知识与财富的链接
稀土离子Pr3+和Nd3+对上转换材料的发光具有特殊的敏化作用,通过在NaLuF4:Yb3+,Er3+纳米晶中共掺杂稀土离子Pr3+和Nd3+并研究它们与发光中心Er3+之间的能量传递机制.采用水热法分别合成了Pr3+和Nd3+掺杂的NaLuF4:Yb3+,Er3+纳米晶,直径约为15 nm,具有六方相结构.发光特性分析表明,随Pr3+离子掺杂浓度增加,NaLuF4:Yb3+,Er3+纳米晶的656 nm红光强度相对于544 nm绿光逐渐减弱;但是随着Nd3+离子掺杂浓度增加,其发光红绿比刚好出现相反的变化.基于功率变换谱和简化能级图分析了Pr3+-Er3+和Nd3+-Er3+之间的能量传递机制,揭示了Er3+的4I11/2能级的电子布居在多个跃迁过程中所起的关键作用.
The doping of rare earth ion Pr3 and Nd3 has unique sensitization effect on the luminescence of upconversion materials. In the submitted work, the energy transfer mechanisms between Pr3 /Nd3 and Er3 were investigated in NaLuF4:Yb3 ,Er3 nanocrystals codoped with Pr3 or Nd3 ions. NaLuF4:Yb3 ,Er3 nanocrystals codoped with Pr3 or Nd3 ions were synthesized by hydrothermal method which had an average diameter of 15 nm and hexagonal phase structures. The luminescent properties analysis indicated that the intensity ratio of 656 nm red to 544 nm green emission decreases with increasing the content of Pr3 ions. But, a completely contrary variation was observed with increasing the content of Nd3 ions. The energy transfer between Pr3 and Er3 or between Nd3 and Er3 were investigated based on the power dependence of emission intensity and simplified energy diagram, which indicated that the population of 4I11/2 state of Er3 ions plays a key role in many transitions.