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分别以(NH4)2CO3、Na2CO3为沉淀剂,采用水热法合成了Sr2CeO4蓝白光荧光粉。利用热重-差热、红外光谱及X射线衍射分析了不同沉淀剂所得前驱体的热分解过程及目标产物的形成过程;利用扫描电镜、荧光分光光度计分别对荧光粉的微观形貌、发光特性进行了分析表征。结果表明:以(NH4)2CO3、Na2CO3为沉淀剂所得前驱体晶相组成相同,均由Ce2(CO3)2O·H2O、CeCO3OH及SrCO3三相组成,经1000℃下焙烧2 h均得到正交晶相的Sr2CeO4。以(NH4)2CO3为沉淀剂所得样品呈类球形,分散性较好;以Na2CO3为沉淀剂所得样品呈不规则形状,团聚现象严重。所得Sr2CeO4的激发光谱均是位于200~400 nm之间的一个宽带双峰结构,发射光谱均是位于400~600 nm之间的一个宽带,最大发射峰位于466 nm左右,归属于Ce4+的f→t1g跃迁,呈蓝白光发射。在最大激发波长下,以(NH4)2CO3为沉淀剂所得样品的发光强度相对较大。
Respectively, (NH4) 2CO3, Na2CO3 as precipitating agent, hydrothermal synthesis Sr2CeO4 blue and white phosphor. The thermal decomposition process and the formation of the target product were analyzed by TG-DTA, FTIR and X-ray diffraction. The microstructure of the phosphor was characterized by scanning electron microscopy (SEM) and fluorescence spectrophotometer Characteristics were analyzed and characterized. The results show that the precursors with (NH4) 2CO3 and Na2CO3 as precipitants have the same crystal phase composition and are composed of Ce2 (CO3) 2O H2O, CeCO3OH and SrCO3. After calcined at 1000 ℃ for 2 h, Phase of Sr2CeO4. The samples obtained with (NH4) 2CO3 as precipitant showed a spherical shape with good dispersibility. The sample with Na2CO3 as precipitant showed irregular shape and the agglomeration was serious. The excitation spectra of Sr2CeO4 are all broadband bimodal structures located at 200-400 nm. The emission spectra of Sr2CeO4 are all broadband at 400-600 nm with the maximum emission at 466 nm. The emission spectra of Sr2CeO4 belong to Ce4 + t1g transition, was blue and white light emission. At the maximum excitation wavelength, the luminescence intensity of samples obtained with (NH4) 2CO3 as precipitant is relatively large.