(1. 贵州师范大学 化学与材料科学学院, 贵阳 550001;
2. 贵州省功能材料化学重点实验室, 贵阳 550001)
摘 要: 利用共沉淀法制备了Er3+/Yb3+共掺杂YPO4上转换发光材料,采用X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)、紫外可见漫反射光谱(UV-vis)和上转换发射光谱(UPL)对合成样品的物相结构、形貌、化学成分和光学性能进行研究,并对Er3+和Yb3+的掺杂量(摩尔分数,%)对合成样品的物相结构及上转换发光性能的影响进行分析。结果表明:制备样品为纯相四方晶系的Er3+/Yb3+共掺杂YPO4晶体,Yb3+的掺杂量对产物的物相结构无显著影响。所制备产物在980 nm的近红外光激发下,发射出Er3+特征的上转换绿色光,其绿色光色纯度达到96% 以上,色温接近日光。YPO4: 1%Er3+/20%Yb3+样品具有相对更优的上转换发光性能;过高浓度Yb3+和Er3+共掺杂导致样品出现浓度猝灭现象。此外,对制备样品的上转换发光材料发光机制及能量跃迁机理进行了讨论。
关键字: YPO4;Er3+/Yb3+共掺杂;上转换发光性能;共沉淀法;色纯度;发光机理
(1. School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550001, China;
2. Key Laboratory for Functional Materials Chemistry of Guizhou Province, Guiyang 550001, China)
Abstract:The Er3+/Yb3+ co-doped YPO4 up-conversion luminescence materials were synthesized by co-precipitation method. The phase structures, morphologies, element components, and optical properties of the as-synthesized samples were characterized by X-ray diffractometry(XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), UV-visible diffuse reflectance spectroscopy (UV-vis) and up-conversion emission spectroscopy (UPL). The effects of Er3+ and Yb3+ doping amounts on the up-conversion luminescence properties and phase structures of the as-prepared samples were analyzed. The results show that the samples are pure phase Er3+/Yb3+ co-doped YPO4 sub-micron crystals with tetragonal structure, and the Yb3+ doping contents have less influence on the phase structure of the samples. The obtained Er3+/Yb3+ co-doped YPO4 samples emit the characteristic up-conversion green emissions of Er3+. The color purity of the green up-conversion emission from Er3+/Yb3+ co-doped YPO4 samples is above 96%. The color temperature of the Er3+/Yb3+ co-doped YPO4 samples is similar to daylight. The doping contents (mole fraction) of the Er3+ and Yb3+ exhibit great influence on the up-conversion luminescence performance of the as-prepared samples. The YPO4:1%Er3+/20%Yb3+ sample displays excellent up-conversion luminescence property. The concentration quenching phenomena will occur for Er3+/Yb3+ co-doped YPO4 samples when the doping content of Yb3+ is above 20% or the doping content of Er3+ is above 1%. In addition, the up-conversion luminescence mechanism and energy transition mechanism of Er3+/Yb3+ co-doped YPO4 samples were discussed.
Key words: YPO4; Er3+/Yb3+ co-doped; up-conversion luminescence properties; co-precipitation method; color purity; luminescence mechanism