Preparation And Testing Of YAG: Ce Phosphor

Phosphor yttrium aluminum garnet Y3 Al5 O1 2( YAG ) ,activated with trivalent( Ce 3+ ) is a kind of photoluminescence material.It can be synthesized by different methods: solid-state reaction, combustion, co-precipitation, sol-gel, spray prolysis, et al. Otherwise, it's easily to change the luminescence property by substituting Gd 3+ for Y 3+ or co-doping other rare earth ions with Ce 3+ . This thesis bases on preparation of wavelength changeable phosphor, improving the white LED performance. Its purpose is to develop the YAG phosphor industry. So doing more study on this method can improve the technique level of our country.Among those methods, Solid-state reaction is the most developed and used one. Based on a patent of our lab, solid-state reaction was applied to the preparation of and phosphor. The properties of phosphor such as stability under high temperature, luminosity and chroma were investigated. The excitation and emission spectra of YAG phosphor were studied. Factors influencing on th intensity of luminescence and the location of emission band of YAG:Ce, such as the grade of reaction temperature, the concentration of Gd, were investigated in detail. Three-dimensional luminescence spectra was studied by programming under MATLAB. The performance of white LED using and phosphor, were studied.The excitation and emission spectra of YAG phosphor were obtained by spectrophotometer. By MATLAB programming, the Three-dimensional luminescence spectra was obtained and studied in detail. The luminosity and chroma property of white LED were measured by PR650.After so many experiments, results were concluded as followed:(1) During the preparation of phosphor, the starting materials were mixed in manual and automatic ways. The grade of reaction temperature can be precisely controlled by temperature controller.(2) Two kinds of grades of reaction temperature were setup successfully, and the speed of temperature increase must be controlled at 2.4℃per minute;(3) It shows a steady correlation between the excitation, emission, three-dimensional luminescence spectra and the property of YAG phosphor;(4) The luminescence property of YAG phosphor was changed by substituting Gd 3+ for Y 3+ , and red shift happened.(5) By testing the performance of white LED, the property of phosphor was studied. The result shows that the is better than phosphor. phosphor is better for white LED.(6) By using phosphor, the white LED was fabricated. Its chromaticity was around (0.33, 0.33), Its CCT was between 3000K~10000K.