排序方式: 共有49条查询结果,搜索用时 15 毫秒
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Quantum cutting downconversion by cooperative energy transfer from Bi3+ to Yb3+ in Y2O3 phosphor 下载免费PDF全文
Bi~(3+) and Yb~(3+) codoped cubic Y2O3 phosphors are prepared by pechini sol-gel method.Strong near-infrared (NIR) emission around 980 nm from Yb~(3+)(2F5/2 → 2F7/2) is observed under ultraviolet light excitation.A broad excitation band ranging from 320 to 360 nm,owing to the 6s 2 →6s6p transition of Bi~(3+) ions,is recorded when the Yb~(3+) emission is monitored,which suggests a very efficient energy transfer from Bi~(3+) ions to Yb~(3+) ions.The Yb~(3+) concentration dependences of both the Bi~(3+) and the Yb~(3+) emissions are investigated.The decay curve of Bi ~(3+) emission under the excitation of 355 nm pulse laser is used to explore the Bi~(3+) →Yb~(3+) energy transfer process.Cooperative energy transfer (CET) is discussed as a possible mechanism for the near-infrared emission. 相似文献
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尹民 《化学物理学报(中文版)》2001,14(1)
当用582.6 nm的黄色激光激发Nd3+:LaCl3的2G7/2+4G5/2能级时,观察到了4D3/2和2G9/2能级的兰光和紫外发射.研究表明,2D3/2上转换的机理是能量传递和激发态吸收,而2G9/2则是由于4G5/2+4Gs/2→2G9/2+4F7/2交叉驰豫过程.通过对12K下4D3/2→4I11/2荧光衰减曲线的分析,得出能量传递几率为wt1=1468 s-1.测量和讨论了Nd3+:LaCl3和NdCl3主要发光能级室温和12K下的寿命. 相似文献
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当用582.6nm的黄色激激发Nd^3+:LaCl的^2G7/2+^4G5/2能级时,观察到了^4D3/2和^2G9/2能级的兰光和紫外发射。研究表明,^2D3/2上转换的机理是能量传递和激发态吸收而^2G9/2则是由于^4G5/2+^G5/2→^2G9/2+^F7/2交叉驰豫过程。通过对12K下^4D3/2→^4I11/2荧光衰减曲线的分析, 得到 能量传递几率为wt1=1468s^-1。测量和讨论了Nd^3+:LaCl3和NdCl3主要发光能级室温和12K下的寿命。 相似文献
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钛酸锶(SrTiO3)具有高介电常数、良好的绝缘性质、优良的物理化学稳定性和在可见光范围内的优异的透明度等优点,是一种重要的无机功能材料。近年来,Al3+,Ga3+等离子共掺杂的SrTiO3:Pr3+做为一种优异的红色场发射显示(FED)荧光粉引起了人们的兴趣。另外,SrTiO3具有相对较小的声子频率,因而它可以作为一种有利于上转换发光的基质材料。以NaCl为助熔剂制备了Er3+,Yb3+共掺杂的SrTiO3超细粉末。在980nm激发下,样品发出很强的来自于Er3+离子的2H11/2→4I15/2,4S3/2→4I15/2(绿光)和4F9/2→4I15/2(红光)跃迁的上转换发光。Yb3+离子的共掺杂对Er3+离子的上转换发光起明显的增强作用。研究了上转换发光强度与稀土离子浓度以及激发光强度之间的依赖关系,表明在Er3+单掺杂和Er3+,Yb3+共掺杂的样品中,绿光和红光都是被双光子激发过程激发的。还对上转换发光的机理做了初步分析。 相似文献
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用溶胶凝胶方法制备了稀土离子掺杂的焦硅酸钇纳米粉末,并用XRD对不同温度处理的样品结构进行了表征,结果表明1000 ℃时产物成α-Y2Si2O7相,粒径约为27 nm,且掺杂离子的浓度并不影响样品的结构,测量了Eu3+和Tb3+离子掺杂的样品的激发谱和发射谱,并对其进行了分析.激发谱中真空紫外区对应基质的吸收,紫外区分别对应Tb3+的4f~5d的吸收Eu3+的电荷迁移带的吸收,对发光强度随掺杂离子浓度的变化关系也进行了讨论.对室温下的寿命进行了测量和分析. 相似文献
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Simulation of the f-d transitions of lanthanide ions in YPO4 using quantum-chemical calculations 下载免费PDF全文
We constructed an effective one-electron Hamiltonian by using the 4f/5d energies and eigenvectors obtained from the first-principles calculation with the relativistic self-consistent discrete variational Slater software package (DV-Xα).From the effective Hamiltonian,we obtained the crystal-field and spin-orbit interaction parameters for the 4f and 5d electrons of lanthanide ions (Ce~(3+),Pr~(3+),Nd~(3+) and Eu~(3+)) doped in YPO4,and these parameters were used to calculate the 4f~N-4f~(N-1) 5d transition.Comparison with experiments shows that the obtained parameters are reasonable and the excitation spectra can be well predicted. 相似文献