稀土掺杂的光谱转换材料及其应用

以LED红色荧光粉材料、近红外下转换材料和上转换生物荧光标记材料为主线,结合我们实验室近期具体的相关研究工作,对稀土掺杂的光谱转换材料及其潜在的应用前景进行了简要介绍.在LED红色荧光粉材料方面,以Eu3＋掺杂的红色荧光材料为对象,研究通过基质或掺杂敏化剂到Eu3＋的能量传递来提高材料在近紫外波段的激发效率,并且在Y2MoO6材料中通过基质的电荷迁移带到Eu3＋的能量传递在395nm的近紫外激发条件下获得了2.3倍于商用LED荧光粉（Y2O2S：Eu3＋）的发光强度.在近红外下转换材料方面,分别研究了通过从其他稀土离子到Yb3＋的逐次能量传递和从基质到Yb3＋的合作能量传递实现近红外下转换,主要介绍了两种典型材料中的能量传递机理,氟化物中Ho3＋到Yb3＋的逐次能量传递和YVO4中VO43-到Yb3＋的合作能量传递.在上转换生物荧光标记材料方面,利用以油酸/十八烯为溶剂的湿化学法合成了单分散、粒径在20nm左右、具有核/壳结构和水溶性的球形NaYF4：Yb3＋,Er3＋（Tm3＋）纳米粒子,并对其在不同环境中的稳定性和在细胞中的荧光成像性质做了研究,在此基础上还对下一步可能的深化研究进行了探讨.不断拓展的研究方向和层出不穷的研究结果表明稀土掺杂的光谱转换材料是新型功能材料的重要研究领域,目前和将来在生物和化学传感、节能环保和新能源等领域有着重要的应用或应用前景,需要深入研究.

Rare-earth doped optical spectral conversion materials with their applications

Based on the research work carried out in our laboratory in recent years,we focus on three categories of rare-earth doped spectral conversion materials,i.e.,red phosphor for white-LED lighting,near-infrared downconversion materials and upconversion nanosized biological fluorescent labeling materials.Our work on the red phosphor for white-LED has been mainly focused on Eu3＋ doped materials,and the energy transfer from sensitizers to Eu3＋ ions is investigated in order to enhance the efficiency under the excitation of near-ultraviolet light.For the purpose of enhancing the efficiency of silicon-based solar cells,we have carried out the studies on near-infrared downconversion materials based on stepwise and cooperative energy transfer mechanisms and have clarified the downconversion mechanisms in NaYF4：Ho3＋,Yb3＋ and YVO4：Yb3＋ materials.Biological fluorescent labeling is another important application of luminescent materials,which has some stringent requirements on the materials,such as the nanoparticle size,water-solubility,non-toxicity and luminescent efficiency.In our recent work,core/shell NaYF4：Yb3＋,Er3＋（Tm3＋）/NaYF4 UCNPs have been successfully synthesized and transferred to aqueous phase by coating a cross-linked PMAO polymer.The cross-linked core/shell nanoparticles are very stable for several days,and are successfully internalized into human prostate cancer cells,which substantiates the utility of these nanoparticles in biolabeling applications.To sum up,due to significant existing and potential applications in biological and chemical sensing,new energy resources,energy saving and environmental protection,rare-earth doped spectral conversion materials have been attracting extensive attention.The future of rare-earth doped optical spectral conversion materials would be bright.