The Research Of Luminescent Properties Of Na₃Y（BO₃）₂:Eu³⁺ Prepared By Sol-gel

Before the Eu3+-doped phosphor materials of borate base are widely investigated, most of our efforts have been focused on YVO4:Eu3+and Y2O3:Eu3+. As traditional red emission phosphor materials, they can beapplied in the region of UV-excited phosphors and integrated optics. But with the rapid development of much more advanced optical devices and Hg-free fluorescent lamps, the phosphor materials with high quantum efficiency and high ultraviolet absorption are required greatly. So, main studies about traditional phosphors are shifted to develop new phosphor materials which can replace the traditional phosphors and match the above demands. In recent, much attention is gradually paid to borate family because the rare earth doped borates can overcome the obstacles that the traditional phosphors have, such as lower PL intensity and worse chromaticity. There are many excellent phosphor materials in borates family, for example, YBO3: Eu3+, GdBO3:Eu3+and REMgB5O10(RE=Y, Gd):Eu3+, etc. Besides, there are also many nonlinear optical (NLO) and laser materials among the borate compounds such as BBO, LBO and CBO and the borate family seems to be promising for NLO materials. Next then, several ternary system of borate family are researched, including La2O3-CaO-B2O3, Li2O-Al2O3-B2O3and Y2O3-Na2O-B2O3, etc.Na3Y(BO3)2:Eu3+is a new fluorescent material prepared in our work, whose strongest emission wavelength is615nm under the excitation wavelength of370nm, which means that the transition of5D0-7F2is realized. The strongest emission wavelength of traditional red materials such as Y2O3:Eu3+locate at594nm, which does not satisfy the requirement of CIE. However, Na3Y(BO3)2:Eu3+makes up the flaw and can be applied in PDP, LCD and LED. Na3Y(BO3)2:Eu3+is a stable fluorescent material of higher quantum effect, broader absorption band and stronger luminescent intensity.Na3Y(BO3)2:Eu3+was prepared by sol-gel in our work and we analyzed the structure, excitation spectrum, emission spectrum and morphology. From the test results, it was indicated that Na3Y(BO3)2:Eu3+belonged to monoclinic system and its space group was P21/c. The best excitation wavelength and strongest emission wavelength were370nm and615nm, respectively. The particles sizes of samples were changed with difference of reaction temperature. In chapter four, we researched the influence of reaction temperature, concentration of Eu3+, reaction time, content of B, and molar ratio of C6H8O2-H2O and oxidants on luminescent intensity. We knew that when changed those factors, the emission spectra were not changed and the strongest emission wavelength was still615nm. The optimal values of former factors were800°C,12.5%,14h,120%(relative to the value of stoichiometric ratio),2:3, respectively. At last, the codope of Eu3+and Gd3+was also discussed. In our work, we want to find optimal reaction conditions and optimize synthetic process in order to get the fluorescent material of superior performance and cheap cost.