Blue-green upconversion emission in ZrO2:Yb3+ nanocrystals

被引：29

作者：

de la Rosa, E. ^{[1
]}

Solis, D. ^{[1
]}

Diaz-Torres, L. A. ^{[1
]}

Salas, P. ^{[2
]}

Angeles-Chavez, C. ^{[3
]}

Meza, O. ^{[1
]}

机构：

[1] Ctr Invest Opt, Leon 37160, Mexico

[2] Univ Nacl Autonoma Mexico, Ctr Fis Aplicada & Tecnol Avanzada, Queretaro 76000, Mexico

[3] Inst Mexicano Petr, Mexico City 07730, DF, Mexico

来源：

JOURNAL OF APPLIED PHYSICS | 2008年 / 104卷 / 10期

关键词：

absorption coefficients; nanostructured materials; paramagnetic resonance; photoexcitation; sol-gel processing; surface recombination; transmission electron microscopy; X-ray diffraction; zirconium compounds;

D O I：

10.1063/1.3014196

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

Strong blue-green cooperative upconversion emission was observed under infrared excitation in 70 nm average crystallite size ZrO2:Yb3+ nanocrystals prepared by sol-gel process. The structural characterization was performed by x-ray diffraction and high resolution transmission electron microscopy suggesting that crystalline phase of nanoparticles is controlled by active ion concentration. The cooperative absorption coefficient eta similar to 2.5x10(-22) is four orders of magnitude larger than the ones reported from bulk crystals. The highest emission intensity was obtained from the doped sample at 4 mol % and was the result of the simultaneous relaxation of two excited Yb ions. Decay time of the upconverted signal tau(CUC)approximate to 0.310 ms is half from the near infrared effective decay time confirming the cooperative process among Yb ions. Such strong cooperative effect is explained in terms of interaction enhancement due to the diminishing of Yb-Yb separation promoted partly by the surface recombination of nanocrystals.

引用

页数：6

共 21 条

[1] Yb3+ ion as a sensitizer for the upconversion luminescence in nanocrystalline Gd3Ga5O12:Ho3+ [J].