Investigation On Synthesis And Optical Properties Of Luminescent Materials Zn₂SiO₄: Pr³⁺ And Ca_x Sr_1-xZrO₃: Pr³⁺(O

In recent years, the white LED play more and more important role in their daily lives, for its small power consumption, long life, clean and fast response of the many advantages ,so that the industry has developed rapidly. Because of their poor color rendering and lighting, the white LED industry using of phosphor blue LED + YAG: Ce can not meet the daily needs, therefore, research to produce highly efficient new light-emitting phosphor colors have become targets of foreign researchers.Luminescent properties of rare earth materials have stable luminescent, high luminous efficiency, high brightness, no radiation and good weather resistance. The silicate matrix light-emitting material has good luminescent properties and the ability in the wet, high temperature, chemical corrosion and other harsh conditions, the advantages of good stability and therefore has a very good prospect of application.In the synthesis of luminescent materials, the sol-gel method was a promising method for the mild reaction conditions and flexible mode of operations. Compared with the high temperature solid-state method, the sol-gel method was more popular for uniform particles and small size. So it becomes research focus in preparation of luminescent materials.In this thesis, the luminescent materials Pr3+-doped zinc silicate were prepared with sol-gel method in different temperature, and characterized with powder X-ray diffraction and excitation and emission spectrum. It was discussed that the relationship between the intensity of the luminescence with the changes in the doping concentration of Pr3+. As the excitation spectra shows, the luminescent materials Pr3+-doped zinc silicate has strong absorption near 210 nm in the far UV region resulting from the matrix absorption, and a broad excitation band. There was a exciting peak at 351 nm, which due to the 4f-5d transition of Pr3+. It shows that the emission peak at 610 nm of the emission spectrum. The characteristic luminescence of the phosphors is determined by the electronic structure of the doped Pr3+, while the width and the relative intensity of the spectra frequently depend on the crystal symmetry of the host matrix.A blue luminescent CaxSr1-xZrO3: Pr3+was successful synthesized by high temperature solid-state method. The optimal condition for preparing this fluorescence is as follows: burning at 1200 oC, adding amount of Pr3+is 0.02 and the doping ratio of Sr2+is 60%. XRD, SEM and excitation and emission spectrum were used to characterize CaxSr1-xZrO3: Pr3+in this thesis, the influences of adding amount of Pr3+and Sr2+were also studied.