Abstract

We report on the structural, morphological, and luminescent properties of Y2O3:Yb3+(2%)Er3+(1%) nanofibers synthesized by a hydrothermal method as a function of the solvent composition ethanol/water. The average length and diameter of the nanofibers ranges from 1.1 to 2.3μm, and from 50 to 110nm, respectively. A cubic crystalline structure was obtained, and no effect of the solvent was observed. However, the increment of OHs, because of the increment of water, modifies the quality of the nanofibers. Such impurities improve the emission bands under 940 and 490nm excitation, especially the red band, via multiphonon relaxation. Relaxation dynamics is explained, based on direct and back energy transfer, multiphonon relaxation, and cross-relaxation. The direct energy transfer coefficients (Cb2, Cb4, and Cb5) calculated by the proposed theoretical model point out the fact that upconverted emissions are notably favored by the increment of OHs. The energy backtransfer (C5b) and cross-relaxation (C51) coefficients depend only on the ion concentration and not on the OH content.

© 2011 Optical Society of America

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    [CrossRef] [PubMed]
  3. F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
    [CrossRef] [PubMed]
  4. H. K. Jung, J. S. Oh, S. Seok, and T. H. Lee, “Preparation and luminescence properties of LaPO4:Er,Yb nanoparticles,” J. Lumin. 114, 307–313 (2005).
    [CrossRef]
  5. D. Solís, T. López-Luke, E. De la Rosa, P. Salas, and C. Angeles-Chavez, “Surfactant effect on the upconversion emission and decay time of ZrO2:Yb–Er nanocrystals,” J. Lumin. 129, 449–455 (2009).
    [CrossRef]
  6. J. F. Suyver, J. Grimm, K. W. Krämer, and H. U. Güdel, “Highly efficient near-infrared to visible up-conversion process in NaYF4:Er3+,Yb3+,” J. Lumin. 114, 53–59 (2005).
    [CrossRef]
  7. M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
    [CrossRef]
  8. A. M. Pires, O. A. Serra, and M. R. Davolos, “Yttrium oxysulfide nanosized spherical particles doped with Yb and Er or Yb and Tm: efficient materials for up-converting phosphor technology field,” J. Alloys Compd. 374, 181–184 (2004).
    [CrossRef]
  9. L. Aarts, B. M. van der Ende, and A. Meijerink, “Downconversion for solar cells in NaYF4:Er,Yb,” J. Appl. Phys. 106, 023522(2009).
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  10. A. Shalav, B. S. Richards, and M. A. Green, “Luminescent layers for enhanced silicon solar cell performance: up-conversion,” Solar Energy Mater. Sol. Cells 91, 829–842 (2007).
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  12. R. T. Wegh, H. Donker, E. V. D. van Loef, K. D. Oskam, and A. Meijerink, “Quantum cutting through downconversion in rare-earth compounds,” J. Lumin. 87, 1017–1019 (2000).
    [CrossRef]
  13. T. K. Anh, P. Benalloul, C. Barthou, L. K. Giang, N. Vu, and L. Q. Minh, “Luminescence, energy transfer, and upconversion mechanisms of Y2O3 nanomaterials doped with Eu3+, Tb3+, Tm3+, Er3+, and Yb3+ ions,” J. Nanomater. 2007, 1–10 (2007).
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  14. A. O. G. Dikovska, P. A. Atanasov, M. Jimenez de Castro, A. Perea, J. Gonzalo, C. N. Afonso, and J. Garcia Lopez, “Optically active Er3+–Yb3+ codoped Y2O3 films produced by pulsed laser deposition,” Thin Solid Films 500, 336–340 (2006).
    [CrossRef]
  15. A. Huignard, A. Aron, P. Aschehoug, B. Viana, J. Thery, A. Laurent, and J. Perriere, “Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical applications,” J. Mater. Chem. 10, 549–554 (2000).
    [CrossRef]
  16. F. Vetrone, J. C. Boyer, J. Capobianco, A. Speghini, and M. Bettinelli, “Significance of Yb3+ concentration on the upconversion mechanisms in codoped Y2O3:Er3+,Yb3+ nanocrystals,” J. Appl. Phys. 96, 661–667 (2004).
    [CrossRef]
  17. L. Yanhong, Z. Yongming, H. Guangyan, and Y. Yingning, “Upconversion luminescence of Y2O3:Er3+,Yb3+ nanoparticles prepared by a homogeneous precipitation method,” J. Rare Earths 26, 450–454 (2008).
    [CrossRef]
  18. H. Guo and Y. M. Qiao, “Preparation, characterization, and strong upconversion of monodisperse Y2O3:Er3+,Yb3+ microspheres,” Opt. Mater. 31, 583–589 (2009).
    [CrossRef]
  19. A. M. Pires, O. A. Serra, S. Heer, and H. U. Güdel, “Low-temperature upconversion spectroscopy of nanosized Y2O3:Er,Yb phosphor,” J. Appl. Phys. 98, 063529 (2005).
    [CrossRef]
  20. G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Upconversion luminescence properties of Y2O3:Yb3+,Er3+ nanostructures,” J. Lumin. 119, 258–263 (2006).
    [CrossRef]
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    [CrossRef]
  22. A. Martinez, J. Morales, P. Salas, C. Angeles-Chavez, L. A. Díaz-Torres, and E. De la Rosa Cruz, “Role of the hydrothermal synthesis conditions on the structure and morphology of co-doped Y2O3:Yb3+–Er3+ nanostructured materials,” J. Nano Research 9, 109–116 (2010).
    [CrossRef]
  23. R. Srinivasan, R. Yogamalar, and A. C. Bose, “Synthesis and structural studies on nanocrystalline yttrium oxide,” Adv. Sci. Lett. 2, 65–69 (2009).
    [CrossRef]
  24. J. Wang, W. Miao, Y. Li, H. Yao, and Z. Li, “Water-soluble Ln3+-doped calcium fluoride nanocrystals: controlled synthesis and luminescence properties,” Mat. Lett. 63, 1794–1796(2009).
    [CrossRef]
  25. H. Liang, G. Chen, H. Liu, and Z. Zhang, “Ultraviolet upconversion luminescence enhancement in Yb3+/Er3+-codoped Y2O3 nanocrystals induced by tridoping with Li+ ions,” J. Lumin. 129, 197–202 (2009).
    [CrossRef]
  26. J. A. Capobianco, F. Vetrone, T. Dialesio, G. Tessari, A. Speghini, and M. Bettinelli, “Optical spectroscopy of nanocrystalline cubic Y2O3:Er3+ obtained by combustion synthesis”, Phys. Chem. Chem. Phys. 2, 3203–3207 (2000).
    [CrossRef]
  27. G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Effect of OH− on the upconversion luminescent efficiency of Y2O3:Yb3+,Er3+ nanostructures,” Sol. State Comm. 137, 483–487 (2006).
    [CrossRef]
  28. L. Zhang and H. Hu, “The effect of OH− on IR emission of Nd3+,Yb3+ and Er3+ doped tetraphosphate glasses,” J. Phys. Chem. Solids 63, 575–579 (2002).
    [CrossRef]
  29. L. Cheng-Ren, X. Wei, D. Bin, L. Shu-Feng, D. Jian-Hua, C. Yu-Qi, and Y. Hai-Tao, “Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses,” Chin. Phys. B 19, 047801 (2010).
    [CrossRef]
  30. L. X. Yi, M. Wang, S. Y. Feng, Y. K. Chen, G. N. Wang, L. L. Hu, and J. J. Zhang, “Emissions properties of Ho3+:I75→I85 transition sensitized by Er3+ and Yb3+ in fluorophosphate glasses,” Opt. Mat. 31, 1586–1590 (2009).
    [CrossRef]
  31. T. F. Coleman and Y. Li, “An interior trust region approach for nonlinear minimization subject to bounds,” SIAM J. Optim. 6, 418–445 (1996).
    [CrossRef]
  32. R. H. Byrd, M. E. Hribar, and J. Nocedal, “An interior point algorithm for large-scale nonlinear programming,” SIAM J. Optim. 9, 877–900 (1999).
    [CrossRef]
  33. L. Laversenne, Y. Guyot, C. Goutaudier, M. Th. Cohen-Adad, and G. Boulon, “Optimization of spectroscopic properties of Yb3+-doped refractory sesquioxides: cubic Y2O3, Lu2O3 and monoclinic Gd2O3,” Opt. Mat. 16, 475–483 (2001).
    [CrossRef]
  34. M. J. Weber, “Radiative and multiphonon relaxation of rare earth ions in Y2O3,” Phys. Rev. 171, 283–291 (1968).
    [CrossRef]
  35. J. A. Capobianco, F. Vetrone, and J. C. Boyer, “Enhancement of red emission (F9/24→I15/24) via upconversion in bulk and nanocrystalline cubic Y2O3:Er3+,” J. Phys. Chem. B 106, 1181–1187 (2002).
    [CrossRef]
  36. Y. Cong, B. Li, B. Lei, X. Wang, C. Liu, J. Liu, and W. Li, “Enhancement of luminescence intensity and increase of emission lifetime in Eu3+-doped 3CdO–Al2O3–3SiO2 amorphous system,” J. Lumin. 128, 105–109 (2008).
    [CrossRef]

2010 (3)

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

A. Martinez, J. Morales, P. Salas, C. Angeles-Chavez, L. A. Díaz-Torres, and E. De la Rosa Cruz, “Role of the hydrothermal synthesis conditions on the structure and morphology of co-doped Y2O3:Yb3+–Er3+ nanostructured materials,” J. Nano Research 9, 109–116 (2010).
[CrossRef]

L. Cheng-Ren, X. Wei, D. Bin, L. Shu-Feng, D. Jian-Hua, C. Yu-Qi, and Y. Hai-Tao, “Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses,” Chin. Phys. B 19, 047801 (2010).
[CrossRef]

2009 (9)

L. X. Yi, M. Wang, S. Y. Feng, Y. K. Chen, G. N. Wang, L. L. Hu, and J. J. Zhang, “Emissions properties of Ho3+:I75→I85 transition sensitized by Er3+ and Yb3+ in fluorophosphate glasses,” Opt. Mat. 31, 1586–1590 (2009).
[CrossRef]

R. Srinivasan, R. Yogamalar, and A. C. Bose, “Synthesis and structural studies on nanocrystalline yttrium oxide,” Adv. Sci. Lett. 2, 65–69 (2009).
[CrossRef]

J. Wang, W. Miao, Y. Li, H. Yao, and Z. Li, “Water-soluble Ln3+-doped calcium fluoride nanocrystals: controlled synthesis and luminescence properties,” Mat. Lett. 63, 1794–1796(2009).
[CrossRef]

H. Liang, G. Chen, H. Liu, and Z. Zhang, “Ultraviolet upconversion luminescence enhancement in Yb3+/Er3+-codoped Y2O3 nanocrystals induced by tridoping with Li+ ions,” J. Lumin. 129, 197–202 (2009).
[CrossRef]

H. Guo and Y. M. Qiao, “Preparation, characterization, and strong upconversion of monodisperse Y2O3:Er3+,Yb3+ microspheres,” Opt. Mater. 31, 583–589 (2009).
[CrossRef]

W. J. Kim, M. Nyk, and P. N. Prasad, “Color-coded multilayer photopatterned microstructures using lanthanide (III) ion co-doped NaYF4 nanoparticles with upconversion luminescence for possible applications in security,” Nanotechnology 20, 185301 (2009).
[CrossRef] [PubMed]

D. Solís, T. López-Luke, E. De la Rosa, P. Salas, and C. Angeles-Chavez, “Surfactant effect on the upconversion emission and decay time of ZrO2:Yb–Er nanocrystals,” J. Lumin. 129, 449–455 (2009).
[CrossRef]

M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
[CrossRef]

L. Aarts, B. M. van der Ende, and A. Meijerink, “Downconversion for solar cells in NaYF4:Er,Yb,” J. Appl. Phys. 106, 023522(2009).
[CrossRef]

2008 (3)

L. Yanhong, Z. Yongming, H. Guangyan, and Y. Yingning, “Upconversion luminescence of Y2O3:Er3+,Yb3+ nanoparticles prepared by a homogeneous precipitation method,” J. Rare Earths 26, 450–454 (2008).
[CrossRef]

A. Martinez, J. Moralesa, P. Salas, C. Angeles-Chavez, L. A. Diaz-Torres, and E. De la Rosa, “Synthesis and photoluminescence of Y2O3:Yb3+–Er3+ nanofibers,” Microelectron. J. 39, 551–555(2008).
[CrossRef]

Y. Cong, B. Li, B. Lei, X. Wang, C. Liu, J. Liu, and W. Li, “Enhancement of luminescence intensity and increase of emission lifetime in Eu3+-doped 3CdO–Al2O3–3SiO2 amorphous system,” J. Lumin. 128, 105–109 (2008).
[CrossRef]

2007 (2)

T. K. Anh, P. Benalloul, C. Barthou, L. K. Giang, N. Vu, and L. Q. Minh, “Luminescence, energy transfer, and upconversion mechanisms of Y2O3 nanomaterials doped with Eu3+, Tb3+, Tm3+, Er3+, and Yb3+ ions,” J. Nanomater. 2007, 1–10 (2007).
[CrossRef]

A. Shalav, B. S. Richards, and M. A. Green, “Luminescent layers for enhanced silicon solar cell performance: up-conversion,” Solar Energy Mater. Sol. Cells 91, 829–842 (2007).
[CrossRef]

2006 (3)

A. O. G. Dikovska, P. A. Atanasov, M. Jimenez de Castro, A. Perea, J. Gonzalo, C. N. Afonso, and J. Garcia Lopez, “Optically active Er3+–Yb3+ codoped Y2O3 films produced by pulsed laser deposition,” Thin Solid Films 500, 336–340 (2006).
[CrossRef]

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Upconversion luminescence properties of Y2O3:Yb3+,Er3+ nanostructures,” J. Lumin. 119, 258–263 (2006).
[CrossRef]

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Effect of OH− on the upconversion luminescent efficiency of Y2O3:Yb3+,Er3+ nanostructures,” Sol. State Comm. 137, 483–487 (2006).
[CrossRef]

2005 (3)

A. M. Pires, O. A. Serra, S. Heer, and H. U. Güdel, “Low-temperature upconversion spectroscopy of nanosized Y2O3:Er,Yb phosphor,” J. Appl. Phys. 98, 063529 (2005).
[CrossRef]

J. F. Suyver, J. Grimm, K. W. Krämer, and H. U. Güdel, “Highly efficient near-infrared to visible up-conversion process in NaYF4:Er3+,Yb3+,” J. Lumin. 114, 53–59 (2005).
[CrossRef]

H. K. Jung, J. S. Oh, S. Seok, and T. H. Lee, “Preparation and luminescence properties of LaPO4:Er,Yb nanoparticles,” J. Lumin. 114, 307–313 (2005).
[CrossRef]

2004 (2)

A. M. Pires, O. A. Serra, and M. R. Davolos, “Yttrium oxysulfide nanosized spherical particles doped with Yb and Er or Yb and Tm: efficient materials for up-converting phosphor technology field,” J. Alloys Compd. 374, 181–184 (2004).
[CrossRef]

F. Vetrone, J. C. Boyer, J. Capobianco, A. Speghini, and M. Bettinelli, “Significance of Yb3+ concentration on the upconversion mechanisms in codoped Y2O3:Er3+,Yb3+ nanocrystals,” J. Appl. Phys. 96, 661–667 (2004).
[CrossRef]

2003 (1)

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

2002 (3)

C. Ronda, “Luminescent materials with quantum efficiency larger than 1, status and prospects,” J. Lumin. 100, 301–305 (2002).
[CrossRef]

L. Zhang and H. Hu, “The effect of OH− on IR emission of Nd3+,Yb3+ and Er3+ doped tetraphosphate glasses,” J. Phys. Chem. Solids 63, 575–579 (2002).
[CrossRef]

J. A. Capobianco, F. Vetrone, and J. C. Boyer, “Enhancement of red emission (F9/24→I15/24) via upconversion in bulk and nanocrystalline cubic Y2O3:Er3+,” J. Phys. Chem. B 106, 1181–1187 (2002).
[CrossRef]

2001 (1)

L. Laversenne, Y. Guyot, C. Goutaudier, M. Th. Cohen-Adad, and G. Boulon, “Optimization of spectroscopic properties of Yb3+-doped refractory sesquioxides: cubic Y2O3, Lu2O3 and monoclinic Gd2O3,” Opt. Mat. 16, 475–483 (2001).
[CrossRef]

2000 (3)

J. A. Capobianco, F. Vetrone, T. Dialesio, G. Tessari, A. Speghini, and M. Bettinelli, “Optical spectroscopy of nanocrystalline cubic Y2O3:Er3+ obtained by combustion synthesis”, Phys. Chem. Chem. Phys. 2, 3203–3207 (2000).
[CrossRef]

R. T. Wegh, H. Donker, E. V. D. van Loef, K. D. Oskam, and A. Meijerink, “Quantum cutting through downconversion in rare-earth compounds,” J. Lumin. 87, 1017–1019 (2000).
[CrossRef]

A. Huignard, A. Aron, P. Aschehoug, B. Viana, J. Thery, A. Laurent, and J. Perriere, “Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical applications,” J. Mater. Chem. 10, 549–554 (2000).
[CrossRef]

1999 (1)

R. H. Byrd, M. E. Hribar, and J. Nocedal, “An interior point algorithm for large-scale nonlinear programming,” SIAM J. Optim. 9, 877–900 (1999).
[CrossRef]

1996 (1)

T. F. Coleman and Y. Li, “An interior trust region approach for nonlinear minimization subject to bounds,” SIAM J. Optim. 6, 418–445 (1996).
[CrossRef]

1968 (1)

M. J. Weber, “Radiative and multiphonon relaxation of rare earth ions in Y2O3,” Phys. Rev. 171, 283–291 (1968).
[CrossRef]

Aarts, L.

L. Aarts, B. M. van der Ende, and A. Meijerink, “Downconversion for solar cells in NaYF4:Er,Yb,” J. Appl. Phys. 106, 023522(2009).
[CrossRef]

Afonso, C. N.

A. O. G. Dikovska, P. A. Atanasov, M. Jimenez de Castro, A. Perea, J. Gonzalo, C. N. Afonso, and J. Garcia Lopez, “Optically active Er3+–Yb3+ codoped Y2O3 films produced by pulsed laser deposition,” Thin Solid Films 500, 336–340 (2006).
[CrossRef]

Angeles-Chavez, C.

A. Martinez, J. Morales, P. Salas, C. Angeles-Chavez, L. A. Díaz-Torres, and E. De la Rosa Cruz, “Role of the hydrothermal synthesis conditions on the structure and morphology of co-doped Y2O3:Yb3+–Er3+ nanostructured materials,” J. Nano Research 9, 109–116 (2010).
[CrossRef]

D. Solís, T. López-Luke, E. De la Rosa, P. Salas, and C. Angeles-Chavez, “Surfactant effect on the upconversion emission and decay time of ZrO2:Yb–Er nanocrystals,” J. Lumin. 129, 449–455 (2009).
[CrossRef]

A. Martinez, J. Moralesa, P. Salas, C. Angeles-Chavez, L. A. Diaz-Torres, and E. De la Rosa, “Synthesis and photoluminescence of Y2O3:Yb3+–Er3+ nanofibers,” Microelectron. J. 39, 551–555(2008).
[CrossRef]

Anh, T. K.

T. K. Anh, P. Benalloul, C. Barthou, L. K. Giang, N. Vu, and L. Q. Minh, “Luminescence, energy transfer, and upconversion mechanisms of Y2O3 nanomaterials doped with Eu3+, Tb3+, Tm3+, Er3+, and Yb3+ ions,” J. Nanomater. 2007, 1–10 (2007).
[CrossRef]

Aron, A.

A. Huignard, A. Aron, P. Aschehoug, B. Viana, J. Thery, A. Laurent, and J. Perriere, “Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical applications,” J. Mater. Chem. 10, 549–554 (2000).
[CrossRef]

Aschehoug, P.

A. Huignard, A. Aron, P. Aschehoug, B. Viana, J. Thery, A. Laurent, and J. Perriere, “Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical applications,” J. Mater. Chem. 10, 549–554 (2000).
[CrossRef]

Atanasov, P. A.

A. O. G. Dikovska, P. A. Atanasov, M. Jimenez de Castro, A. Perea, J. Gonzalo, C. N. Afonso, and J. Garcia Lopez, “Optically active Er3+–Yb3+ codoped Y2O3 films produced by pulsed laser deposition,” Thin Solid Films 500, 336–340 (2006).
[CrossRef]

Barthou, C.

T. K. Anh, P. Benalloul, C. Barthou, L. K. Giang, N. Vu, and L. Q. Minh, “Luminescence, energy transfer, and upconversion mechanisms of Y2O3 nanomaterials doped with Eu3+, Tb3+, Tm3+, Er3+, and Yb3+ ions,” J. Nanomater. 2007, 1–10 (2007).
[CrossRef]

Benalloul, P.

T. K. Anh, P. Benalloul, C. Barthou, L. K. Giang, N. Vu, and L. Q. Minh, “Luminescence, energy transfer, and upconversion mechanisms of Y2O3 nanomaterials doped with Eu3+, Tb3+, Tm3+, Er3+, and Yb3+ ions,” J. Nanomater. 2007, 1–10 (2007).
[CrossRef]

Bettinelli, M.

F. Vetrone, J. C. Boyer, J. Capobianco, A. Speghini, and M. Bettinelli, “Significance of Yb3+ concentration on the upconversion mechanisms in codoped Y2O3:Er3+,Yb3+ nanocrystals,” J. Appl. Phys. 96, 661–667 (2004).
[CrossRef]

J. A. Capobianco, F. Vetrone, T. Dialesio, G. Tessari, A. Speghini, and M. Bettinelli, “Optical spectroscopy of nanocrystalline cubic Y2O3:Er3+ obtained by combustion synthesis”, Phys. Chem. Chem. Phys. 2, 3203–3207 (2000).
[CrossRef]

Bin, D.

L. Cheng-Ren, X. Wei, D. Bin, L. Shu-Feng, D. Jian-Hua, C. Yu-Qi, and Y. Hai-Tao, “Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses,” Chin. Phys. B 19, 047801 (2010).
[CrossRef]

Bose, A. C.

R. Srinivasan, R. Yogamalar, and A. C. Bose, “Synthesis and structural studies on nanocrystalline yttrium oxide,” Adv. Sci. Lett. 2, 65–69 (2009).
[CrossRef]

Boulon, G.

L. Laversenne, Y. Guyot, C. Goutaudier, M. Th. Cohen-Adad, and G. Boulon, “Optimization of spectroscopic properties of Yb3+-doped refractory sesquioxides: cubic Y2O3, Lu2O3 and monoclinic Gd2O3,” Opt. Mat. 16, 475–483 (2001).
[CrossRef]

Boyer, J. C.

F. Vetrone, J. C. Boyer, J. Capobianco, A. Speghini, and M. Bettinelli, “Significance of Yb3+ concentration on the upconversion mechanisms in codoped Y2O3:Er3+,Yb3+ nanocrystals,” J. Appl. Phys. 96, 661–667 (2004).
[CrossRef]

J. A. Capobianco, F. Vetrone, and J. C. Boyer, “Enhancement of red emission (F9/24→I15/24) via upconversion in bulk and nanocrystalline cubic Y2O3:Er3+,” J. Phys. Chem. B 106, 1181–1187 (2002).
[CrossRef]

Byrd, R. H.

R. H. Byrd, M. E. Hribar, and J. Nocedal, “An interior point algorithm for large-scale nonlinear programming,” SIAM J. Optim. 9, 877–900 (1999).
[CrossRef]

Cao, C.

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Upconversion luminescence properties of Y2O3:Yb3+,Er3+ nanostructures,” J. Lumin. 119, 258–263 (2006).
[CrossRef]

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Effect of OH− on the upconversion luminescent efficiency of Y2O3:Yb3+,Er3+ nanostructures,” Sol. State Comm. 137, 483–487 (2006).
[CrossRef]

Capobianco, J.

F. Vetrone, J. C. Boyer, J. Capobianco, A. Speghini, and M. Bettinelli, “Significance of Yb3+ concentration on the upconversion mechanisms in codoped Y2O3:Er3+,Yb3+ nanocrystals,” J. Appl. Phys. 96, 661–667 (2004).
[CrossRef]

Capobianco, J. A.

J. A. Capobianco, F. Vetrone, and J. C. Boyer, “Enhancement of red emission (F9/24→I15/24) via upconversion in bulk and nanocrystalline cubic Y2O3:Er3+,” J. Phys. Chem. B 106, 1181–1187 (2002).
[CrossRef]

J. A. Capobianco, F. Vetrone, T. Dialesio, G. Tessari, A. Speghini, and M. Bettinelli, “Optical spectroscopy of nanocrystalline cubic Y2O3:Er3+ obtained by combustion synthesis”, Phys. Chem. Chem. Phys. 2, 3203–3207 (2000).
[CrossRef]

Chen, G.

H. Liang, G. Chen, H. Liu, and Z. Zhang, “Ultraviolet upconversion luminescence enhancement in Yb3+/Er3+-codoped Y2O3 nanocrystals induced by tridoping with Li+ ions,” J. Lumin. 129, 197–202 (2009).
[CrossRef]

Chen, H.

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

Chen, Y. K.

L. X. Yi, M. Wang, S. Y. Feng, Y. K. Chen, G. N. Wang, L. L. Hu, and J. J. Zhang, “Emissions properties of Ho3+:I75→I85 transition sensitized by Er3+ and Yb3+ in fluorophosphate glasses,” Opt. Mat. 31, 1586–1590 (2009).
[CrossRef]

Cheng-Ren, L.

L. Cheng-Ren, X. Wei, D. Bin, L. Shu-Feng, D. Jian-Hua, C. Yu-Qi, and Y. Hai-Tao, “Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses,” Chin. Phys. B 19, 047801 (2010).
[CrossRef]

Cohen-Adad, M. Th.

L. Laversenne, Y. Guyot, C. Goutaudier, M. Th. Cohen-Adad, and G. Boulon, “Optimization of spectroscopic properties of Yb3+-doped refractory sesquioxides: cubic Y2O3, Lu2O3 and monoclinic Gd2O3,” Opt. Mat. 16, 475–483 (2001).
[CrossRef]

Coleman, T. F.

T. F. Coleman and Y. Li, “An interior trust region approach for nonlinear minimization subject to bounds,” SIAM J. Optim. 6, 418–445 (1996).
[CrossRef]

Cong, Y.

Y. Cong, B. Li, B. Lei, X. Wang, C. Liu, J. Liu, and W. Li, “Enhancement of luminescence intensity and increase of emission lifetime in Eu3+-doped 3CdO–Al2O3–3SiO2 amorphous system,” J. Lumin. 128, 105–109 (2008).
[CrossRef]

Cui, Y.

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Effect of OH− on the upconversion luminescent efficiency of Y2O3:Yb3+,Er3+ nanostructures,” Sol. State Comm. 137, 483–487 (2006).
[CrossRef]

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Upconversion luminescence properties of Y2O3:Yb3+,Er3+ nanostructures,” J. Lumin. 119, 258–263 (2006).
[CrossRef]

Davolos, M. R.

A. M. Pires, O. A. Serra, and M. R. Davolos, “Yttrium oxysulfide nanosized spherical particles doped with Yb and Er or Yb and Tm: efficient materials for up-converting phosphor technology field,” J. Alloys Compd. 374, 181–184 (2004).
[CrossRef]

De, G.

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Upconversion luminescence properties of Y2O3:Yb3+,Er3+ nanostructures,” J. Lumin. 119, 258–263 (2006).
[CrossRef]

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Effect of OH− on the upconversion luminescent efficiency of Y2O3:Yb3+,Er3+ nanostructures,” Sol. State Comm. 137, 483–487 (2006).
[CrossRef]

De la Rosa, E.

D. Solís, T. López-Luke, E. De la Rosa, P. Salas, and C. Angeles-Chavez, “Surfactant effect on the upconversion emission and decay time of ZrO2:Yb–Er nanocrystals,” J. Lumin. 129, 449–455 (2009).
[CrossRef]

A. Martinez, J. Moralesa, P. Salas, C. Angeles-Chavez, L. A. Diaz-Torres, and E. De la Rosa, “Synthesis and photoluminescence of Y2O3:Yb3+–Er3+ nanofibers,” Microelectron. J. 39, 551–555(2008).
[CrossRef]

De la Rosa Cruz, E.

A. Martinez, J. Morales, P. Salas, C. Angeles-Chavez, L. A. Díaz-Torres, and E. De la Rosa Cruz, “Role of the hydrothermal synthesis conditions on the structure and morphology of co-doped Y2O3:Yb3+–Er3+ nanostructured materials,” J. Nano Research 9, 109–116 (2010).
[CrossRef]

Dialesio, T.

J. A. Capobianco, F. Vetrone, T. Dialesio, G. Tessari, A. Speghini, and M. Bettinelli, “Optical spectroscopy of nanocrystalline cubic Y2O3:Er3+ obtained by combustion synthesis”, Phys. Chem. Chem. Phys. 2, 3203–3207 (2000).
[CrossRef]

Diaz-Torres, L. A.

A. Martinez, J. Moralesa, P. Salas, C. Angeles-Chavez, L. A. Diaz-Torres, and E. De la Rosa, “Synthesis and photoluminescence of Y2O3:Yb3+–Er3+ nanofibers,” Microelectron. J. 39, 551–555(2008).
[CrossRef]

Díaz-Torres, L. A.

A. Martinez, J. Morales, P. Salas, C. Angeles-Chavez, L. A. Díaz-Torres, and E. De la Rosa Cruz, “Role of the hydrothermal synthesis conditions on the structure and morphology of co-doped Y2O3:Yb3+–Er3+ nanostructured materials,” J. Nano Research 9, 109–116 (2010).
[CrossRef]

Dikovska, A. O. G.

A. O. G. Dikovska, P. A. Atanasov, M. Jimenez de Castro, A. Perea, J. Gonzalo, C. N. Afonso, and J. Garcia Lopez, “Optically active Er3+–Yb3+ codoped Y2O3 films produced by pulsed laser deposition,” Thin Solid Films 500, 336–340 (2006).
[CrossRef]

Donker, H.

R. T. Wegh, H. Donker, E. V. D. van Loef, K. D. Oskam, and A. Meijerink, “Quantum cutting through downconversion in rare-earth compounds,” J. Lumin. 87, 1017–1019 (2000).
[CrossRef]

Feng, S. Y.

L. X. Yi, M. Wang, S. Y. Feng, Y. K. Chen, G. N. Wang, L. L. Hu, and J. J. Zhang, “Emissions properties of Ho3+:I75→I85 transition sensitized by Er3+ and Yb3+ in fluorophosphate glasses,” Opt. Mat. 31, 1586–1590 (2009).
[CrossRef]

Garcia Lopez, J.

A. O. G. Dikovska, P. A. Atanasov, M. Jimenez de Castro, A. Perea, J. Gonzalo, C. N. Afonso, and J. Garcia Lopez, “Optically active Er3+–Yb3+ codoped Y2O3 films produced by pulsed laser deposition,” Thin Solid Films 500, 336–340 (2006).
[CrossRef]

Gates, B.

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

Giang, L. K.

T. K. Anh, P. Benalloul, C. Barthou, L. K. Giang, N. Vu, and L. Q. Minh, “Luminescence, energy transfer, and upconversion mechanisms of Y2O3 nanomaterials doped with Eu3+, Tb3+, Tm3+, Er3+, and Yb3+ ions,” J. Nanomater. 2007, 1–10 (2007).
[CrossRef]

Gonzalo, J.

A. O. G. Dikovska, P. A. Atanasov, M. Jimenez de Castro, A. Perea, J. Gonzalo, C. N. Afonso, and J. Garcia Lopez, “Optically active Er3+–Yb3+ codoped Y2O3 films produced by pulsed laser deposition,” Thin Solid Films 500, 336–340 (2006).
[CrossRef]

Goutaudier, C.

L. Laversenne, Y. Guyot, C. Goutaudier, M. Th. Cohen-Adad, and G. Boulon, “Optimization of spectroscopic properties of Yb3+-doped refractory sesquioxides: cubic Y2O3, Lu2O3 and monoclinic Gd2O3,” Opt. Mat. 16, 475–483 (2001).
[CrossRef]

Green, M. A.

A. Shalav, B. S. Richards, and M. A. Green, “Luminescent layers for enhanced silicon solar cell performance: up-conversion,” Solar Energy Mater. Sol. Cells 91, 829–842 (2007).
[CrossRef]

Grimm, J.

J. F. Suyver, J. Grimm, K. W. Krämer, and H. U. Güdel, “Highly efficient near-infrared to visible up-conversion process in NaYF4:Er3+,Yb3+,” J. Lumin. 114, 53–59 (2005).
[CrossRef]

Guangyan, H.

L. Yanhong, Z. Yongming, H. Guangyan, and Y. Yingning, “Upconversion luminescence of Y2O3:Er3+,Yb3+ nanoparticles prepared by a homogeneous precipitation method,” J. Rare Earths 26, 450–454 (2008).
[CrossRef]

Güdel, H. U.

A. M. Pires, O. A. Serra, S. Heer, and H. U. Güdel, “Low-temperature upconversion spectroscopy of nanosized Y2O3:Er,Yb phosphor,” J. Appl. Phys. 98, 063529 (2005).
[CrossRef]

J. F. Suyver, J. Grimm, K. W. Krämer, and H. U. Güdel, “Highly efficient near-infrared to visible up-conversion process in NaYF4:Er3+,Yb3+,” J. Lumin. 114, 53–59 (2005).
[CrossRef]

Guo, H.

H. Guo and Y. M. Qiao, “Preparation, characterization, and strong upconversion of monodisperse Y2O3:Er3+,Yb3+ microspheres,” Opt. Mater. 31, 583–589 (2009).
[CrossRef]

Guyot, Y.

L. Laversenne, Y. Guyot, C. Goutaudier, M. Th. Cohen-Adad, and G. Boulon, “Optimization of spectroscopic properties of Yb3+-doped refractory sesquioxides: cubic Y2O3, Lu2O3 and monoclinic Gd2O3,” Opt. Mat. 16, 475–483 (2001).
[CrossRef]

Hai-Tao, Y.

L. Cheng-Ren, X. Wei, D. Bin, L. Shu-Feng, D. Jian-Hua, C. Yu-Qi, and Y. Hai-Tao, “Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses,” Chin. Phys. B 19, 047801 (2010).
[CrossRef]

Han, Y.

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

Heer, S.

A. M. Pires, O. A. Serra, S. Heer, and H. U. Güdel, “Low-temperature upconversion spectroscopy of nanosized Y2O3:Er,Yb phosphor,” J. Appl. Phys. 98, 063529 (2005).
[CrossRef]

Hon, M.

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

Hou, W.

M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
[CrossRef]

Hribar, M. E.

R. H. Byrd, M. E. Hribar, and J. Nocedal, “An interior point algorithm for large-scale nonlinear programming,” SIAM J. Optim. 9, 877–900 (1999).
[CrossRef]

Hu, H.

L. Zhang and H. Hu, “The effect of OH− on IR emission of Nd3+,Yb3+ and Er3+ doped tetraphosphate glasses,” J. Phys. Chem. Solids 63, 575–579 (2002).
[CrossRef]

Hu, L. L.

L. X. Yi, M. Wang, S. Y. Feng, Y. K. Chen, G. N. Wang, L. L. Hu, and J. J. Zhang, “Emissions properties of Ho3+:I75→I85 transition sensitized by Er3+ and Yb3+ in fluorophosphate glasses,” Opt. Mat. 31, 1586–1590 (2009).
[CrossRef]

Huignard, A.

A. Huignard, A. Aron, P. Aschehoug, B. Viana, J. Thery, A. Laurent, and J. Perriere, “Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical applications,” J. Mater. Chem. 10, 549–554 (2000).
[CrossRef]

Jian-Hua, D.

L. Cheng-Ren, X. Wei, D. Bin, L. Shu-Feng, D. Jian-Hua, C. Yu-Qi, and Y. Hai-Tao, “Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses,” Chin. Phys. B 19, 047801 (2010).
[CrossRef]

Jimenez de Castro, M.

A. O. G. Dikovska, P. A. Atanasov, M. Jimenez de Castro, A. Perea, J. Gonzalo, C. N. Afonso, and J. Garcia Lopez, “Optically active Er3+–Yb3+ codoped Y2O3 films produced by pulsed laser deposition,” Thin Solid Films 500, 336–340 (2006).
[CrossRef]

Jung, H. K.

H. K. Jung, J. S. Oh, S. Seok, and T. H. Lee, “Preparation and luminescence properties of LaPO4:Er,Yb nanoparticles,” J. Lumin. 114, 307–313 (2005).
[CrossRef]

Kim, F.

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

Kim, W. J.

W. J. Kim, M. Nyk, and P. N. Prasad, “Color-coded multilayer photopatterned microstructures using lanthanide (III) ion co-doped NaYF4 nanoparticles with upconversion luminescence for possible applications in security,” Nanotechnology 20, 185301 (2009).
[CrossRef] [PubMed]

Krämer, K. W.

J. F. Suyver, J. Grimm, K. W. Krämer, and H. U. Güdel, “Highly efficient near-infrared to visible up-conversion process in NaYF4:Er3+,Yb3+,” J. Lumin. 114, 53–59 (2005).
[CrossRef]

Laurent, A.

A. Huignard, A. Aron, P. Aschehoug, B. Viana, J. Thery, A. Laurent, and J. Perriere, “Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical applications,” J. Mater. Chem. 10, 549–554 (2000).
[CrossRef]

Laversenne, L.

L. Laversenne, Y. Guyot, C. Goutaudier, M. Th. Cohen-Adad, and G. Boulon, “Optimization of spectroscopic properties of Yb3+-doped refractory sesquioxides: cubic Y2O3, Lu2O3 and monoclinic Gd2O3,” Opt. Mat. 16, 475–483 (2001).
[CrossRef]

Lee, T. H.

H. K. Jung, J. S. Oh, S. Seok, and T. H. Lee, “Preparation and luminescence properties of LaPO4:Er,Yb nanoparticles,” J. Lumin. 114, 307–313 (2005).
[CrossRef]

Lei, B.

Y. Cong, B. Li, B. Lei, X. Wang, C. Liu, J. Liu, and W. Li, “Enhancement of luminescence intensity and increase of emission lifetime in Eu3+-doped 3CdO–Al2O3–3SiO2 amorphous system,” J. Lumin. 128, 105–109 (2008).
[CrossRef]

Li, B.

Y. Cong, B. Li, B. Lei, X. Wang, C. Liu, J. Liu, and W. Li, “Enhancement of luminescence intensity and increase of emission lifetime in Eu3+-doped 3CdO–Al2O3–3SiO2 amorphous system,” J. Lumin. 128, 105–109 (2008).
[CrossRef]

Li, F.

M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
[CrossRef]

Li, W.

Y. Cong, B. Li, B. Lei, X. Wang, C. Liu, J. Liu, and W. Li, “Enhancement of luminescence intensity and increase of emission lifetime in Eu3+-doped 3CdO–Al2O3–3SiO2 amorphous system,” J. Lumin. 128, 105–109 (2008).
[CrossRef]

Li, Y.

J. Wang, W. Miao, Y. Li, H. Yao, and Z. Li, “Water-soluble Ln3+-doped calcium fluoride nanocrystals: controlled synthesis and luminescence properties,” Mat. Lett. 63, 1794–1796(2009).
[CrossRef]

T. F. Coleman and Y. Li, “An interior trust region approach for nonlinear minimization subject to bounds,” SIAM J. Optim. 6, 418–445 (1996).
[CrossRef]

Li, Z.

J. Wang, W. Miao, Y. Li, H. Yao, and Z. Li, “Water-soluble Ln3+-doped calcium fluoride nanocrystals: controlled synthesis and luminescence properties,” Mat. Lett. 63, 1794–1796(2009).
[CrossRef]

Liang, H.

H. Liang, G. Chen, H. Liu, and Z. Zhang, “Ultraviolet upconversion luminescence enhancement in Yb3+/Er3+-codoped Y2O3 nanocrystals induced by tridoping with Li+ ions,” J. Lumin. 129, 197–202 (2009).
[CrossRef]

Lim, C. S.

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

Liu, C.

Y. Cong, B. Li, B. Lei, X. Wang, C. Liu, J. Liu, and W. Li, “Enhancement of luminescence intensity and increase of emission lifetime in Eu3+-doped 3CdO–Al2O3–3SiO2 amorphous system,” J. Lumin. 128, 105–109 (2008).
[CrossRef]

Liu, H.

H. Liang, G. Chen, H. Liu, and Z. Zhang, “Ultraviolet upconversion luminescence enhancement in Yb3+/Er3+-codoped Y2O3 nanocrystals induced by tridoping with Li+ ions,” J. Lumin. 129, 197–202 (2009).
[CrossRef]

Liu, J.

Y. Cong, B. Li, B. Lei, X. Wang, C. Liu, J. Liu, and W. Li, “Enhancement of luminescence intensity and increase of emission lifetime in Eu3+-doped 3CdO–Al2O3–3SiO2 amorphous system,” J. Lumin. 128, 105–109 (2008).
[CrossRef]

Liu, J. L.

M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
[CrossRef]

Liu, X.

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

López-Luke, T.

D. Solís, T. López-Luke, E. De la Rosa, P. Salas, and C. Angeles-Chavez, “Surfactant effect on the upconversion emission and decay time of ZrO2:Yb–Er nanocrystals,” J. Lumin. 129, 449–455 (2009).
[CrossRef]

Lu, Y.

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

Martinez, A.

A. Martinez, J. Morales, P. Salas, C. Angeles-Chavez, L. A. Díaz-Torres, and E. De la Rosa Cruz, “Role of the hydrothermal synthesis conditions on the structure and morphology of co-doped Y2O3:Yb3+–Er3+ nanostructured materials,” J. Nano Research 9, 109–116 (2010).
[CrossRef]

A. Martinez, J. Moralesa, P. Salas, C. Angeles-Chavez, L. A. Diaz-Torres, and E. De la Rosa, “Synthesis and photoluminescence of Y2O3:Yb3+–Er3+ nanofibers,” Microelectron. J. 39, 551–555(2008).
[CrossRef]

Mayers, B.

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

Meijerink, A.

L. Aarts, B. M. van der Ende, and A. Meijerink, “Downconversion for solar cells in NaYF4:Er,Yb,” J. Appl. Phys. 106, 023522(2009).
[CrossRef]

R. T. Wegh, H. Donker, E. V. D. van Loef, K. D. Oskam, and A. Meijerink, “Quantum cutting through downconversion in rare-earth compounds,” J. Lumin. 87, 1017–1019 (2000).
[CrossRef]

Mi, C. C.

M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
[CrossRef]

Miao, W.

J. Wang, W. Miao, Y. Li, H. Yao, and Z. Li, “Water-soluble Ln3+-doped calcium fluoride nanocrystals: controlled synthesis and luminescence properties,” Mat. Lett. 63, 1794–1796(2009).
[CrossRef]

Minh, L. Q.

T. K. Anh, P. Benalloul, C. Barthou, L. K. Giang, N. Vu, and L. Q. Minh, “Luminescence, energy transfer, and upconversion mechanisms of Y2O3 nanomaterials doped with Eu3+, Tb3+, Tm3+, Er3+, and Yb3+ ions,” J. Nanomater. 2007, 1–10 (2007).
[CrossRef]

Morales, J.

A. Martinez, J. Morales, P. Salas, C. Angeles-Chavez, L. A. Díaz-Torres, and E. De la Rosa Cruz, “Role of the hydrothermal synthesis conditions on the structure and morphology of co-doped Y2O3:Yb3+–Er3+ nanostructured materials,” J. Nano Research 9, 109–116 (2010).
[CrossRef]

Moralesa, J.

A. Martinez, J. Moralesa, P. Salas, C. Angeles-Chavez, L. A. Diaz-Torres, and E. De la Rosa, “Synthesis and photoluminescence of Y2O3:Yb3+–Er3+ nanofibers,” Microelectron. J. 39, 551–555(2008).
[CrossRef]

Nocedal, J.

R. H. Byrd, M. E. Hribar, and J. Nocedal, “An interior point algorithm for large-scale nonlinear programming,” SIAM J. Optim. 9, 877–900 (1999).
[CrossRef]

Nyk, M.

W. J. Kim, M. Nyk, and P. N. Prasad, “Color-coded multilayer photopatterned microstructures using lanthanide (III) ion co-doped NaYF4 nanoparticles with upconversion luminescence for possible applications in security,” Nanotechnology 20, 185301 (2009).
[CrossRef] [PubMed]

Oh, J. S.

H. K. Jung, J. S. Oh, S. Seok, and T. H. Lee, “Preparation and luminescence properties of LaPO4:Er,Yb nanoparticles,” J. Lumin. 114, 307–313 (2005).
[CrossRef]

Oskam, K. D.

R. T. Wegh, H. Donker, E. V. D. van Loef, K. D. Oskam, and A. Meijerink, “Quantum cutting through downconversion in rare-earth compounds,” J. Lumin. 87, 1017–1019 (2000).
[CrossRef]

Perea, A.

A. O. G. Dikovska, P. A. Atanasov, M. Jimenez de Castro, A. Perea, J. Gonzalo, C. N. Afonso, and J. Garcia Lopez, “Optically active Er3+–Yb3+ codoped Y2O3 films produced by pulsed laser deposition,” Thin Solid Films 500, 336–340 (2006).
[CrossRef]

Perriere, J.

A. Huignard, A. Aron, P. Aschehoug, B. Viana, J. Thery, A. Laurent, and J. Perriere, “Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical applications,” J. Mater. Chem. 10, 549–554 (2000).
[CrossRef]

Pires, A. M.

A. M. Pires, O. A. Serra, S. Heer, and H. U. Güdel, “Low-temperature upconversion spectroscopy of nanosized Y2O3:Er,Yb phosphor,” J. Appl. Phys. 98, 063529 (2005).
[CrossRef]

A. M. Pires, O. A. Serra, and M. R. Davolos, “Yttrium oxysulfide nanosized spherical particles doped with Yb and Er or Yb and Tm: efficient materials for up-converting phosphor technology field,” J. Alloys Compd. 374, 181–184 (2004).
[CrossRef]

Prasad, P. N.

W. J. Kim, M. Nyk, and P. N. Prasad, “Color-coded multilayer photopatterned microstructures using lanthanide (III) ion co-doped NaYF4 nanoparticles with upconversion luminescence for possible applications in security,” Nanotechnology 20, 185301 (2009).
[CrossRef] [PubMed]

Qiao, Y. M.

H. Guo and Y. M. Qiao, “Preparation, characterization, and strong upconversion of monodisperse Y2O3:Er3+,Yb3+ microspheres,” Opt. Mater. 31, 583–589 (2009).
[CrossRef]

Qin, W.

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Upconversion luminescence properties of Y2O3:Yb3+,Er3+ nanostructures,” J. Lumin. 119, 258–263 (2006).
[CrossRef]

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Effect of OH− on the upconversion luminescent efficiency of Y2O3:Yb3+,Er3+ nanostructures,” Sol. State Comm. 137, 483–487 (2006).
[CrossRef]

Richards, B. S.

A. Shalav, B. S. Richards, and M. A. Green, “Luminescent layers for enhanced silicon solar cell performance: up-conversion,” Solar Energy Mater. Sol. Cells 91, 829–842 (2007).
[CrossRef]

Ronda, C.

C. Ronda, “Luminescent materials with quantum efficiency larger than 1, status and prospects,” J. Lumin. 100, 301–305 (2002).
[CrossRef]

Salas, P.

A. Martinez, J. Morales, P. Salas, C. Angeles-Chavez, L. A. Díaz-Torres, and E. De la Rosa Cruz, “Role of the hydrothermal synthesis conditions on the structure and morphology of co-doped Y2O3:Yb3+–Er3+ nanostructured materials,” J. Nano Research 9, 109–116 (2010).
[CrossRef]

D. Solís, T. López-Luke, E. De la Rosa, P. Salas, and C. Angeles-Chavez, “Surfactant effect on the upconversion emission and decay time of ZrO2:Yb–Er nanocrystals,” J. Lumin. 129, 449–455 (2009).
[CrossRef]

A. Martinez, J. Moralesa, P. Salas, C. Angeles-Chavez, L. A. Diaz-Torres, and E. De la Rosa, “Synthesis and photoluminescence of Y2O3:Yb3+–Er3+ nanofibers,” Microelectron. J. 39, 551–555(2008).
[CrossRef]

Seok, S.

H. K. Jung, J. S. Oh, S. Seok, and T. H. Lee, “Preparation and luminescence properties of LaPO4:Er,Yb nanoparticles,” J. Lumin. 114, 307–313 (2005).
[CrossRef]

Serra, O. A.

A. M. Pires, O. A. Serra, S. Heer, and H. U. Güdel, “Low-temperature upconversion spectroscopy of nanosized Y2O3:Er,Yb phosphor,” J. Appl. Phys. 98, 063529 (2005).
[CrossRef]

A. M. Pires, O. A. Serra, and M. R. Davolos, “Yttrium oxysulfide nanosized spherical particles doped with Yb and Er or Yb and Tm: efficient materials for up-converting phosphor technology field,” J. Alloys Compd. 374, 181–184 (2004).
[CrossRef]

Shalav, A.

A. Shalav, B. S. Richards, and M. A. Green, “Luminescent layers for enhanced silicon solar cell performance: up-conversion,” Solar Energy Mater. Sol. Cells 91, 829–842 (2007).
[CrossRef]

Shu-Feng, L.

L. Cheng-Ren, X. Wei, D. Bin, L. Shu-Feng, D. Jian-Hua, C. Yu-Qi, and Y. Hai-Tao, “Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses,” Chin. Phys. B 19, 047801 (2010).
[CrossRef]

Solís, D.

D. Solís, T. López-Luke, E. De la Rosa, P. Salas, and C. Angeles-Chavez, “Surfactant effect on the upconversion emission and decay time of ZrO2:Yb–Er nanocrystals,” J. Lumin. 129, 449–455 (2009).
[CrossRef]

Speghini, A.

F. Vetrone, J. C. Boyer, J. Capobianco, A. Speghini, and M. Bettinelli, “Significance of Yb3+ concentration on the upconversion mechanisms in codoped Y2O3:Er3+,Yb3+ nanocrystals,” J. Appl. Phys. 96, 661–667 (2004).
[CrossRef]

J. A. Capobianco, F. Vetrone, T. Dialesio, G. Tessari, A. Speghini, and M. Bettinelli, “Optical spectroscopy of nanocrystalline cubic Y2O3:Er3+ obtained by combustion synthesis”, Phys. Chem. Chem. Phys. 2, 3203–3207 (2000).
[CrossRef]

Srinivasan, R.

R. Srinivasan, R. Yogamalar, and A. C. Bose, “Synthesis and structural studies on nanocrystalline yttrium oxide,” Adv. Sci. Lett. 2, 65–69 (2009).
[CrossRef]

Sun, Y.

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

Suyver, J. F.

J. F. Suyver, J. Grimm, K. W. Krämer, and H. U. Güdel, “Highly efficient near-infrared to visible up-conversion process in NaYF4:Er3+,Yb3+,” J. Lumin. 114, 53–59 (2005).
[CrossRef]

Tessari, G.

J. A. Capobianco, F. Vetrone, T. Dialesio, G. Tessari, A. Speghini, and M. Bettinelli, “Optical spectroscopy of nanocrystalline cubic Y2O3:Er3+ obtained by combustion synthesis”, Phys. Chem. Chem. Phys. 2, 3203–3207 (2000).
[CrossRef]

Thery, J.

A. Huignard, A. Aron, P. Aschehoug, B. Viana, J. Thery, A. Laurent, and J. Perriere, “Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical applications,” J. Mater. Chem. 10, 549–554 (2000).
[CrossRef]

van der Ende, B. M.

L. Aarts, B. M. van der Ende, and A. Meijerink, “Downconversion for solar cells in NaYF4:Er,Yb,” J. Appl. Phys. 106, 023522(2009).
[CrossRef]

van Loef, E. V. D.

R. T. Wegh, H. Donker, E. V. D. van Loef, K. D. Oskam, and A. Meijerink, “Quantum cutting through downconversion in rare-earth compounds,” J. Lumin. 87, 1017–1019 (2000).
[CrossRef]

Vetrone, F.

F. Vetrone, J. C. Boyer, J. Capobianco, A. Speghini, and M. Bettinelli, “Significance of Yb3+ concentration on the upconversion mechanisms in codoped Y2O3:Er3+,Yb3+ nanocrystals,” J. Appl. Phys. 96, 661–667 (2004).
[CrossRef]

J. A. Capobianco, F. Vetrone, and J. C. Boyer, “Enhancement of red emission (F9/24→I15/24) via upconversion in bulk and nanocrystalline cubic Y2O3:Er3+,” J. Phys. Chem. B 106, 1181–1187 (2002).
[CrossRef]

J. A. Capobianco, F. Vetrone, T. Dialesio, G. Tessari, A. Speghini, and M. Bettinelli, “Optical spectroscopy of nanocrystalline cubic Y2O3:Er3+ obtained by combustion synthesis”, Phys. Chem. Chem. Phys. 2, 3203–3207 (2000).
[CrossRef]

Viana, B.

A. Huignard, A. Aron, P. Aschehoug, B. Viana, J. Thery, A. Laurent, and J. Perriere, “Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical applications,” J. Mater. Chem. 10, 549–554 (2000).
[CrossRef]

Vu, N.

T. K. Anh, P. Benalloul, C. Barthou, L. K. Giang, N. Vu, and L. Q. Minh, “Luminescence, energy transfer, and upconversion mechanisms of Y2O3 nanomaterials doped with Eu3+, Tb3+, Tm3+, Er3+, and Yb3+ ions,” J. Nanomater. 2007, 1–10 (2007).
[CrossRef]

Wang, F.

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

Wang, G. N.

L. X. Yi, M. Wang, S. Y. Feng, Y. K. Chen, G. N. Wang, L. L. Hu, and J. J. Zhang, “Emissions properties of Ho3+:I75→I85 transition sensitized by Er3+ and Yb3+ in fluorophosphate glasses,” Opt. Mat. 31, 1586–1590 (2009).
[CrossRef]

Wang, J.

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

J. Wang, W. Miao, Y. Li, H. Yao, and Z. Li, “Water-soluble Ln3+-doped calcium fluoride nanocrystals: controlled synthesis and luminescence properties,” Mat. Lett. 63, 1794–1796(2009).
[CrossRef]

Wang, M.

M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
[CrossRef]

L. X. Yi, M. Wang, S. Y. Feng, Y. K. Chen, G. N. Wang, L. L. Hu, and J. J. Zhang, “Emissions properties of Ho3+:I75→I85 transition sensitized by Er3+ and Yb3+ in fluorophosphate glasses,” Opt. Mat. 31, 1586–1590 (2009).
[CrossRef]

Wang, X.

Y. Cong, B. Li, B. Lei, X. Wang, C. Liu, J. Liu, and W. Li, “Enhancement of luminescence intensity and increase of emission lifetime in Eu3+-doped 3CdO–Al2O3–3SiO2 amorphous system,” J. Lumin. 128, 105–109 (2008).
[CrossRef]

Wang, Y.

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Effect of OH− on the upconversion luminescent efficiency of Y2O3:Yb3+,Er3+ nanostructures,” Sol. State Comm. 137, 483–487 (2006).
[CrossRef]

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Upconversion luminescence properties of Y2O3:Yb3+,Er3+ nanostructures,” J. Lumin. 119, 258–263 (2006).
[CrossRef]

Weber, M. J.

M. J. Weber, “Radiative and multiphonon relaxation of rare earth ions in Y2O3,” Phys. Rev. 171, 283–291 (1968).
[CrossRef]

Wegh, R. T.

R. T. Wegh, H. Donker, E. V. D. van Loef, K. D. Oskam, and A. Meijerink, “Quantum cutting through downconversion in rare-earth compounds,” J. Lumin. 87, 1017–1019 (2000).
[CrossRef]

Wei, X.

L. Cheng-Ren, X. Wei, D. Bin, L. Shu-Feng, D. Jian-Hua, C. Yu-Qi, and Y. Hai-Tao, “Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses,” Chin. Phys. B 19, 047801 (2010).
[CrossRef]

Wu, X. L.

M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
[CrossRef]

Wu, Y.

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

Xia, Y.

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

Xu, J.

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

Xu, S. K.

M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
[CrossRef]

Yan, H.

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

Yang, P.

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

Yanhong, L.

L. Yanhong, Z. Yongming, H. Guangyan, and Y. Yingning, “Upconversion luminescence of Y2O3:Er3+,Yb3+ nanoparticles prepared by a homogeneous precipitation method,” J. Rare Earths 26, 450–454 (2008).
[CrossRef]

Yao, H.

J. Wang, W. Miao, Y. Li, H. Yao, and Z. Li, “Water-soluble Ln3+-doped calcium fluoride nanocrystals: controlled synthesis and luminescence properties,” Mat. Lett. 63, 1794–1796(2009).
[CrossRef]

Yi, L. X.

L. X. Yi, M. Wang, S. Y. Feng, Y. K. Chen, G. N. Wang, L. L. Hu, and J. J. Zhang, “Emissions properties of Ho3+:I75→I85 transition sensitized by Er3+ and Yb3+ in fluorophosphate glasses,” Opt. Mat. 31, 1586–1590 (2009).
[CrossRef]

Yin, Y.

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

Yingning, Y.

L. Yanhong, Z. Yongming, H. Guangyan, and Y. Yingning, “Upconversion luminescence of Y2O3:Er3+,Yb3+ nanoparticles prepared by a homogeneous precipitation method,” J. Rare Earths 26, 450–454 (2008).
[CrossRef]

Yogamalar, R.

R. Srinivasan, R. Yogamalar, and A. C. Bose, “Synthesis and structural studies on nanocrystalline yttrium oxide,” Adv. Sci. Lett. 2, 65–69 (2009).
[CrossRef]

Yongming, Z.

L. Yanhong, Z. Yongming, H. Guangyan, and Y. Yingning, “Upconversion luminescence of Y2O3:Er3+,Yb3+ nanoparticles prepared by a homogeneous precipitation method,” J. Rare Earths 26, 450–454 (2008).
[CrossRef]

Yu-Qi, C.

L. Cheng-Ren, X. Wei, D. Bin, L. Shu-Feng, D. Jian-Hua, C. Yu-Qi, and Y. Hai-Tao, “Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses,” Chin. Phys. B 19, 047801 (2010).
[CrossRef]

Zhang, C.

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

Zhang, J.

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Effect of OH− on the upconversion luminescent efficiency of Y2O3:Yb3+,Er3+ nanostructures,” Sol. State Comm. 137, 483–487 (2006).
[CrossRef]

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Effect of OH− on the upconversion luminescent efficiency of Y2O3:Yb3+,Er3+ nanostructures,” Sol. State Comm. 137, 483–487 (2006).
[CrossRef]

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Upconversion luminescence properties of Y2O3:Yb3+,Er3+ nanostructures,” J. Lumin. 119, 258–263 (2006).
[CrossRef]

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Upconversion luminescence properties of Y2O3:Yb3+,Er3+ nanostructures,” J. Lumin. 119, 258–263 (2006).
[CrossRef]

Zhang, J. J.

L. X. Yi, M. Wang, S. Y. Feng, Y. K. Chen, G. N. Wang, L. L. Hu, and J. J. Zhang, “Emissions properties of Ho3+:I75→I85 transition sensitized by Er3+ and Yb3+ in fluorophosphate glasses,” Opt. Mat. 31, 1586–1590 (2009).
[CrossRef]

Zhang, L.

L. Zhang and H. Hu, “The effect of OH− on IR emission of Nd3+,Yb3+ and Er3+ doped tetraphosphate glasses,” J. Phys. Chem. Solids 63, 575–579 (2002).
[CrossRef]

Zhang, Y. X.

M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
[CrossRef]

Zhang, Z.

H. Liang, G. Chen, H. Liu, and Z. Zhang, “Ultraviolet upconversion luminescence enhancement in Yb3+/Er3+-codoped Y2O3 nanocrystals induced by tridoping with Li+ ions,” J. Lumin. 129, 197–202 (2009).
[CrossRef]

Adv. Mater. (1)

Y. Xia, P. Yang, Y. Sun, Y. Wu, B. Mayers, B. Gates, Y. Yin, F. Kim, and H. Yan, “One-dimensional nanostructures: synthesis, characterization, and applications,” Adv. Mater. 15, 353–389 (2003).
[CrossRef]

Adv. Sci. Lett. (1)

R. Srinivasan, R. Yogamalar, and A. C. Bose, “Synthesis and structural studies on nanocrystalline yttrium oxide,” Adv. Sci. Lett. 2, 65–69 (2009).
[CrossRef]

Chin. Phys. B (1)

L. Cheng-Ren, X. Wei, D. Bin, L. Shu-Feng, D. Jian-Hua, C. Yu-Qi, and Y. Hai-Tao, “Up-conversion photoluminescence characteristics of Yb3+:Er3+:Tm3+ co-doped borosilicate glasses,” Chin. Phys. B 19, 047801 (2010).
[CrossRef]

J. Alloys Compd. (2)

M. Wang, C. C. Mi, J. L. Liu, X. L. Wu, Y. X. Zhang, W. Hou, F. Li, and S. K. Xu, “One-step synthesis and characterization of water-soluble NaYF4:Yb,Er/polymer nanoparticles with efficient up-conversion fluorescence,” J. Alloys Compd. 485, L24–L27(2009).
[CrossRef]

A. M. Pires, O. A. Serra, and M. R. Davolos, “Yttrium oxysulfide nanosized spherical particles doped with Yb and Er or Yb and Tm: efficient materials for up-converting phosphor technology field,” J. Alloys Compd. 374, 181–184 (2004).
[CrossRef]

J. Appl. Phys. (3)

L. Aarts, B. M. van der Ende, and A. Meijerink, “Downconversion for solar cells in NaYF4:Er,Yb,” J. Appl. Phys. 106, 023522(2009).
[CrossRef]

F. Vetrone, J. C. Boyer, J. Capobianco, A. Speghini, and M. Bettinelli, “Significance of Yb3+ concentration on the upconversion mechanisms in codoped Y2O3:Er3+,Yb3+ nanocrystals,” J. Appl. Phys. 96, 661–667 (2004).
[CrossRef]

A. M. Pires, O. A. Serra, S. Heer, and H. U. Güdel, “Low-temperature upconversion spectroscopy of nanosized Y2O3:Er,Yb phosphor,” J. Appl. Phys. 98, 063529 (2005).
[CrossRef]

J. Lumin. (8)

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Upconversion luminescence properties of Y2O3:Yb3+,Er3+ nanostructures,” J. Lumin. 119, 258–263 (2006).
[CrossRef]

C. Ronda, “Luminescent materials with quantum efficiency larger than 1, status and prospects,” J. Lumin. 100, 301–305 (2002).
[CrossRef]

R. T. Wegh, H. Donker, E. V. D. van Loef, K. D. Oskam, and A. Meijerink, “Quantum cutting through downconversion in rare-earth compounds,” J. Lumin. 87, 1017–1019 (2000).
[CrossRef]

H. K. Jung, J. S. Oh, S. Seok, and T. H. Lee, “Preparation and luminescence properties of LaPO4:Er,Yb nanoparticles,” J. Lumin. 114, 307–313 (2005).
[CrossRef]

D. Solís, T. López-Luke, E. De la Rosa, P. Salas, and C. Angeles-Chavez, “Surfactant effect on the upconversion emission and decay time of ZrO2:Yb–Er nanocrystals,” J. Lumin. 129, 449–455 (2009).
[CrossRef]

J. F. Suyver, J. Grimm, K. W. Krämer, and H. U. Güdel, “Highly efficient near-infrared to visible up-conversion process in NaYF4:Er3+,Yb3+,” J. Lumin. 114, 53–59 (2005).
[CrossRef]

H. Liang, G. Chen, H. Liu, and Z. Zhang, “Ultraviolet upconversion luminescence enhancement in Yb3+/Er3+-codoped Y2O3 nanocrystals induced by tridoping with Li+ ions,” J. Lumin. 129, 197–202 (2009).
[CrossRef]

Y. Cong, B. Li, B. Lei, X. Wang, C. Liu, J. Liu, and W. Li, “Enhancement of luminescence intensity and increase of emission lifetime in Eu3+-doped 3CdO–Al2O3–3SiO2 amorphous system,” J. Lumin. 128, 105–109 (2008).
[CrossRef]

J. Mater. Chem. (1)

A. Huignard, A. Aron, P. Aschehoug, B. Viana, J. Thery, A. Laurent, and J. Perriere, “Growth by laser ablation of Y2O3 and Tm:Y2O3 thin films for optical applications,” J. Mater. Chem. 10, 549–554 (2000).
[CrossRef]

J. Nano Research (1)

A. Martinez, J. Morales, P. Salas, C. Angeles-Chavez, L. A. Díaz-Torres, and E. De la Rosa Cruz, “Role of the hydrothermal synthesis conditions on the structure and morphology of co-doped Y2O3:Yb3+–Er3+ nanostructured materials,” J. Nano Research 9, 109–116 (2010).
[CrossRef]

J. Nanomater. (1)

T. K. Anh, P. Benalloul, C. Barthou, L. K. Giang, N. Vu, and L. Q. Minh, “Luminescence, energy transfer, and upconversion mechanisms of Y2O3 nanomaterials doped with Eu3+, Tb3+, Tm3+, Er3+, and Yb3+ ions,” J. Nanomater. 2007, 1–10 (2007).
[CrossRef]

J. Phys. Chem. B (1)

J. A. Capobianco, F. Vetrone, and J. C. Boyer, “Enhancement of red emission (F9/24→I15/24) via upconversion in bulk and nanocrystalline cubic Y2O3:Er3+,” J. Phys. Chem. B 106, 1181–1187 (2002).
[CrossRef]

J. Phys. Chem. Solids (1)

L. Zhang and H. Hu, “The effect of OH− on IR emission of Nd3+,Yb3+ and Er3+ doped tetraphosphate glasses,” J. Phys. Chem. Solids 63, 575–579 (2002).
[CrossRef]

J. Rare Earths (1)

L. Yanhong, Z. Yongming, H. Guangyan, and Y. Yingning, “Upconversion luminescence of Y2O3:Er3+,Yb3+ nanoparticles prepared by a homogeneous precipitation method,” J. Rare Earths 26, 450–454 (2008).
[CrossRef]

Mat. Lett. (1)

J. Wang, W. Miao, Y. Li, H. Yao, and Z. Li, “Water-soluble Ln3+-doped calcium fluoride nanocrystals: controlled synthesis and luminescence properties,” Mat. Lett. 63, 1794–1796(2009).
[CrossRef]

Microelectron. J. (1)

A. Martinez, J. Moralesa, P. Salas, C. Angeles-Chavez, L. A. Diaz-Torres, and E. De la Rosa, “Synthesis and photoluminescence of Y2O3:Yb3+–Er3+ nanofibers,” Microelectron. J. 39, 551–555(2008).
[CrossRef]

Nanotechnology (1)

W. J. Kim, M. Nyk, and P. N. Prasad, “Color-coded multilayer photopatterned microstructures using lanthanide (III) ion co-doped NaYF4 nanoparticles with upconversion luminescence for possible applications in security,” Nanotechnology 20, 185301 (2009).
[CrossRef] [PubMed]

Nature (1)

F. Wang, Y. Han, C. S. Lim, Y. Lu, J. Wang, J. Xu, H. Chen, C. Zhang, M. Hon, and X. Liu, “Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping,” Nature 463, 1061–1065 (2010).
[CrossRef] [PubMed]

Opt. Mat. (2)

L. X. Yi, M. Wang, S. Y. Feng, Y. K. Chen, G. N. Wang, L. L. Hu, and J. J. Zhang, “Emissions properties of Ho3+:I75→I85 transition sensitized by Er3+ and Yb3+ in fluorophosphate glasses,” Opt. Mat. 31, 1586–1590 (2009).
[CrossRef]

L. Laversenne, Y. Guyot, C. Goutaudier, M. Th. Cohen-Adad, and G. Boulon, “Optimization of spectroscopic properties of Yb3+-doped refractory sesquioxides: cubic Y2O3, Lu2O3 and monoclinic Gd2O3,” Opt. Mat. 16, 475–483 (2001).
[CrossRef]

Opt. Mater. (1)

H. Guo and Y. M. Qiao, “Preparation, characterization, and strong upconversion of monodisperse Y2O3:Er3+,Yb3+ microspheres,” Opt. Mater. 31, 583–589 (2009).
[CrossRef]

Phys. Chem. Chem. Phys. (1)

J. A. Capobianco, F. Vetrone, T. Dialesio, G. Tessari, A. Speghini, and M. Bettinelli, “Optical spectroscopy of nanocrystalline cubic Y2O3:Er3+ obtained by combustion synthesis”, Phys. Chem. Chem. Phys. 2, 3203–3207 (2000).
[CrossRef]

Phys. Rev. (1)

M. J. Weber, “Radiative and multiphonon relaxation of rare earth ions in Y2O3,” Phys. Rev. 171, 283–291 (1968).
[CrossRef]

SIAM J. Optim. (2)

T. F. Coleman and Y. Li, “An interior trust region approach for nonlinear minimization subject to bounds,” SIAM J. Optim. 6, 418–445 (1996).
[CrossRef]

R. H. Byrd, M. E. Hribar, and J. Nocedal, “An interior point algorithm for large-scale nonlinear programming,” SIAM J. Optim. 9, 877–900 (1999).
[CrossRef]

Sol. State Comm. (1)

G. De, W. Qin, J. Zhang, J. Zhang, Y. Wang, C. Cao, and Y. Cui, “Effect of OH− on the upconversion luminescent efficiency of Y2O3:Yb3+,Er3+ nanostructures,” Sol. State Comm. 137, 483–487 (2006).
[CrossRef]

Solar Energy Mater. Sol. Cells (1)

A. Shalav, B. S. Richards, and M. A. Green, “Luminescent layers for enhanced silicon solar cell performance: up-conversion,” Solar Energy Mater. Sol. Cells 91, 829–842 (2007).
[CrossRef]

Thin Solid Films (1)

A. O. G. Dikovska, P. A. Atanasov, M. Jimenez de Castro, A. Perea, J. Gonzalo, C. N. Afonso, and J. Garcia Lopez, “Optically active Er3+–Yb3+ codoped Y2O3 films produced by pulsed laser deposition,” Thin Solid Films 500, 336–340 (2006).
[CrossRef]

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Figures (11)

Fig. 1
Fig. 1

a) X-ray diffraction pattern of Y 2 O 3 : Yb 3 + ( 2 % ) Er 3 + ( 1 % ) annealed at 1000 ° C for 1 : 5 ethanol/water SR and b) TEM image of the 1 : 5 SR sample.

Fig. 2
Fig. 2

FTIR spectra of Y 2 O 3 : Yb 3 + ( 2 % ) Er 3 + ( 1 % ) samples with different ethanol/water SRs.

Fig. 3
Fig. 3

Visible UC and NIR emission of Y 2 O 3 : Yb 3 + ( 2 % ) Er 3 + ( 1 % ) samples with an ethanol/water SR of 1 : 5 and 1 : 6 , respectively. Inset, curves of emission intensity of the 1 : 5 SR sample as a function of pump power.

Fig. 4
Fig. 4

Green, red, and NIR emission band intensities as a function of SR after excitation at 940 nm .

Fig. 5
Fig. 5

R/G ratio for UC and DC.

Fig. 6
Fig. 6

Visible and infrared DC emission spectra of Y 2 O 3 : Yb 3 + ( 2 % ) Er 3 + ( 1 % ) sample with an ethanol/water SR of 1 : 6 .

Fig. 7
Fig. 7

Green, red, and NIR emission band intensities as a function of SR after 490 nm excitation.

Fig. 8
Fig. 8

Energy level diagram for a) DC and b) UC emission.

Fig. 9
Fig. 9

Experimental decay times fitted by the theoretical model for the samples with an SR of a)  1 : 6 and b)  1 : 4 . Both graphics show the decay curves corresponding to the emissions: 563 ( Er 3 + ) , 663 ( Er 3 + ) , 1038 ( Yb 3 + ) , and 1538 nm ( Er 3 + ) .

Fig. 10
Fig. 10

Effective decay time for the green and red emission bands as a function of SR in UC.

Fig. 11
Fig. 11

Effective decay time for 1038 and 1538 nm emiss0ion bands as a function of the SR.

Tables (2)

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Table 1 Size of Nanofibers According to the Ethanol/Water Solvent Ratio

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Table 2 Theoretical Values of the Energy Transfer, Backtransfer, and Cross-Relaxation Coefficients for Upconversion ( λ exc = 940 nm According to the Solvent Ratio

Equations (8)

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d N b d t = C b 5 N 2 N b C b 4 N 1 N b C b 2 N 0 N b + C 5 b N a N 5 W b N b ,
d N 1 d t = C b 4 N 1 N b + C 51 N 5 N 0 + C 5 b N a N 5 + W 21 N 2 W 1 N 1 ,
d N 2 d t = C b 2 N 0 N b C b 5 N 2 N b W 2 N 2 + W 32 N 3 W 21 N 2 ,
d N 3 d t = W 32 N 3 + W 43 N 4 + C 51 N 5 N 0 ,
d N 4 d t = C b 4 N 1 N b W 43 N 4 W 4 N 4 + W 54 N 5 ,
d N 5 d t = C b 5 N 2 N b W 5 N 5 W 54 N 5 C 51 N 0 C 5 b N a N 5 ,
f = R i time ( N i ( t , S R ) N i Exp ( t , S R ) ) 2 N i Exp ( t , S R ) ,
τ eff = 0 t I ( t ) d t / 0 I ( t ) d t .

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