论文部分内容阅读
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
It is reported that Judd Ofelt theory is used to study the spectral properties of the cubic nanocrystalline Gd2 O3: Eu3 + at 77 K. With 5D0 → 7F1 transitions that are hardly affected by the surrounding environment as the reference, the transitions of 5D0 → 7F2 and 5D0 → 7F4 from The intensity parameter Ωλ (λ = 2, 4) was experimentally determined. It was found that the field strength parameter Ωλ of the nanosized Gd2 O3: Eu3 + material changed with the variation of the nanocrystalline grain size and was significantly different from that of the bulk material. The smaller the diameter, the shorter the lifetime of the emission level 5D0, the lower the quantum efficiency, because the smaller the crystallite size is, the stronger the quantum confinement effect is, and the larger the gauge ratio is, the more surface defects The effect is enhanced.For the charge (Eu3 + O2 -) migration state and multi-phonon process, two other non-radiative channels are also discussed