Y_xAl_5O_(12)∶Ce^(3+)荧光粉的微结构及其发光特性

Microstructure and Luminescence Characteristics of Y_xAl_5O_(12)∶Ce^(3+) Phosphor

采用共沉淀法合成YxAl5O12∶Ce3+系列荧光粉,用多晶X射线衍射、SEM及荧光光谱对YxAl5O12∶Ce3+系列荧光粉的晶体结构、形貌及发光性能进行表征。结果表明:随着x从2.64递增到3.06,波长先缓慢红移,然后迅速蓝移;发光强度先增强,然后迅速减弱;当x=2.88时,出现了最大发射峰值波长(λem=537 nm)和最高相对发光强度。当x<2.64时,出现Al2O3杂相;x>3.06时,粉体中出现YAM杂相。x在2.76～2.88区间时,材料结晶度高,容易分散。

YxAl5O12∶Ce3＋ phosphors have been synthesized by co-precipitation method.The crystalline structure,morphology and luminescence properties of YxAl5O12∶Ce3＋ phosphors have been investigated by X-ray diffraction（XRD）,Scanning Electron Microscope（SEM） and fluorescence spectrophotometer.The results show that the emission wavelengths of as-prepared phosphors display red-shift at first and then blue-shift appears with the molar of Y3＋ increasing from 2.64 to 3.06.The emission intensity increases slowly with the mole of Y3＋ increasing from 2.64 to 2.88,but the intensity decreases sharply with different Y3＋ content when it was beyond 2.94.The maximum emission wavelength（λem=537 nm） at the maximum intensity appears when x is 2.88.The impure phase-Al2O3 appears when the content of Y3＋ is below 2.64.When the mole of Y3＋exceeds 3.06,the impure phase-YAM appears,which has negative effects on the luminescence property of as-prepared phosphors.When the molar ratio of yttrium rises from 2.76 to 2.88,the powder is observed with high crystalline and easy dispersion.