1Key Laboratory of High-Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 2Graduate School of Chinese Academy of Sciences, Beijing 100049 3Laboratory of Glasses and Ceramics, University of Rennes, Rennes 35042, France
Upconversion Luminescence of Er3+ Ions in Transparent Germanate Glass Ceramics Containing CaF2 Nanocrystals
1Key Laboratory of High-Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 2Graduate School of Chinese Academy of Sciences, Beijing 100049 3Laboratory of Glasses and Ceramics, University of Rennes, Rennes 35042, France
The visible upconversion and near-infrared luminescence of Er3+ ions in germanate glass ceramics containing CaF2 nanocrystals are investigated. The nanocrystals are characterized by x-ray diffraction (XRD) and transmission electron microscopy, showing their mean sizes less than 20 nm. High transmittance of the glass ceramics is displayed by absorption spectra. The upconversion luminescence intensity in the glass ceramics increases significantly with increasing temperature. Both the shifts of the XRD peaks and the Stark-split shown in the luminescence spectra indicate the entrance of the Er3+ ions into the CaF2 nanocrystals, which is confirmed by a Judd-Ofelt analysis. Possible mechanisms of the upconversion luminescence are analyzed.
The visible upconversion and near-infrared luminescence of Er3+ ions in germanate glass ceramics containing CaF2 nanocrystals are investigated. The nanocrystals are characterized by x-ray diffraction (XRD) and transmission electron microscopy, showing their mean sizes less than 20 nm. High transmittance of the glass ceramics is displayed by absorption spectra. The upconversion luminescence intensity in the glass ceramics increases significantly with increasing temperature. Both the shifts of the XRD peaks and the Stark-split shown in the luminescence spectra indicate the entrance of the Er3+ ions into the CaF2 nanocrystals, which is confirmed by a Judd-Ofelt analysis. Possible mechanisms of the upconversion luminescence are analyzed.
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2010, Vol. 27 
