Preparation and Characterization of YAG:Ce Phosphors with Different Particle Size

• Main Authors: Yu-Lian Wen, 溫佑良
• Other Authors: In-Gann Chen
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/27798069993421224075

碩士 === 國立成功大學 === 材料科學及工程學系碩博士班 === 91 === This research is to investigate the effect of particle size of Ce-doped Y3Al5O12 (YAG: Ce) phosphors on luminescence. The effect of Si elements on luminescence properties of YAG: Ce phosphor is also studied here. The nano-scale with well crystalline and single phase powder of Ce-doped Y3Al5O12 was synthesized by heat treatment of co-precipitation method, citric gel method and nano solid state method. Then, the different particle size of phosphors were changed by chemical and physics methods, for example, by varying calcinations temperature, holding time and grinding time. The X-ray diffraction, EDS, and FTIR were utilized in the characterization of crystal structure and phase purity. The particle size of YAG: Ce phosphors were calculated by X-ray diffraction pattern. Particle size analyzer and TEM were also utilized in the characterization of particle size. Photoluminescence (PL) spectroscopy was used to characterize the optical properties (emission intensity). The minimum grain size was found to be 22.0 to 34.4nm for YAG phase synthesized by co-precipitation method. The minimum grain size was found to be 24.4 to 34.8nm for YAG phase synthesized by citric gel method. The minimum grain size was found to be 51.8 to 57.9nm for YAG phase synthesized by nano solid state method. The intensity of luminescence emission for Ce-doped YAG phase was found to increase with increasing particle size. The effect of Si in YAG PL property was studied by two processing method, (a) Silicon oxide (SiO2) powders was added co-precipitation YAG and (b) HMDS (the organics compound of Si) was added in the citric gel YAG, respectively. The intensity of luminescence emission for Ce-doped YAG phase was found to increase with increasing SiO2 concentration, then reach a maximum and decrease as it further increase. Therefore, the Si element enhances the PL intensity of luminescence emission.