低温燃烧法合成SrZnO_2:Sm^(3+),Li^+及其发光性能研究

Luminescent Properties and Preparation of SrZnO_2: Sm^(3+),Li^+ by Low-temperature Combustion Synthesis

采用低温燃烧法合成了SrZnO2:Sm3+,Li+红色荧光体,并用X射线衍射谱、扫描电镜图及荧光光谱对样品结构、形貌和发光性能进行了研究。结果表明,Sm3+离子和Li+离子成功地掺入了SrZnO2基质中,所得样品为正交晶系结构的SrZnO2物相;Sm3+离子在SrZnO2基质中主要占据Sr2+离子不对称性格位,发射来源于5G5/2→6H7/2605nm为主的橙红色光;样品呈比较规则的球形颗粒,分散性好,粒径为100～400nm;Li+离子的掺入能显著提高SrZnO2:Sm3+发光强度,当掺杂比n(Sm3+)∶n(Li+)=1∶3时,发光强度增幅最大。

SrZnO2： Sm3＋ ,Li ＋ red-emitting phosphors were prepared by low-temperature combustion synthesis （LCS） and characterized by X-ray diffraction patterns （XRD） ,scan electron microscopy （SEM） and fluorescence （FL） spectrum.The crystal structure,shape and luminescent properties were also investigated.According to the results,it showed that the crystal structures of SrZnO2： Sm3 ＋ ,Li ＋ was in the orthorhombic system in the space group Pnma according to their XRD patterns,Sm3 ＋ and Li ＋ were both successfully doped into the crystal lattice of SrZnO2 matrix and Sr2 ＋ asymmetry cationic sites were preferentially occupied by Sm3 ＋ ions.An emission at wavelength of 605nm orange-red light originated from 5G5/2 to 6H7/2 transition of SrZnO2： Sm3 ＋ ,Li ＋ was observed.Otherwise,due to the energy transfer from a percolation cluster of the nearly-two-dimensional Sm3 ＋ sublattice to killer centers such as crystal defects,the concentration quenching of SrZnO2： Sm3 ＋ appeared in varying degrees.Most of the red phosphors were spherical particles with a diameter of about 100 ～ 400nm,and few of them had an ellipsoidal shape with similar particle size variable range.The luminescence intensity of SrZnO2： Sm3 ＋ can be significantly enhanced by co-doped with Li ＋ ions probably owing to charge compensation mechanism,and the relative luminescence intensity was the highest while Sm3 ＋ and Li ＋ were in the ratio of 1∶3.