【摘要】 采用化学自发燃烧法制备了立方相不同粒径的纳米晶Y2O3:Eu(1 mol%),并通过退火处理得到了体相材料,测量了它们的发射谱和处在C2格位上Eu3+的5D0能级室温和10 K下的荧光衰减曲线。利用发射光谱数据计算了Eu3+在不同粒径纳米晶体Y2O3中的光学跃迁强度参数Ωλ(λ=2,4),通过对室温和低温下5D0能级荧光衰减的测量,用两种不同方法估计了处在C2格位上Eu3+的5D0能级的量子效率,对所获得的结果进行了讨论,并对两种获得量子效率不同方法进行了评价。更多还原

【Abstract】 In the present the authors are trying to work out how the quantum efficiency depends on the nanocrystalline size.Cubic nanocrystalline Y₂O₃:Eu³⁺ samples were prepared by chemical self-combustion.The bulk Y₂O₃:Eu³⁺ was obtained by annealing the nanocrystalline at 1 000 ℃ for 2 h.The emission spectra,XRD and fluorescence decay showed that the emission intensities are increased and fluorescence decay becomes slow with an increase in particle diameter of the samples.Two routes were used to estimate the quantum efficiency of the⁵D₀ level of Eu³⁺ at C₂ site.The quantum efficiencies of⁵D₀ level of Eu³⁺ at C₂ site in the samples depend on the nanocrystalline sizes.Finally,a detailed discussion about these two approaches for estimating the quantum efficiencies was made.更多还原