【摘要】 报道用Judd Ofelt理论研究立方相纳米晶Gd2 O3:Eu3+ 材料在 77K下的光谱性质 .以几乎不受周围晶场环境影响的5D0 →7F1 跃迁为参考 ,利用5D0 →7F2 和5D0 →7F4 跃迁 ,从实验上确定强度参数Ωλ(λ =2 ,4 ) .发现纳米Gd2 O3:Eu3+ 材料晶场强度参数Ωλ 随纳米晶粒径的变化而改变 ,与体材料相比有显著的不同 .随微晶粒径减小 ,发射能级5D0 的寿命变短、量子效率降低 .这是因为微晶粒径越小 ,量子限域效应越强 ,表体比越大 ,在无序体调制的表面上表面缺陷作用增强而引起的 .对电荷 (Eu3+ O2 - )迁移态和多声子过程另外两种无辐射通道也进行讨论更多还原

【Abstract】 The spectral properties of nanoparticles Gd 2O 3:Eu 3+ have been investigated by using Judd-Ofelt theory at 77K. Intensity parameters Ω λ(λ=2,4) were calculated using the experimental data of 5D 0→ 7F 2 and 5D 0→ 7F 4 transitions by taking the magnetic dipole transition 5D 0→ 7F 1 as reference. The intensity of the transition is almost completely unaffected by the local environment. It is indicated that intensity parameter Ω λ changes with the variation of diameter of nanoparticles Gd 2O 3:Eu 3+,dramatically different from that of the bulk material.With decreasing diameter of the nanoparticles Gd 2O 3: Eu 3+ from 135 to 15nm,the quantum efficiency of the emitting level 5D 0 reduces from 23.6% to 4.6%. The smaller the diameter of nanoparticles Gd 2O 3:Eu 3+, the bigger the ratio of surface to volume and the more the surface defect.It is the enhancing of the non-radiation channels that results in the decrease of the quantum efficiency. The other two non-radiation channels, charge (Eu 3+-O 2-) transfer state and multiphonon nonradiative re-excitaton, were also studied.更多还原