SrMoO_4∶Sm^(3+),Na^+红色荧光粉的形貌调控和发光性能

Controllable Morphology and Luminescence Properties of SrMoO_4∶Sm^(3+),Na^+ Red Emitting Phosphors

以Sm^(3+)为激活剂,Na^+为电荷补偿剂,柠檬酸为配位剂,乙二醇作为辅助配位剂,采用溶胶-凝胶法合成前驱体,然后在800℃下焙烧,成功制备了一系列SrMoO_4∶Sm^(3+),Na^+红色荧光粉。用X射线衍射仪、扫描电镜、荧光光谱和傅里叶变换红外光谱等手段对样品的物相、形貌、组成、发光性能和量子效率等进行测试和表征。分析结果表明:制备的SrMoO_4∶Sm^(3+),Na^+荧光粉均为四方晶系结构,掺杂离子的加入对基质晶体结构影响不大。在403 nm近紫外光激发下,产物有4个发射峰,分别位于563、600、647和707 nm处,归属于~5G_(5/2)→~6HJ(J=5/2,7/2,9/2,11/2)的电子跃迁,其中位于647 nm处的主发射峰的相对发光强度最大。当Sm^(3+)的掺杂物质的量分数为1%~3%时,发光强度最好,当浓度超过1%~3%时,会发生荧光猝灭。对实验数据进行分析,确定荧光猝灭机理是由于钐离子间交换作用引起的,并计算了能量传递的临界距离为1.77~2.56 nm。此外,还详细研究了乙二醇对SrMoO_4∶Sm^(3+),Na^+荧光粉形貌的影响,研究结果表明:乙二醇加入量为5 m L时,产物形貌均匀,呈球形或椭球形;且分散性较好;荧光强度最大。

With Sm^3＋ as activator, Na^＋ as doping charge compensatory, citric acid as complexing agent, ethylene glycol as auxiliary complexing agent by sol-gel method red phosphors precursor was synthesized, then a series of SrMoO4：Sm^3＋,Na^＋ red phosphor samples were sintered at 800℃. The crystalline phase, morphology and luminescence properties and quantum efficiency of the samples were characterized by X-ray diffraction, scanning electron microscopy, fluorescence spectrophotometry and fourier transform infrared spectroscopy, respectively. The results show that the synthesized NaSrMoO4：Sm^3＋ crystallines are a tetragonal structure. The doped ions have little impact on the matrix crystal structure. The emission spectra of the samples are composed of four peaks, 563, 600, 647 and 707 nm belonging to the 5G5/2→6HJ （J=5/2,7/2,9/2,11/2）under the near UV excitation of 403 nm, the relative luminous intensity at 647 nm main emission peak is maximum. When the doping molar fraction of Sm^3＋ is 1%~3%, the emission intensity is the maximum, luminescence concentration quenching could be observed when the doping molar fraction of Sm^3＋ ions was more than 1%~3%. The energy transfer type between Sm^3＋ ions was determined to be the exchange interaction and the critical energy transfer distance （Dc）was calculated to be 1.77~2.56 nm. In addition, Influences of ethylene glycol on the performance of SrMoO4：Sm^3＋,Na^＋ phosphors were investigated in detail. The research result shows that when ethylene glycol addition amount was 5 mL, the sample grains show spherical or elliptical and the structure is uniform and loose and the fluorescence intensity is optimal.