Preparation And Luminescence Properties Of Ce, RE(Pr/Sm) Dope YAG Glass Ceramics

White light emitting diodes(W-LEDs)have many excellent properties, such as long life,environmental protection, energy-saving,stability, which are used as backlight of LCD and mobile telephone, light source of cars and So on.W-LEDs are regarded as"the fourth-generation of light Source"century.At present, white LED can be generated by mixing primary light from a blue LED with light created by using the blue LED to excite cerium doped yttrium aluminum garnet(YAG:Ce)yellow phosphor, and the products have already got application commercially. The serious objection of phosphors on temperature related luminescence intensity decline, color coordinates drifting and etc lead to degradation of device performance. In order to slove these problems, it is essential for developing new high-quality materials, which are heat stable,the light fades slightly and etc.In this thesis ,using Y₂O₃-A1₂O₃-SiO₂-Li₂O as Ce-dope or Ce,Sm codope glass matrix, Ce:YAG and Ce, Pr/Sm:YAG glass ceramics for White-LED were prepared by means of heating treatment the glass matrix. The crystalline phase structure, Ce-doped valence states, morphology, and photoluminescence properties of the glass ceramics were investigated by using of X-ray diffractometer, X-ray photoelectron spectroscopy, Field-emission scanning electron microscopy, Photoluminescence, etc. The results showed:1. The experiment on the glass content indicated that the composition of the (21-x)Y₂O₃-34Al₂O₃-42SiO₂-3Li₂O-xCeO₂ glass is a good component to melt glass. And the composition of glass can precipitated the formation of YAG phase relatively favorable. The pure YAG phase structure could be obtained at 1380oC. Ce-doped valence states were mostly Ce³⁺ in the glass ceramics. The characteristic excitation peak located at 454 nm in the glass ceramics. A broad emission band center located at 531 nm, which indicated that the glass-ceramics could be used in white LED by blue GaN light chip. And the PL emission intensity of the glass-ceramics was better when mole fraction of CeO2 in the glass-ceramics was 0.75 %.2. While a emission peak located at 609nm in Ce,Pr:YAG glass ceramic by using the 460nm blue light stimulation. The doping ratio Ce:Pr in 5:3 to 5:10 is quite good.3. Meanwhile, there are four small emission peaks located at 566,602,615,650nm in Ce,Sm:YAG glass ceramic by using the 460nm blue light. The doping ratio in 5:2 to 5:10 is quite appropriate.4. By using Ce:YAG or Ce,(Sm/Pr):YAG, the white light LED was fabricated, its fluorescence efficiency is relatively low. The rare earth co-dope of the YAG glass ceramic is possible to enhance the color rendering index truly, but color temperature is relatively high.