微波辅助法制备钼酸盐稀土上转换发光材料及表征

发布时间：2018-03-20 04:25

  本文选题：稀土上转换　切入点：CaMoO_4　出处：《海南大学》2015年硕士论文　论文类型：学位论文

【摘要】：稀土上转换荧光纳米材料由于光稳定性强,发射带窄,荧光寿命长,可用近红外光源连续激发等优点,使其在光纤、生物成像、载药、太阳能电池、显示器件中有潜在应用,从而吸引了广泛关注。微波辅助法是一种新型的上转换荧光材料的制备方法,具有操作简单,快速,高效节能,省时,无污染,能够在短时间内合成结晶度高、颗粒尺寸小、分散均匀的纳米材料等特点。金属钼酸盐的微波介电常数和其吸收特性十分利于通过用微波法制备出复杂几何结构,所以本文采用了微波辅助法合成了钼酸钙上转换材料。 采用扫描电子显微镜、X射线衍射仪、透射电子显微镜和荧光光谱仪对样品的形貌、晶体结构、发光性质进行表征,研究了不同因素(pH、微波时间、烧结温度、微波介质)对其发光性能的影响。CaMoO4:Er~(3+)/Yb~(3+)样品的荧光光谱520-540n1n,540-570nm两个区域范围分别对应2~H11/2→4I15/2,4S3/2→4I15/2(?)能级跃迁,样品发射出纯度较高的绿光。稀土元素(?).Er比为9：1时,荧光强度最大。当固定微波时间(9mmin),烧结温度(800℃)和微波介质(乙二醇),改变pH,pH为3时荧光强度最强；当固定烧结温度(800℃),pH(pH=7)和微波介质(乙二醇),改变微波时间,微波时间为9min荧光强度最强；当固定微波时间(9min),pH(pH=7)和微波介质(乙二醇),改变烧结温度,烧结温度为800℃样品的荧光强度最强；当固定微波时间(9min),烧结温度(800℃)和pH(pH=7),微波介质为油酸时荧光强度最强。当选择发光中心为Ho3+.Tm3+,敏化离子是Yb3+,且Ho3+/Tm3+/Yb3+的掺杂比例分别是0.8：0.2：15时,成功制备得到了白光发射的钼酸钙荧光材料。
[Abstract]:Due to the advantages of strong optical stability, narrow emission band, long fluorescence lifetime and continuous excitation by Near-infrared light source, rare earth up-conversion fluorescent nanomaterials have potential applications in optical fiber, biological imaging, drug loading, solar cells and display devices. Microwave assisted method is a new preparation method of up-conversion fluorescent material, which has the advantages of simple operation, fast operation, high efficiency and energy saving, time saving, no pollution, high crystallinity and small particle size in a short time. The microwave dielectric constant and absorption properties of molybdate are favorable to the preparation of complex geometry by microwave method, so the microwave assisted method is used to synthesize calcium molybdate upconversion material. The morphology, crystal structure and luminescent properties of the samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and fluorescence spectrometer. The pH of different factors, microwave time and sintering temperature were studied. Effect of microwave media on luminescence properties of CaMoO _ 4: Ernio _ 3 / Yb _ 3). 鈫，

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