Preparation And Properties Of YAG Phosphor

Because of their special electronic configuration, rare earth elements haveexcellent optical, electric and magnetic properties，and become the treasure houseof new materials. Rare earth luminescent materials are widely used in lighting,display and detection of three areas. In the preparation of white LED, Thepreparation of fluorescent materials is a very important key technology. Fluorescentmaterial directly affect the performance of white LED the luminous efficiency andtransformation efficiency, color temperature and color rendering. Phosphor powderis a kind of common optical conversion materials, and the research shows thatquantum cutting effect will occur by doping with Ce and Yb under certain conditions,and transfer the bands of solar spectrum which cant be absorbed by solar cell intoabsorbable wavelengths. Therefore as window layer for solar cell they will greatlyimprove the conversion efficiency of solar cells.In this work, the YAG phosphor powder is prepared by molten salt method. Theeffect of different preparation conditions on the morphology and various propertiesof phosphor powder are studied, and the best preparation conditions of the moltensalt method is found. The YAG: Ce ions doped with different concentration of Ce3+phosphors excitation spectra and emission spectra, as well as the Ce ions dopingconcentration fluorescence intensity and the influence of the relative intensity of thesample are studied. Main conclusions are as follows:1. Particle size of phosphor particles can be well controlled by changing thesynthesis temperature and time. The particles show different properties withdifferent molten salt method.2. Yttrium aluminum garnet structure phosphor particles were successfullyprepared through NaCl-KCl molten salt method by keeping the sample at400℃four hours. Under this condition, the sample particles showed the best morphologyand uniformly distributed.3. Yttrium aluminum garnet structure phosphor particles were successfullyprepared through NaNO₂-KNO₂molten salt method by keeping the sample at 1100℃four hours. The prepared particles were polygon structure with the sizearound210nm.4. Single-phase yttrium aluminum garnet structure phosphor particles weresuccessfully prepared through NaCl-H₃BO₃molten salt method with optimalsynthesis temperature at1300℃.5. Doping amount of Ce had a great influence on the phosphor luminescentproperties. With the doping amount of10%, the properties perform best.