Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-24T14:33:29.933Z Has data issue: false hasContentIssue false

The effects of surface and surface coatings on fluorescence properties of hollow NaYF4:Yb,Er upconversion nanoparticles

Published online by Cambridge University Press:  01 January 2011

Karvianto
Affiliation:
Department of Materials Science and Engineering, National University of Singapore, Singapore 117574, Republic of Singapore
G.M. Chow*
Affiliation:
Department of Materials Science and Engineering, National University of Singapore, Singapore 117574, Republic of Singapore
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Hollow nanoparticles of hexagonal close-packed (hcp)-NaYF4:Yb,Er were synthesized by thermal decomposition of trifluoroacetate precursors at 340 °C via vacancy diffusion, likely due to the Kirkendall effect and Ostwald ripening mechanism. The average outer diameter, inner diameter, and shell thickness of these hollow particles were 14 ± 3 nm, 7 ± 2 nm, and 4 ± 1 nm, respectively. The surface effects on the fluorescence properties of these hollow particles were studied by comparing with that of solid NaYF4:Yb,Er (average size ∼15 ± 3 nm) and solid NaYF4 core/NaYF4:Yb,Er shell (NaYF4 core ∼10 ± 1 nm and NaYF4:Yb,Er shell ∼3 ± 2 nm) nanoparticles containing similar composition of Yb and Er ions. The green, red, and total emission intensities decreased with increasing upconversion active volume-normalized surface area. Surface coatings of undoped NaYF4 on both inner and outer surfaces of the hollow nanoparticles enhanced the total emission intensity by ∼19 and ∼5 times compared with those of the hollow and solid NaYF4:Yb,Er nanoparticles, respectively.

Type
Articles
Copyright
Copyright © Materials Research Society 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Burda, C., Chen, X., Narayanan, R., and El-Sayed, M.A.: Chemistry and properties of nanocrystals of different shapes. Chem. Rev. 105, 1025 (2005).CrossRefGoogle ScholarPubMed
2.Menyuk, N., Dwight, K., and Pierce, J.W.: NaYF4:Yb, Er—An efficient upconversion phosphor. Appl. Phys. Lett. 21, 159 (1972).CrossRefGoogle Scholar
3.Wang, Y., Tu, L., Zhao, J., Sun, Y., Kong, X., and Zhang, H.: Upconversion luminescence of β-NaYF4:Yb3+, Er3+@β-NaYF4 core/shell nanoparticles: Excitation power density and surface dependence. J. Phys. Chem. C 113, 7164 (2009).CrossRefGoogle Scholar
4.Yuan, D., Yi, G.S., and Chow, G.M.: Effects of size and surface on luminescence properties of submicron upconversion NaYF4:Yb, Er particles. J. Mater. Res. 24, 2042 (2009).CrossRefGoogle Scholar
5.Qian, L.P., Yuan, D., Yi, G.S., and Chow, G.M.: Critical shell thickness and emission enhancement of NaYF4:Yb, Er/NaYF4/silica core/shell/shell nanoparticles. J. Mater. Res. 24, 3559 (2009).CrossRefGoogle Scholar
6.Heer, S., Kömpe, K., Güdel, H.U., and Haase, M.: Highly efficient multicolour upconversion emission in transparent colloids of lanthanide-doped NaYF4 nanocrystals. Adv. Mater. 16, 2102 (2004).CrossRefGoogle Scholar
7.Stouwdam, J.W., Hebbink, G.A., Huskens, J., and van Veggel, F.C.J.M.: Lanthanide-doped nanoparticles with excellent luminescent properties in organic media. Chem. Mater. 15, 4604 (2003).CrossRefGoogle Scholar
8.Shan, J., Uddi, M., Wei, R., Yao, N., and Ju, Y.: The hidden effects of particle shape and criteria for evaluating the upconversion luminescence of the lanthanide doped nanophosphors. J. Phys. Chem. C 114, 2452 (2010).CrossRefGoogle Scholar
9.Lim, S.F., Ryu, W.S., and Austin, R.H.: Particle size dependence of the dynamic photophysical properties of NaYF4:Yb, Er nanocrystals. Opt. Express 18, 2309 (2010).CrossRefGoogle ScholarPubMed
10.Yi, G.S. and Chow, G.M.: Water-soluble NaYF4:Yb, Er(Tm)/NaYF4/polymer core/shell/shell nanoparticles with significant enhancement of upconversion fluorescence. Chem. Mater. 19, 341 (2007).CrossRefGoogle Scholar
11.Mai, H.X., Zhang, Y.W., Sun, L.D., and Yan, C.H.: Highly efficient multicolor up-conversion emissions and their mechanisms of monodisperse NaYF4:Yb, Er core and core/shell-structured nanocrystals. J. Phys. Chem. C 111, 13721 (2007).CrossRefGoogle Scholar
12.Li, L., Chu, Y., Liu, Y., and Dong, L.: Template-free synthesis and photocatalytic properties of novel Fe2O3 hollow spheres. J. Phys. Chem. C 111, 2123 (2007).CrossRefGoogle Scholar
13.Ghadiri, E., Taghavinia, N., Zakeeruddin, S.M., Grätzel, M., and Moser, J.E.: Enhanced electron collection efficiency in dye-sensitized solar cells based on nanostructured TiO2 hollow fibers. Nano Lett. 10, 1632 (2010).CrossRefGoogle Scholar
14.Li, Z.Z., Wen, L.X., Shao, L., and Chen, J.F.: Fabrication of porous hollow silica nanoparticles and their applications in drug release control. J. Controlled Release 98, 245 (2004).CrossRefGoogle ScholarPubMed
15.Liu, S., Xing, R., Lu, F., Rana, R.K., and Zhu, J.J.: One-pot template-free fabrication of hollow magnetite nanospheres and their application as potential drug carriers. J. Phys. Chem. C 113, 21042 (2009).CrossRefGoogle Scholar
16.Ding, J. and Liu, G.: Water-soluble hollow nanospheres as potential drug carriers. J. Phys. Chem. B 102, 6107 (1998).CrossRefGoogle Scholar
17.Tu, K.N. and Gösele, U.: Hollow nanostructures based on the Kirkendall effect: Design and stability considerations. Appl. Phys. Lett. 86, 093111 (2005).CrossRefGoogle Scholar
18.Ren, N., Wang, B., Yang, Y.H., Zhang, Y.H., Yang, W.L., Yue, Y.H., Gao, Z., and Tang, Y.: General method for the fabrication of hollow microcapsules with adjustable shell compositions. Chem. Mater. 17, 2582 (2005).CrossRefGoogle Scholar
19.Wang, Y., Angelatos, A.S., and Caruso, F.: Template synthesis of nanostructured materials via layer-by-layer assembly. Chem. Mater. 20, 848 (2008).CrossRefGoogle Scholar
20.Buchold, D.H.M. and Feldmann, C.: Nanoscale γ-AlO(OH) hollow spheres: Synthesis and container-type functionality. Nano Lett. 7, 3489 (2007).CrossRefGoogle ScholarPubMed
21.Lin, Y.S., Wu, S.H., Tseng, C.T., Hung, Y., Chang, C., and Mou, C.Y.: Synthesis of hollow silica nanospheres with a microemulsion as the template. Chem. Commun. (Camb.) 3542 (2009).CrossRefGoogle ScholarPubMed
22.Zhang, F., Shi, Y., Sun, X., Zhao, D., and Stucky, G.D.: Formation of hollow upconversion rare-earth fluoride nanospheres: Nanoscale Kirkendall effect during ion exchange. Chem. Mater. 21, 5237 (2009).CrossRefGoogle Scholar
23.Shan, J., Yao, N., and Ju, Y.: Phase transition induced formation of hollow structures in colloidal lanthanide-doped NaYF4 nanocrystals. J. Nanopart. Res. 12, 1429 (2010).CrossRefGoogle Scholar
24.Yin, Y., Rioux, R.M., Erdonmez, C.K., Hughes, S., Somorjai, G.A., and Alivisatos, A.P.: Formation of hollow nanocrystals through the nanoscale Kirkendall effect. Science 304, 711 (2004).CrossRefGoogle ScholarPubMed
25.Yin, Y., Erdonmez, C.K., Cabot, A., Hughes, S., and Alivisatos, A.P.: Colloidal synthesis of hollow cobalt sulfide nanocrystals. Adv. Funct. Mater. 16, 1389 (2006).CrossRefGoogle Scholar
26.Fan, H.J., Gösele, U., and Zacharias, M.: Formation of nanotubes and hollow nanoparticles based on Kirkendall and diffusion processes: A review. Small 3, 1660 (2007).CrossRefGoogle ScholarPubMed
27.Cabot, A., Ibáñez, M., Guardia, P., and Alivisatos, A.P.: Reaction regimes on the synthesis of hollow particles by the Kirkendall effect. J. Am. Chem. Soc. 131, 11326 (2009).CrossRefGoogle ScholarPubMed
28.Wang, Y., Cai, L., and Xia, Y.: Monodisperse spherical colloids of Pb and their use as chemical templates to produce hollow particles. Adv. Mater. 17, 473 (2005).CrossRefGoogle Scholar
29.Kirkendall, E.O.: Diffusion of zinc in alpha brass. Trans. AIME 147, 104 (1942).Google Scholar
30.Smigelskas, A.D. and Kirkendall, E.O.: Zinc diffusion in alpha brass. Trans. AIME 171, 130 (1947).Google Scholar
31.Yang, H.G. and Zeng, H.C.: Preparation of hollow anatase TiO2 nanospheres via Ostwald ripening. J. Phys. Chem. B 108, 3492 (2004).CrossRefGoogle ScholarPubMed
32.Li, J. and Zeng, H.C.: Hollowing Sn-doped TiO2 nanospheres via Ostwald ripening. J. Am. Chem. Soc. 129, 15839 (2007).CrossRefGoogle ScholarPubMed
33.Lin, G., Zheng, J., and Xu, R.: Template-free synthesis of uniform CdS hollow nanospheres and their photocatalytic activities. J. Phys. Chem. C 112, 7363 (2008).CrossRefGoogle Scholar
34.Yi, G.S. and Chow, G.M.: Synthesis of hexagonal-phase NaYF4:Yb, Er and NaYF4:Yb, Tm nanocrystals with efficient up-conversion fluorescence. Adv. Funct. Mater. 16, 2324 (2006).CrossRefGoogle Scholar
35.Mai, H.X., Zhang, Y.W., Si, R., Yan, Z.G., Sun, L.D., You, L.P., and Yan, C.H.: High-quality sodium rare-Earth fluoride nanocrystals: Controlled synthesis and optical properties. J. Am. Chem. Soc. 128, 6426 (2006).CrossRefGoogle ScholarPubMed
36.Wang, L. and Li, Y.: Controlled synthesis and luminescence of lanthanide doped NaYF4 nanocrystals. Chem. Mater. 19, 727 (2007).CrossRefGoogle Scholar
37.Liu, C., Wang, H., Li, X., and Chen, D.: Monodisperse, size-tunable and highly efficient β-NaYF4:Yb, Er(Tm) up-conversion luminescent nanospheres: Controllable synthesis and their surface modifications. J. Mater. Chem. 19, 3546 (2009).CrossRefGoogle Scholar
38.Feng, W., Sun, L.D., Zhang, Y.W., and Yan, C.H.: Solid-to-hollow single-particle manipulation of a self-assembled luminescent NaYF4:Yb, Er nanocrystal monolayer by electron-beam lithography. Small 5, 2057 (2009).CrossRefGoogle Scholar
39.Zhang, Y.W., Sun, X., Si, R., You, L.P., and Yan, C.H.: Single-crystalline and monodisperse LaF3 triangular nanoplates from a single-source precursor. J. Am. Chem. Soc. 127, 3260 (2005).CrossRefGoogle ScholarPubMed
40.Roberts, J.E.: Lanthanum and neodymium salts of trifluoroacetic acid. J. Am. Chem. Soc. 83, 1087 (1961).CrossRefGoogle Scholar
41.Yoshimura, Y. and Ohara, K.: Thermochemical studies on the lanthanoid complexes of trifluoroacetic acid. J. Alloys Compd. 408412, 573 (2006).CrossRefGoogle Scholar