| Original Articles |
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Upconversion Luminescence Dynamics in Er3+Yb3+ Codoped Nanocrystalline Yttria |
| SONG Hong-Wei1,2;XIA Hai-Ping1;SUN Bao-Juan2;LU Shao-Zhe2;LIU Zhong-Xin2;YU Li-Xin2 |
| 1Laboratory of Photoelectronic Materials, Ningbo University, Ningbo 315211
2Key Laboratory of Excited State Physics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130023 |
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| Cite this article: |
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SONG Hong-Wei, XIA Hai-Ping, SUN Bao-Juan et al 2006 Chin. Phys. Lett. 23 474-478 |
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Abstract The upconversion luminescence and dynamics in Er3+/Yb3+ codoped nanocrystalline yttria (7--65nm) are studied under 980-nm pulsed laser excitation. It is found that the red emission of 4F9/2--4I15/2 and the green emission of 2H11/2/4S3/2 in nanoparticles with lower concentration of Yb3+ result from a two-photon excitation. In nanocrystals with higher Yb3+ concentration, the red emissions from a two-photon excitation, while the green emissions from a three-photon excitation. The luminescence dynamics indicates that as the particle size decreases, both the rise and the decay time constants become shorter. As the size decreases to several nanometres, the rise process nearly disappears, suggesting that the upconversion luminescence originates mainly from self-excitation of Er3+, instead of the energy transfer of Yb3+ to Er3+.
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| Keywords:
78.55.Am
78.67.Bf
78.90.+t
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Published: 01 February 2006
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| PACS: |
78.55.Am
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78.67.Bf
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(Nanocrystals, nanoparticles, and nanoclusters)
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78.90.+t
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(Other topics in optical properties, condensed matter spectroscopy and other interactions of particles and radiation with condensed matter)
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