,Tb3+ separately are the most commonly used as the activator in red and green phosphors, which are for more the key points in this paper. This paper aims at the research, of luminous materials obtaining impured with Eu3+ and Tb3+ and their water-solubility, mainly summarized as follows:1. Using methanol as solvent, along with using co-precipitation method, to get the hydrophilic CaF2:Ln3+nanoparticles without using any surfactant. These particles can be well dispersed and distributed in water, and the average particle size is about 20nm, without agglomeration. This method is simple, reproducible, high yield, and very suitable for mass production.2. Separately by adopting PVP and citric acid as surfactants, plus co-precipitation method and hydrothermal process to get he hydrophilic CaF2:Ln3+nanoparticles. And these particles are well distibuted. We deeply study its structure and its fluorescence property.3. Generally spherical CaF2:Ln3+particles are difficult to obtain. By catalyzation and hydrolyzation of TEOS we can get the monodispersed spherical SiO2 particles, and then under the effect of other activator, we can coat its surface a layer with the fluorescence properties of CaF2:Eu3+. Doing this, we not only get a spherical luminescent material, but save the tombarthite elements and reduce costs.4. By using hydrothermal process we can synthesize CaPxW1-xO4:Eu3+ nano materials doped with Eu3+ and. Taking XRD and TEM and fluorescent optical spectrum into analysis, it reveals that granul it the typical rod-like scheelite structure. The combination of PO43- ions can effectively adjust the intensity of fluorescent optical spectrum. Varying the doping density of PO43- ions can get a different emitting intensity of fluorescent materials.