1. Enhancement of violet and ultraviolet upconversion emissions in Yb3+/Er3+-codoped YF3 nanocrystals
- Author
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Wang, Guofeng, Qin, Weiping, Zhang, Jisen, Zhang, Jishuang, Wang, Yan, Cao, Chunyan, Wang, Lili, Wei, Guodong, Zhu, Peifen, and Kim, Ryongjin
- Subjects
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YTTRIUM , *NANOCRYSTALS , *FLUORESCENCE , *YTTERBIUM , *SPECTRUM analysis , *THULIUM , *ERBIUM , *PHOTONICS - Abstract
Abstract: Pumped with a 980-nm diode laser, violet/ultraviolet upconversion fluorescence was presented in Y0.83Yb0.15Er0.02F3 nanocrystals. Observed emissions at 318nm and 379nm were affirmed coming from a four-photon excitation process. In comparison with a bulk sample having the same chemical compositions, the nanocrystals had a markedly enhanced ability of emitting violet/ultraviolet upconversion fluorescence. By employing Tm3+ ions as structural probes in the samples, we found that the enhancement could be attributed to the decrease of Judd–Ofelt parameter Ω 2. A model for revealing the four-photon excitation process was proposed based on spectral analysis. [Copyright &y& Elsevier]
- Published
- 2008
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