Upconversion properties of Er^3＋/Yb^3＋ co-doped TeO2-Nb2O5-Li2O glasses

The Er^3＋/Yb^3＋ co-doped TeO2-Nb2O5-Li2O glass is prepared by conventional melting method, and its upconversion spectra are measured. The intense green upconversion luminescence upon excitation with a 976 nm laser diode is observed with the naked eyes. The dependence of luminescence intensity on the ratio of Yb^3＋/Er^3＋ is discussed in detail, and the relationship between the ratio of green luminescence intensity to red luminescence intensity and the ratio of Yb^3＋/Er^3＋ is also studied, The luminescence intensity increases with the ratio of Yb^3＋/Er^3＋ increasing. The ratio of Yb^3＋/Er^3＋ plays a more important role than the concentration of Er^3＋ in determining the upconversion luminescence intensity. The ratio of green luminescence intensity to red luminescence intensity reaches a maximum when ratio of Yb^3＋/Er^3＋ is 3. Thus the glass could be one of the potential candidates for LD pumping solid-state lasers.     

化学环境对掺过渡金属功能材料发光性能的影响

分析了掺过渡金属离子的发光功能材料的发光性能对化学环境变化的敏感性,由于源于过渡金属离子d电子没有像稀土离子f电子那样受到外层电子严格的屏蔽,所导致的声子-电子耦合强度大,因而就对母体材料化学环境更敏感。文章详细地介绍了化学结构类型、配位体间相连方式及其晶格半径对掺Mn2+发光材料发光性能的影响,分析晶体场强度参数(10Dq)对含Cr3+材料室温自发辐射4T2g→4A2g和激发态吸收4T2g→4T1g(4F)跃迁最大能量差的影响,探讨了共价性强弱对Os4+材料光谱性能的影响。说明了利用掺过渡金属的发光材料对母体材料的化学环境变化的敏感性对发光材料研发的指导意义,可以利用这种敏感性改善和优化材料设计,从而寻求具有更优异发光性能的发光材料。