光学学报, 2017, 37 (6): 0616002, 网络出版: 2017-06-08
Li+掺杂对SrLu2O4∶Ho3+/Yb3+荧光粉上转换发光性能的影响 下载: 1007次
Effect of Li+ Doping on Upconversion Luminescence Property of SrLu2O4∶Ho3+/Yb3+ Phosphors
材料 上转换发光 共掺杂 晶体场对称性 materials upconversion luminescence co-doped crystal field symmetry SrLu2O4 SrLu2O4
摘要
采用高温固相反应法制备了一系列Li+掺杂的SrLu2O4∶Ho3+/Yb3+荧光粉。Li+掺杂并没有改变样品原有的斜方晶系结构, Li+离子能够以替代掺杂和间隙掺杂的方式进入主晶格。适当的Li+掺杂可以改善样品的团聚现象, 颗粒粒径约为3 μm。Li+的引入还可减少高声子能量杂质基团(OH-,CO32-), 从而减少荧光猝灭中心,增强发光。在980 nm激光照射下, 样品发出强烈的绿光和很弱的红光, 分别归因于Ho3+的5F4, 5S2→5I8和5F5→5I8跃迁。与SrLu2O4∶Ho3+/Yb3+样品相比, Li+的掺杂使得上转换发光强度明显增强, 其原因是Li+可以修饰Ho3+周围局域晶体场的对称性。与其他碱金属离子掺杂相比, Li+半径最小、电负性最强, 导致发光强度增强最多。抽运依赖分析结果表明, 绿光与红光发射均为双光子过程。
Abstract
A series of Li+ doped SrLu2O4∶Ho3+/Yb3+ phosphors are prepared with high-temperature solid-state reaction method. The Li+ doped samples maintain the primary orthorhombic structure. The Li+ ions can be introduced into the host lattice through the approach of substitutional doping and interstitial doping. By adding appropriate Li+ ions to the samples, the agglomeration of samples can be minimized and the average diameter of particles is about 3 μm. The impurities (OH- and CO32-) with high phonon energy can be reduced, which reduces the quenching centers and increases upconversion emission intensity. The intense green emission and weak red emission are observed under the excitation of the 980 nm laser, which are attributed to the 5F4, 5S2→5I8 and 5F5→5I8 transitions, respectively. With the introduction of Li+ ions to the SrLu2O4∶Ho3+/Yb3+ sample, the upconversion emission is found to be significantly enhanced, which is attributed to the modification of local crystal field symmetry around Ho3+ ions by Li+ doping. Compared with other alkali-metal-ion dopings, the Li+ doped sample has the strongest luminescence intensity due to the smallest ionic radius and the strongest electronegativity of Li+ ions. The analysis result of pump-power dependence show that the green and red emissions are both involved in a two-phonon process.
刘松彬, 陈梦瑶, 刘水富, 牛虎, 叶信宇, 侯得健, 游维雄. Li+掺杂对SrLu2O4∶Ho3+/Yb3+荧光粉上转换发光性能的影响[J]. 光学学报, 2017, 37(6): 0616002. Liu Songbin, Chen Mengyao, Liu Shuifu, Niu Hu, Ye Xinyu, Hou Dejian, You Weixiong. Effect of Li+ Doping on Upconversion Luminescence Property of SrLu2O4∶Ho3+/Yb3+ Phosphors[J]. Acta Optica Sinica, 2017, 37(6): 0616002.